Systems and methods for nucleic acid expression in vivo

Abstract

The present invention provides compositions, systems, kits, and methods for generating expression of one or more proteins and/or biologically active nucleic acid molecules in a subject (e.g., at therapeutic levels for extended periods required to produce therapeutic effects). In certain embodiments, systems and kits are provided that comprise a first composition comprising a first amount of polycationic structures, and a second composition comprising a therapeutically effective amount of expression vectors (e.g., non-viral expression vectors not associated with liposomes) that are CpG-free or CpG-reduced, where the expression vectors comprise a first nucleic acid sequence encoding: i) a first therapeutic protein or proteins, and/or ii) a first biologically active nucleic acid molecule or molecules.

Claims

1. A method of expressing an antibody light chain and/or heavy chain in a subject comprising: a) administering intravenously a first composition to a subject, wherein said first composition comprises a first amount of polycationic structures, and wherein said first composition is free, or essentially free, of nucleic acid molecules; and b) administering intravenously a second composition to said subject within about 300 minutes of administering said first composition, wherein said second composition comprises non-viral expression vectors, wherein said non-viral expression vectors are CpG-free or CpG-reduced, wherein said non-viral expression vectors each comprise a first nucleic acid sequence encoding an antibody light chain and/or heavy chain, wherein the ratio of said first amount of said polycationic structures to said non-viral expression vectors is 5:1 to 25:1, and wherein, as a result of said administering said first composition and said administering said second composition, said antibody light chain and/or heavy chain is expressed in said subject at a level of at least 50 pg/ml in serum for at least 7 consecutive days; and c) administering intravenously a drug agent, in said first and/or second composition, or present in a third composition, wherein said drug agent increases or decreases said expression level of said antibody light chain and/or heavy chain and/or the length of time of said expression compared to when said drug agent is not administered to said subject.

2. The method of claim 1, wherein said polycationic structures comprise empty liposomes.

3. The method of claim 2, wherein said empty liposomes present in said first composition have a z-average diameter of about 20-85 nm.

4. The method of claim 1, wherein: A) said ratio is 10:1 to 18:1; and/or B) 2.0% to 6.0% of said first composition comprises dexamethasone or dexamethasone palmitate.

5. The method of claim 1, wherein each of said non-viral expression vectors each comprise only a single expression cassette, wherein said single expression cassette comprises said first nucleic acid sequence encoding said antibody light chain, and a second nucleic acid sequence encoding said antibody heavy chain.

6. The method of claim 1, wherein said drug agent is selected from colchicine, dexamethasone, dexamethasone palmitate, neutral lipids, valproic acid, theophylline, sildenafil, amlexanox, chloroquine, suberanilohydroxamic acid (SAHA), and L-arginine+sildenafil.

7. The method of claim 1, wherein said first amount of polycationic structures in said first composition comprises a mixture of cationic lipid and neutral lipid that reduces the expression of said antibody light and/or heavy chain compared to such expression when only said cationic lipid is employed in said method.

8. The method of claim 1, wherein said antibody light and/or heavy chain is expressed at said level in said subject for at least 21 consecutive days.

9. The method of claim 1, wherein said antibody light chain comprises a Rituximab light chain.

10. The method of claim 1, wherein said antibody heavy chain comprises a Rituximab heavy chain.

11. The method of claim 1, wherein said antibody light chain and/or heavy chain comprises said antibody light chain.

12. The method of claim 1, wherein said antibody light chain and/or heavy chain comprises said heavy chain.

13. The method of claim 1, wherein said antibody light chain and/or heavy chain comprises both said antibody light chain and heavy chain.

14. The method claim 13, wherein said first nucleic acid sequence further encodes a self-cleaving peptide between said antibody light chain and heavy chain.

15. The method of claim 1, wherein said non-viral expression vectors are CpG-free.

16. The method of claim 1, wherein said non-viral expression vectors are CpG-reduced.

17. The method of claim 1, wherein said second composition is administered to said subject between about 2 and 10 minutes after administering of said first composition.

18. The method of claim 1, wherein there are no detectable polycationic structures present in said second composition.

19. The method of claim 1, wherein said polycationic structures comprise liposomes, wherein said liposomes comprise 1,2-Dioleoyl-3-trimethylammonium propane (DOTAP).

20. The method of claim 1, wherein said subject is intravenously administered said third composition, wherein said third composition comprises dexamethasone and/or dexamethasone palmitate.

21. The method of claim 1, wherein said drug agent is in said first composition.

22. A method of expressing an antibody light chain and/or heavy chain in a subject comprising: a) administering intravenously a first composition to a subject, wherein said first composition comprises a first amount of polycationic structures, and wherein said first composition is free, or essentially free, of nucleic acid molecules; and b) administering intravenously a second composition to said subject within about 300 minutes of administering said first composition, wherein said second composition comprises non-viral expression vectors, wherein said non-viral expression vectors are CpG-free or CpG-reduced, wherein said non-viral expression vectors each comprise a first nucleic acid sequence encoding an antibody light chain and/or heavy chain, and c) administering intravenously dexamethasone, dexamethasone palmitate, and/or neutral lipids to said subject, either in said first and/or second composition, or present in a third composition, wherein, as a result of said administering said first composition, said administering said second composition, and said administering of said dexamethasone, dexamethasone palmitate, and/or neutral lipid, said antibody light chain and/or heavy chain is expressed in said subject at a level of at least 50 pg/ml in serum for at least 7 consecutive days.

23. The method of claim 22, wherein said antibody light and/or heavy chain is expressed at said level in said subject for at least 21 consecutive days.

24. The method of claim 22, wherein said second composition is administered to said subject between about 2 and 10 minutes after administering of said first composition.

25. The method of claim 22, wherein there are no detectable polycationic structures present in said second composition.

26. The method of claim 22, wherein said polycationic structures comprise liposomes, wherein said liposomes comprise 1,2-Dioleoyl-3-trimethylammonium propane (DOTAP).

27. The method of claim 22, wherein said subject is intravenously administered said third composition, wherein said third composition comprises dexamethasone and/or dexamethasone palmitate.

28. The method of claim 22, wherein said drug agent is in said first composition.

Description

DESCRIPTION OF THE FIGURES

(1) FIG. 1 shows a schematic representation of the various CPG-free plasmid constructs used in Example 1.

(2) FIG. 2 shows the CpG-free modified nucleic sequence of h-GCSF (SEQ ID NO:1) and the amino acid sequence of h-GCSF (SEQ ID NO:2). The positions where CpG di-nucleotides have been eliminated are shown in underline in SEQ ID NO:1.

(3) FIG. 3 shows a graph of serum human G-CSF levels produced in mice by sequential, IV cationic liposome injection followed by IV DNA vector injection.

(4) FIG. 4 shows a histogram of WBC and absolute neutrophil counts, 21 days after sequential, IV cationic liposome then DNA vector injection.

(5) FIG. 5 shows serum human G-CSF levels produced in mice by sequential IV injection of either single or dual cassette, hG-CSF single plasmid vectors.

(6) FIG. 6 shows serum hG-CSF levels in mice, 21 days after IV injection of cationic liposomes, then DNA containing different promoter-enhancer combinations linked to the hG-CSF gene.

(7) FIG. 7 shows mouse lung luciferase levels, 7 days after sequential IV injection of cationic liposomes, then single cassette, EF1-luciferase DNA alone or together with a particular drug.

(8) FIG. 8 shows mouse lung luciferase levels, 7 days after sequential IV injection of cationic liposomes, then dual cassette, EF1-hG-CSF-EF1-luciferase DNA alone or with certain drug(s).

(9) FIG. 9 shows mouse lung luciferase levels, 10 days after sequential IV injection of cationic liposomes, then a DNA vector containing one of a series of different promoter-enhancer combinations, each either with or without MARs, and all linked to the luciferase gene.

(10) FIG. 10 shows mouse lung luciferase levels, 1 or 5 days after IV injection of PEI:EF-1 Luc DNA complexes or sequential IV injection of cationic liposomes, then the identical EF-1 Luc DNA.

(11) FIG. 11 shows mouse lung luciferase levels, 1 day after sequential IV injection of one of seven different cationic liposome formulations, then single cassette, EF1-luciferase DNA.

(12) FIG. 12 shows mouse spleen luciferase levels, 1 day after IV injection of PEI:EF-1 Luc DNA complexes alone or mixed with one of four different drugs.

(13) FIG. 13 shows mouse lung luciferase levels, 1 or 7 days after sequential IV injection of cationic liposomes, then one of a series of dual cassette, EF-1-Luc-hG-CSF DNA vectors.

(14) FIG. 14 shows serum human G-CSF levels produced in mice, 1 day after sequential, IV cationic liposome injection, with or without co-injection of neutral liposomes, followed by IV injection of a dual cassette, single plasmid vector.

(15) FIG. 15 shows serum human G-CSF levels produced in mice, 1 or 7 days after sequential, IV cationic liposome co-injection with neutral liposomes, followed by IV injection of a dual cassette plasmid vector.

(16) FIG. 16 shows serum human G-CSF levels produced in mice 7 days after sequential, IV cationic liposome injection with SUV, 0.1 m extruded or MLV cationic liposomes, followed by IV injection of a EF1-hG-CSF plasmid vector.

(17) FIG. 17 shows results from Example 2, wherein one sequential IV injection of cationic liposomes followed by a CPG-free, human G-CSF DNA vector produces supra-therapeutic human G-CSF serum protein levels in mice for at least the next 428 days.

(18) FIG. 18 shows results from Example 3, wherein it was shown that one sequential IV injection of cationic liposomes followed by a CPG-free, human G-CSF DNA vector produces supra-therapeutic human G-CSF serum protein, WBC and ANC levels, with normal ALT (alanine aminotransferase) and AST (aspartate aminotransferase) in rats.

(19) FIG. 19 shows results from Example 3, where it was shown that cationic liposomes generated from DPTAP mediate in vivo transfection.

(20) FIG. 20 shows that toxicity as measured by serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are elevated 2 to 5 fold at 24 hrs and return to control levels by 48 hours after sequential injection of cationic liposomes then plasmid DNA.

(21) FIG. 21 shows incorporation of 2.5 mole % dexamethsone palmitate (DexP) into cationic DOTAP liposomes increases expression of hG-CSF at 24 hours after sequential IV injection while simultaneously reducing toxicity, as measured by ALT levels to close to background levels.

(22) FIG. 22 shows that IV injection of DOTAP liposomes containing 2.5% dexamethasone palmitate reduces toxicity, as measured by ALT levels to background levels while significantly increasing human G-CSF protein levels.

(23) FIG. 23 shows pre- and post-injection of Dexamethasone significantly increases hG-CSF protein levels while reducing toxicity, as measured by ALT levels to close to background levels.

(24) FIG. 24 shows manipulating Lipid:DNA Ratios increases hG-CSF levels while reducing toxicity, as measured by ALT levels to background levels.

(25) FIG. 25 shows that IP pre-injection of dexamethasone, followed by 2.5 mole % dexamethsone palmitate in cationic DOTAP liposomes then a dual cassette, single plasmid DNA vector encoding Rituximab significantly increases serum Rituximab levels over time in mice.

(26) FIG. 26 shows dexamethasone pre-injection followed by one IV sequential injection of DexP cationic liposomes plus neutral lipid then a dual cassette, single plasmid DNA vector encoding Rituximab produces extended serum levels of fully functional Rituximab protein in mice.

(27) FIG. 27 shows mouse serum tested at 6 weeks following IV sequential injection of a dual cassette, single plasmid Rituximab DNA vector binds target CD20+ human B lymphoma (Raji) cells similarly to recombinant Rituximab protein.

(28) FIG. 28 Rituximab protein in serum from Rituximab DNA vector-injected mice induces lysis of Raji CD20+ human B cells at levels similar to recombinant Rituximab.

(29) FIG. 29 shows IP pre-injection of dexamethasone, then neutral lipid plus 2.5 mole % dexamethsone palmitate in DOTAP liposomes increases serum Rituximab levels over time in rats.

(30) FIG. 30 shows codon-optimization of Rituximab dual cassette, single plasmid DNA vectors further increases serum Rituximab levels 24 hours after sequential IV injection.

(31) FIG. 31 shows that one sequential, IV cationic liposome injection of codon-optimized dual cassette, single plasmid Rituximab DNA vectors produces extended serum Rituximab levels.

(32) FIG. 32 shows that pre-injection of selected drugs significantly increases serum Rituximab levels produced by sequential IV, cationic liposome injection of a codon-optimized dual cassette, single plasmid Rituximab DNA vector.

(33) FIG. 33 shows sequential IV injection of a single cassette DNA vector encoding the Rituximab heavy and light chains separated by a 2A self cleaving peptide sequence produces significant serum Rituximab protein levels.

(34) FIG. 34 shows that manipulating Lipid:DNA Ratios increases serum Rituximab levels while reducing toxicity, as measured by ALT levels to close to background levels.

(35) FIG. 35 shows that pretreatment with either valproic acid or theophylline significantly increases serum human factor nine levels produced by sequential IV, cationic liposome injection of a codon-optimized, EF-1-driven plasmid vector encoding a human factor IX cDNA.

(36) FIG. 36 shows the arrangement of the Rituximab (anti-CD20) dual cassette plasmids used in the Examples. In this figure, the following abbreviations apply: M: Mar (M1:-Glo, M2:21q21 and M3:IFN); K: Kozak Sequence (K1:AAGCTTTCC, SEQ ID NO:3; K2:AAGCCACC, SEQ ID NO:4); Enhancer: mCMV or hCMV; Promoter: CMV or EF1; 5UTR: I126 or htlv; H: Chimeric Heavy Chain cDNA; L: Chimeric Light Chain cDNA; and pA: polyA

(37) FIG. 37 shows the arrangement of the Rituximab (anti-CD20) single (bisicontronic) plasmid used in the Examples. In this figure, the following abbreviations apply: K: Kozak Sequence (K1:AAGCTTTCC K2, SEQ ID NO:3; AAGCCACC, SEQ ID NO:4); Enhancer: mCMV or hCMV; Promoter: CMV or EF1; 5UTR: 1126 or htlv H: Chimeric Heavy Chain cDNA; L: Chimeric Light Chain cDNA; F: Furin (F1: RHQR; F2: RAKR); 2A Peptide: P2A or F2A; and pA: polyA.

(38) FIG. 38 shows the arrangement of the human Factor IX plasmids used in the Examples.

(39) The following abbreviations apply in this figure: M: Mar (M1: -Glo, and M3: IFN); Kozak2: Kozak Sequence2 (AAGCCACC, SEQ ID NO:4); Enhancer: mCMV; Promoter: EF1; 5UTR: I126; hFIX: human Factor XI cDNA; and pA: polyA

(40) FIG. 39 shows one example (No. 8, G4) of a bicistronic, single cassette plasmid construct (SEQ ID NO:5) used in the Examples below that expresses the heavy and light chains (underlined) of Rituximab.

(41) FIG. 40 shows one example (No. 2) of a dual cassette non-optimized anti-CD20 CpG free plasmid construct (SEQ ID NO:6) used in the Examples below that expresses the heavy and light chains (underlined) of Rituximab.

(42) FIG. 41 shows one example (No. 4) of a dual cassette non-optimized anti-CD20 CpG free plasmid construct (SEQ ID NO:7) used in the Examples below that expresses the heavy and light chains (underlined) of Rituximab.

(43) FIG. 42 shows one example (No. 4) of a dual cassette MAR-less optimized anti-CD20 plasmid construct (SEQ ID NO:8) used in the Examples below that expresses the heavy and light chains (underlined) of Rituximab.

(44) FIG. 43 shows one example (No. 6) of a dual cassette MAR-containing optimized anti-CD20 plasmid construct (SEQ ID NO:9) used in the Examples below that expresses the heavy and light chains (underlined) of Rituximab.

(45) FIG. 44 shows one example (No. 4) of a plasmid construct (SEQ ID NO:10) used in the Examples below that expresses human Factor IX.

DEFINITIONS

(46) As used herein, the phrase CpG-reduced refers to a nucleic acid sequence or expression vector that has less CpG di-nucleotides than present in the wild-type versions of the sequence or vector. CpG-free means the subject nucleic acid sequence or vector does not have any CpG di-nucleotides. An initial sequence, that contains CpG dinucleotides (e.g., wild-type version of human G-CSF), may be modified to remove CpG dinucleotides by altering the nucleic acid sequence. Such CpG di-nucleotides can be suitably reduced or eliminated not just in a coding sequence, but also in the non-coding sequences, including, e.g., 5 and 3 untranslated regions (UTRs), promoter, enhancer, polyA, ITRs, introns, and any other sequences present in the nucleic acid molecule or vector.

(47) As used herein, empty liposomes refers to liposomes that do not contain nucleic acid molecules but that may contain other bioactive molecules (e.g., liposomes that are only composed of the lipid molecules themselves, or only lipid molecules and a small molecule drug).

(48) As used herein, empty cationic micelles refers to cationic micelles that do not contain nucleic acid molecules but that may contain other bioactive molecules (e.g., micelles that are only composed of lipid and surfactant molecules themselves, or only lipid and surfactant molecules and a small molecule drug).

(49) As used herein, empty cationic emulsions refers to cationic emulsions or micro-emulsions that do not contain nucleic acid molecules but that may contain other bioactive molecules.

DETAILED DESCRIPTION

(50) The present invention provides compositions, systems, kits, and methods for generating expression of a protein or biologically active nucleic acid molecule in a subject (e.g., at therapeutic levels for extended periods of time). In certain embodiments, systems and kits are provided that comprise a first composition comprising a first amount polycationic structures (e.g., empty cationic liposomes, empty cationic micelles, or empty cationic emulsions), and a second composition comprising a therapeutically effective amount of expression vectors (e.g., non-viral expression vectors not associated with liposomes) that are CpG-free or CpG-reduced, where the expression vectors comprise a first nucleic acid sequence encoding: i) a first therapeutic protein, and/or ii) a first biologically active nucleic acid molecule. In other embodiments, such first and second compositions are sequentially administered (e.g., systemically) to a subject such that the first therapeutic protein and/or the biologically active nucleic acid molecule is/are expressed in the subject (e.g., at a therapeutic level, for at least 5 or at least 50 days, such that a disease or condition is treated or a physiological trait is altered).

(51) Work conducted during the development of embodiments of the present disclosure has shown that a single injection (e.g., intravenous injection) of cationic liposomes, followed shortly thereafter by injection (e.g., intravenous injection) of CpG-free vectors encoding a therapeutic protein produces circulating protein levels many times (e.g., 10-20 times higher) than the therapeutic serum level for the protein for a prolonged period. Such administration also increased circulating neutrophil counts many fold weeks after the treatment.

(52) Work conducted during the development of embodiments of the present disclosure (e.g., as shown in Example 1 below) has shown that a single intravenous injection of cationic liposomes, followed two minutes later by intravenous injection of CpG-free plasmid vectors encoding human granulocyte-colony stimulating factor (hG-CSF) produces circulating hG-CSF protein levels 10-20 times higher than the therapeutic serum hG-CSF level (greater than or equal to 100 pg/ml) for at least 63 days (see, FIG. 3). Such administration also increased circulating neutrophil counts 10 fold, 3 weeks following intravenous injection into mice (FIG. 4). In contrast, one systemic injection of cationic liposome-DNA complexes containing a similar, but CpG-containing) hG-CSF plasmid vector was unable to produce detectable (>20 pg/ml) hG-CSF protein levels even at day 3 after injection, and failed to increase neutrophil counts at any point after injection (see, Tu et al., JBC, 275 (39):30408-30416, 2000; herein incorporated by reference in its entirety). Moreover, the approach presented in Example 1 that was used to prolong expression at therapeutic levels of human G-CSF did not appear to cause significant toxicity in the mice.

(53) Thus, the approach provided herein for expression in vivo overcomes the critical limitation that has up to now precluded the successful therapeutic application of systemic non-viral gene delivery. Namely, its inability to express delivered genes at therapeutic levels for the extended periods generally required to produce important therapeutic or physiological endpoints. As shown in Example 1, embodiments of the methods provided herein accomplish such long lasting expression of a therapeutic protein with non-viral vectors without having to incorporate viral genes into the vectors. This is important as other approaches relied on the insertion of at least one viral gene plus the viral DNA sequence to which its protein product binds (the EBNA-1 gene together with the EBV family of repeat sequences inserted into the DNA vector) has been required in order to overcome this transient gene expression limitation (see, Tu et al., above). Moreover, in addition to the high hG-CSF protein levels found after 63 days in Example 1 (FIG. 1), similar high levels of expression were measured and found on days 14, 21, 28, and 49 after injection, indicating that once achieved, these high therapeutic levels are maintained longer term. Also, Example 2 shows, in FIG. 17, over 400 days of high levels of expression. This high level and long term expression is significantly better than the mRNA approach provided by MODERNA, which, as shown in FIG. 3 of U.S. Pat. No. 8,754,062 for hG-CSF, only produced therapeutic levels of up to 4 days after a single IV injection.

(54) In addition, the systems, methods, and compositions provided herein provide a versatile (e.g., non-viral) gene delivery and expression platform that can much more precisely control the duration of expression of delivered genes at therapeutic levels. This ability to control the duration of expression of delivered genes addresses another up to now critical unmet need within the gene therapy field, the ability to control the duration at which proteins are expressed at therapeutic levels. Specifically, there is now a wide and expanding spectrum of FDA-approved, recombinant, secreted human protein therapies. Different approved protein therapies must be present at therapeutic levels for very different durations in order to both effectively and safely treat patients. Recommended treatment durations of different protein therapies vary from less than two weeks (hG-CSF) to the lifetime of the patient (factor IX). For example, recombinant human G-CSF protein, Neupogen, is given daily for only the first 10 days of each three-week chemotherapy cycle. Serum hG-CSF levels return to baseline approximately 14 hours after each daily Neupogen dose. This 10 day treatment schedule is used because its neutrophil increasing effect is indicated only during this approximately 10 day period of chemotherapy-induced neutropenia. G-CSF elevation from days 11 to 21 is generally not beneficial, as the patient's own neutrophil producing capacity returns. Giving Neupogen beyond day 10 can cause toxic, neutrophilia-related side effects. In contrast, anti-TNF antibodies are routinely administered for months or years, and factor IX replacement for the lifetime of the patient. Thus, different proteins must be produced at therapeutic levels for different durations, from less than two weeks to the lifetime of the patient. Therefore, a gene therapy approach that can control the duration of gene expression at therapeutic levels it produces in patients achieves therapeutic endpoints while avoiding toxic side effects for a wide spectrum of now FDA-approved, human therapeutic proteins. Provided herein are various technologies that can be employed to provide this control. Five exemplary approaches are described below.

(55) First, in certain embodiments, a second expression cassette is inserted into a single plasmid DNA vector or other vector. As shown in Example 1, in contrast to the single expression cassette hG-CSF plasmid vector that was used, which produces therapeutic hG-CSF levels for at least 63 days (FIG. 3), adding the second cassette limited therapeutic levels of hG-CSF protein produced to less than two weeks in mice (FIG. 5). Of note, the second expression cassette which drives the luciferase gene, is also expressed at high, controllable levels in IV injected mice.

(56) Second, as shown in Example 1, a series of different, CPG-free promoter-enhancer combinations were generated in single cassette plasmid vectors that express hG-CSF at therapeutic levels for a range of different durations following a single IV injection in mice (FIG. 6). Of note, multi-expression cassette, single plasmid DNA vectors that contain different cassettes incorporating different promoter enhancer combinations are capable of expressing different therapeutic proteins at different levels for different durations from a single DNA vector. This allows a single DNA vector to express multiple different therapeutic proteins (e.g., one, two, three, four, five, six or more therapeutic proteins). Each individual protein is then expressed for the required duration at its appropriate therapeutic level. Such an approach is one way to overcome the prohibitive costs now incurred by combining two or more recombinant protein therapies in a single patient.

(57) Third, as described in Example 1, it was shown that co-injecting now FDA-approved drugs, singly or in selected combinations with the cationic liposomes can selectively either increase or decrease the level/duration of expression of the gene subsequently delivered by sequential IV injection in mice (FIGS. 7 and 8).

(58) Fourth, as demonstrated in Example 1, varying the cationic liposome size, as well as the lipid composition can also control the level and duration of expression of genes delivered by sequential cationic liposome then DNA injection (FIG. 11).

(59) Fifth, as demonstrated in example 14, the addition of neutral lipids together with dexamethasone and dexamethasone palmitate can increase the duration of gene expression (FIGS. 26 and 29). In contrast, the administration of neutral lipid alone can decrease the duration of gene expression (FIGS. 14 and 15).

(60) In addition, some literature also describes that matrix attachment regions (MAR) should be incorporated into DNA vectors in order to produce prolonged expression following their IV injection (Argyros et al., J Mol Med (2011) 89:515-529, herein incorporated by reference in its entirety). In contrast, work conducted during development of embodiments of the present disclosure indicate that the presence of such MAR elements do not increase, and in some vectors decrease the duration of gene expression produced by IV, sequential injection of cationic liposomes followed by CPG-free plasmid DNA (FIG. 9).

(61) In certain embodiments, the present disclosure employs polycationic structures (e.g., empty cationic liposomes, empty cationic micelles, or empty cationic emulsions) not containing vector DNA, which are administered to a subject prior to vector administration. In certain embodiments, the polycationic structures are cationic lipids and/or are provided as an emulsion. The present disclosure is not limited to the cationic lipids employed, which can be composed, in some embodiments, of one or more of the following: DDAB, dimethyldioctadecyl ammonium bromide; DPTAP (1,2-dipalmitoyl 3-trimethylammonium propane); DHA; prostaglandin, N-[1-(2,3-Dioloyloxy)propyl]-N,N,N-trimethylammonium methyl sulfate; 1,2-diacyl-3-trimethylammonium-propanes, (including but not limited to, dioleoyl (DOTAP), dimyristoyl, dipalmitoyl, disearoyl); 1,2-diacyl-3-dimethylammonium-propanes, (including but not limited to, dioleoyl, dimyristoyl, dipalmitoyl, disearoyl) DOTMA, N-[1-[2,3-bis(oleoyloxy)]propyl]-N,N,N-trimethylammoniu-m chloride; DOGS, dioctadecylamidoglycylspermine; DC-cholesterol, 3.beta.-[N-(N,N-dimethylaminoethane)carbamoyl]cholesterol; DOSPA, 2,3-dioleoyloxy-N-(2(sperminecarboxamido)-ethyl)-N,N-dimethyl-1-propanami-nium trifluoroacetate; 1,2-diacyl-sn-glycero-3-ethylphosphocholines (including but not limited to dioleoyl (DOEPC), dilauroyl, dimyristoyl, dipalmitoyl, distearoyl, palmitoyl-oleoyl); beta-alanyl cholesterol; CTAB, cetyl trimethyl ammonium bromide; diC14-amidine, N-t-butyl-N-tetradecyl-3-tetradecylaminopropionamidine; 14Dea2, O,O-ditetradecanolyl-N-(trimethylammonioacetyl) diethanolamine chloride; DOSPER, 1,3-dioleoyloxy-2-(6-carboxy-spermyl)-propylamide; N,N,N,N-tetramethyl-N,N-bis(2-hydroxylethyl)-2,3-dioleoyloxy-1,4-butan-ediammonium iodide; 1[2-acyloxy)ethyl]2-alkyl (alkenyl)-3-(2-hydroxyethyl-) imidazolinium chloride derivatives such as 1-[2-(9(Z)-octadecenoyloxy)eth-yl]-2-(8(Z)-heptadecenyl-3-(2-hydroxyethyl)imidazolinium chloride (DOTIM), 1-[2-(hexadecanoyloxy)ethyl]-2-pentadecyl-3-(2-hydroxyethyl)imidazolinium chloride (DPTIM); 1-[2-tetradecanoyloxy)ethyl]-2-tridecyl-3-(2-hydroxyeth-yl)imidazolium chloride (DMTIM) (e.g., as described in Solodin et al. (1995) Biochem. 43:13537-13544, herein incorporated by reference); 2,3-dialkyloxypropyl quaternary ammonium compound derivates, containing a hydroxyalkyl moiety on the quaternary amine, such as 1,2-dioleoyl-3-dimethyl-hydroxyethyl ammonium bromide (DORI); 1,2-dioleyloxypropyl-3-dimethyl-hydroxyethyl ammonium bromide (DORIE); 1,2-dioleyloxypropyl-3-dimethyl-hydroxypropyl ammonium bromide (DORIE-HP), 1,2-dioleyloxypropyl-3-dimethyl-hydroxybutyl ammonium bromide (DORIE-HB); 1,2-dioleyloxypropyl-3-dimethyl-hydroxypentyl ammonium bromide (DORIE-HPe); 1,2-dimyristyloxypropyl-3-dimethyl-hydroxylethyl ammonium bromide (DMRIE); 1,2-dipalmityloxypropyl-3-dimethyl-hydroxyethyl ammonium bromide (DPRIE); 1,2-disteryloxypropyl-3-dimethyl-hydroxyethyl ammonium bromide (DSRIE) (e.g., as described in Felgner et al. (1994) J. Biol. Chem. 269:2550-2561, herein incorporated by reference in its entirety). Many of the above-mentioned lipids are available commercially from, e.g., Avanti Polar Lipids, Inc.; Sigma Chemical Co.; Molecular Probes, Inc.; Northern Lipids, Inc.; Roche Molecular Biochemicals; and Promega Corp.

(62) In certain embodiments, the present disclosure employs CpG-reduced or CpG-free expression vectors. An initial sequence that contains CpG dinucleotides (e.g., wild-type version of human G-CSF), may be modified to remove CpG dinucleotides by altering the nucleic acid sequence. FIG. 2 shows a CpG-free version of human G-CSF, with sequences that have been changed to removed CpGs underlined. Such CpG di-nucleotides can be suitably reduced or eliminated not just in a coding sequence, but also in the non-coding sequences, including, e.g., 5 and 3 untranslated regions (UTRs), promoter, enhancer, polyA, ITRs, introns, and any other sequences present in the nucleic acid molecule or vector. CpG di-nucleotides may be located within a codon triplet for a selected amino acid. There are five amino acids (serine, proline, threonine, alanine, and arginine) which have one or more codon triplets that contain a CpG di-nucleotide. All five of these amino acids have alternative codons not containing a CpG di-nucleotide that can be changed to, to avoid the CpG but still code for the same amino acid as shown in Table 1 below. Therefore, the CpG di-nucleotides allocated within a codon triplet for a selected amino acid may be changed to a codon triplet for the same amino acid lacking a CpG di-nucleotide.

(63) TABLE-US-00001 TABLE1 DNACodons DNACodons AminoAcid ContainingCpG LackingCpG Serine TCG TCT,TCC,TCA, (SerorS) AGT,AGC Proline CCG CCT,CCC,CCA, (ProorP) Threonine ACG ACA,ACT,ACC (ThrorT) Alanine GCG GCT,GCC,GCA (AlaorA) Arginine CGT,CGC, AGA,AGG (ArgorR) CGA,CGG
In addition, within the coding region, the interface between triplets should be taken into consideration. For example, if an amino acid triplet ends in a C-nucleotide which is then followed by an amino acid triplet which can start only with a G-nucleotide (e.g., Valine, Glycine, Glutamic Acid, Alanine, Aspartic Acid), then the triplet for the first amino acid triplet is changed to one which does not end in a C-nucleotide. Methods for making CpG sequences are shown, for example, in U.S. Pat. No. 7,244,609, which is herein incorporated by reference. A commercial service provided by INVIVOGEN is also available to produce CpG free (or reduced) nucleic acid sequences and vectors.

(64) Provided below in Table 2 are exemplary promoters and enhancers that may be used in the vectors described herein. Such promoters, and other promoters known in the art, may be used alone or with any of the enhancers, or enhancers, known in the art. Additionally, when multiple proteins or biologically active nucleic acid molecules (e.g., two, three, four, or more) are expressed from the same vector, the same or different promoters may be used in conjunction with the subject nucleic acid sequence.

(65) TABLE-US-00002 TABLE 2 Promoter Enhancer CMV human CMV EF1 mouse CMV Ferritin (Heavy/Light) Chain SV40 GRP94 Ubc U1 AP1 UbC hr3 Beta Actin IE2 PGK1 IE6 GRP78 E2-RS CAG MEF2 SV40 C/EBP TRE HNF-1

(66) The present disclosure is not limited by the type of therapeutic proteins that is expressed. In certain embodiments, the therapeutic protein comprises an antibody or antibody fragments (e.g., F(ab) or F(ab)2). In other embodiments, the therapeutic protein is selected from the group consisting of an anti-inflammatory protein, coagulation protein, anti-cancer protein, anti-sepsis protein, etc.

EXAMPLES

Example 1

In Vivo Protein Expression Using Sequential Injection of Cationic Liposomes Followed by CPG-Free Expression Vectors

(67) This example describes various work using in vivo protein expression using sequential injection of cationic liposomes followed closely in time by CPG-free expression vectors.

Methods

Liposome Preparation

(68) Pure DOTAP lipid as a lyophilized powder was purchased from Avanti polar lipids. Pure DOTAP cationic liposomes were prepared by re-suspending the lyophilized powder in a solution of 5% dextrose in water at a lipid concentration of 20 millimolar. The solution was then vortexed for 15 minutes to form multi-lamellar vesicles (MLV), mean particle size 350 nm, as measured by laser light scattering. Small uni-lamellar vesicles (SUV), mean particle size 75 nm, were then formed from MLV by sonication in a bath sonicator.

Plasmid Construction

(69) General schematics for the vectors employed are provided in FIG. 1. In general, a CpG free DNA plasmid vector is typically composed of the following elements: enhancer/promoter/5UTR of either mCMV/EF1/I126 (851 bp) or hCMV/hCMV/HTLV (873 bp), linked to a gene of interest (such as h-GCSF (615 bp) or soLux (1653 bp)), minimal polyA (63 bp), MARs derived from either Globin (434 bp), 21q21 (1055 bp) or IFN (820 bp) and an R6K Ori/Kan.sup.r (Kanamycin antibiotic resistant) expression cassette (1206 bp). R6KOri/Kan.sup.r DNA was designed as a base vector containing three endonuclease restriction enzyme sites, DraIII, EcoRI and NheI. It was assembled from gBlock four DNA fragments (IDT, IA) using the Gibson Assembly technique (NEB, MA). For MAR containing plasmids, a Globin MAR was inserted into the base vector at DraIII-EcoRI sites. The CpG-free nucleic acid sequence for h-GCSF is shown in FIG. 2.

(70) The expression cassette was constructed using the puc19 plasmid backbone by sequentially inserting each DNA element between EcoRI and XbaI. Enhancer/Promoter elements containing 5 EcoRI and NheI sites were ligated to the 5UTR, gene, pA or pA-MAR, as well as puc19 at EcoRI, EcoRV, BstEII, BglII and XbaI sites, respectively. The expression cassette was then digested with EcoRI-XbaI and inserted into the base vector at EcoRI-NheI, producing an expression plasmid containing restriction sites that can be used to insert a second expression cassette insertion. Dual (Luc- and GCSF) cassette expression plasmids were then constructed by inserting the hG-CSF expression cassette into the base vector at EcoRI-NheI. The second, Luc expression cassette was subsequently inserted into the G-CSF expression plasmid at EcoRI-NheI, producing a dual cassette, Luc and GCSF containing, single plasmid vector.

Plasmid Purification

(71) Endotoxin-free plasmids were purified on 5Prime Endo-free Maxi columns as follows. Briefly, 200 ml of bacteria containing the plasmid are grown overnight at 37C and then collected. Bacterial cells are lysed per the manufacturer's protocol. Endotoxin is removed using an EndoFree filter CS. Isopropanol is added to the lysate and then loaded onto a column. After successive washes, the column is centrifuged and air-dried for 10 min to ensure residual ethanol is removed. DNA is then eluted from the column with 1 ml of Lactated Ringers.

Mice

(72) 21 g female, CD-1 mice were purchased from Charles River. Housing, care and all procedures were performed according to IACUC approved guidelines.

Sequential Injection of Cationic Liposomes, then Plasmid DNA in Mice

(73) Three to five mice were injected per group. Each mouse received a single IV injection of cationic liposomes (MLV or SUV), followed two minutes later by a single IV injection of a CPG-free, plasmid DNA vector.

Obtaining and Then Analyzing Mouse Serum for Human G-CSF Levels

(74) Each mouse was anesthetized and then bled via the submandibular vein. Serum was then isolated from whole blood and human G-CSF levels measured in pg/ml, as performed strictly according to the manufacturer's specifications, using an R and D systems human G-CSF ELISA.

Obtaining and Then Analyzing Mouse Tissue for Luciferase Activity

(75) Lung was homogenized with 500 ul of 1 Lysis buffer (Promega, Wis.). The homogenate was centrifuged at 3000g at 4C for 10 min. and the supernatant collected. Luciferase activity was assayed using 20 l of supernatant and 100 l of Luciferase reagent for 10 seconds using a GloMax Luminometer (Promega, Wis.).

Results/Description

Serum Human G-CSF Levels Produced in Mice by Sequential, IV Cationic Liposome Injection Followed by IV DNA Vector Injection

(76) Five mice were injected per group. Each mouse received a single IV injection of 800 nmoles of pure DOTAP cationic liposomes (MLV or SUV), followed two minutes later by a single IV injection of 80 g of an mCMV-EF1-hGCSF, an hCMV-hCMV-hGCSF or an mCMV-EF1-luciferase, CPG-free, plasmid DNA vector. Serum hG-CSF levels were assessed beginning at day seven after IV injection, and at seven-day intervals thereafter.

(77) As shown in FIG. 3, all three DNA vectors containing the hG-CSF gene produced supra-therapeutic hG-CSF levels (100 pg/ml is required to increase neutrophil levels), at day seven after injection. Thereafter, hG-CSF levels rose progressively until day 21, and then remained stable until day 63, the last time point analyzed. In contrast, hG-CSF levels produced by identical, IV sequential injection of the EF1-luciferase DNA vector were undetectable throughout the course of the experiment.

WBC and Absolute Neutrophil Counts, 21 Days After Sequential, IV Cationic Liposome Then DNA Vector Injection

(78) Whole blood was collected from groups of 4 mice at day 21 following sequential, IV injection of DOTAP MLV, followed two minutes later by a single IV injection of either an EF1-hGCSF or an EF-1 luciferase-containing, CPG-free plasmid DNA vector. Blood from each mouse was then analyzed, in a blinded fashion, for total WBC, as well as absolute neutrophil counts by the University of California Davis veterinary diagnostics laboratory.

(79) As shown in FIG. 4, one sequential IV injection of DOTAP cationic liposomes followed by IV injection of EF1-hG-CSF DNA increased absolute neutrophil counts approximately 10 fold and total WBC approximately 4 fold, 21 days following injection when compared to mock-injected control mice receiving sequential injection of an EF1-luciferase, plasmid DNA vector. These results document that the hG-CSF gene encoded protein product was fully functional in treated mice. Taken together, the high-level increases in absolute neutrophil counts produced by the EF1-hG-CSF DNA vector, coupled with the 10 to 15 fold above therapeutic hG-CSF protein levels produced at day 21 (see FIG. 3) demonstrate that a single, sequential IV injection of a cationic liposomes followed by a CPG-free DNA vector can produce prolonged therapeutic effects of a now FDA-approved recombinant human protein therapy.

Serum Human G-CSF Levels Produced in Mice by Sequential IV Injection of Either Single or Dual Cassette, hG-CSF Single Plasmid Vectors

(80) Sera were collected from groups of four mice at either day 6 or 14 following sequential, IV injection of 800 nmoles of pure DOTAP MLV cationic liposomes, followed two minutes later by IV injection of 40 g either an EF1-luciferaseEF1-hGCSF (2 expression cassette) or an EF1-hGCSF (1 expression cassette), CPG-free, single plasmid DNA vector.

(81) As shown in FIG. 5, the single as well as dual cassette DNA vectors containing the hG-CSF gene each produced supra-therapeutic serum hG-CSF levels (100 pg/ml required to increase neutrophil counts) at day six after injection, 951 and 423 pg/ml, respectively. The single cassette vector produced even higher therapeutic levels, 1941 pg/ml, at day 14. In contrast, hG-CSF levels produced at day 14 by the dual cassette, single plasmid DNA vector had fallen to a sub-therapeutic level (93 pg/ml), as hG-CSF protein levels below 100 pg/ml are sub-therapeutic. Thus, adding a second expression cassette can control the duration of expression of the gene contained in the first cassette.

Serum hG-CSF Levels in Mice, 21 Days After IV Injection of Cationic Liposomes, then DNA Containing Different Promoter-enhancer Combinations Linked to the hG-CSF Gene

(82) Sera were collected from groups of four mice, 21 days following sequential, IV injection of 800 nmoles of pure DOTAP MLV cationic liposomes, followed two minutes later by IV injection of 60 g of the hG-CSF gene, linked to one of the following enhancer-promoter combinations, mCMV-EF1, hCMV-hCMV, hCMV-hferritin light chain, hCMV-hferritin heavy chain, hCMV-glucose-regulated protein 78 or mCMV-hferritin light chain, each in a CPG-free, single cassette, DNA vector.

(83) As shown in FIG. 6, a range of supra-therapeutic, hG-CSF serum levels were produced at day 21 by the mCMV-EF-1 (2120 pg/ml), hCMV-hCMV (1516 pg/ml), hCMV-FerL (699 pg/ml), hCMV-Grp78 (343 pg/ml) and mCMV-FerL (303 pg/ml)-driven DNA vectors, each linked to the hG-CSF gene. In contrast, the hCMV-FerH-hG-CSF DNA vector (52 pg/ml) produced a sub-therapeutic hG-CSF level. Taken together, these results reveal that changing the promoter-enhancer combination can produce a range of different hG-CSF protein levels, from more than 20 fold above therapeutic to sub therapeutic, 21 days after a single injection. (hG-CSF protein levels 100 pg/ml are required to increase neutrophil counts).

Mouse Lung Luciferase Levels, 7 Days After Sequential IV Injection of Cationic Liposomes, then Single Cassette, EF1-luciferase DNA Alone or Together with a Drug

(84) Lungs were collected from groups of four mice, 7 days following sequential, IV injection of 800 nmoles of pure DOTAP MLV cationic liposomes alone, or containing 2 mg/kg of L-arginine, 0.01 mg/kg of colchicine or 1 mg/kg of dexamethasone. In each case, cationic liposome injection was followed two minutes later by IV injection of 40 g of an mCMV-EF1-luciferase, CPG-free, single cassette, DNA vector.

(85) As shown in FIG. 7, when compared to mice receiving sequential injection of DOTAP MLV alone (control), mice receiving either colchicine or dexamethasone together with the liposomes showed higher luciferase activity in the lung. In contrast, mice receiving L-arginine together with liposomes failed to increase gene expression levels. Thus, co-injecting selected drugs together with the liposomes can increase the level and duration of expression of genes delivered by sequential cationic liposome then DNA injection.

Mouse Lung Luciferase Levels, 7 Days After Sequential IV Injection of Cationic Liposomes, Then Dual Cassette, EF1-hG-CSF-EF1-luciferase DNA Alone or With Drug(s)

(86) Lungs were collected from groups of four mice, 7 days following sequential, IV injection of 800 nmoles of pure DOTAP MLV cationic liposomes alone, or containing 2 mg/kg of L-arginine, 1 mg/kg of dexamethasone, 0.02 mg/kg of sildenafil, 0.1 mg/kg of valproic acid or 2 mg/kg of L-arginine plus 0.02 mg/kg of sildenafil (VIAGRA). In each case, cationic liposome injection was followed two minutes later by IV injection of 40 g of EF1-luciferaseEF1-hGCSF, a 2 expression cassette, CPG-free single plasmid DNA vector.

(87) As shown in FIG. 8, when compared to mice receiving sequential injection of DOTAP MLV alone (control), mice receiving dexamethasone, valproic acid or sildenafil alone, or L-arginine plus sildenafil together with the liposomes showed higher luciferase activity in the lung. In contrast, mice receiving either L-arginine or valproic acid together with liposomes were either lower than or comparable to controls. Thus, depending on the drug co-injected, expression levels of the delivered gene can be increased or reduced.

Mouse Lung Luciferase Levels, 10 Days After Sequential IV Injection of Cationic Liposomes, Then a DNA Vector Containing One of a Series of Different Promoter-Enhancer Combinations, Each Either With or Without MARs and all Linked to the Luciferase Gene

(88) Lungs were collected from groups of three mice, 10 days following sequential, IV injection of 800 nmoles of pure DOTAP MLV cationic liposomes, followed two minutes later by IV injection of 40 g of the luciferase gene, linked to one of the following enhancer-promoter combinations: hCMV-hCMV, hCMV-human ferritin heavy chain, hCMV-CBOX (human Carboxypeptidase B1), mCMV-hCMV, mCMV-CBOX and mCMV-EF1, each linked to the luciferase gene in a CPG-free, single cassette, DNA vector.

(89) FIG. 9 shows that DNA vectors lacking MARs, and containing the hCMV enhancer linked to the hCMV, ferritin heavy chain or CBOX promoters produced higher lung luciferase levels than the corresponding vectors containing MAR elements. In contrast, DNA vectors containing both MARs and the mCMV enhancer linked to the hCMV, EF1 or CBOX promoters failed to produce lung luciferase levels as high as the corresponding vectors lacking MAR elements. Thus, CPG-free DNA vectors lacking MARs can produce more durable expression than MAR-containing vectors.

Mouse Lung Luciferase Levels, 1 or 5 Days After IV Injection of PEI:EF-1 Luc DNA Complexes or Sequential IV Injection of Cationic Liposomes, then the Identical EF-1 Luc DNA

(90) Lungs were collected from groups of three mice, 1 or 5 days following IV injection of either 12.5 g of CPG-free EF-1-Luc DNA vector complexed to 22 kDa linear PEI at a 1:4 N:P ratio, or sequential, IV injection of 900 nmoles of pure DOTAP MLV cationic liposomes, followed two minutes later by IV injection of 40 g of the same EF-1-Luc DNA vector.

(91) FIG. 10 shows lung luciferase levels were consistently higher in the PEI:DNA injected mice than in the mice injected sequentially with cationic liposomes then DNA at day one following injection. However, lung luciferase levels had fallen approximately 100 fold in the PEI:DNA injected mice by day five. In direct contrast, lung luciferase levels from the sequentially IV injected mice had risen by day 5 after injection. Luciferase levels were up to 150 fold higher in sequentially-injected mice than those present in PEI:DNA injected mice also sacrificed at day 5. Thus, sequential cationic liposome then DNA injection produces higher levels of gene expression at later time points when compared to the same CPG free DNA injected as a PEI:DNA complex.

Mouse Lung Luciferase Levels, 1 Day After Sequential IV Injection of One of Seven Different Cationic Liposome Formulations, Then Single Cassette, EF1-Luciferase DNA

(92) Lungs were collected from groups of four mice, 1 day following sequential, IV injection of 800 nmoles of pure DOTAP MLV, pure DOTAP SUV, DOTAP:cholesterol 2:1 MLV, DOTAP:diolelyl phosphatidylcholine (DOPC) 1:1 MLV, DSTAP MLV, ethyl DSPC MLV or DOTAP:DOBAQ 1:1 MLV cationic liposomes. In each case, cationic liposome injection was followed two minutes later by IV injection of 80 g of an mCMV-EF1-luciferase, CPG-free, single cassette, DNA vector.

(93) As shown in FIG. 11, when compared to lung luciferase levels in mice receiving sequential IV injection of pure DOTAP MLV, mice receiving DOTAP SUV, DOTAP:chol or DOTAP:DOPC cationic liposome formulations produced gene expression levels approximating DOTAP MLV or higher. In contrast, mice receiving DSTAP, ethyl DSPC or DOTAP:DOBAQ MLV produced either very low or nearly undetectable lung luciferase levels. That DOTAP SUV produced gene expression levels approximating DOTAP MLV was unexpected because DOTAP MLV produces more than 1700 fold higher levels of gene expression than DOTAP SUV when injected as cationic liposome:DNA complexes (see, Nature Biotechnology, 15:167-173; 1996, herein incorporated by reference in its entirety).

(94) Mouse Spleen Luciferase Levels, 1 Day After IV Injection Of PEI:EF-1 Luc DNA Complexes Alone or Mixed With One of Four Different Drugs

(95) Spleens were collected from groups of three mice, 1 day following IV injection of 12.5 g of CPG-free EF-1-Luc DNA vector complexed to 22 kDa linear PEI at a 1:4 N:P ratio. Mice received an intraperitoneal injection of one ml of 5% DMSO either alone, or containing 200 g of amlexanox, 1 mg of chloroquine, 200 g of SAHA or 300 g of tofacitinib per mouse, two hours prior to receiving IV PEI:DNA complexes.

(96) FIG. 12 shows pre-injection of the anti-inflammatory agents amlexanox, chloroquine or SAHA prior to injecting CPG-free DNA increased gene expression levels, whereas tofacitinib failed to increase gene expression. Amlexanox in particular, a selective inhibitor of the TBK1-induced interferon activation pathway, increased gene expression levels. Thus, pre-injection of selected anti-inflammatory agents may further increase the effectiveness of CPG-free DNA for gene therapy.

(97) Mouse Lung Luciferase Levels, 1 or 7 Days After Sequential IV Injection of Cationic Liposomes, Then One of a Series of Dual Cassette, EF-1-LuchG-CSF DNA Vectors

(98) Lungs were collected from groups of four mice, 1 or 7 days following sequential, IV injection of 800 nmoles of pure DOTAP MLV cationic liposomes followed two minutes later by 40 g of EF1-LucEF1-hGCSF, EF1-LuchCMV-hCMV-hGCSF, EF1-LuchCMV-hCBOX-hGCSF, EF1-LuchCMV-hREG1-hGCSF or EF1-LucmCMV-hCBOX-hGCSF 2 expression cassette, CPG-free single plasmid DNA vector.

(99) FIG. 13 shows that when compared to mice receiving sequential injection of EF1-LucEF1-hGCSF dual cassette vector, containing the EF1 promoter in each cassette (control), mice receiving each of the other four dual cassette DNA vectors containing the EF1 promoter in one cassette and another promoter in the second cassette showed consistently higher luciferase activity in the lung at both day one and seven after injection. Dual cassette vectors containing a different promoter in each cassette produced lung luciferase levels up to tenfold or more higher at each time point than produced by the dual cassette vector containing the EF-1 promoter in both cassettes. Thus, using different promoter elements in different cassettes of multi-cassette vectors can significantly increase the level and duration of gene expression they produce.

Serum Human G-CSF Levels Produced in Mice, 1 Day After Sequential, IV Cationic Liposome Injection, With or Without Co-Injection of Neutral Liposomes, Followed by IV Injection of a Dual Cassette, Single Plasmid Vector

(100) Neutral MLV liposomes were prepared from Phospholipon 90H, Lipoid GmbH. The fatty acid content of this product is 15% palmitic acid, 85% stearic acid. Liposomes were prepared either by drying down the lipids in organic solvent on a rotary evaporator, then re-suspending the dried lipid film in a solution of 5% dextrose in water at a lipid concentration of 50 millimolar or by hydrating the lipid as a dry powder in 5% w/v dextrose. Both were prepared at 60 degrees C. The solution was then vortexed for 15 minutes to form MLV. Sera were collected from groups of four mice at day 1 following sequential, IV injection of buffer alone (control), 1000 nmoles of pure DOTAP SUV cationic liposomes, alone or co-injected with 1000 nmol of neutral MLV, followed two minutes later by IV injection of 120 g an EF1-luciferaseEF1-hGCSF (2 expression cassette), CPG-free, single plasmid DNA vector or 1400 nmoles of pure DOTAP SUV cationic liposomes, alone or co-injected with 1000 nmol of neutral MLV, followed two minutes later by IV injection of 100 g of EF1-luciferaseEF1-hGCSF DNA.

(101) As shown in FIG. 14, serum hG-CSF levels produced one day after sequentially co-injecting pure DOTAP SUV together with neutral MLV then EF1-luciferaseEF1-hGCSF DNA were increased from 3 to 600 fold when compared to sequential injection of DOTAP SUV without neutral MLV. Thus, co-injecting neutral liposomes together with cationic liposomes can significantly increase peak levels of gene expression produced. In addition, co-injecting neutral liposomes appears to eliminate the variation in gene expression levels produced by sequentially injecting different ratios of cationic liposomes to DNA without co-injecting neutral liposomes.

Serum Human G-CSF Levels Produced in Mice, 1 or 7 Days After Sequential, IV Cationic Liposome Co-Injection with Neutral Liposomes, Followed by IV Injection of a Dual Cassette Plasmid Vector

(102) Sera were collected from groups of four mice at day 7 following sequential, IV injection of 1000 nmoles pure DOTAP SUV cationic liposomes co-injected with 1000 nmol of neutral MLV, followed two minutes later by IV injection of 120 g of CPG-free, EF1-luciferaseEF1-hGCSF DNA or 1000 nmoles of pure DOTAP SUV cationic liposomes co-injected with 1400 nmol of neutral MLV, followed two minutes later by IV injection of 100 g of EF1-luciferaseEF1-hGCSF DNA. Sera were also collected from groups of four mice at day 1 following sequential, IV injection of buffer only (control), 800 nmoles of pure DOTAP SUV cationic liposomes co-injected with 1000, 750, 500, 250 or 100 nmol of neutral MLV respectively, followed two minutes later by IV injection of 90 g of EF1-luciferaseEF1-hGCSF.

(103) As shown in FIG. 15, serum hG-CSF levels produced by co-injecting pure DOTAP SUV together with neutral MLV dropped by approximately 100 fold compared to the hG-CSF levels produced in the same mice one day after injection, (See FIG. 14 for hG-CSF levels produced at day 1 following injection of these same mice). Thus, co-injecting neutral liposomes with cationic liposomes can strongly alter both peak as well as longer-term expression of delivered genes. In addition, the ratio of neutral to cationic liposomes co-injected determines the extent to which co-injected neutral liposomes increase the expression of sequentially delivered genes.

Mouse Serum Hg-CSF Levels, 7 Day After Sequential IV Injection of Different Cationic Liposome Formulations, then Single Cassette, CPG-Free EF1-Hg-CSF DNA

(104) Sera were collected from groups of four mice, 7 days following sequential, IV injection of either 800 or 1000 nmoles of pure DOTAP SUV, or MLV cationic liposomes. Injection of each of the three cationic liposome formulations was followed two minutes later by IV injection of either 100 or 120 g of an mCMV-EF1-h-G-CSF, CPG-free, single cassette, DNA vector. 0.1 m extruded cationic liposomes were prepared from MLV by sequential extrusion through sized polycarbonate membranes under high argon gas pressure in a Lipex extrusion device.

(105) As shown in FIG. 16, and in part depending on the ratio of nmoles cationic liposomes to g DNA ratio injected, pure DOTAP SUV and 0.1 m extruded cationic liposomes produced extended, high-level expression of hG-CSF as efficiently as that produced by MLV cationic liposomes. Therefore, SUV as well as 0.1 m extruded (oligolamellar) cationic liposomes are as effective as MLV when used for sequential cationic liposome then CPG-free DNA injection.

Example 2

Long-Term Expression

(106) In this Example, five mice per group were sequentially injected with 800 nmol of either DOTAP MLV or SUV followed by 90 ug of a CPG-free plasmid vector containing an EF1- or hCMV-driven hG-CSF cDNA. Serum levels of human G-CSF protein were assessed at 7- or 14-day intervals for the subsequent 428 days following injection. Obtaining and analyzing mouse serum for human G-CSF levels was performed as follows. Each mouse was anesthetized and bled via submandibular vein. Serum was isolated from whole blood using serum separator tubes from BD. Human G-CSF levels were measured in pg/ml via an ELISA performed strictly according to the manufacturer's specifications, using an R&D systems human G-CSF ELISA. The results are shown in FIG. 17, and show that supra-therapeutic levels of human G-CSF protein were produced in fully immune-competent mice for at least 428 days after receiving a single IV injection of DOTAP SUV liposomes then an EF1-huG-CSF plasmid DNA vector.

Example 3

Protein Expression in Rats

(107) In this Example, 250 gm Sprague-Dawley female rats #22 and 23 were sequentially injected with 6000 nmol of DOTAP SUV then 300 ug of a CPG-free plasmid vector containing an EF1-driven hG-CSF DNA vector. Serum levels of human G-CSF protein, WBC and absolute neutrophil counts (ANC) were assessed at 7-day intervals following injection. Serum ALT and AST levels were assessed at day 1 only. All were assessed by the UC Davis Comparative Pathology lab. As shown in FIG. 18, and Table 3 below, supra-therapeutic levels of hG-CSF protein, as well as significantly elevated WBC and ANC, were produced in EF1-huG-CSF injected rats for at least 22 days following a single IV injection. ALT and AST measured at day 1 after injection were comparable to background control levels in un-injected rats.

(108) TABLE-US-00003 TABLE 3 WBC Day 1 Day 8 Day 15 Day 22 ALT Day 1 #22 6.56 27.36 23.68 27.20 Ctrl 4.57 #22 30.30 Ctrl 12-67 #23 11.04 15.74 12.90 20.08 SEM 0.27 #23 29.40 ANC Day 1 Day 8 Day 15 Day 22 AST Day 1 #22 4.99 17.31 12.32 15.69 Ctrl 1.39 #22 89.80 Ctrl 14-113 #23 5.07 8.07 6.68 10.57 SEM 0.13 #23 74.00

Example 4

DPTAP Liposomes

(109) In this Example, three mice were injected per group. Each mouse received a single IV injection of 900 nmoles of DOTAP, DMTAP, or DPTAP (1,2-dipalmitoyl 3-trimethylammonium propane) SUV liposomes followed two minutes later by a single IV injection of 70 ug of an EF-1 plasmid DNA vector encoding hG-CSF. Serum levels of hG-CSF were determined by ELISA 24 hours following injection. FIG. 19 shows that HuG-CSF protein was present in serum from mice treated with DOTAP or DPTAP but not DMTAP. These data indicate that multiple cationic lipids can mediate transfection in vivo, and that level of protein production can be controlled by selection of the lipid carrier.

Example 5

Toxicity Resolves Within 48 Hours

(110) In this Example, three mice were injected per group. Mice were purchased from Charles River Labs. Each mouse received a single IV injection of 1000 nmoles, 1200 nmoles, or 1400 nmoles of DOTAP SUV liposomes as indicated, followed two minutes later by a single IV injection of 100 g, 120 g, or 140 g of a CPG-free EF-1 driven plasmid DNA vector encoding luciferase. Serum was collected at 24 hrs or 48 hrs after injection. ALT and AST measurements were assayed at the UC Davis Comparative Pathology lab. As shown in FIG. 20, at 24 hours following sequential injection, serum levels of ALT and AST were elevated from two to five fold in all lipid then DNA groups. At 48 hours, serum ALT and AST levels returned to control (background) levels (shown by the mock-injected group). These data indicate that toxicity as measured by ALT/AST is acute (present within 24 hrs of injection) and transient (gone by 48 hrs).

Example 6

Liposomes with DexP

(111) In this Example, three mice were injected per group. Each mouse received a single IV injection of 900 nmoles of either pure DOTAP SUV liposomes or each mouse received a single IV injection of 900 nmoles of either pure DOTAP SUV liposomes or liposomes containing indicated mole % s of dexamethasone covalently linked to palmitate (DexP) incorporated into the liposome bilayer. Incorporation of 5% cholesteryl palmitate (CholP) into the liposome bilayer served as a control. This was followed two minutes later by a single IV injection of 90 ug of plasmid DNA encoding hG-CSF. Serum levels of hG-CSF were determined by ELISA 24 hours following injection and ALT measurements were assayed at the UC Davis Comparative Pathology lab. As shown in FIG. 21, at 24 hours following sequential injection, toxicity as measured by ALT levels is 2-3 fold higher than seen in animals that were mock injected with lactated ringer's solution only (ALT Control). Incorporation of 2.5% dexamethasone palmitate (DexP) into the liposome bilayer produced a dual effect of increasing peak expression of hG-CSF as well as reducing ALT levels to within 1.5 fold of background (normal) levels at 24 hours.

Example 7

DexP Reduces Toxicity and Increases Expression

(112) In this Example, three mice were injected per group. Each mouse received a single IV injection of 900 nmoles of either pure DOTAP SUV liposomes or liposomes containing 2.5 mole % of dexamethasone covalently linked to palmitate (DexP) incorporated into the liposome bilayer of DOTAP liposomes. This was followed two minutes later by a single IV injection of either 130 ug (high) or 40 ug (low) of an EF-1 driven plasmid DNA vector encoding hG-CSF. Two groups were treated two hours prior to IV injection with an IP injection of 1 umole of dexamethasone palmitate. Serum levels of hG-CSF were determined by ELISA 24 hours following injection and ALT measurements were assayed at 24 hours by the UC Davis

(113) Comparative Pathology lab. As shown in FIG. 22, sequential injection of 130 ug of DNA produced significantly higher hG-CSF protein levels than 40 ug of DNA 24 hours later. Inclusion of 2.5 mole % dexamethasone palmitate in the liposomes at either DNA dose further increased hG-CSF protein levels. In addition, incorporation of dexamethasone palmitate in liposomes reduced ALT levels to within 1.5 fold of background (normal) levels, even at the much higher DNA dose.

Example 8

Pre and Post Dex Injection

(114) In this Example, mice were pre-injected IP with 15 mg/kg of Tofacitinib or 40 mg/kg of Dexamethasone, followed 2 hours later by sequential IV injections of 900 nmol DOTAP SUV, then 70 ug of a CPG-free, EF-1 driven hG-CSF plasmid vector. Another IP injection of Tofacitinib or Dexamethasone was administered 2 hours after injection of DNA. As shown in FIG. 23, administration of dexamethasone prior to, as well as following, sequential cationic liposome then DNA injection both significantly increased HuG-CSF protein levels while concurrently reducing toxicity within 1.5 fold of background (normal) levels. In contrast, pre- and post-injection of the immunosuppressive agent Tofacitinib did neither.

Example 9

Lipid to DNA Ratio

(115) In this Example, three mice per group were given IV injections of 900, 1000, 1200, or 1500 nmols of DOTAP SUV liposomes containing 2.5 mole % of dexamethasone covalently linked to palmitate (DexP) incorporated into the liposome bilayer of DOTAP liposomes, suspended in Lactated Ringer's (LR) to a final volume of 100 uL per injection, followed 2 minutes later by 40, 60, or 75 ug of a CPG-free, EF-1 driven, hG-CSF plasmid vector at 100 L per injection. Mock-injected mice received LR only without lipid or DNA. Serum levels of hG-CSF protein and ALT were assayed 24 hours later. As shown in FIG. 24, hG-CSF protein and ALT levels of mice sequentially injected with DOTAP SUV lipid to plasmid DNA (nmole lipid:mg DNA) ratios lower than 26:1 produced significantly higher hG-CSF protein levels while preventing toxicity, as documented by producing ALT levels either within 1.5 fold of or equal to background (normal) levels in control mice that received neither lipid nor DNA injection.

Example 10

Rituximab Expression

(116) In this Example, three mice were injected per group. Each mouse received a single IV injection of 1000 nmoles of either pure DOTAP cationic liposomes or liposomes containing 2.5 mole % of dexamethasone covalently linked to palmitate (DexP) incorporated into the liposome bilayer of DOTAP liposomes. This was followed two minutes later by a single IV injection of 100 ug of a dual cassette, single plasmid DNA vector encoding the Rituximab heavy and light chains (see constructs in FIGS. 36, 40, and 41). Serum Rituximab levels were determined by ELISA 24 hours following injection and then at 7-day intervals. Mice were bled and serum isolated as for G-CSF. Rituximab levels were measured using an Immunoguide ELISA obtained from Eagle Biosciences, and performed according to instructions. As shown in FIG. 25, IP dexamethasone pretreatment plus incorporation of 2.5 mole % dexamethasone palmitate in DOTAP liposomes increases serum Rituximab levels by more than five fold for at least three weeks after injection.

Example 11

Rituximab Expression

(117) In this Example, three mice were injected per group. Each mouse received a single IV injection of 1000 nmoles of either pure DOTAP cationic liposomes or liposomes containing 2.5 mole % of dexamethasone covalently linked to palmitate (DexP) incorporated into the liposome bilayer of DOTAP liposomes. This was followed two minutes later by a single IV injection of 100 ug of an EF-1-driven, dual cassette, single plasmid DNA vector encoding Rituximab (see constructs in FIGS. 36, 40, and 41). One group was treated two hours prior to IV injection with an IP injection of 40 mg/kg dexamethasone (Dex) and 1000 nmoles the neutral lipid (NL), DMPC. Serum Rituximab levels injected mice were determined by ELISA 24 hours following injection and at 7-day intervals thereafter. As shown in FIG. 26, all mice produced significant levels of serum Rituximab protein for at least 12 weeks following one injection. Mice receiving the combination of Dex, DexP and NL produced significantly higher serum Rituximab levels over time. These data show that a single sequential injection of a dual cassette Rituximab plasmid DNA vector can produce significant levels of serum Rituximab protein in animals for greater than 90 days.

Example 12

Dual Cassette, Single Plasmid Rituximab Expression

(118) In this Example, Raji cells (1 million/sample) were incubated with mouse serum samples or recombinant Rituximab (50 ng/ml) for 1 hr at 4C, in FACS binding buffer containing EDTA and 0.5% BSA. Following washes, samples were incubated with fluorescently labeled secondary antibody (anti-human IgG-PE) for 30 min, washed and analyzed using an Accuri flow cytometer. Between 3500-5000 events were recorded for each sample. The experiment was repeated twice with similar results.

(119) FIG. 27 shows a FACS plots display fluorescence intensity for four experimental conditions. The upper panels show samples containing mouse serum from control (HuG-CSF) DNA plasmid vector injected mice or secondary antibody alone, which display low, background levels of fluorescence in the PE channel (300). The lower two panels show recombinant Rituximab protein (left panel) and mouse serum following Rituximab plasmid DNA vector administration (right panel). Both samples show fluorescence intensities over 10 fold higher than the background as shown in Table 4 below, demonstrating that Rituximab present in the mouse serum binds to target CD20-expressing human Raji B cells to an extent similar to recombinant Rituximab protein. Thus, the Rituximab present in mouse serum six weeks after injection of a dual cassette, single plasmid Rituximab DNA vector binds CD20+ target human B cells in a fully functional manner.

(120) TABLE-US-00004 TABLE 4 Sample designation Mean Fluorescence Intensity Secondary antibody alone 331.86 Mouse Serum (injected with control 279.32 plasmid) Recombinant Rituximab (50 ug/ml) 5781.87 Mouse Serum (injected with anti-CD20 3532.40 plasmid)

Example 13

Functional Rituximab is Expressed

(121) In this Example, Raji cells (510.sup.4 cells/well) were plated in 96 well plates using RPMI+10% FBS medium. Next day cells were incubated with Rituximab (1, 10 ug/ml) or mouse serum samples (20 l/well) for 1 hour at room temperature. Twenty ul of pooled normal human plasma (Innovative Research) was then added to all wells (except the Rituximab control condition) and the plates incubated for another 12 h at 37C. Cell viability was measured using the Promega Cell titer glo reagent according to the manufacturer's instructions. In FIG. 28, values are shown as percentage change from the control conditions in which serum from mice injected with a huG-CSF DNA plasmid DNA vector was used. Individual mouse sera were tested from five different mouse groups that received a single sequential injection of a dual cassette, single plasmid Rituximab DNA vector from 8 to 78 days prior to serum collection.

(122) Results of this Example are shown in FIG. 28. Sera from mice previously injected with a dual cassette, single plasmid Rituximab DNA vector were analyzed first by ELISA to quantitate serum Rituximab concentrations. Adding these Rituximab-containing sera in a cell lysis assay then showed that they lyse CD-20+ human Raji B cells in a manner comparable to recombinant Rituximab (Invivogen). Moreover, functional serum Rituximab protein with documented lytic activity was isolated from animals across five separate injection experiments over a eleven-week period, demonstrating its reproducible lytic efficacy over time.

Example 14

Enhanced Expression of Rituximab

(123) In this Example, two, 250 gm Sprague-Dawley female rats per group were were first pre-injected with 40 mg/kg dexamethasone, then sequentially injected with 4400 nmol of DOTAP SUV liposomes containing 2.5 mole % of dexamethasone covalently linked to palmitate (DexP) incorporated into the liposome bilayer, with or without 4400 nmol of neutral DMPC lipid, then 360 g of a dual cassette, single plasmid DNA vector containing an EF1-driven Rituximab cDNA (see constructs in FIGS. 36, 40, and 41). Serum levels of human Rituximab protein were assessed at 7-day intervals following injection. FIG. 29 shows significantly higher levels of serum Rituximab protein were produced in rats also receiving neutral lipid for at least 15 days following a single IV injection.

Example 15

Codon-Optimized Rituximab Expression

(124) In this Example, three mice were injected per group. Each mouse received a single IV injection of 1000 nmoles of liposomes containing 2.5 mole % of dexamethasone covalently linked to palmitate (DexP) incorporated into the liposome bilayer of DOTAP liposomes. This was followed two minutes later by a single IV injection of 100 ug of dual cassette, single plasmid EF-1-driven DNA vector encoding Rituximab (see constructs in FIGS. 36, 42, and 43). Numbered plasmids (in FIG. 30) were codon-optimized versions of the original, CpG-free but not codon optimized Rituximab DNA sequence. Serum levels of Rituximab were determined by ELISA 24 hours following injection. FIG. 30 shows that at 24 hours following sequential injection, codon-optimized DMA vector 6 produced significantly higher levels of serum Rituximab protein than non-codon optimized rituximab DNA vectors.

Example 16

Codon-Optimized Rituximab Expression

(125) In this Example, three mice were injected per group. Each mouse received a single IV injection of DOTAP cationic liposomes (900 nmoles or 1050 nmoles as indicated) containing 2.5 mole % of dexamethasone covalently linked to palmitate (DexP) incorporated into the liposome bilayer. This was followed two minutes later by a single IV injection of 75 ug of a dual cassette, codon-optimized single plasmid DNA encoding Rituximab (see constructs in FIGS. 36, 42, and 43). Both groups were treated two hours prior to IV injection with an IP injection of 40 mg/kg dexamethasone. Serum levels of Rituximab were determined by ELISA 24 hours following injection and at 7-day intervals thereafter. FIG. 31 shows that one sequential IV injection of codon-optimized dual cassette, single plasmid Rituximab DNA vectors produces extended serum Rituximab levels for at least the next 60 days. Serum Rituximab levels rise over time after a single IV sequential injection.

Example 17

Valproic Acid and Theophylline Increase Protein Expression

(126) In this Example, three mice were injected per group. Each mouse received a single IV injection of 1050 nmoles of liposomes containing 2.5 mole % of dexamethasone covalently linked to palmitate (DexP) incorporated into the liposome bilayer of DOTAP liposomes. This was followed two minutes later by a single IV injection of 75 ug of dual cassette plasmid DNA encoding Rituximab. All groups were treated two hours prior to IV injection with an IP injection of 40 mg/kg dexamethasone. Where indicated in FIG. 32, animals were also pretreated by IP injection of 15 mg/kg Valproic Acid (VPA), 2 mg/kg VPA, 30 mg/kg Theophylline (Theo) or 15 mg/kg Theo. Serum Rituximab levels were determined by ELISA 24 hours following injection. FIG. 32 shows serum Rituximab levels produced were significantly increased by pre-treatment with the drugs Valproic Acid or Theophylline, thus providing a framework for further enhancing protein levels without altering the dose of lipid or DNA.

Example 18

Dual or Single Cassette Rituximab Expression

(127) In this Example, mice were pre-injected with 40 mg/kg Dexamethasone IP. Two hours later, they were sequentially injected with either 1050 or 1500 nmols of DOTAP SUV liposomes containing 2.5 mole % of dexamethasone covalently linked to palmitate (DexP) incorporated into the liposome bilayer, followed by 60 g or 75 g of plasmid DNA. Plasmid DNA constructs injected were either codon optimized, double-cassette, single plasmid DNA vectors (see constructs in FIGS. 36, 42, and 43) or codon optimized single-cassette plasmids (see constructs in FIGS. 36, 37, and 39) containing Rituximab heavy and light chain sequences separated by a 2A self-cleaving peptide DNA sequence. Serum Rituximab levels were determined by ELISA 24 hours following injection. FIG. 33 shows that at 24 hours following sequential injection, mice that received 2A peptide containing single cassette vectors encoding Rituximab produced serum levels approaching 400 ng/ml, approximately one-third the level produced by the dual cassette vector. Thus, significant Rituximab serum levels can be produced by either dual- or single-cassette, 2A peptide-containing DNA vectors.

Example 19

Lipid to DNA Ratio and Rituximab Expression

(128) In this Example, three mice per group were given IV injections of 900, 1050, 1200, 1500 or 1650 nmols of DOTAP SUV liposomes containing 2.5 mole % of dexamethasone covalently linked to palmitate (DexP) incorporated into the liposome bilayer, suspended in Lactated Ringer's (LR) to a final volume of 100 uL per injection, followed 2 minutes later by 75 ug of a CPG-free, dual cassette, single plasmid Rituximab vector at 100 uL per injection. Mock-injected mice received LR only without lipid or DNA. Serum levels of Rituximab protein and ALT were assayed 24 hrs later. FIG. 34 shows Rituximab protein and ALT levels of mice sequentially injected with DOTAP SUV lipid to plasmid DNA (nmole lipid:mg DNA) ratios lower than 15:1 produced significantly higher Rituximab protein levels while producing serum ALT levels within 1.5 fold of background (normal) ALT levels in control mice that received neither lipid nor DNA injection.

Example 20

Factor IX Expression with Valproic Acid or Theophylline

(129) In this Example, three mice were injected per group. Each mouse received a single IV injection of 1500 nmoles of DOTAP SUV liposomes containing 2.5 mole % of dexamethasone covalently linked to palmitate (DexP) incorporated into the liposome bilayer. This was followed two minutes later by a single IV injection of 60 ug of a codon optimized, EF-1-driven single cassette DNA vector encoding the human factor IX cDNA (see constructs in FIGS. 38 and 44). All groups were treated two hours prior to IV injection with an IP injection of 40 mg/kg dexamethasone. Where indicated, animals were also pretreated by IP injection of 2 mg/kg Valproic Acid (VPA) or 30 mg/kg Theophylline (Theo). Serum human factor IX levels were determined by ELISA 24 hours following injection. Each mouse was bled as for G-CSF. Blood was collected into tubes containing Potassium EDTA or Sodium Citrate to prevent coagulation and centrifuged to obtain plasma. An AssayPro ELISA specific to human Factor IX was used according to manufacturer's instructions to measure Factor IX expression. FIG. 35 shows serum human factor IX levels produced at 24 hrs were significantly higher in mice receiving the human factor IX DNA vector plus pre-treatment with either Valproic Acid or Theophylline.

Example 21

Size Determination of Liposomes

(130) In this Example, the sizes of various liposomes were determined. In particular, the liposomes in Table 5 were prepared in 5% w/w glucose, and the size was determined using quasi elastic laser light scattering. The Z-Average particle size of these DOTAP liposomes is shown in Table 5.

(131) TABLE-US-00005 TABLE 5 Liposome Type Z-Average Particle Size (nm) DOTAP Multilamellar Liposomes (MLV) 339 DOTAP 0.1 micron Extruded MLV 146 DOTAP Sonicated Liposomes (SUV) 74

(132) All publications and patents mentioned in the present application are herein incorporated by reference. Various modification and variation of the described methods and compositions of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention that are obvious to those skilled in the relevant fields are intended to be within the scope of the following claims.