Functional lipid constructs
09802981 · 2017-10-31
Assignee
Inventors
- Nicolai Vladimirovich Bovin (Moscow, RU)
- Stephen Micheal Henry (Auckland, NZ)
- Igor Leonidovich Rodionov (Moscow, RU)
- Cristina-Simona Weinberg (Rotorua, NZ)
- Alexander Borisovich Tuzikov (Moscow, RU)
Cpc classification
A61K47/65
HUMAN NECESSITIES
C07K7/02
CHEMISTRY; METALLURGY
C07K5/02
CHEMISTRY; METALLURGY
C07F9/6561
CHEMISTRY; METALLURGY
International classification
C07K7/02
CHEMISTRY; METALLURGY
C07K5/02
CHEMISTRY; METALLURGY
C07F9/6561
CHEMISTRY; METALLURGY
Abstract
The invention relates to methods for effecting qualitative and quantitative changes in the functional moieties expressed at the surface of cells and multi-cellular structures, and functional lipid constructs for use in such methods. In particular, the invention relates to functional lipid constructs and their use in diagnostic and therapeutic applications, including serodiagnosis, where the functional moiety is a carbohydrate, peptide, chemically reactive group, conjugator or fluorophore.
Claims
1. A functional lipid construct of the structure: ##STR00029## where L is phosphatidylethanolamide; M is CH.sub.3 or H; g is the integer 1, 2 or 3; h is the integer 1, 2, 3 or 4; v is the integer 3, 4 or 5; and Func-S.sub.1 is selected from the group consisting of: ##STR00030## where w is the integer 1 or 2 and Func is S of a cysteine residue of a peptide; and ##STR00031## where k is the integer 3, 4, or 5.
2. The construct of claim 1 of the structure: ##STR00032## where w is the integer 1 or 2.
3. The construct of claim 1 of the structure: ##STR00033## where w is the integer 1 or 2 and Func is S of a cysteine residue of a peptide.
4. The construct of claim 1 of the structure: ##STR00034## where k is the integer 3, 4, or 5.
Description
BRIEF DESCRIPTION OF DRAWINGS
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DETAILED DESCRIPTION
(14) The invention resides primarily in conjugating functional moieties to a diacyl or dialkyl lipid (L) via a spacer (S) to provide a construct (F-S-L) that is dispersible in biocompatible media, but will also spontaneously incorporate into the lipid bilayer of a cell membrane or multi-cellular structure.
(15) The invention resides secondarily in the use of the selected structural motif (CMG) in the applications described and the advantages that accrue from using this structural motif and derivatives thereof.
(16) Despite the advances in cell surface modification described in the specifications accompanying the international PCT applications referred to under the heading Background Art, the availability of constructs for use in the “one-step method”, in particular peptide-lipid constructs, and the availability of BioG for use in the “two-step method”, places a limitation on the broad application of these methods.
(17) For example, a two-step method of localizing peptide antigen to the surface of cells or multi-cellular structures that avoids the use of BioG, or other conjugates obtained from biological sources, is desirable.
(18) Although it was recognized that the biotinylation of the carbohydrate-lipid constructs described in the specification accompanying international application no. PCT/NZ2005/000052 provided a substitute for BioG in the “two-step method”, it remains desirable to be able to use a biotin-lipid construct that has the favourable properties of these biotinylated carbohydrate-lipid constructs and could be used in the “one-step method”.
(19) In contrast with the preparation of constructs where the function (F) is a carbohydrate, the preparation of constructs where F is a peptide presents additional technical problems.
(20) Firstly, it is desirable for the peptide (F) ligated to the L-S or S-L moiety to be dispersible in water such as a buffered solution of solutes, e.g. PBS, or at least a biocompatible solvent.
(21) Overcoming this difficulty may require the selection of a proximal terminal sequence (PTS) to promote solubility without modifying the desired biological properties of the construct.
(22) Secondly, it is desirable for the peptide-lipid construct to be dispersible in water, or at least a biocompatible buffered solution or serum, according to the requirements of the proposed application (i.e. it is desirable for the construct to be “water soluble” as defined herein).
(23) Overcoming this difficulty requires the selection of a spacer (S) to promote solubility of the construct.
(24) Thirdly, where the proposed application is the modification of cells such as red blood cells (RBCs) for use in diagnostic applications, or as quality controls in blood group typing, it is required for the construct to be dispersible in a biocompatible buffered solution without participating in antigen-antibody cross reactivity not specific to the diagnostic peptide or blood group type antigen.
(25) Satisfying this requirement requires the identification of suitable structural motifs for the spacer (S) and/or proximal terminal sequence (PTS) when the latter is present.
(26) Where the application is for use in the modification of the surface of cells or multi-cellular structures (e.g. an embryo) with a view to promoting the association of the modified cell or modified multi-cellular structure with a target surface (e.g. the endometrium) exposing the cell or multi-cellular structure to solvents or buffered solutions that are not biocompatible must be avoided.
(27) Fourthly, the presentation of the peptide of the peptide lipid construct at the surface of the modified cell or multi-cellular structure will have an influence on the extent of cross reactivity with diagnostic markers.
(28) The ability to localise peptides to the surface of cells or multi-cellular structures via a residue proximal to either the N- or C-terminus of the peptide may allow the naturally occurring configuration of the peptide sequence relative to the cell surface to be approximated.
(29) The presentation of the peptide sequence in the tertiary (or quaternary) structure of the parent polypeptide (or protein) may therefore be mimicked. It is contemplated that peptides may be localised to the surface of cells via multiple residues. For example, where both a residue proximal to the amino terminus and a residue proximal to the carboxyl terminus are used to localise the peptide a “looped” configuration of the peptide may be promoted at the surface.
(30) The poly-ethylene glycol (PEG) spacer of known peptide-lipid constructs is selected to provide solubility. However, polymers of PEG may interfere with the expression and function of the peptide at the surface.
(31) The as yet unpublished specification accompanying international application number PCT/NZ2008/000239 describes the preparation of peptide-lipid constructs for use in methods of effecting qualitative and quantitative changes in the level of peptides expressed at the surface of cells and multi-cellular structures where an oligomer of ethylene glycol is used as a spacer covalently linking lipid of the construct to the peptide moiety. The use of the constructs to prepare cells for use in serodiagnosis is described.
(32) In the peptide-lipid constructs of the present invention the structural motif designated CMG is used as a component (S.sub.1) of the spacer (S) covalently linking the lipid (L) and peptide (F). Inclusion of this structural motif provides a degree of rigidity to the spacer, distancing the functional moiety (peptide) of the peptide-lipid construct from the surface of the modified cell or multi-cellular structure.
(33) It will be recognized that this attribute of the invention may be favourably applied to the development of other functional lipid constructs as demonstrated here with reference to the use of constructs including this structural motif where the functional moiety is a carbohydrate, such as the glycotope of the antigens of the ABO blood grouping, a fluorophore such as fluorescein (or one of its derivatives), or a conjugator, such as biotin.
(34) Biotin ([3aS-(3aα,4β,6aα)]-hexahydro-2-oxo-1H-thieno[3,4-d]imidazole-4-pentanoic acid) is a water soluble vitamin of the B complex, also referred to as vitamin H. Biotin is a growth factor present in minute amounts in every living cell. The compound plays an indispensable role in numerous naturally occurring carboxylation reactions, including the production of fatty acids.
(35) Biotin has a solubility (25° C.) in water of approximately 22 mg/100 mL and approximately 80 mg/100 mL in 95% alcohol. The compound has increased solubility in hot water and in dilute alkali, but is relatively insoluble in other common organic solvents. The ability to localize this functional moiety to the surface of cells and multi-cellular structures provides a number of applications as demonstrated.
(36) Whilst not wishing to be bound by theory it is believed that the properties of the functional lipid constructs may be modified and refined to suit particular applications by byselection of the cation (M.sup.+) or derivation of the free carboxyl groups of the structural motif to provide modified structural motifs, e.g. by substitution with methyl (CH.sub.3; MCMG).
(37) The properties of the functional-lipid constructs for use in the claimed methods must be such that they can be readily dispersed in biologically compatible media in the absence of solvents or detergents, but incorporate into the lipid bilayer of a membrane when a solution of the construct is contacted with a suspension of cells or multi-cellular.
(38) Peptide-lipid constructs with these potentially conflicting properties are prepared by selection of other components of the spacer (S) in addition to the inclusion of the unmodified (CMG) or modified (e.g. MCMG) structural motif and/or the inclusion of a proximal terminal sequence (PTS) in the peptide (F).
(39) The preparation of the peptide-lipid constructs where S is linked to F via a sulphide bond formed with a terminal Cys (Cys) residue of the peptide at the carboxy-terminus of the peptide is preferred as the peptide is less prone to oxidation.
(40) A range of peptides may therefore be prepared as peptide-lipid constructs for use in methods of effecting qualitative and quantitative changes in the levels of peptide expressed at the surface of cells and multi-cellular structures.
(41) A particular advantage of the biotin-lipid constructs is that they permit cells or multi-cellular structures to be localized to surfaces with minimal detriment to the biological activity and viability of the cells or multi-cellular structure.
(42) Examples of the localization of cells to a surface are provided. It will be noted that where the localization to a surface is achieved by means of avidin-coated magnetic beads the localization is reversible, thereby providing the opportunity to control the selection and positioning of cells on a surface.
(43) The utility of the constructs in sub-cellular fractionation and localization of membrane bound organelles to surfaces is contemplated. The utility of the constructs in promoting the aggregation of populations of cells as may be required in the generation of hybridomas is also contemplated.
(44) ##STR00024##
(45) It will be understood that for a non-specific interaction, such as the interaction between diacyl- or dialkyl-glycerolipids or glycerophospholipids and a membrane, structural and stereo-isomers of naturally occurring lipids can be functionally equivalent.
(46) For example, it is contemplated that diacylglycerol 2-phosphate could be substituted for phosphatidate (diacylglycerol 3-phosphate). Furthermore it is contemplated that the absolute configuration of phosphatidate can be either R or S.
(47) The structural motif (CMG) may be prepared by the method summarized in Scheme I and Scheme II to provide the substructures designated MCMG(1) and CMG(2).
(48) The preparation of the structural motif, the preparation of functional-lipid constructs utilizing this structural motif, and the use of these constructs in chemical and biological applications is described below
(49) Preparation of the Structural Motif Designated CMG
(50) Materials and Methods
(51) Acetone, benzene, chloroform, ethylacetate, methanol, toluene and o-xylene were from Chimmed (Russian Federation). Acetonitrile was from Cryochrom (Russian Federation). DMSO, DMF, CF.sub.3COOH, Et.sub.3N, N,N′-dicyclohexylcarbodiimide and N-hydroxysuccinimide were from Merck (Germany). Iminodiacetic acid dimethyl ester hydrochloride was from Reakhim (Russian Federation).
(52) Dowex 50X4-400 and Sephadex LH-20 were from Amersham Biosciences AB (Sweden). Silica gel 60 was from Merck (Germany). Tetraamine (H.sub.2N—CH.sub.2).sub.4C×2H.sub.2SO.sub.4 was synthesized as described by Litherland et al. (1938). Thin-layer chromatography was performed using silica gel 60 F.sub.254 aluminium sheets (Merck, 1.05554) with detection by charring after 7% H.sub.3PO.sub.4 soaking.
Preparation of {[2-(2-tert-butoxycarbonylamino-acetylamino)-acetyl]-methoxycarbonylmethyl-amino}-acetic acid methyl ester (SCHEME I)
(53) To a stirred solution of (methoxycarbonylmethyl-amino)-acetic acid methyl ester hydrochloride (988 mg, 5 mmol) in DMF (15 ml) were added Boc-GlyGlyNos (3293 mg, 10 mmol) and (CH.sub.3CH.sub.2).sub.3N (3475 μL, 25 mmol) were added. The mixture was stirred overnight at room temperature and then diluted with o-xylene (70 ml) and evaporated.
(54) Flash column chromatography on silica gel (packed in toluene, and eluted with ethyl acetate) resulted in a crude product. The crude product was dissolved in chloroform and washed sequentially with water, 0.5 M NaHCO.sub.3 and saturated KCl.
(55) The chloroform extract was evaporated and the product purified on a silica gel column (packed in chloroform and eluted with 15:1 (v/v) chloroform/methanol). Evaporation of the fractions and drying under vacuum of the residue provided a colourless thick syrup. Yield 1785 mg, (95%). TLC: R.sub.f=0.49 (7:1 (v/v) chloroform/methanol).
(56) .sup.1H NMR (500 MHz, [D.sub.6]DMSO, 30° C.) δ, ppm: 7.826 (t, J=5.1 Hz, 1H; NHCO), 6.979 (t, J=5.9 Hz, 1H; NHCOO), 4.348 and 4.095 (s, 2H; NCH.sub.2COO), 3.969 (d, J=5.1 Hz, 2H; COCH.sub.2NH), 3.689 and 3.621 (s, 3H; OCH.sub.2), 3.559 (d, J=5.9 Hz, 2H; COCH.sub.2NHCOO), 1.380 (s, 9H; C (CH.sub.2).sub.2).
Preparation of {[2-(2-tert-butoxycarbonylamino-acetylamino)-acetyl]-methoxycarbonylmethyl-amino}-acetic acid (SCHEME I)
(57) To a stirred solution of {[2-(2-tert-butoxycarbonylamino-acetylamino)-acetyl]-methoxycarbonylmethyl-amino}-acetic acid methyl ester (1760 mg, 4.69 mmol) in methanol (25 ml) 0.2 M aqueous NaOH (23.5 ml) was added and the solution kept for 5 min at room temperature. The solution was then acidified with acetic acid (0.6 ml) and evaporated to dryness.
(58) Column chromatography of the residue on silica gel (packed in ethyl acetate and eluted with 2:3:1 (v/v/v) i-PrOH/ethyl acetate/water) resulted in a recovered {[2-(2-tert-butoxycarbonylamino-acetylamino)-acetyl]-methoxycarbonylmethyl-amino}-acetic acid methyl ester (63 mg, 3.4%) and target compound (1320 mg). The intermediate product was then dissolved in methanol/water/pyridine mixture (20:10:1, 30 ml) and passed through an ion exchange column (Dowex 50X4-400, pyridine form, 5 ml) to remove residual sodium cations.
(59) The column was then washed with the same solvent mixture, the eluant evaporated, the residue dissolved in chloroform/benzene mixture (1:1, 50 ml) and then evaporated and dried under vacuum. Yield of 10 was 1250 mg (74%), white solid. TLC: R.sub.f=0.47 (4:3:1 (v/v/v) i-PrOH/ethyl acetate/water).
(60) .sup.1H NMR (500 MHz, [D.sub.6]DMSO, 30° C.), mixture of cis- and trans-conformers of N-carboxymethylglycine unit c.3:1. Major conformer; δ, ppm: 7.717 (t, J=5 Hz, 1H; NHCO), 7.024 (t, J=5.9 Hz, 1H; NHCOO), 4.051 (s, 2H; NCH.sub.2COOCH.sub.3), 3.928 (d, J=5 Hz, 2H; COCH.sub.2NH), 3.786 (s, 2H; NCH.sub.2COOH), 3.616 (s, 3H; OCH.sub.3), 3.563 (d, J=5.9 Hz, 2H; COCH.sub.2NHCOO), 1.381 (s, 9H; C(CH.sub.3).sub.3) ppm; minor conformer, δ=7.766 (t, J=5 Hz, 1H; NHCO), 7.015 (t, J=5.9 Hz, 1H; NHCOO), 4.288 (s, 2H; NCH.sub.2COOCH.sub.3), 3.928 (d, J=5 Hz, 2H; COCH.sub.2NH), 3.858 (s, 2H; NCH.sub.2COOH), 3.676 (s, 3H; OCH.sub.3), 3.563 (d, J=5.9 Hz, 2H; COCH.sub.2NHCOO), 1.381 (s, 9H; C(CH.sub.3).sub.3).
Preparation of {[2-(2-tert-Butoxycarbonylamino-acetylamino)-acetyl]-methoxycarbonylmethyl-amino}-acetic acid N-oxysuccinimide ester (Boc-Gly2(MCMGly)Nos) (SCHEME I)
(61) To an ice-cooled stirred solution of {[2-(2-tert-butoxycarbonylamino-acetylamino)-acetyl]-methoxycarbonylmethyl-amino}-acetic acid (1200 mg, 3.32 mmol) and N-hydroxysuccinimide (420 mg, 3.65 mmol) in DMF (10 ml) was added N,N′-dicyclohexylcarbodiimide (754 mg, 3.65 mmol). The mixture was stirred at 0° C. for 30 min, then for 2 hours at room temperature.
(62) The precipitate of N,N′-dicyclohexylurea was filtered off, washed with DMF (5 ml), and filtrates evaporated to a minimal volume. The residue was then agitated with (CH.sub.3CH.sub.2).sub.2O (50 ml) for 1 hour and an ether extract removed by decantation. The residue was dried under vacuum providing the active ester (1400 mg, 92%) as a white foam. TLC: R.sub.f=0.71 (40:1 (v/v) acetone/acetic acid).
(63) .sup.1H NMR (500 MHz, [D.sub.6]DMSO, 30° C.), mixture of cis- and trans-conformers of N-carboxymethylglycine unit c. 3:2.
(64) Major conformer; δ, ppm: 7.896 (t, J=5.1 Hz, 1H; NHCO), 6.972 (t, J=5.9 Hz, 1H; NHCOO), 4.533 (s, 2H; NCH.sub.2COON), 4.399 (s, 2H; NCH.sub.2COOCH.sub.3), 3.997 (d, J=5.1 Hz, 2H; COCH.sub.2NH), 3.695 (s, 3H; OCH.sub.3), 3.566 (d, J=5.9 Hz, 2H; COCH.sub.2NHCOO), 1.380 (s, 9H; C(CH.sub.3).sub.3).
(65) Minor conformer; δ, ppm: 7.882 (t, J=5.1 Hz, 1H; NHCO), 6.963 (t, J=5.9 Hz, 1H; NHCOO), 4.924 (s, 2H; NCH.sub.2COON), 4.133 (s, 2H; NCH.sub.2COOCH.sub.3), 4.034 (d, J=5.1 Hz, 2H; COCH.sub.2NH), 3.632 (s, 3H; OCH.sub.3), 3.572 (d, J=5.9 Hz, 2H; COCH.sub.2NHCOO), 1.380 (s, 9H; C(CH.sub.3).sub.3).
(66) The active ester (1380 mg) was dissolved in DMSO to provide a volume of 6 ml and used as a 0.5 M solution (stored at −18° C.).
(67) ##STR00025## ##STR00026##
Preparation of {[2-(2-tert-Butoxycarbonylamino-acetylamino)-acetyl]-methoxycarbonylmethyl-amino}-acetic acid methyl ester
(68) To the stirred solution of (methoxycarbonylmethyl-amino)-acetic acid methyl ester hydrochloride (988 mg, 5 mmol) in DMF (15 ml) Boc-GlyGlyNos (3293 mg, 10 mmol) and Et.sub.3N (3475 μl, 25 mmol) were added.
(69) The mixture was stirred overnight at room temperature (r.t.), then diluted with o-xylene (70 ml) and evaporated. Flash column chromatography on silica gel (packed in toluene and eluted with ethyl acetate) resulted in crude product.
(70) The crude product was dissolved in chloroform and washed sequentially with water, 0.5 M NaHCO.sub.3 and saturated KCl. The chloroform extract was evaporated, and the product was purified on a silica gel column (packed in chloroform and eluted with chloroform/methanol 15:1).
(71) Evaporation of fractions and vacuum drying of residue resulted in a colorless thick syrup of (3) (1785 mg, 95%).
(72) TLC: R.sub.f=0.49 (chloroform/methanol 7:1).
(73) .sup.1H NMR (500 MHz, [D.sub.6]DMSO, 30° C.) δ=7.826 (t, J=5.1 Hz, 1H; NHCO), 6.979 (t, J=5.9 Hz, 1H; NHCOO), 4.348 and 4.095 (s, 2H; NCH.sub.2COO), 3.969 (d, J=5.1 Hz, 2H; COCH.sub.2NH), 3.689 and 3.621 (s, 3H; OCH.sub.3), 3.559 (d, J=5.9 Hz, 2H; COCH.sub.2NHCOO), 1.380 (s, 9H; CMe.sub.3) ppm.
Preparation of {[2-(2-tert-Butoxycarbonylamino-acetylamino)-acetyl]-methoxycarbonylmethyl-amino}-acetic acid
(74) To the stirred solution of {[2-(2-tert-Butoxycarbonylamino-acetylamino)-acetyl]-methoxycarbonylmethyl-amino}-acetic acid methyl ester (1760 mg, 4.69 mmol) in methanol (25 ml) 0.2 M aqueous NaOH (23.5 ml) was added. The solution was kept for 5 min at r.t., then acidified with acetic acid (0.6 ml) and evaporated to dryness.
(75) Column chromatography of the residue on silica gel (packed in ethyl acetate and eluted with iPrOH/ethyl acetate/water (2:3:1)) resulted in recovered (3) (63 mg, 3.4%) and crude target compound (1320 mg).
(76) The crude target compound was dissolved in methanol/water/pyridine mixture (20:10:1, 30 ml) and passed through an ion-exchange column (Dowex 50X4-400, pyridine form, 5 ml) to remove residual Na cations.
(77) The column was washed with the same mixture, eluant evaporated, dissolved in chloroform/benzene mixture (1:1, 50 ml) then evaporated and dried in vacuum to provide a yield of pure (10) was 1250 mg (74%), white solid.
(78) TLC: R.sub.f=0.47 (iPrOH/ethyl acetate/water (4:3:1)).
(79) .sup.1H NMR (500 MHz, [D.sub.6]DMSO, 30° C.) of mixture of cis- and trans-conformers of N-carboxymethyl-glycine unit c.3:1.
(80) Major conformer: δ=7.717 (t, J=5 Hz, 1H; NHCO), 7.024 (t, J=5.9 Hz, 1H; NHCOO), 4.051 (s, 2H; NCH.sub.2COOMe), 3.928 (d, J=5 Hz, 2H; COCH.sub.2NH), 3.786 (s, 2H; NCH.sub.2COOH), 3.616 (s, 3H; OCH.sub.3), 3.563 (d, J=5.9 Hz, 2H; COCH.sub.2NHCOO), 1.381 (s, 9H; CMe.sub.3) ppm.
(81) Minor conformer: δ=7.766 (t, J=5 Hz, 1H; NHCO), 7.015 (t, J=5.9 Hz, 1H; NHCOO), 4.288 (s, 2H; NCH.sub.2COOMe), 3.928 (d, J=5 Hz, 2H; COCH.sub.2NH), 3.858 (s, 2H; NCH.sub.2COOH), 3.676 (s, 3H; OCH.sub.3), 3.563 (d, J=5.9 Hz, 2H; COCH.sub.2NHCOO), 1.381 (s, 9H; CMe.sub.3) ppm.
Preparation of {[2-(2-tert-Butoxycarbonylamino-acetylamino)-acetyl]-methoxycarbonylmethyl-amino}-acetic acid N-oxysuccinimide ester Boc-Gly2(MCMGly)Nos
(82) To an ice-cooled stirred solution of {[2-(2-tert-Butoxycarbonylamino-acetylamino)-acetyl]-methoxycarbonylmethyl-amino}-acetic acid (1200 mg, 3.32 mmol) and N-hydroxysuccinimide (420 mg, 3.65 mmol) in DMF (10 ml) N,N′-dicyclohexylcarbodiimide (754 mg, 3.65 mmol) was added. The mixture was stirred at 0° C. for 30 min, then for 2 h at r.t.
(83) The precipitate of N,N′-dicyclohexylurea was filtered off, washed with DMF (5 ml) and the filtrates evaporated to a minimal volume.
(84) The residue was agitated with Et.sub.2O (50 ml) for 1 h. An ether extract was removed by decantation, and the residue dried in vacuum to yield the target compound (1400 mg, 92%) as a white foam.
(85) TLC: R.sub.f=0.71 (acetone/acetic acid 40:1).
(86) .sup.1H NMR (500 MHz, [D.sub.6]DMSO, 30° C.), mixture of cis- and trans-conformers of N-carboxymethyl-glycine unit c. 3:2.
(87) Major conformer: δ=7.896 (t, J=5.1 Hz, 1H; NHCO), 6.972 (t, J=5.9 Hz, 1H; NHCOO), 4.533 (s, 2H; NCH.sub.2COON), 4.399 (s, 2H; NCH.sub.2COOMe), 3.997 (d, J=5.1 Hz, 2H; COCH.sub.2NH), 3.695 (s, 3H; OCH.sub.3), 3.566 (d, J=5.9 Hz, 2H; COCH.sub.2NHCOO), 1.380 (s, 9H; CMe.sub.3) ppm.
(88) Minor conformer: δ=7.882 (t, J=5.1 Hz, 1H; NHCO), 6.963 (t, J=5.9 Hz, 1H; NHCOO), 4.924 (s, 2H; NCH.sub.2COON), 4.133 (s, 2H; NCH.sub.2COOMe), 4.034 (d, J=5.1 Hz, 2H; COCH.sub.2NH), 3.632 (s, 3H; OCH.sub.3), 3.572 (d, J=5.9 Hz, 2H; COCH.sub.2NHCOO), 1.380 (s, 9H; CMe.sub.3) ppm.
Preparation of DOPE-Ad-CMG(I)amine (SCHEME III)
(89) DOPE-Ad-CMG(2)amine was prepared from {[2-(2-tert-butoxycarbonylamino-acetylamino)-acetyl]-methoxycarbonylmethyl-amino}-acetic acid N-oxysuccinimide ester Boc-Gly.sub.2(MCMGly)Nos according to Scheme III.
(90) ##STR00027##
(91) ##STR00028##
Preparation of functional lipid constructs (F-S-L) (SCHEME IV)
Preparation of DOPE-Ad-CMG(2)-βAla-Mal-Milt(K,M) (X)
(92) The construct DOPE-Ad-CMG(2)-βAla-Mal-Milt(K,M)(X) was prepared according to Scheme IV.
(93) DOPE-Ad-CMG(2)amine was treated with 5-fold excess of 3-maleimidopropionic acid oxybenztriazol ester (12) in i-PrOH-water.
(94) Conversion of DOPE-Ad-CMG(2) into was somewhat low maleimido-derivative (about 70%), presumably due to fast hydrolysis of the intermediate promoted by the amount of organic base, diisopropylethylamine, required to be added to keep DOPE-Ad-CMG(2) in solution.
(95) The maleimido-derivative was isolated in 40% yield after gel-permeation chromatography on Sephadex LH-20 (i-PrOH-water, 1:2).
(96) Initially, the conjugation of the maleimido-derivative with peptide was attempted using i-PrOH-TRIS buffer, pH 8 (1:2), but the intermediate appeared to be almost insoluble in this medium. However, addition of pyridin (1 μl/mg of intermediate) resulted in immediate dissolution of reactants and a surprisingly clean and substantially complete conversion.
(97) Notably, although no reducing agent was used to prevent oxidative deactivation of the peptide, MS analysis of the whole reaction mixture revealed no traces of S-S dimer.
(98) The desired construct (X) was purified on a Sephadex LH-20 column. A solubility problem was again encountered as fractions containing (X) were slightly opaque.
(99) This would appear to indicate that the amount of base added to the eluent was insufficient to keep compounds properly charged and soluble in the concentration range of 1-5 mg/ml.
(100) The structure of purified construct (X) was unambiguously established by NMR and MS spectra.
(101) NMR spectrum revealed the expected peptide: DOPE ratio as deduced from the signal ratio for the most characteristic aromatic and olefin protons.
(102) According to MS data, almost half of the final product (X) spontaneously formed pyroglutamyl derivative ([M-17].sup.+ ion).
(103) In MALDI MS spectra of (X) peaks corresponding to unmodified peptide are present while the related peaks are absent in ESI-MS spectrum of the same substance. This is ascribed to facile fragmentation at the thiosuccinimide bond (retro-Michael reaction) under MALDI ionization conditions (destructive technique).
(104) The general method of preparing peptide-lipid constructs was applied with minor modification to the preparation of constructs including peptides (F) selected from the following List of Peptides:
(105) TABLE-US-00005 SEQ List of Peptides ID NO Cys(Xaa).sub.zTrpThrProProArgAlaGlnIleThrGlyTyrLeuThrValGlyLeuThrArgArg 19 Cys(Xaa).sub.zTrpThrProProArgAlaGlnIleThrGlyTyrArgLeuThrValGlyLeuThrArgArg 20 Cys(Xaa).sub.zValMetTyrAlaSerSerGly 21 Cys(Xaa).sub.zTyrProAlaHisThrAlaAsnGlu 22 ValMetTyrAlaSerSerGly(Xaa).sub.zCys 23 AspTyrHisArgValMetTyrAlaSerSerGly(Xaa).sub.zCys 24 ThrAsnGlyGluThrGlyGlnLeuValHisArgPhe(Xaa).sub.zCys 25 ThrAsnGlyGluMetGlyGlnLeuValHisArgPhe(Xaa).sub.zCys 26 AspThrTyrProAlaHisThrAlaAsnGluValSerGlu(Xaa).sub.zCys 27 ThrTyrProAlaHisThrAlaAsnGluVal(Xaa).sub.zCys 28 ProAlaHisThrAlaAsnGluVal(Xaa).sub.zCys 29 TyrProAlaHisThrAlaAsnGlu(Xaa).sub.zCys 30 ThrTyrProAlaHisThrAlaAsn(Xaa).sub.zCys 31 ThrTyrProAlaHisThrAlaAsnGlu(Xaa).sub.zCys 32 TyrProAlaHisThrAlaAsnGluVal(Xaa).sub.zCys 33 TyrProAlaHisThrAlaAsnGlu(Xaa).sub.zCys 34 ProAlaHisThrAlaAsnGluValSer(Xaa).sub.zCys 35 AspThrTyrProAlaHisThrAlaAsnGlu(Xaa).sub.zCys 36 TyrProAlaHisThrAlaAsnGluValSer(Xaa).sub.zCys 37 SerGlnThrAsnAspLysHisLysArgAsp(Xaa).sub.zCys 38 GlnThrAsnAspLysHisLysArgAspThrTyr(Xaa).sub.zCys 39 GlnThrAsnAspLysHisLysArgAspThrTyrSerSerGlnThrAsnAspMetHisLysArgAspThrTyr(Xaa).sub.zCys 40 GlnThrAsnAspMetHisLysArgAspThrTyr(Xaa).sub.zCys 41 SerSerGlnThrAsnAspLysHisLysArg(Xaa).sub.zCys 42 SerSerGlnThrAsnAspLysHisLysArgAspThrTyr(Xaa).sub.zCys 43 SerSerGlnThrAsnAspMetHisLysArgAspThrTyr(Xaa).sub.zCys 44 SerSerGlnThrAsnAspLysHisLysArgAspThrTyrSerSerGlnThrAsnAspMetHisLysArgAspThrTyr(Xaa).sub.zCys 45 GlnThrAsnAspLysHisLysArgAspThr(Xaa).sub.zCys 46 SerGlnThrAsnAspLysHisLysArgAspThr(Xaa).sub.zCys 47 ThrAsnAspLysHisLysArgAspThrTyrPro(Xaa).sub.zCys 48 GluGluThrGlyGluThrGlyGlnLeuVal(Xaa).sub.zCys 49 GluGluGluThrGlyGluThrGlyGlnLeu(Xaa).sub.zCys 50 GluThrGlyGluThrGlyGlnLeuValHis(Xaa).sub.zCys 51 SerProProArgArgAlaArgValThr(Xaa).sub.zCys 52 TyrArgTyrArgTyrThrProLysGluLysThrGlyProMetLysGlu(Xaa).sub.zCys 53 TrpGlnProProArgAlaArgIle(Xaa).sub.zCys 54 ThrIleThrGlyLeuGluProGlyThrGlu(Xaa).sub.zCys 55
(106) The use of the peptide-lipid constructs in methods for effecting qualitative and quantitative changes in the levels of peptide expressed at the surface of cells and multi-cellular structures was illustrated with reference to serodiagnosis.
(107) In the following table cross-reactivity of polyclonal sera and monoclonal antibodies of known specificities and red blood cells (RBCs) modified with the construct DOPE-Ad-CMG(I)-βAla-Mal-Mur(D14C)(XI) (2 hours, 37° C.) is summarized.
(108) TABLE-US-00006 EIA/Miltenberger Reagent ID Type Specificity 2 T217 Human group AB serum Reactive with MUT-T peptides by EIA 3 T165 Human group O serum Reactive with MUR peptides by EIA 4 T7202 Human group B serum Reactive with MUT-M peptides by EIA 6 T6025 Human group A serum Reactive with MUT-T peptides by EIA 7 T8445 Human group O serum Uncertain 8 T5896 Human group O serum Uncertain 9 MIII Monoclonal antibody Reactive with Mi III red cells 10 Mia Monoclonal antibody Reactive with Mi III red cells 11 Mur Monoclonal antibody Reactive with Mur positive red cells 12 Gam IgG monoclonal Reactive with Mi antibody III red cells 13 BoxH Human serum Uncertain 14 TAP1 Human group O serum Presumed MUT-K specificity 15 TAP2 Human serum Presumed MUR specificity Trans- Untrans- Anti- formed formed body ID Specificities cells cells Expected T165 serum Mur 10 0 postives T6025 serum K + Mur 5 0 T8445 serum Mur + Hil + 5 0 Tsen T5896 serum M + K + 0 0 (Mur) Expected Japan MoAb Mur 0 0 negatives T4130 serum Hil + Tsen 0 0 T217 serum T 0 0 T7202 serum M 0 0 T8012 serum M + K + T 0 0 Japan MoAb Mi III (1:10) 0 0 Box serum ? 0 0 Hill Japan MoAb Mi.sup.a (1:50) 0 0 E119 KBL MoAb Mia 0 0 7201 GAMMA(1:100)
Modification of Red Blood Cells with Peptide-Lipid Constructs
(109) Red blood cells are modified by mixing 1 part by volume of washed packed red blood cells with 1 part by volume of peptide-lipid construct dispersed at a concentration of 10 to 1000 μg/ml in cell media (Celpresol™).
(110) The suspensions are either: 1. incubated for 2 hours at 37° C. before being washed and suspended in a cell medium for serological analysis at a concentration of 0.8 to 3% (Method 1); or 2. incubated for 3 to 4 hours at room temperature (circa 25° C.) followed by 18 hours at 4° C. before being washed and suspended in a cell medium for serological analysis at a concentration of 0.8 to 3% (Method 2).
Tube Serology Testing of Modified Red Blood Cells
(111) Serological reactions are graded or scored by either of two established systems (0 or ‘−’=no agglutination, 1+ or 3=very weak agglutination, 2+ or 5=weak agglutination, 3+ or 8=moderate strong agglutination, 4+ or 10/12=strong agglutination)
(112) Serological platforms used are Tube (addition of reagents and reactants into plastic or glass serology tubes and after appropriate incubations, washing and centrifugation observing reactions macroscopically by eye and a 10× magnification eyepiece and scoring) and BioVue™ (addition of reactants into cassettes containing beads (including some reactants) and after appropriate incubations and centrifugation observing the reaction patterns trapped within the Gel matrix). BioVue is the serological column agglutination platform of Ortho-Clinical Diagnostics. Diamed is the serological column agglutination platform of Diamed AG.
(113) Serum samples were available from 47 blood donors of negative antibody screen status. These samples were designated “negative samples”, but not determined not to have anti-Miltenberger antibodies).
(114) Three serum samples known to have Miltenberger related antibodies T217, T6025, T5896. These samples were designated “positive samples”, but not determined to have anti-antibodies against the peptide of the peptide of the construct designated DOPE-PEG.sub.6-βAla-Mal-Milt(K) (M00).
(115) A suspension of 3% modified RBCs was prepared in PBS and 30 μl of the suspension mixed with 30 μl serum sample. The mixtures were then incubated for 45 min at 37° C. Following incubation the RBCs were centrifuged for 10 s in an Immufuge™ (setting: “high”) and observed for agglutination before being washed 3 times with PBS.
(116) After washing one drop of Epiclone™ anti-human globulin (AHG) was added and the tubes then centrifuged for 10 s in an Immufuge™ (setting: “high”). Tubes were then read and serology scores recorded.
(117) Comments on the observed serology scores are provided in the legends to the following tables.
(118) TABLE-US-00007 TABLE 1 Summary of reactivity of samples of serum from 47 blood donors not expected to have anti-Miltenberger activity (“negative samples”). AHG+ means sample reacted by the anti-human globulin test. AHG− means sample is unreactive. RBCs were modified with the peptide-lipid construct designated DOPE-PEG.sub.6- βAla-Mal-Milt (K) at the concentrations indicated. Sera were tested against modified RBCs following 3 days storage. Age of Concentration of modified DOPE-PEG.sub.6-βAla-Mal-Milt (K) (M00) (mg/ml) RBCs Se- 1.0 0.5 0.25 (days) rum (n = 47) (n = 21) (n = 21) 3 Neg- AHG+ AHG− AHG+ AHG− AHG+ AHG− ative 1 46 0 21 0 21 sam- ples
(119) TABLE-US-00008 TABLE 2 Results by tube serology of 3 serums known to contain antibodies against antigens of the Miltenberger complex. Score results show sample reactivity by the anti-human globulin test, 1+ = weak, 2+ = medium, 3+ = medium/strong, 4+ = strong, — means sample is unreactive. RBCs were modified with the peptide-lipid construct at the concentrations indicated. Sera were tested against modified RBCs following 3 days and 24 days storage. Age of Concentration of DOPE-PEG.sub.6-βAla- modified Mal-Milt(K)(M00) (mg/ml) RBCs (days) Serum 1.0 0.5 0.25 3 T217 2+ 1+ — 3 T6025 4+ 4+ 4+ 3 T5896 — — — 24 T217 — — n.t. 24 T6025 2+ 2+ n.t. 24 T5896 — — n.t. (n.t.—not tested).
(120) TABLE-US-00009 TABLE 3 Results by Diamed column serology of 3 serums known to contain antibodies against the Miltenberger complex. Score results show sample reactivity by the anti-human globulin test, 1+ = weak, 2+ = medium, 3+ = medium/strong, 4+ = strong, — means sample is unreactive. RBCs were modified with the peptide-lipid construct at the concentrations indicated. Sera were tested against modified RBCs following 3 days and 24 days storage. Age of Concentration of DOPE-PEG.sub.6-βAla- modified Mal-Milt(K)(M00) (mg/ml) RBCs (days) Serum 1.0 0.5 0.25 3 T217 — — 1+ 3 T6025 1+ 2+ 1+ 3 T5896 — — — 24 T217 — — — 24 T6025 2+ 2+ 1+ 24 T5896 — — —
(121) TABLE-US-00010 TABLE 6 Identification of naturally occurring Miltenberger antigen positive (Milt.sup.+) human red cells as determined in BioVue AHG cards. Polyclonal sera Monoclonal antibodies 2 3 4 6 7 8 14 15 9 10 11 12 Cell ID Antigen T217 T165 T7202 T6025 T8445 T5896 TAP1 TAP2 MIII Mia Mur Gam 9422184 Vw 8 5 3 0 8 0 5 0 0 10 0 12 11297161 MiIII 12 10 12 12 10 10 10 10 10 12 12 4131850 MiIV 12 12 10 0 10 12 12 1523 MiVI 12 12 8 0 10 12 10 T1569 MiVII 0 0 0 0 10 0 0 0 0 0 0 C.BR Mi?X 12 10 12 12 8 12 12 8 0 10 10 10
(122) TABLE-US-00011 TABLE 7 Identification of peptide-lipid constructs. Lowercase ‘c’ denotes a cysteine residue (Cys). All peptide-lipid constructs (F-S-L or L-S-F) were prepared as the DOPE (L) variant. M refers to a shorthand name for the molecule construct and is used in the following tables. The terminal peptide sequence is as indicated with “little c” representing Cys via which S is linked to L. Spacer refers to the structural motif of the spacer (S). CMG denotes the peptide-lipid constructs described in this specification. PEG denotes peptide-lipid constructs of the structure described as the second aspect of the invention in the specification accompanying the international PCT application filed on 11 Sep. 2008 at the Intellectual Property Office of New Zealand as receiving Office (RO/NZ). All constructs were prepared as the DOPE variant. Peptide sequence Leader Spacer 13 MUTK Ser Ser Gln Thr Asn Asp Lys His Lys Arg Asp Thr Tyr c PEG6 34 MUTK Ser Ser Gln Thr Asn Asp Lys His Lys Arg c CMG(2) 21 MUTK Ser Gln Thr Asn Asp Lys His Lys Arg Asp c CMG(2) 22 MUTK Ser Gln Thr Asn Asp Lys His Lys Arg Asp c CMG(2) 36 MUTK Ser Gln Thr Asn Asp Lys His Lys Arg Asp Thr c CMG(2) 35 MUTK Gln Thr Asn Asp Lys His Lys Arg Asp Thr c CMG(2) 1 MUTK Gln Thr Asn Asp Lys His Lys Arg Asp Thr Tyr AAAAA PEG6 2 MUTK Gln Thr Asn Asp Lys His Lys Arg Asp Thr Tyr GSerGSerGc PEG6 3 MUTM Gln Thr Asn Asp Met His Lys Arg Asp Thr Tyr GSerGSerGc PEG6 9 MUTK Gln Thr Asn Asp Lys His Lys Arg Asp Thr Tyr GSerGSerGc CMG(2) 33 MUTK Gln Thr Asn Asp Lys His Lys Arg Asp Thr Tyr c CMG(2) 37 MUTK Thr Asn Asp Lys His Lys Arg Asp Thr Tyr Pro c CMG(2) 14 Mur Asp Thr Tyr Pro Ala His Thr Ala Asn Glu Val Ser Glu c CMG(2) 14 Mur Asp Thr Tyr Pro Ala His Thr Ala Asn Glu Val Ser Glu c CMG(2) 14 Mur Asp Thr Tyr Pro Ala His Thr Ala Asn Glu Val Ser Glu c CMG(2) 30 Mur Asp Thr Tyr Pro Ala His Thr Ala Asn Glu c CMG(2) 16 Mur Thr Tyr Pro Ala His Thr Ala Asn Glu Val c PEG 17 Mur Thr Tyr Pro Ala His Thr Ala Asn Glu Val c CMG(2) 28 Mur Thr Tyr Pro Ala His Thr Ala Asn Glu c CMG(2) 27 Mur Thr Tyr Pro Ala His Thr Ala Asn c CMG(2) 25 Mur Tyr Pro Ala His Thr Ala Asn Glu c CMG(2) 26 Mur Tyr Pro Ala His Thr Ala Asn Glu Val c CMG(2) 31 Mur Tyr Pro Ala His Thr Ala Asn Glu Val Ser c CMG(2) 18 Mur Pro Ala His Thr Ala Asn Glu Val c CMG(2) 19 Mur Pro Ala His Thr Ala Asn Glu Val c CMG(2) 29 Mur Pro Ala His Thr Ala Asn Glu Val Ser c CMG(2) 40 Hil Glu Glu Glu Thr Gly Glu Thr Gly Gln Leu c CMG(2) 23 Hil Glu Glu Thr Gly Glu Thr Gly Gln Leu Val c CMG(2) 24 Hil Glu Glu Thr Gly Glu Thr Gly Gln Leu Val c CMG(2) 41 Hil Glu Thr Gly Glu Thr Gly Gln Leu Val His c CMG(2)
(123) TABLE-US-00012 TABLE 8 Analysis of sorted data for the reactivity against the Miltenberger Antibody Positive Panel of RBCs modified to incorporate the MUT peptide-lipid constructs identified at the concentration indicated. Constructs were able to show reactivity with one or more polyclonal serums indicating specificity to one or more peptide variations. Miltenberger Antibody Positive Panel 4 8 2 6 3 14 7 9 10 11 12 13 15 M μg/ml T7202 T5896 T217 T6025 T165 TAP1 T8445 MIII Mia Mur Gam BoxH TAP2 13 250 8 3 8 8 0 0 0 0 0 0 8 34 50 0 0 0 0 3 0 21 200 0 0 0 8 8 0 0 0 0 3 5 22 200 0 0 0 10 0 0 0 0 0 3 0 36 50 0 0 0 0 8 0 35 50 0 0 0 0 5 0 1 500 5 0 3 8 0 0 0 5 0 8 2 500 8 8 8 8 5 0 0 5 0 8 9 300 8 10 8 8 8 3 0 0 0 8 10 33 50 0 0 0 0 8 0 37 50 8 0 5 0 8 0 3 1000 8 10 0 5 0 0 0 0 5
(124) TABLE-US-00013 TABLE 9 Analysis of sorted data for the reactivity against the Miltenberger Antibody Positive Panel of RBCs modified to incorporate the MUR peptide-lipid constructs identified at the concentration indicated. Constructs were able to show reactivity with one or more polyclonal serums indicating specificity to one or more peptide variations. Miltenberger Antibody Positive Panel 3 6 7 4 8 2 15 9 10 11 12 13 M μg/ml T165 T6025 T8445 T7202 T5896 T217 TAP2 MIII Mia Mur Gam BoxH 14 10 10 8 5 0 0 0 0 0 0 0 14 50 10 5 8 3 0 0 0 0 0 14 100 10 10 5 5 0 3 0 0 0 0 30 50 8 10 0 0 8 16 100 10 5 12 5 0 0 0 0 0 0 0 17 100 10 10 10 8 0 0 0 0 0 0 0 28 50 8 10 0 0 8 27 50 0 10 0 0 0 25 50 3 0 3 0 0 0 8 0 0 0 0 26 50 10 8 8 0 0 0 3 0 0 0 0 31 50 8 10 0 0 0 18 100 10 10 8 0 0 0 0 0 0 0 19 100 10 8 10 0 3 0 0 0 0 0 29 50 10 0 0 8
(125) TABLE-US-00014 TABLE 10 Negative serum reactivity. Miltenberger negative red cells were modified with the peptide-lipid construct M22 at a transformation concentration of 50 μg/ml and tested against antibody negative serums in the field to determine rates of false positivity. Studies were undertaken in clinical laboratories in Australia, Malaysia and Philippines using three different serological platforms; Column agglutination platforms BioVue and DiaMed as well as the simple technique of tube reactivity. Equal volumes of packed RBCs and a solution containing 50 μg/ml of the construct were contacted for 3 hours at room temperature and then 18 hours at 4° C. This field trial found that clinical antibody negative serums reacted with M22 transformed cells at rates 0.4 to 4.5% in the BioVue ™ platform and at a rate of 0.4% in the DiaMed ™ platform. No reactivity was observed in the tube platform. These results can be considered as false positive reactions. Number Tested Number Positive % Positive Country Laboratory BioVue DiaMed Tube BioVue DiaMed Tube BioVue DiaMed Tube Australia CSL 100 3 3.0 Melb Path 45 2 4.5 RNSH 500 500 2 2 0.4 0.4 Malaysia UMMC 749 19 2.5 Philippines Metrop Hosp 60 0 0
(126) TABLE-US-00015 TABLE 11 Positive serum reactivity. Miltenberger negative red cells were modified with the peptide-lipid construct M22 at a transformation concentration of 50 μg/ml, M17 at a transformation concentration of 200 μg/ml, M24 at a transformation concentration of 200 μg/ml, and tested against natural Mi III antibody reactive human serums in the field to determine rates of reactivity. Equal volumes of packed RBCs and a solution containing 50 μg/ml of the construct were contacted for 3 hours at room temperature and then 18 hours at 4° C. The three different constructs of MUT, MUR and HIL were able to discriminate most natural Mi III reactive polyclonal antibodies into specific reactivity profiles. Twelve serums were unreactive with the modified cells, suggesting they may have specificity against another Mi III antigen. 22 (50 17 (200 24 (200 Sample No. μg/ml) μg/ml) μg/ml) Interpretation 488-6 10 K 9327986660 8 3 0 K 9325490091 5 5 0 K 9328791834 5 3 0 K 621-3 5 K 922390844-5 0 12 0 Mur 9322338631 0 10 0 Mur 914146821-8 0 10 0 Mur 932809044-1 0 8 0 Mur 942433813-3 0 8 0 Mur 942404708-4 0 5 0 Mur 942421413-0 0 5 0 Mur 942223755-1 0 5 0 Mur 942442720-2 0 5 0 Mur 927619701-8 0 3 0 Mur 912485657-9 0 3 0 Mur 926190919-0 0 3 0 Mur 9328154853 0 10 3 Mur + Hil 9328118428 0 10 5 Mur + Hil 9425256505 0 8 8 Mur + Hil 942433855-3 0 8 8 Mur + Hil 942753165-4 0 8 8 Mur + Hil 9424292604 0 8 5 Mur + Hil 9427455417 0 5 5 Mur + Hil S-3 0 3 5 Mur + Hil 942448627-8 0 0 5 Hil 942423002-4 0 0 3 Hil 942762589-1 0 0 3 Hil 9424248012 0 0 0 other 9427615156 0 0 0 other 9424396133 0 0 0 other 9427613497 0 0 0 other 927175131-4 0 0 0 other 932467774-5 0 0 0 other 927299700-1 0 0 0 other 926555294-1 0 0 0 other 932360876-4 0 0 0 other 927516053-2 0 0 0 other 942404708-4 0 0 0 other 589-6 0 other
(127) TABLE-US-00016 TABLE 12 Anti-MUT serum reactivity. Miltenberger negative RBCs were modified with the peptide-lipid constructs M22 at concentrations ranging from 10 to 200 μg/ml, M17 at a concentration of 50 μg/ml and M24 at a concentration of 50 μg/ml. The modified cells were tested against a natural Mi III antibody reactive Taiwan human serum (TAP1) detected in the field to determine reactivity profile. Reactivity was compared against natural Mi III antigen positive cells. TAP1 (Taiwan Miltenberger antibody positive sample). TAP1 serum was shown to contain both IgG and IgM antibodies (the latter being saline reactive) directed against natural MiIII positive cells. The lack of reactivity against Abtectcell ™ and Phenocell ™ antibody screening and identification panels concludes no other antibodies against red cells are present. Reactivity with M22 modiifed cells over transformation concentrations of 10 to 200 μg/ml (and not with untransformed cells - 0 μg/ml) concludes the presence of an antibody directed against MUT. The failure of the M22 modified cells to detect a saline reaction, suggests the assay is sensitive to the IgG class of antibody and not IgM - a clinically favourable result. The lack of reactivity with the M17 and M24 transformed cells concludes and absence of antibodies to the MUR and HIL mutations. TAP 1 Serum RBCs Saline AHG Natural Mi III positive cells R2R2, 11297161 8 10 R1Rz 11291347 8 10 Abtectcell III 8245009 10 Peptide-lipid Construct (μg/ml) Modified cells M22 (MUT) 200 0 10 M22 (MUT) 100 0 8 M22 (MUT) 50 0 8 M22 (MUT) 20 0 8 M22 (MUT) 10 0 5 M22 (MUT) 0 0 0 M17 (Mur) 0 0 M24 (Hil) 0 0 Antibody Screen/ID panel 0 Abtectcell III Batch 2223005 Cells I-III Phenocell B Batch 2653046 0 Cells 1-11
(128) TABLE-US-00017 TABLE 13 Anti-MUT serum reactivity. Miltenberger negative red cells were transformed with the peptide-lipid constructs M28 at a concentration of 100 μg/ml and M22 at a concentration of 100 μg/ml and tested against a natural Mi III antibody reactive Taiwan human serum (TAP2) detected in the field to determine reactivity profile. Reactivity was compared against natural Mi III antigen positive cells. TAP 2 (Taiwan Miltenberger antibody positive sample). TAP2 serum was shown to contain IgG antibodies antibodies directed against natural Mi III positive cells. The lack of reactivity against Abtectcell ™ antibody screening and identification panels concludes no other antibodies against red cells are present. Reactivity with M28 modified cells and not with M22 modiifed cells concludes the presence of an antibody directed against the MUR peptide. TAP 2 Serum RED CELLS BioVue AHG Natural Mi III positive cells Mi III PDN No. 54 5 Mi IV No; 4131850 10 Mi VI 1523A 8 Mi ?x ID: CBR 8 Vw No: 9422184 0 Peptide-lipid construct (μg/ml) M28 (MUR) 100 10 M22 (MUT) 100 0 Antibody Screen panel Abtectcell III Batch 2223009 Cells I-III 0
(129) TABLE-US-00018 TABLE 14 Identification of the M37 sequence as a candidate for the detection of anti-MUT. Miltenberger negative cells were modified with the peptide-lipid constructs M22, M33, M34, M35, M36, M37, M40 and M41 a concentration of 50 μg/ml. Modified cells were tested against serums 2, 3, 4 and 8 of the Miltenberger Antibody Positive Panel and Taiwan Mi III antibody positive serum TAP1 to determine its MUT reactivity profile. TAP 1 (Taiwan Miltenberger antibody positive sample). Cells modified with the peptide-lipid construct M37 were able to detect the anti-MUT activity of Miltenberger Antibody Positive Panel samples 2 and 4. Sample 3 containing MUR activity was expected negative. Sample 8 containing multiple antibodies was unexpectedly negative, but may have lost specificity. TAP1 serum was able to detect all MUT variations, indicating some polyclonal serums may have less defined anti-MUT activity than others. Positive BioVue Sample ID Specificities M22 M33 M34 M35 M36 M37 M40 M41 Unmodified 3 T165 Mur 0 0 0 0 0 0 0 0 0 8 T5896 M + K + Mur 0 0 0 0 0 0 0 0 0 2 T217 T 0 0 0 0 0 5 0 0 0 4 T7202 M 0 0 0 0 0 8 0 0 0 TAP1 8 3 5 5 8 8 0 0 0 MUT MUT/MUR MUR MUT peptides #2 #4 TAP1 #8 #3 34 MUTK4 S S Q T N D K H K R − − ++ − − 22 MUTK3 S Q T N D K H K R D − − +++ − − 36 MUTK6 S Q T N D K H K R D T − − +++ − − 35 MUTK5 Q T N D K H K R D T − − ++ − − 33 MUTK1 Q T N D K H K R D T − − + − − 37 MUTK7 T N D K H K R D T ++ +++ +++ − − MUT MUT/MUR MUR HIL peptides #2 #4 TAP1 #2 #4 40 Hil 2 E E E T G E T G Q L − − − − − 41 Hil 3 E T G E T G Q L V H − − − − −
(130) TABLE-US-00019 TABLE 15 Anti-MUT serum (TAP1) reactivity. Miltenberger negative cells were modified with the peptide-lipid constructs M22, M33, M34, M35, M36, M37, M40 and M41 at a concentration of 50 μg/ml (2 hours, 37° C.). Modified cells were tested against Taiwan Mi III antibody positive serum TAP1 to determine its MUT reactivity profile. TAP 1 (Taiwan Miltenberger antibody positive sample). The TAP1 serum is able to recognize some, but not all, peptide variations of MUT. The lack of reactivity with M40 and M41 (HIL peptide) modified cells and the untransformed cells is expected. Reactivity MUT Peptides 34 MUTK4 S S Q T N D K H K R 5 22 MUTK3 S Q T N D K H K R D 8 36 MUTK6 S Q T N D K H K R D T 8 35 MUTK5 Q T N D K H K R D T 5 33 MUTK1 Q T N D K H K R D T 3 37 MUTK7 T N D K H K R D T 8 HIL peptides 40 Hil 2 E E E T G E T G Q L — 41 Hil 3 E T G E T G Q L V H —
(131) TABLE-US-00020 TABLE 16 Anti-MUR serum (TAP1) reactivity. Miltenberger negative cells were modified with the peptide-lipid constructs M17, M19, M25, M26, M27, M28, M29, M30 and M31 at a concentration of 50 μg/ml (2 hours, 37° C.). Modified cells were tested against antibody positive serum #7 from the Miltenberger Antibody Positive Panel to determine their MUR reactivity profile. Panel Serum #7 (T8445) 30 Mur 9 D T Y P A H T A N E 8 17 Mur 2 T Y P A H T A N E V 10 28 Mur 6 T Y P A H T A N E 8 27 Mur 5 T Y P A H T A N — 25 Mur 4 Y P A H T A N E 3 26 Mur 7 Y P A H T A N E V 10 31 Mur 10 Y P A H T A N E V S 8 19 Mur 3 P A H T A N E V 8 29 Mur 8 P A H T A N E V S 8
(132) TABLE-US-00021 TABLE 17 False positive MUT construct reactions with negative serums. The rate of false positive reactions was determined against a panel of 51 blood donor plasma samples (PAC1-51). Plasma were tested against cells modified with the peptide-lipid constructs M22, M34, M36, M37 and M40 of peptide-lipid constructs at a concentration of 50 μg/ml (2 hours, 37° C.) and tested in BioVue AHG cards. The amino acid sequence can influence the rate of false positive reactions. One more or less amino acid at either end of the polypeptide chain can increase the chances of non-specific reactions occurring with serum. Reaction scores-BioVue AHG PAC Samples No. M22 M34 M36 M37 M40 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 0 0 0 0 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 49, 50, 52, 53 47 0 0 3 0 0 48 0 3 5 0 0 51 0 5 0 0 0 % False Positives 0 3.8% 3.8% 0 0 Reactivity MUT Peptides 34 MUTK4 S S Q T N D K H K R 3.8% 22 MUTK3 S Q T N D K H K R D 0 36 MUTK6 S Q T N D K H K R D T 3.8% 37 MUTK7 T N D K H K R D T 0 HIL peptides 40 Hil 2 E E E T G E T G Q L 0
(133) TABLE-US-00022 TABLE 18 False positive MUR M17 construct reactions with 102 negative serums. Cells modified with the peptide-lipid construct M17 were tested against 102 negative serum samples. Cells modified with the peptide-lipid construct M17 give the most “false positive” reactive construct showing up to 36% false positive rate with negative serums. False positive reactions with M17 Score 12-10 8-5 3 0 (n = 102) 17 18 3 65 17% 18% 3% 64%
(134) TABLE-US-00023 TABLE 19 “M17-false-positive” negative serum reactivity against other Mur constructs. The 6 most false positive negative serums reactive against cells modified with the peptide-lipid construct M17 were tested against cells modified by contacting with the peptide-lipid constructs M19, M25, M26, M27, M28, M29, M30 and M31 at a concentration of 50 μg/ml (2 hour 37° C.). The modified cells were tested in BioVue ™ AHG cards. Cell modified with the peptide-lipid construct M17 provided the most “false positive” reactions with negative serums. The reactivity of the 6 most false positive samples when tested against other modified cells shows that some are unreactive (M28, M27), some are poorly reactive or show a single discrete reactivity (M5, M29, M19) while others are more reactive (M31, M26). Minor changes in amino acid sequence can influence the rate of false positive reactivity. Cells modified with the constructs M30 and M28 show both specificity and low non-specificity. T series reactives (n = 58) % 2 4 31 44 61 18 21 28 55 42 63 62 7 20 48 22 39 23 30 positive M17 10 8 8 10 10 12 12 12 12 10 10 8 8 8 8 8 5 3 3 33% M28 10 8 8 10 10 0 0 0 0 0 0 0 0 0 0 0 0 0 0 9% M30 10 8 8 10 10 0 0 0 0 0 0 0 0 0 0 0 0 0 0 9% 39 T negative samples were negative with all 3 constructs. Larger series = 102 T18 T21 T28 T55 T78 T92 30 Mur 9 D T Y P A H T A N E — — — — — — 17 Mur 2 T Y P A H T A N E V 12 12 12 12 12 12 28 Mur 6 T Y P A H T A N E — — — — — — 27 Mur 5 T Y P A H T A N — — — — — — 25 Mur 4 Y P A H T A N E — — — — 5 — 26 Mur 7 Y P A H T A N E V 5 10 12 10 10 12 31 Mur 10 Y P A H T A N E V S — 10 12 — 8 12 19 Mur 3 P A H T A N E V — — — 12 — — 29 Mur 8 P A H T A N E V S — — 5 — — 8 5 samples reacted with all 3 constructs Panel Serum #7 False (T8445) Positivity 30 Mur 9 D T Y P A H T A N E 8 − 17 Mur 2 T Y P A H T A N E V 10 +++ 28 Mur 6 T Y P A H T A N E 8 − 27 Mur 5 T Y P A H T A N — − 25 Mur 4 Y P A H T A N E 3 26 Mur 7 Y P A H T A N E V 10 +++ 31 Mur 10 Y P A H T A N E V S 8 ++ 19 Mur 3 P A H T A N E V 8 + 29 Mur 8 P A H T A N E V S 8 +
(135) TABLE-US-00024 TABLE 20 Sera reactive with RBCs modified to incorporate the M1 peptide-lipid construct or M2 peptide-lipid construct constructs by contacting the cells with a 500 μg/ml dispersion of the construct (Method 1) were “neutralised” with the peptide QTNDKHKRDTY and retested against the modified cells. Sera were neutralized by adding 10 μL of 1 mg/ml solution of peptide to a 50 μL volume of sera and incubating for 30 minutes at 37° C. Testing was performed using BioVue ™ cards. M1 modified cells M2 cells vs serum Identity of sera #4 #5 #6 #2 #6 #8 Serum alone 5 5 10 8 8 8 Serum + peptide 0 0 0 0 2 0
(136) TABLE-US-00025 TABLE 21 Sera reactive with RBCs modified to incorporate the M13 peptide- lipid construct by contacting the cells with a 500 μg/ml dispersion of the construct (Method 1) were “neutralised” with the peptide SSQTNDKHKRDTY and retested against the modified cells. Sera were neutralized by adding 10 μL of 1 mg/ml solution of peptide to a 50 μL volume of sera and incubating for 30 minutes at 37° C. Testing was performed using BioVue ™ cards. M13 modified cells Identity of sera #3 #42 #37 #34 Serum alone 8 8 8 8 Serum + peptide 0 0 0 0
(137) TABLE-US-00026 TABLE 22 Cells were modified by the peptide-lipid construct M22 (2 hours, 37° C.) and two positive reactions were identified. Neutralisation experiments were then performed. A volume of 40 μl of plasma was incubated with 10 μl of peptide or Ac-C at a concentration of 1.0 mg/ml for 30 minutes at 37° C. The standard AHG test in BioVue ™ was then performed. The false positive reaction for PAC74 was confirmed as a reaction not neutralised by addition of peptide. The true positive reaction for TAP1 confirmed as reaction neutralised by peptide and the whole construct, but not the construct bearing only acetylated cysteine. PAC74 TAP1 8 8 Post- neutralisation Pre-neutralisation serology serology (cells (cells modified with the modified with peptide-lipid construct M22) the peptide-lipid Neutraliser F Linker construct M22) nil nil nil 8 8 M22 peptide SQTNDKHKRDC nil 8 — M28 peptide TYPAHTANEC nil 8 8 M22 molecule SQTNDKHKRDC CMG(2) — — Cys-CMG-DE Ac-C CMG(2) — 8 VMYASSG? 8 8
(138) TABLE-US-00027 TABLE 23 Cells were modified by the peptide-lipid construct M28 (2 hours, 37° C.) and four positive reactions were identified. Neutralisation experiments were then performed. A volume of 40 μl of plasma was incubated with 10 μl of peptide or Ac-C at a concentration of 1.0 mg/ml for 30 minutes at 37 ° C. The standard AHG test in BioVue ™ was then performed. The neutralisations of PAC70, 71 and 72 with the M28 peptide suggests specificity. The fact that the unrelated peptide M22 was also able to cause neutralisation of serums PAC71 and PAC72, together with reductions in score with other unrelated structures, revises the results for these two sera as being false positive reactivity. The fact that PAC70 does not react with Miltenberger positive cells suggests that although an antibody appears to be present to the peptide sequence it is not blood group specific. In contrast although TAP2 was not fully inhibited by peptide, the substantial reduction in score suggests specificity, although it is possible that specificity may be present with a low level of non specificity as suggested by the reaction score reduction against Cys-CMG-DE. PAC70 PAC71 PAC72 TAP2 8 5 5 8 Pre-neutralisation serology Post-neutralisation (cells modified with the serology (cells modified peptide-lipid construct M28) with the peptide-lipid Neutraliser F group Linker construct M22) saline nil nil 8 5 5 8 M22 peptide SQTNDKHKRDC nil 8 — — 3 M28 peptide TYPAHTANEC nil — — — 8 Cys-CMG-DE Ac-C CMG(2) 8 3 3 5 Atri-CMG-DE GalNAcα3[Fucα2]Galβ CMG(2) 8 3 5 8 Atri- GalNAcα3[Fucα2]Galβ adipate 8 3 5 8 adipate-DE VMYASSG? 8 5 5 8
(139) Consideration of the MUT peptide reactivities presented in the foregoing in Tables shows that peptides M22, M36 and M37 all showed superior sensitivity and specificity towards a human polyclonal antibody panel when compared with sequence 1, the sequence identified in the prior art (Reid and Lomas-Francis (2004)).
(140) Modification of Red Blood Cells with Peptide-Lipid Constructs with Peptide in Alternative Configurations
(141) Peptide-lipid constructs comprising CMG(2) and the following peptides were prepared:
(142) TABLE-US-00028 ThrTyrProAlaHisThrAlaAsnGluCys(M44) and CysThrTyrProAlaHisThrAlaAsnGlu(M45)
(143) The termini of the peptides were formylated and amidated to provide “capped” peptides. The reactivity of random Miltenberger antibody positive samples and three false positive antibody negative samples were tested against RBCs modified to incorporate these “capped” peptide-lipid constructs (50 μg/mL, 2 hours at 37° C.).
(144) The reactivity was assessed and recorded in Table 24. The capping of the peptide did not affect reactivity with positive samples, nor did it appear to affect reactivity with false-positive antibody-negative samples. However, linkage of the peptide via a Cys residue located at the amino terminus (as opposed to the carboxy terminus) appeared to reduce the likelihood of reactivity with the false-positive antibody negative samples and improve reactivity with the known antibody positive samples.
(145) Whilst not wishing to be bound by theory it is speculated that the presentation of the peptide by cells modified to incorporate M45 may be more analogous to the presentation of the corresponding peptide sequence expressed by the naturally occurring antigen.
(146) TABLE-US-00029 TABLE 24 Natural Not MiIII Sample M44 M45 modified cells Antibody 71 10 10 0 8 positive 67 8 10 0 5 serums 65 10 8 0 12 55 8 8 0 10 61 8 5 0 8 942-433813-3 0 5 0 12 68 0 0 0 10 False- PAC302 5 0 0 0 positive PAC332 12 0 0 0 antibody PAC340 5 0 0 0 negative serums
Modification of Cells and Multi-Cellular Structures with Biotin-Lipid Constructs
(147) The modification of red blood cells (RBCs) and murine embryos by the construct designated Biotin-CMG(2)-Ad-DOPE was demonstrated using Avidin-Alexafluor (Avidin AF).
(148) Materials
(149) A stock solution of the construct designated Biotin-CMG(2)-Ad-DOPE (100 μL) was prepared in water at a concentration of 10 mg/mL. A stock solution of Avidin-Alexafluor (Avidin-AF) was prepared in sterile phosphate buffered saline (PBS) at a concentration of 2 mg/mL. A stock solution of biotinylated gangliocide (BioG) was prepared in sterile PBS at a concentration of 5 mg/mL.
(150) Red Blood Cells
(151) Dilution series of the construct designated Biotin-CMG(2)-Ad-DOPE and BioG (positive control) were prepared at concentrations of 0.001, 0.1, 0.1 and 1 mg/mL with Celpresol™. O group red blood cells (RBCs) were modified by incubation of 15 μL of packed RBCs and 5 μL of a dilution of the construct designated biotin-CMG(2)-Ad-DOPE or BioG. Incubations were performed in a plastic ependorf tube of nominal volume 1.5 mL for 2 hours at 37° C. in a water bath. O group RBCs were incubated with a solution of BioG at a concentration of 0.33 mg/mL as a positive control.
(152) Incubated RBCs were washed 3 times with PBS in a mini centrifuge. Fluorescent labeling of the washed, modified RBCs was performed by adding 10 μL of a solution of Avidin-AF at a concentration of 0.1 mg/mL. The RBCs were then incubated in the dark for 1 hour at 37° C. in a water bath and washed 3 times with PBS.
(153) 85% solution of the washed, fluorescent labeled RBCs were viewed on a slide with cover slip under a fluorescent microscope at 488 nm and photographic exposure of 1.903 (
(154) An aliquot of the washed, modified RBCs obtained from incubation with the construct designated biotin-CMG(2)-Ad-DOPE at a concentration of 1 mg/mL was retained and stored at 14° C. for 14 days. Retention of the construct by the RBCs was assessed by incubation with Avidin-AF as before.
(155) The assessment of the fluorescence is recorded in Table 25.
(156) TABLE-US-00030 TABLE 25 Dilution (mg/ml) 1 0.1 0.01 0.001 0 Biotin-CMG(2)-Ad-DOPE 4 2 1 0 0 Day 0 Biotin-CMG(2)-Ad-DOPE 4 — — — — Day 14 BioG 3 2 0 0 0 Day 0
Murine Embryos
(157) Murine embryos (morula/early blastocyst stage, 3.5 day) were incubated in 50 microliter microdrops in Blastassis™ culture media. Embryos were incubated with construct designated biotin-CMG(2)-Ad-DOPE at a concentration of 0.1, 1 or 2 mg/mL or BioG at a concentration of 0.5 mg/mL (positive control).
(158) The zona pellucida of the embryos was removed by treatment with 0.5% pronase (4 minute incubation) and washing 3 times in embryo handling media prior to introduction into the microdrops. Each microdrop was equilibrated 5% CO.sub.2 at 37° C. overnight prior to introduction of the embryos.
(159) Microdrops containing embryos and the construct designated biotin-CMG(2)-Ad-DOPE were incubated for 2 hours in 5% CO.sub.2 at 37° C. Microdrops containing embryos and BioG were incubated for 40 minutes in 5% CO.sub.2 at 37° C.
(160) Following incubation each group of embryos was washed 3 times in handling media and transferred to 50 microliter microdrops containing 2 mg/mL Avidin-AF microdrops for fluorescent labelling. The microdrops containing transferred embryos were incubated at 37° C. for 30 minutes in the dark.
(161) Each group of embryos was then washed 3 times in handling media and mounted on a glass microscope slide for viewing. Embryos were viewed under a fluorescent microscope at 488 nm. The intensity of the fluorescence was recorded using a scoring system of 0 (no fluorescence) to 4 (maximum fluorescence).
(162) TABLE-US-00031 TABLE 26 Biotin- Biotin- Biotin- CMG(2)-Ad- CMG(2)-Ad- CMG(2)-Ad- DOPE DOPE DOPE BioG Media 0.1 mg/mL 1 mg/mL 2 mg/mL 0.5 mg/mL alone 2 1 1 3 1 n = 21 n = 19 n = 19 n = 19 n = 19
Immobilization of Spermatozoa and Cells
(163) The immobilization of spermatozoa and red blood cells (RBCs) was demonstrated by use of the construct designated Biotin-CMG(2)-Ad-DOPE and streptavidin beads (Dynabeads® M-280).
(164) Materials
(165) A stock solution of the construct designated Biotin-CMG(2)-Ad-DOPE (100 μL) was prepared in water at a concentration of 10 mg/mL and diluted in culture media (Medicult 10310060A) to provide a test dilution at 0.1 mg/mL.
(166) The spermatozoa in fresh semen (less than one day old) were assessed for motility (80%, grade 3 (fast, forward progression) by 10-fold dilution in culture medium (Medicult 10310060A; pre-incubated for a minimum of 2 hours at 37° C. in a 5% CO.sub.2 atmosphere). Spermatozoa counts (91.5×10/mL) were performed by 10-fold dilution in deionised water.
(167) Spermatozoa were washed and isolated by layering 1.1 mL of fresh semen over a gradient of SpermGrad 125 (Vitrolife 10099; 2 mL of 40% solution over 2 mL of 80% solution in a 15 mL round bottom tube) and centrifuging at 500×g for 20 min.
(168) The bottom layer of the gradient (c. 0.7 mL was transferred to 4 mL round bottom tubes and c. 2 mL flushing (handling) media (Medicult 10840125A) added. The tube was centrifuged at 300×g for 10 min and the spermatozoa washed two more times (mixing by tube inversion).
(169) Samples of washed spermatozoa were incubated overnight at 37° C. in a 5% CO.sub.2 atmosphere. Spermatozoa counts (c. 25×10.sup.6/mL) were performed post overnight incubation by 10-fold dilution in deionised water.
(170) Spermatozoa
(171) A volume of 100 μl of the test dilution of the construct designated Biotin-CMG(2)-Ad-DOPE (I) was added to each of four 0.6 mL ependorf tubes (A-D) and 100 μL of culture media added to one 0.6 mL ependorf tube (E).
(172) Open tubes were incubated at 37° C. in a 5% CO.sub.2 atmosphere prior to addition of c. 70 μL spermatozoa (c. 25×10.sup.6/mL) to each tube and incubation for 120 min (A), 60 min (B), 30 min (C), 10 min (B) and 120 min (E).
(173) Following incubation a couple of drops of flushing media were added and the tubes centrifuged at 300×g for 5 min. The spermatozoa were washed two more times with flushing media and before being re-suspended in culture media to a final volume of 100 μL.
(174) Streptavidin beads at a concentration of c. 6.25×10.sup.6/100 μL were diluted 35 times in BSA plus flushing media to provide a ratio of 0.1 beads/spermatozoa when mixed in equal volume with a diluted suspension of the modified spermatozoa.
(175) A volume of 5 μL of a diluted suspension of the modified spermatozoa was mixed on a slide with 5 μL of a diluted suspension of streptavidin beads and covered with a coverslip.
(176) The mixture was observed under a microscope at 400× magnification.
(177) The assessment of the attachment of streptavidin beads to modified spermatozoa is recorded in Table 27.
(178) TABLE-US-00032 TABLE 27 Biotin-CMG(2)- Number of beads attached Ad-DOPE (I) Incubation to spermatozoa treatment time (min) Immediate 30 min A 120 10-12 10-15 (with cross-linking) B 460 2, 4, 8 8 C 30 1-3 3 D 10 1 1 E (Control) 120 0 0
(179) Spermatozoa were observed to retain motile capacity despite attachment of beads (no acrosome reaction was evident) with a preference of attachment to motile spermatozoa.
(180) Red Blood Cells
(181) A dilution of the construct designated Biotin-CMG(2)-Ad-DOPE was prepared at a concentration of 1 mg/mL with Celpresol™. A volume of 60 μL washed A group red blood cells (RBCs) was modified by incubation with 20 μL of the dilution of the construct at 37° C. for 2 hours.
(182) The modified RBCs were washed twice in PBS and once in Celpresol™ as described above. A 2% cell suspension of washed cells (modified or control) was prepared in Celpresol™ and cell concentration (150×10.sup.6/mL) determined using a haemocytometer. Similarly the concentration of a suspension streptavidin beads (134×10.sup.6/mL) was determined.
(183) A volume of 50 μL of the suspension of streptavidin beads was added to the wells of a 96-well plat with a Neodymium (Rare-Earth) Super magnet (Magnets NZ Limited) affixed to the base. A volume of 50 μL of a suspension of RBCs was added to provide a bead to RBC ratio of c. 1:1 and incubated at room temperature for 1 hour to allow RBCs to settle.
(184) The wells were washed 3× with PBS, aspirating the washing solution with a pipette. The washed wells were observed under a microscope and the RBCs determined to be retained (
(185) Separation of Populations of Cells
(186) A 0.5 mg/ml solution of the construct designated Biotin-CMG(2)-Ad-DOPE was prepared in Celpresol™ and a volume of 10 μl used to modify 30 μl packed cell volume of group 0 RBCs in a 1 ml eppendorf tube to provide a first population of cells. Unmodified group A RBCs were used as a second population of cells.
(187) Both populations of cells were incubated for 37° C. for 2 hrs in a water bath and then washed 2× in PBS and 1× in Celpresol using an Immufuge II (low, 1 min). The concentration of cells in each suspension was made up to 2% by adding 1.5 mL.
(188) The suspensions of RBCs were mixed with avidinylated magnetic Dynabeads at an approximate ratio of RBC:bead of 1 and incubated for 10 min at room temperature on a gyrator.
(189) Samples of the first and second populations of RBCs were then mixed in equal volumes (35 μl each) in an ependorf tube for two minutes.
(190) The contents of the ependorf were transferred to the well of a 96-well plate and a magnet was applied to the underside of the well for 1 minute. The supernatant was carefully removed with the magnet applied and without disruption of the beads. The blood grouping of the cells of the supernatants were then assessed by applying 30 μl of supernatant and 30 μl anti-A antibody to a Dynamed™ gel card. Cards were spun for 10 min in a centrifuge. Retention of the O group RBCs by the magnet was demonstrated by the absence of a pellet of group O cells.
(191) Modification of Cell Layers with Biotin-Lipid Constructs
(192) The modification of monolayers of the cell line RL95-2 (established from a human endometrial adenocarcinoma (ATCC HTB CRL 1671)) in serum-free and serum-containing media was evaluated.
(193) D-MEM/F12 (Gibco 11320-033, Invitrogen NZ) containing 1% penicillin/streptomycin (Gibco 15140-122, Invitrogen NZ) was used as a serum-free medium. D-MEM/F12 10% FBS (Gibco 10091-130, Invitrogen NZ) containing 1% penicillin/streptomycin and 5 μg/mL insulin (Gibco 12585-014, Invitrogen NZ) was used as a serum-containing medium.
(194) A suspension of the cell line RL95-2 was diluted in pre-warmed serum-containing media to the required concentration e.g. 4×10.sup.5 cells/mL. A 25 μL volume of the suspension was used to seed the required wells in a Terasaki tray so that each treatment was performed in duplicate. The plates were incubated overnight in a 5% CO.sub.2, 37° C. incubator until the monolayer was approximately 60% confluent.
(195) Dilutions of Biotin-CMG(2)-Ad-DOPE were prepared and 12 μl volumes added to wells containing washed cell layers to provide final concentrations of 20, 100 or 500 μg/mL. Trays were incubated at 37° C., 5% CO.sub.2 for 120 min.
(196) The cells were then washed and a 12 μl volume of a 0.1 mg/mL solution of Avidin Alexa Fluor® 488 added. The cells were then incubated at room temperature for a further 30 minutes in the dark.
(197) The monolayers were finally washed 3 times with PBS, the trays inverted and photographed using an Olympus BX51 fluorescent microscope at 200× magnification, exposure time 475 ms (
(198) When the construct is inserted in serum-free media at 20, 100 and 500 μg/mL, a homogenous intense fluorescent signal is observed in the cell membrane that intensifies with increasing concentration of the construct (
(199) When the construct is inserted in serum-free media at 20, 100 and 500 μg/mL, an homogenous intense fluorescent signal is observed in the cell membrane that intensifies with increasing concentration of construct. The intensity of the fluorescence also increased with increasing insertion time (Table 28). These results imply that optimal insertion of construct into cell membranes occurs with increased concentration of construct and/or increased insertion time.
(200) TABLE-US-00033 TABLE 28 Optimal insertion of construct into cell membranes occurs with increased concentration of construct and/or increased insertion time. Mean Fluorescence* Concentration of biotin- Insertion time CMG(2)-Ad-DOPE (μg/mL) 10 30 60 120 20 1+ 1-2+ 2-3+ 3-4+ 100 2+ 3 3+ 4+ 500 3+ 3-4+ na na Media alone 0 0 0 0 ‘na’ denotes “not assessed”.
(201) When avidin Alexa Fluor® 488 was added to construct modified RL95-2 cells and incubated at 37° C. for 4 and 24 hr the fluorescence gradually shifted from the cell surface to the cell interior (
(202) Fluorescence was detected in construct modified RL95-2 cells 24 hr post-insertion when cultured in serum-free media, albeit with reduced fluorescence from T=0 (Table 29). However, when cells were cultured in serum-containing media a fluorescence score of 1+ was detected at the highest concentration of construct (500 mg/mL), but not at lower. These results imply that the construct is optimally retained in cell membranes 24 hr post-insertion when cultured in serum-free media, but not in serum-containing media.
(203) TABLE-US-00034 TABLE 29 Retention of construct 24 hours post-insertion. The construct was detected in cells cultured for 24 hr post-insertion in serum-free media, but was only detected at the highest concentration in serum-containing media. Concentration of biotin- Mean Fluorescence* CMG(2)-Ad-DOPE T = 24 hr (μg/mL) T = 0 Serum-free Serum-containing 20 3-4+ 1-2+ 0 100 4+ 2-3+ 0 500 4+ 1+ Media alone 0 0 0 ‘na’ denotes “not assessed”.
Modification of Antigen Presentation
(204) The amount of construct used in the manufacture of quality controls cells as described in the specification accompanying international application no. PCT/NZ2005/000052 (publication no. WO 2005/090368) is a determinant of the cost of manufacture.
(205) It was anticipated that presentation of antigen at a distance from the immediate milieu of the cell surface may promote recognition by cross-reactive antibody and subsequent agglutination. The estimated distances from the cell surface for an antigen (F) of a functional lipid construct (F-S-L) where the spacer (S) includes the structural motif of the present invention are 7.2 nm (CMG(2)) and 11.5 nm (CMG(4)). These distances compare with 1.9 nm for the antigen of a construct (F-S-L) where the spacer is one described in the specification accompanying international application no. PCT/NZ2005/000052 (publication no. WO 2005/090368), i.e. A.sub.tri-sp-Ad-DOPE (I).
(206) To test the hypothesis solutions of four different trisaccharide (A.sub.tri)-lipid constructs were prepared as 50 μM, 10 μM and 5 μM solutions in Celpresol™. Modified red blood cells were then prepared by contacting 0.6 mls (pcv) of washed RBCs with 0.6 mls of the relevant solution. The mixtures were incubated at 37° C. for 2 hours and then washed 3 times to provide a modified cell suspension.
(207) The modified cell suspensions were prepared in 0.8% in Celpresol LISS™ suitable for BioVue serology cards. A volume of 0.05 mls of CSL monoclonal anti-A (026129801) followed by 0.05 mls of modified cell suspension was applied to each card. Reactions were recorded following centrifugation in a BioVue cassette centrifuge (Table 29).
(208) A comparison of the recorded reaction for molar equivalents of the A.sub.tri-lipid constructs demonstrates that less CMG(2) or CMG(4) construct is required to provide an equivalent serological result. There was no significant gain with CMG(2) compared with CMG(4). There was a minor, but not significant change for MCMG (2).
(209) Although the invention has been described by way of examples it should be appreciated that variations and modifications may be made to the claimed methods without departing from the scope of the invention. As noted it will be understood that for a non-specific interaction, such as the interaction between the diacyl- or dialkyl-glycerolipid portion of the functional-lipid constructs and a membrane, structural and stereo-isomers of naturally occurring lipids can be functionally equivalent.
(210) Where known equivalents exist to specific features, such equivalents are incorporated as if specifically referred to in this specification. For example, it is contemplated that diacylglycerol 2-phosphate could be substituted for phosphatidate (diacylglycerol 3-phosphate) and that the absolute configuration of phosphatidate could be either R or S.
(211) TABLE-US-00035 TABLE 29 A.sub.tri-lipid construct Structural motif of Conc Serological result at reciprocal of dilution of anti-A spacer (μM) Neat 2 4 8 16 32 64 128 256 512 1024 0 Adipate 50 12 12 12 12 12 12 10 8 8 3 — — 10 10 10 10 8 8 8 8 3 — — — — 5 8 8 5 3 — — — — — — — — CMG (2) 50 12 12 12 12 12 12 10 10 8 5 3 — 10 12 12 12 10 10 10 10 8 5 3 — — 5 10 10 10 10 8 8 8 5 3 — — — mCMG (2) 50 12 12 12 12 12 12 12 10 10 8 5 — 10 12 12 12 12 12 10 10 8 8 5 — — 5 10 10 10 10 10 8 8 5 3 — — — CMG (4) 50 12 12 12 12 12 12 10 10 8 5 3 — 10 12 12 12 10 10 10 10 8 8 3 — — 5 10 10 10 10 8 8 8 5 3 — — —
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