Provided herein are improved gene therapy vectors and methods of use, in some embodiments, comprising sequences for improved expression and cellular targeting of a therapeutic protein.

Disclosed herein include methods, compositions, and kits enabling expression of multiple proteins from a single mRNA with a predetermined stoichiometry. There are provided, in some embodiments, nucleic acid compositions comprising a promoter operably linked to a polynucleotide comprising a first nucleic acid unit encoding first unit payload protein(s) and a second nucleic acid unit encoding second unit payload protein(s). The first nucleic acid unit and the second nucleic acid unit can each comprise a 3′ engineered translation initiation site (eTIS) comprising a three-nucleotide tunable element immediately upstream of a start codon. The eTIS of each of the first nucleic acid unit and the second nucleic acid unit can be configured to achieve a predetermined stoichiometry of the first unit payload protein(s) and the second unit payload protein(s) in a cell or cell-like environment.

Provided herein are improved gene therapy vectors and methods of use, in some embodiments, comprising sequences for improved expression and cellular targeting of a therapeutic protein.

Described are DNA molecules which can be transcribed into an mRNA harbouring novel UTR sequences combining the advantages of being extremely short and at the same time allowing for high translation efficiencies of RNA molecules containing them. Further, described are vectors comprising such a DNA molecule and to host cells comprising such a vector. Moreover, described are corresponding RNA molecules containing such UTRs. Further, described is a pharmaceutical composition comprising the described RNA molecule and optionally a pharmaceutically acceptable carrier as well as to the use of the described UTRs for translating a coding region of an RNA molecule into a polypeptide or a protein encoded by said coding region.

Synthetic polynucleotides encoding human propionyl-CoA carboxylase beta (synPCCB) and exhibiting augmented expression in cell culture and/or in a subject are described herein. An adeno-associated viral (AAV) gene therapy vector encoding synPCCB successfully rescued the neonatal lethal phenotype displayed by propionyl-CoA carboxylase beta (Pccb.sup.−/−) deficient mice, lowered circulating methylcitrate levels in the treated animals, and resulted in prolonged hepatic expression of the product of the synPCCB transgene in vivo.

There is disclosed a trans-acting functional nucleic acid molecule comprising a eukaryotic target binding sequence comprising a sequence reverse complementary to a target mRNA sequence for which protein translation is to be enhanced, and a regulatory sequence comprising an internal ribosome entry site (IRES) sequence or an internal ribosome entry site (IRES) derived sequence and enhancing translation of the target mRNA sequence, wherein the regulatory sequence is located 3′ of the target binding sequence.

The present invention discloses methods and compositions for modulating the quality of an immune response to a target antigen in a mammal, which response results from the expression of a polynucleotide that encodes at least a portion of the target antigen, wherein the quality is modulated by replacing at least one codon of the polynucleotide with a synonymous codon that has a higher or lower preference of usage by the mammal to confer the immune response than the codon it replaces.

Described herein are methods and compositions for producing a gene of interest (GOD, which, in certain embodiments, can reduce the metabolic burden on cells and reduce decoupling of GOI production from marker production, as compared to prior art methods. The methods relate to positive selection and negative selection approaches to establishing high GOI-producing cell lines, e.g., CHO lines. In certain embodiments, the methods comprise transfecting a cell with (a) an oligonucleotide comprising a GOI and a non-coding RNA, and (b) an oligonucleotide encoding a selection protein; wherein the non-coding RNA promotes or inhibits production of the selection protein. The cell producing the can be identified and/or selected as a result of or by detecting the absence or the presence of the selection protein.

Described herein are methods and compositions for producing a gene of interest (GOI) which, in certain embodiments, can reduce the metabolic burden on cells and reduce decoupling of GOI production from marker production, as compared to prior art methods. The methods relate to positive selection and negative selection approaches to establishing high GOI-producing cell lines, e.g., CHO lines. In certain embodiments, the methods comprise transfecting a cell with (a) an oligonucleotide comprising a GOI and a non-coding RNA, and (b) an oligonucleotide encoding a selection protein; wherein the non-coding RNA promotes or inhibits production of the selection protein. The cell producing the GOI can be identified and/or selected as a result of or by detecting the absence or the presence of the selection protein.

Provided is a polynucleotide, the polynucleotide can be used as a WXRE transcriptional regulatory element used to increase the protein expression level of a protein expression system. A protein expression vector or a protein expression system comprising the above-mentioned WXRE transcriptional regulatory element as well as the use thereof are also provided. The use of the WXRE transcriptional regulatory element can increase the expression level of a heterologous protein greatly with its biological activity unchanged.