The disclosure provides a novel method for treating genetic disorders where a peptide sequence targets proteins produced via gene therapy into exosomes. These protein-loaded exosomes can enter into non-transduced cells and correct pathology. Also, gene therapy compositions, protein replacement therapy composition, pharmaceutical compositions, methods of treatment, and uses of the gene therapy compositions and the recombinant proteins are also disclosed. The method can also be used to improve in vitro recombinant protein yield.

The present application relates to methods of producing exosomes. The application also provides a method for preparing a protein composition comprising culturing an exosome-producing cell expressing a Nef-fusion protein comprising a Nef-derived peptide fused to a protein of interest; isolating exosomes from the exosome-producing cell culture; and purifying the protein of interest from the isolated exosomes. The application further discloses compositions that comprise exosomes containing the Nef-fusion protein, as well as methods of using the Nef-fusion protein and exosomes containing the Nef-fusion protein.

The present application relates to methods of producing exosomes. The application also provides a method for preparing a protein composition comprising culturing an exosome-producing cell expressing a Nef-fusion protein comprising a Nef-derived peptide fused to a protein of interest; isolating exosomes from the exosome-producing cell culture; and purifying the protein of interest from the isolated exosomes. The application further discloses compositions that comprise exosomes containing the Nef-fusion protein, as well as methods of using the Nef-fusion protein and exosomes containing the Nef-fusion protein.

The invention relates to a gene transfer-based method to protect a subject from diabetes or obesity. The method comprises administering to a salivary gland of the subject an AAV virion comprising an AAV vector that encodes an exendin-4 protein. Also provided are exendin-4 proteins and nucleic acid molecules that encode such exendin-4 proteins. Also provided are AAV vectors and AAV virions that encode an exendin-4 protein. One embodiment is an exendin-4 protein that is a fusion protein comprising an NGF secretory segment joined to the amino terminus of an exendin-4 protein domain.

The present application relates to methods of producing exosomes. The application also provides a method for preparing a protein composition comprising culturing an exosome-producing cell expressing a Nef-fusion protein comprising a Nef-derived peptide fused to a protein of interest; isolating exosomes from the exosome-producing cell culture; and purifying the protein of interest from the isolated exosomes. The application further discloses compositions that comprise exosomes containing the Nef-fusion protein, as well as methods of using the Nef-fusion protein and exosomes containing the Nef-fusion protein.

Provided herein are recombinant CTLA-4 binding proteins, which are, inter alia, useful for the treatment of cancer. The recombinant proteins provided herein are, inter alia, capable of binding CTLA-4 proteins on a tumor cell. In a first aspect, there is provided a recombinant CTLA-4 binding protein including (i) a CTLA-4 binding domain; (ii) a CTLA-4 binding domain masking peptide; and (iii) a cleavable peptide linker connecting the CTLA-4 binding domain masking peptide to the CTLA-4 binding domain. In another aspect, there is provided a dimerizing domain covalently attached to the CTLA-4 binding domain, wherein the binding protein domains are bound together.

The present invention is based on the surprising finding that Wnt7a, and other Wnt family members, are trafficked to extracellular vesicles (EVs) via interactions with coatomer proteins. Extracellular vesicle signal peptides (ESPs), each comprising at least one key Coatomer binding motif (CBM), are described, and these mediate EV trafficking of Wnt family members. The ESPs may be used to target other proteins for display on EVs. Herein is described an EV comprising: COPI, and a recombinant EV-directed polypeptide comprising: a cargo polypeptide, and an ESP comprising a CBM, wherein the cargo polypeptide is tethered to an external surface of the EV via the coatomer binding motif. Also described are recombinant EV-directed polypeptides comprising an ESP and a cargo. Additionally described are recombinant skeletal muscle-targeted EVs comprising a pay load polypeptide; and recombinant Wnts having mutated CBM or ESPs, which are less trafficked to EVs for production/recovery of free Wnts.

The present invention provides a modified oleosin protein, a polynucleotide sequence encoding the modified protein, and a method for regulating subcellular lipid distribution by recombinantly expressing the modified oleosin protein. This invention also provides a method for generating cells and organisms comprising the modified oleosin protein and exhibiting an altered subcellular lipid distribution pattern, as well as cells and organisms generated by such a method.

The present invention provides gene editing systems comprising gene editing dimerization switches comprising a first and second gene editing switch domain that allow for the regulation of a gene editing function by the introduction, e.g., administration, of a gene editing dimerization molecule having the ability to bring together a first gene editing switch domain and a second gene editing switch domain. A regulated gene editing function provides, e.g., less off-target side effects, and increases the therapeutic window. The present invention also provides improved FKBP/FRB-based dimerization switches wherein the FRB switch domain or the FKBP switch domain, or both the FRB and FKBP switch domains, comprise one or more mutations that optimize performance, e.g., that alter, e.g., enhance the formation of a complex between the first switch domain, the second switch domain, and the dimerization molecule, rapamycin, or a rapalog, e.g., RAD001.

The present application relates to methods of producing exosomes. The application also provides a method for preparing a protein composition comprising culturing an exosome-producing cell expressing a Nef-fusion protein comprising a Nef-derived peptide fused to a protein of interest; isolating exosomes from the exosome-producing cell culture; and purifying the protein of interest from the isolated exosomes. The application further discloses compositions that comprise exosomes containing the Nef-fusion protein, as well as methods of using the Nef-fusion protein and exosomes containing the Nef-fusion protein.