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.

Methods for expressing a polypeptide of interest in an astroglial cell. The methods permit the localization and transport of nucleic acids in microglial exosomes, the reprogramming of astroglial cells to neuronal cells, and the treatment of ischemic stroke or traumatic brain injury patients.

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 invention relates to a novel enhancer of protein production in host cells. It discloses a vector for expressing recombinant proteins in these cells, comprising a nucleotide sequence encoding a) a secretion peptidic signal, b) a 6-methylguanine-DNA-methyltransferase enzyme (MGMT, EC 2.1.1.63), a mutant or a catalytic domain thereof, and c) a recombinant protein. Said MGMT enzyme is preferably the so-called SNAP protein.

Methods for expressing a polypeptide of interest in an astroglial cell. The methods permit the localization and transport of nucleic acids in microglial exosomes, the reprogramming of astroglial cells to neuronal cells, and the treatment of ischemic stroke or traumatic brain injury patients.

The present invention relates to a novel enhancer of protein production in host cells. It discloses a vector for expressing recombinant proteins in these cells, comprising a nucleotide sequence encoding a) a secretion peptidic signal, b) a 6-methylguanine-DNA-methyltransferase enzyme (MGMT, EC 2.1.1.63), a mutant or a catalytic domain thereof, and c) a recombinant protein. Said MGMT enzyme is preferably the so-called SNAP protein.

Described herein are compositions and techniques related to generation and therapeutic application of artificial synapses. Artificial synapses are engineered extracellular vesicles, including exosomes, which incorporate sticky binders on their surface to anchor signaling domains against biological targets, such as receptors. These engineered additives can be organized in genetic vector constructs, expressed in mammalian cells, wherein the sticky binders attach to extracellular vesicles such as exosomes, thereby presenting their joined signaling domains which are rapidly taken up by recipient cells. Artificial synapses adopt the hallmark biophysical and biochemical features of extracellular vesicles, allowing for rapid deployment and scale-up. Importantly, this strategy can allow for kinetically favorable signal generation and signal propagation. This includes, for example, increasing density of agonist presentation to support receptor clusteringan onerous barrier for traditional receptor targeting strategies.

Proteins, nucleic acids encoding the proteins, compositions comprising the proteins, and methods are provided. The proteins have the ability to be self-targeted to ICAM-1 and, if desired, enzymatically-released at acidic pH. The ICAM-1-targeting peptides are provided as single copies or multiples repeats, and can be separated by linkers from the enzyme segment, from which the ICAM-1 targeting peptides can be released, if desired, at acidic pH. These fusion proteins enhance the activity of the enzyme segment within or liberated from the fusion protein, and provide increased recognition and targeting of diseased organs, transport from the bloodstream across the endothelium into said diseased organ, and intracellular uptake and lysosomal trafficking by cells in them, both in peripheral tissues and the central nervous system. Representative nucleotide and amino acid sequences of these fusion proteins, as well as in vitro, cellular, and in vivo animal data are provided. The described proteins can be used as a protein therapy, a gene therapy, or an implanted cell therapy.

Proteins, nucleic acids encoding the proteins, compositions comprising the proteins, and methods are provided. The proteins have the ability to be self-targeted to ICAM-1 and, if desired, enzymatically-released at acidic pH. The ICAM-1-targeting peptides are provided as single copies or multiples repeats, and can be separated by linkers from the enzyme segment, from which the ICAM-1 targeting peptides can be released, if desired, at acidic pH. These fusion proteins enhance the activity of the enzyme segment within or liberated from the fusion protein, and provide increased recognition and targeting of diseased organs, transport from the bloodstream across the endothelium into said diseased organ, and intracellular uptake and lysosomal trafficking by cells in them, both in peripheral tissues and the central nervous system. Representative nucleotide and amino acid sequences of these fusion proteins, as well as in vitro, cellular, and in vivo animal data are provided. The described proteins can be used as a protein therapy, a gene therapy, or an implanted cell therapy.

Described herein are compositions and techniques related to generation and therapeutic application of artificial synapses. Artificial synapses are engineered extracellular vesicles, including exosomes, which incorporate sticky binders on their surface to anchor signaling domains against biological targets, such as receptors. These engineered additives can be organized in genetic vector constructs, expressed in mammalian cells, wherein the sticky binders attach to extracellular vesicles such as exosomes, thereby presenting their joined signaling domains which are rapidly taken up by recipient cells. Artificial synapses adopt the hallmark biophysical and biochemical features of extracellular vesicles, allowing for rapid deployment and scale-up. Importantly, this strategy can allow for kinetically favorable signal generation and signal propagation. This includes, for example, increasing density of agonist presentation to support receptor clusteringan onerous barrier for traditional receptor targeting strategies.