Abstract: Described herein are engineered antigen presenting cells that can be capable of modulating a target T-cell in a T-cell antigen specific manner. In some embodiments, the engineered APCs can include a modified antigen presentation pathway. Also described herein are methods of making and using the engineered antigen presenting cells.

Abstract: Described in certain example embodiments herein are engineered delivery vesicle generations systems capable of producing engineered delivery vesicles containing two or more different retroelement polypeptides. Also described herein are methods of making and using the engineered delivery vesicles, such as to deliver one or more cargoes.

Abstract: Provided herein are compositions, systems, and methods for delivering cargo to a target cell. The compositions, systems, and methods comprise one or more polynucleotides encoding one or more LTR retroelement polypeptides for forming a delivery vesicle and one or more capture moieties for packaging a cargo within the delivery vesicle. The one or more LTR retroelement polypeptides for forming a delivery vesicle may comprise two or more of an LTR retroelement gag protein, a retroelement envelope protein, an LTR retroelement reverse transcriptase, or a combination thereof. The LTR retroelement polypeptide alone, the LTR retroelement envelope protein alone, or both the LTR retroelement-derived polypeptide and LTR retroelement envelope protein may be endogenous.

Abstract: Described herein are engineered antigen presenting cells that can be capable of modulating a target T-cell in a T-cell antigen specific manner. In some embodiments, the engineered APCs can include a modified antigen presentation pathway. Also described herein are methods of making and using the engineered antigen presenting cells.

Abstract: Provided herein are compositions, systems, and methods for delivering cargo to a target cell. The compositions, systems, and methods comprise one or more polynucleotides encoding one or more LTR retroelement polypeptides for forming a delivery vesicle and one or more capture moieties for packaging a cargo within the delivery vesicle. The one or more LTR retroelement polypeptides for forming a delivery vesicle may comprise two or more of an LTR retroelement gag protein, a retroelement envelope protein, a an LTR retroelement reverse transcriptase, or a combination thereof. The LTR retroelement polypeptide alone, the LTR retroelement envelope protein alone, or both the LTR retroelement-derived polypeptide and LTR retroelement envelope protein may be endogenous.

Abstract: Described herein are engineered antigen presenting cells that can be capable of modulating a target T-cell in a T-cell antigen specific manner. In some embodiments, the engineered APCs can include a modified antigen presentation pathway. Also described herein are methods of making and using the engineered antigen presenting cells.