Abstract: Provided herein are compositions and methods of use thereof for screening a plurality of uniquely identifiable therapeutic moieties by identifying one or more reporters indicative of a cell state. The methods include the administration of a library of expression cassettes, comprising a plurality of nucleic acid sequences, each encoding a different therapeutic moiety operably linked to a therapeutic moiety barcode; a plurality of nucleic acid sequences encoding one or more reporters that collectively, when expressed in a cell or an isolated nucleus, are indicative of a cell state or a likelihood of a cell state of the cell; and one or more sequences encoding a non-coding nuclear retention RNA motif.

Abstract: Provided herein are compositions and methods of use thereof for screening a plurality of uniquely identifiable therapeutic moiety in vivo by identifying one or more reporters indicative of a cell state.

Abstract: Provided herein are libraries of delivery vehicles and methods of uses thereof. The delivery vehicles provided include distinct variants of a virus and nucleic acid sequences encoding a distinct virus-identifying barcode region specific for each virus variants, and a nucleic acid sequence encoding at least one reporter. The methods provided herein include methods of identifying a vehicle effective in targeting a particular cell type.

Abstract: Provided herein are compositions and methods of use thereof for screening a plurality of uniquely identifiable therapeutic moiety in vivo by identifying one or more reporters indicative of a cell state.