The finding that phosphatidylserine (PtdSer) exposure on the outer leaflet of virally transduced cells triggers their engulfment by resident immune cells is described. It is demonstrated that inhibition of phospholipid scramblase 1 (PLSCR1) activity prevents PtdSer externalization and enables prolonged protection of vector-transduced cells from phagocytosis. Methods of inhibiting a virus vector-induced inflammatory response in tissue, methods of prolonging virus vector encoded transgene expression, and methods of modulating an inflammatory response in tissue of a subject, by administering an inhibitor of PLSCR1 are described.

Described herein are pseudotyped oncolytic viruses comprising nucleic acids encoding an engager molecule. In some embodiments, the pseudotyped oncolytic viruses comprises nucleic acids encoding an engager molecule and one or more therapeutic molecules. Pharmaceutical compositions containing the pseudotyped oncolytic virus and methods of treating cancer using the pseudotyped oncolytic viruses are further provided herein.

The present invention provides a recombinant herpes simplex virus (HSV), comprising (a) a mutation of the glycoprotein B (gB) at position 285 or 549, (b) a plurality of copies of one or more microRNA target sequences inserted into a locus of an HSV gene required for HSV replication, wherein said target sequence is the reverse complement of microRNA miR-124 and wherein said target sequence is present in the ICP4 gene, and (c) a transgene encoding a matrix metalloproteinase. The present invention also provides a method of killing a cancerous cell using a recombinant HSV according to the invention and a pharmaceutical composition comprising a pharmaceutically acceptable carrier and a recombinant HSV according to the invention.

The present invention provides a recombinant oncolytic Herpes Simplex Virus (oHSV) comprising a non-HSV ligand specific for a molecule (protein, lipid, or carbohydrate determinant) present on the surface of a cell (such as a cancer cell) and one or more copies of one or more microRNA target sequences inserted into one or more HSV gene loci, preferably one or more HSV gene(s) required for replication of HSV in normal (i.e., non-cancerous) cells. The invention further provides stocks and pharmaceutical compositions comprising the inventive oHSV and methods for killing tumor cells employing the inventive oHSV.