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.