Cell-Type-Specific Innate Immune Response to Oncolytic Newcastle Disease Virus

Abstract Virotherapy of cancer exploits the potential of naturally occurring and engineered oncolytic viruses to selectively replicate in and cause cytotoxicity to tumor cells without affecting healthy normal cells. The tumor selectivity of Newcastle disease virus (NDV), a member of the family Paramyxoviridae, depends on the differential type I interferon (IFN) response. Further understanding of the key mechanisms and immune effector molecules involved will aid in augmenting the oncolytic properties of NDV. Here we report on the infection kinetics and innate immune responses to a recombinant LaSota strain of NDV (rLaSota eGFP) in human tumor and normal cells. We observed varying replicative fit and cytotoxicity of rLaSota eGFP depending on the tumor cell type, with severely restricted replication in normal cells. The absence of retinoic acid-inducible gene I (RIG-I), a cytosolic RNA sensor, determined sensitivity to NDV. Productive NDV infection with a moderate IFN-α induction in human multiple myeloma ce...