INTERFERON INDUCTION BY VIRUSES .22. VESICULAR STOMATITIS VIRUS-INDIANA - M-PROTEIN AND LEADER RNA DO NOT REGULATE INTERFERON INDUCTION IN CHICKEN-EMBRYO CELLS

Several field isolates, strains, mutants, and revertants of vesicular stomatitis virus (VSV), Indiana (IN) serotype, were studied that diffe red greatly in their capacity to induce interferon (IFN) in aged chick embryo cells. The predicted M-protein amino acid sequence of a wild-t ype field isolate that induced greater than or equal to 10,000 units/m l IFN in chicken embryo cells was identical to that of a wild-type fie ld isolate that induced <2 units/ml and of a noninducing wild-type lab oratory strain. The 47-base plus-strand leader RNA sequences were the same for five IFN-inducing, and eight noninducing independent isolates of wild-type VSV IN. Our data show that the M-protein and plus-strand leader RNA do not of themselves regulate the induction of IFN in this system. Because the capacity of VSV IN to induce IFN resides in virio n-associated elements (Marcus and Sekellick, 1987, J. Interferon Res. 7, 269-284), the differences in IFN yield observed with various isolat es must result from changes in other virion components that remain to be determined.