IN VITRO INTERACTION OF MOUSE HEPATITIS VIRUS AND MACROPHAGES FROM GENETICALLY RESISTANT MICE : II. BIOLOGICAL CHARACTERIZATION OF A VARIANT VIRUS MHV(C(3)H) ISOLATED FROM STOCKS OF MHV(PRI)

Shif, Ilan; Bang, Frederik B.

Since the original report of Bang and Warwick in 1960, (2) it had been continually noticed that resistant C3H cells were destroyed by very large amounts of the original "wild" strain of virus, but the phenomenon was assumed to be due to "toxicity" and was not investigated. It is clear from the studies here reported that destruction of resistant cells by a high multiplicity of the wild virus is uniformly associated with the emergence of a new strain of the virus MHV(C~H) which in low dilutions is virulent for C3H cells and young adult C3H mice. It may then be asked whether the original MHV(PRI) virus itself has any effect on the C3H cells. In a later paper, we examine some factors influencing the conversion of MHV(PRI) virus from C3H-nonvirulent to C3Hvirulent virus. 2 1 Abbreviations used in this paper: MHV, mouse hepatitis virus; pfu, plaque-forming units; PRI, Princeton strain mice; TCIDs0, tissue culture infective dose, median.