Coronavirus induction of class I major histocompatibility complex expression in murine astrocytes is virus strain specific

To determine whether the lack of ability to stimulate class I expression in astrocytes is specific for JHMV, a panel of virus strains derived from wild-type JHMV or from JHM-DL were tested. The results indicate that none of the JHMV strains isolated in our laboratories stimulated class I ( Table 2 ). In addition, JHM-X, which was derived from JHMV passage in Japan and has been shown to have extensive deletions in the S gene (11), did not affect dass I expression. By contrast, all of the viral strains in a panel of more hepatotropic isolates of MHV, including MHV-NuU, MHV-K, MHV-D, MHV-1, MHV-2, and MHV-3, were effective stimulators of class I expression. The magnitude of stimulation, expressed as percent change relative to uninfected cells, varied with the individual viral strain 2-10fold over that in uninfected cells. A59 and MHV-2 were the most potent inducers of the class I K b molecule, and both inconsistently induced a low-level expression of D b. It should be mentioned that the Kd-specific mAb SF1-1.1.1 occasionally yielded a low level of nonspecific binding; however, it was significantly lower than the specific binding observed with the Kb-specific antibody.