In vivo and in vitro models of demyelinating diseases, XX: Replication of coronaviruses in primary neural cultures from genetically resistant and susceptible mice.

Resistance of SJL mice to JHMV could be associated with explanted oligodendrocytes and astrocytes in primary neural cultures from newborn mice. The restriction demonstrated is not at the stage of adsorption, uptake by the host or RNA synthesis and does not occur with the serorelated MHV3 strain. Experiments with neural cells from F1 hybrid mice bred from resistant and sensitive parents show that resistance is a recessive trait. It is hypothesized that the defect may involve proteolysis at the cell surface, but to date no clear cut experimental data have been obtained to substantiate this idea. In more general terms our in-vitro observations demonstrate that resistance of SJL mice pertains to both embryonic and newborn animals and involves neural and non neural cell types. Thus, the SJL restriction of JHMV, evident at the cellular level, does not involve an age-related maturation process associated with rat and mouse oligodendrocytes studied previously (1, 14).