Immunological studies of hsv-infection of resistant and susceptible inbred strains of mice.

DBA/2 mice were found to be quite susceptible to infection with herpes simplex virus (HSV) while C57BL/6 mice and F1 hybrids between the 2 strains were relatively resistant. This difference was most marked after ip infection, but could also be demonstrated after intracerebral, intravenous or subcutaneous infection. In both strains the LD50 was considerably higher after ip infection than after iv infection, and a dose of X-irradiation was required to kill the mice by sc infection. A/J and BALB/c mice were equally susceptible after ip infection but differed significantly after iv infection. C57BL/6 were made susceptible to ip infection by immunosuppression with antilymphocyte serum or cyclophosphamide. LPS, when given simultaneously with HSV also markedly increased the susceptibility of C57BL/6 mice. Susceptible DBA/2 mice which surrvived a low dose of HSV ip were not immune but C57BL/6 mice surviving a high dose were immune against rechallenge. Both strains of mice could be protected by an apathogenic, tissue-culture-attenuated strain of HSV against infection with the virulent strain. They could also be protected by iv injection of a sublethal dose against a lethal ip infection.