Restricted replication of herpes simplex virus in spinal ganglia of resistant mice is accompanied by an early infiltration of immunoglobulin G-bearing cells.

In an attempt to define the nature of the difference in the susceptibility of C57BL/6 (resistant) and A/J (susceptible) mice to herpes simplex virus type 1, we initiated a study of virus progression through the nervous system. After inoculation of virus in a rear footpad, C57BL/6 mice were found to be more than 500-fold more resistant, but resistance did not extend to pseudorabies virus. In additional investigations, it was found that the virus was selectively restricted at the level of spinal ganglia in C57BL/6 mice. No intrinsic difference in the ability of this tissue from either mouse strain to replicate virus was found. However, by 4 days after infection, morphological investigations indicated that a mononuclear cell infiltrate was present surrounding infected neurons and satellite cells both earlier and in greater numbers in the ganglia of C57BL/6 mice. Immunohistochemical methods showed that most of these cells did not express Thy 1.2 antigen, but the vast majority bore immunoglobulin G. The mechanism by which these infiltrating cells could restrict virus spread is discussed.