Effects of genetic resistance against Herpes simplex virus in vaginally infected mice

Pathogenesis of genital herpes simplex virus infection in mice. IV. Quantitative aspects of viral latency

Experiments in the mouse model of herpes simplex virus (HSV) infection involving the intact genital mucous membranes as inoculation site yielded the following results. In untreated mice the extent of latency was correlated with the degree of peripheral virus replication. This correlation could not be observed when the course of infection was interrupted by chemotherapy, interferon, or passive immunization. Acyclovir had little effect on peripheral virus multiplication, but markedly reduced latent ganglionic infection. As acute ganglionic infection and virus concentration in the spinal nerves were already reduced, acyclovir is assumed to inhibit either virus penetration into the nerve endings or virus replication in the ganglia. Interferon apparently has an active role in the elimination of virus infected cells from the ganglia, as its effect was restricted to a reduced rate of latency and of lethality. Passive immunization with antiserum led to similar results as ACV-treatment. While lacking a pronounced effect on virus replication in the mucous membranes, specific antibody was found to influence both virus elimination from the ganglia, and conversion from productive to latent ganglionic infection. Immune lymphocytes proved to be the only agent capable of suppressing peripheral infection, thereby inhibiting the neural spread of the virus. These results suggest that the decrease in latency may result from modulations occurring at different stages in the course of infection.

Pathogenesis of genital herpes simplex virus infection in mice. III. Comparison of the virulence of wild and mutant strains

This study was undertaken to establish the role of virulence of various herpes simplex virus (HSV) strains in the course of infection when applying the virus to the non-injured mucous membranes of mice. Wild-type HSV-type 1 (HSV-1) strains with marked differences in their neurovirulence following intracerebral inoculation showed minor differences in virulence after vaginal inoculation, but essentially their neurovirulence in cerebral infection corresponded to their virulence on the mucous membranes. In comparison with the wild-types, however, there were pronounced differences among syn- and TK--mutants of HSV-1 and HSV-2 in the degree of virulence at different sites in the course of virus infection. Whereas syn-mutants proved avirulent on the mucous membranes but not in neural tissues, TK--mutants were avirulent both on mucous membranes and in neural tissues. Ts-mutants of HSV-2 were not found to establish themselves when administered to the non-injured mucous membranes, nor did they induce neutralizing antibodies, but a later challenge with the wild-type virus at the same site lead only to an attenuated course of infection.