Disease parameters following ocular herpes simplex virus type 1 infection are similar in male and female BALB/C mice

Sex related differences in the incidence or severity of infection have been described for multiple viruses. With herpes simplex viruses, the best example is HSV-2 genital infection where women have a higher incidence of infection and can have more severe infections than men. HSV-1 causes several types of infections including skin and mucosal ulcers, keratitis, and encephalitis in humans that do not appear to have a strong biological sex component. Given that mouse strains differ in their MHC loci it is important to determine if sex differences occur in multiple strains of mice. Our goal was to answer two questions: Are virus related sex differences present in BALB/C mice and does virulence of the viral strain have an effect? We generated a panel of recombinant HSV-1 viruses with differing virulence phenotypes and characterized multiple clinical correlates of ocular infection in BALB/c mice. We found no sex-specific differences in blepharitis, corneal clouding, neurovirulence, and viral titers in eye washes. Sex differences in neovascularization, weight loss and eyewash titers were observed for some recombinants, but these were not consistent across the phenotypes tested for any recombinant virus. Considering these findings, we conclude that there are no significant sex specific ocular pathologies in the parameters measured, regardless of the virulence phenotype following ocular infection in BALB/c mice, suggesting that the use of both sexes is not necessary for the bulk of ocular infection studies.