Testosterone promotes intestinal replication and dissemination of Coxsackievirus B3 in an oral inoculation mouse model

Enteroviruses initiate infection in the gastrointestinal tract, and sex is often a biological variable that impacts pathogenesis. Previous data suggest that sex hormones can influence intestinal replication of Coxsackievirus B3 (CVB3), an enterovirus in the Picornaviridae family. However, the specific sex hormone(s) that regulate intestinal CVB3 replication is poorly understood. To determine if testosterone promotes intestinal CVB3 replication, we orally inoculated male and female Ifnar -/- mice that were treated with either placebo or testosterone-filled capsules. Following oral inoculation, we found that testosterone-treated male and female mice shed significantly more CVB3 in the feces than placebo-treated mice indicating that testosterone enhances intestinal replication. Similarly, testosterone enhanced viral dissemination in both sexes as we observed higher viral loads in peripheral tissues following infection. Further, male mice treated with testosterone also had a higher mortality rate than testosterone-depleted male mice. Finally, we observed that testosterone significantly affected the immune response to CVB3. We found that testosterone broadly increased pro-inflammatory cytokines and chemokines while decreasing the number of splenic B cells and dendritic cells following CVB3 infection. Moreover, while testosterone did not affect the early CD4 T cell response to CVB3, testosterone reduced the activation of CD8 T cells. These data indicate that testosterone can promote intestinal CVB3 replication and dissemination while impacting the subsequent viral immune response. Importance Biological sex plays a significant role in the outcome of various infections and diseases. The impact of sex hormones on intestinal replication and dissemination of Coxsackievirus B3 remains poorly understood. Using an oral inoculation model, we found that testosterone enhances CVB3 shedding and dissemination in male and female mice. Further, testosterone can alter the immune response to CVB3. This work highlights the role of testosterone in CVB3 pathogenesis and suggests that sex hormones can impact the replication and dissemination of enteric viruses.