Additionally, we hypothesized that minocycline might also indirectly reduce CNS infection through its effects on various immune system-related mechanisms that contribute to the magnitude of CNS (and CSF) infection, including: CD4+ T cell traffic that brings both infected cells and uninfected targets into the CNS, and CD4+ T cell and macrophage activation that enhance viral replication in these cell types. Here, CD4 is linked to infection.