Infection with rPS-YE significantly increased the levels of IL-2, IL-17, TNF-β, and CD8 in brain and thymus, CD4 in brain, and IFN- γ in thymus, and significantly reduced the levels of IFN-γ in brain and CD4 in thymus, as compared to those observed for the parental backbone virus rPS. The gene discussed is CD4; the disease is infection.