IL2 and AIDS: Reasoning that both HIV-infected humans and LP-BM5-infected mice exhibit a profound systemic shift in cytokine production from a Th1 profile to a Th2 profile during progression of AIDS and MAIDS, respectively [56,57], we performed experiments whereby two Th1 cytokines, interleukin-2 (IL-2) and IL-12, were evaluated for their ability to restore protection against development of MCMV retinitis upon systemic administration.