Nonprogressive and Progressive Primate Immunodeficiency Lentivirus Infections  Jason M. Brenchley, Guido Silvestri, Daniel C. Douek  Immunity  Volume 32, Issue 6, Pages 737-742 (June 2010) DOI: 10.1016/j.immuni.2010.06.004 Copyright © 2010 Elsevier Inc. Terms and Conditions

Figure 1 Frequencies of CCR5+CD4+ T Cells in Progressive and Nonprogressive Infections Depletion of GI tract CCR5+ CD4+ T cells during the acute and chronic phases of HIV in humans (black line) and SIV in rhesus macaques (red line), sooty mangabeys (blue line), and African green monkeys (green line). Graphs are based upon published data. Neither African green monkeys nor sooty mangabeys (naturally infected animals that do not progress to AIDS) are as dramatically depleted of their initial GI tract CD4+ T cell populations during the acute phase of infection as are SIV-infected rhesus macaques or HIV-infected humans. African green monkeys and sooty mangabeys have very low frequencies of CCR5+CD4+ T cells prior to infection, unlike humans and rhesus macaques. Moreover, progressive depletion of GI tract CCR5+CD4+ T cells does not seem to occur in SIV-infected sooty mangabeys and African green monkeys during the chronic phase of infection. Immunity 2010 32, 737-742DOI: (10.1016/j.immuni.2010.06.004) Copyright © 2010 Elsevier Inc. Terms and Conditions

Figure 2 Uncoupling of Disease Progression from Virus Production Top: In an uninfected host, naive CD4+ T cells mature into central memory (CCR7+CD62L+, markers not shown). CD4+ T cells that may be regarded as having self-renewing potential. Effector memory CD4+ T cells (defined as CCR7−CD62L−) and activated CD4+ T cells are more prone to activation-induced cell death. Center: In an HIV- or SIV-infected host that progresses to AIDS, the infection and death of central memory CD4+ T cells eventually depletes this important cellular source and results in disease progression to AIDS. The infection and death of effector memory and activated CD4+ T cells produces the bulk of virus but makes little impact on these cellular pools because they are nonetheless destined to die by AICD. Bottom: In nonprogressive SIV infection of natural hosts, virus load is maintained by the infection of effector memory and activated CD4+ T cells. The resistance of the central memory CD4+ T cells (defined as CCR7+CD62L+) to infection, by coreceptor downregulation, prevents their depletion, thus ensuring immune competence and precluding disease progression. Immunity 2010 32, 737-742DOI: (10.1016/j.immuni.2010.06.004) Copyright © 2010 Elsevier Inc. Terms and Conditions