title: Understanding the benign nature of SIV infection in natural hosts.
abstract: In striking contrast to HIV infection, natural SIV infection of African nonhuman primates is asymptomatic and usually does not induce significant CD4+ T cell depletion despite high levels of virus replication. Recently, significant progress has been made in understanding the mechanisms underlying the remarkable difference in infection outcome between natural and nonnatural HIV/SIV hosts. These advances include the identification of limited immune activation as a key factor protecting natural SIV hosts from AIDS and the discovery of low CC chemokine receptor 5 expression on CD4+ T cells as a specific and consistent immunologic feature in these animals. Further elucidation of the pathways by which the differences in immune activation between natural and nonnatural hosts are manifest holds promise for the design of novel therapeutic approaches to HIV infection.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA. gsilvest@mail.med.upenn.edu
authors.forename: Guido
authors.initials: G
authors.lastname: Silvestri
authors.forename: Mirko
authors.initials: M
authors.lastname: Paiardini
authors.forename: Ivona
authors.initials: I
authors.lastname: Pandrea
authors.forename: Michael M
authors.initials: MM
authors.lastname: Lederman
authors.forename: Donald L
authors.initials: DL
authors.lastname: Sodora
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D015658:HIV Infections / Q000276:immunology*; D006801:Humans; D018419:Primate Diseases / Q000821:virology*; D019713:Receptors, CCR5 / Q000276:immunology; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology*; D015302:Simian Immunodeficiency Virus / Q000378:metabolism*
chemical_list: D019713:Receptors, CCR5