title: CD4-like immunological function by CD4- T cells in multiple natural hosts of simian immunodeficiency virus.
abstract: Many species of African nonhuman primates are natural hosts for individual strains of simian immunodeficiency virus (SIV). These infected animals do not, however, develop AIDS. Here we show that multiple species of African nonhuman primate species characteristically have low frequencies of CD4(+) T cells and high frequencies of both T cells that express only the alpha-chain of CD8 and double-negative T cells. These subsets of T cells are capable of eliciting functions generally associated with CD4(+) T cells, yet these cells lack surface expression of the CD4 protein and are, therefore, poor targets for SIV in vivo. These data demonstrate that coevolution with SIV has, in several cases, involved downregulation of receptors for the virus by otherwise-susceptible host target cells. Understanding the genetic factors that lead to downregulation of these receptors may lead to therapeutic interventions that mimic this modulation in progressive infections.
authors.affiliation: Laboratory of Molecular Microbiology, NIAID, NIH, Bethesda, MD 20892, USA.
authors.forename: Carol
authors.initials: C
authors.lastname: Vinton
authors.forename: Nichole R
authors.initials: NR
authors.lastname: Klatt
authors.forename: Levelle D
authors.initials: LD
authors.lastname: Harris
authors.forename: Judith A
authors.initials: JA
authors.lastname: Briant
authors.forename: Brigitte E
authors.initials: BE
authors.lastname: Sanders-Beer
authors.forename: Richard
authors.initials: R
authors.lastname: Herbert
authors.forename: Ruth
authors.initials: R
authors.lastname: Woodward
authors.forename: Guido
authors.initials: G
authors.lastname: Silvestri
authors.forename: Ivona
authors.initials: I
authors.lastname: Pandrea
authors.forename: Cristian
authors.initials: C
authors.lastname: Apetrei
authors.forename: Vanessa M
authors.initials: VM
authors.lastname: Hirsch
authors.forename: Jason M
authors.initials: JM
authors.lastname: Brenchley
mesh_terms: D000818:Animals; D015704:CD4 Antigens / Q000032:analysis*; D011323:Primates / Q000821:virology*; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology; D015302:Simian Immunodeficiency Virus / Q000254:growth & development* / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000737:chemistry / Q000276:immunology* / Q000821:virology*
chemical_list: D015704:CD4 Antigens