title: Simian immunodeficiency virus infection of CD8+ lymphocytes in vivo.
abstract: To determine the lymphoid target cells of simian immunodeficiency virus (SIV) in vivo, peripheral blood lymphocytes (PBL) and lymph node lymphocytes (LNL) were positively selected (>97% purity) for surface expression of CD4, CD8, or CD20 and then analyzed for SIV provirus using semiquantitative DNA amplification. We found provirus in CD4+ and CD8+ lymphocytes but none in CD20+ lymphocytes. During acute SIV infection (< or = 214 days postinoculation), the percentage of PBL and LNL CD4+ cells containing proviral DNA ranged from 0.2 to 20% and from 0.2 to 2%, respectively. Proviral burden in the CD8+ population of either PBL or LNL ranged from 0.01 to 0.2%. Virus isolation by cocultivation was positive for both CD4+ and CD8+ purified populations. No difference in proviral burden was observed between PBL and LNL subsets during acute SIV infection. Up to 19.4% of positively selected CD8+ cells also expressed CD4, and thus the provirus may reside within a dual-positive population. This dual-positive population may represent activated lymphocytes that are particularly susceptible to infection and may provide an opportunity for virus entry into the CD8+ CD4- lymphocytes in vivo.
authors.affiliation: Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis 95616, USA.
authors.forename: G A
authors.initials: GA
authors.lastname: Dean
authors.forename: G H
authors.initials: GH
authors.lastname: Reubel
authors.forename: N C
authors.initials: NC
authors.lastname: Pedersen
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000821:virology*; D008251:Macaca; D011533:Proviruses; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology* / Q000821:virology; D015302:Simian Immunodeficiency Virus / Q000502:physiology*; D016176:T-Lymphocyte Subsets / Q000821:virology; D019065:Virus Assembly