title: Simian immunodeficiency virus infection of CD4+CD8+ T cells in a macaque with an unusually high peripheral CD4+CD8+ T lymphocyte count.
abstract: We assessed the possible role in vivo CD4(+) CD8(+) T cells as a viral reservoir for simian immunodeficiency virus (SIV), in a macaque with 50% CD4(+) CD8(+) T cells in peripheral blood. During primary infection (day 14) of this rhesus macaque with the pathogenic SIVmac251 strain, proviruses were detected at similar frequencies in CD4(+) CD8(+) T cells (1/10) and CD4(+) T cells (1/10) and at a lower frequency in CD8(+) T cells (1/800). On day 235, no viral DNA was detected in CD8(+) cells, despite the persistent high viral load, indicating that CD8(+) cells do not constitute a reservoir during the chronic phase of SIV infection. Infection induced early lymphopenia of CD4(+), CD4(+) CD8(+), and CD8(+) cells; only the CD8(+) cell population returned to initial levels and expanded further. We found that CD4(+) CD8(+) T cells expressed the costimulatory CD28 molecule less and were more prone to die in vitro after phytohemagglutinin/interleukin 2 stimulation than were CD4(+) T cells. Taken together, massive death of CD4(+) CD8(+) T cells during acute stages of SIV infection may explain why CD8(+) T cells did not represent a major reservoir for SIV at the onset of infection.
authors.affiliation: Unité de Physiopathologie des Infections Lentivirales, Institut Pasteur, 75724 Paris Cedex 15, France. ekhatiss@pasteur.fr
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Khatissian
authors.forename: Valérie
authors.initials: V
authors.lastname: Monceaux
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Cumont
authors.forename: Raphaël
authors.initials: R
authors.lastname: Ho Tsong Fang
authors.forename: Jérôme
authors.initials: J
authors.lastname: Estaquier
authors.forename: Bruno
authors.initials: B
authors.lastname: Hurtrel
mesh_terms: D000818:Animals; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000821:virology*; D018414:CD8-Positive T-Lymphocytes / Q000821:virology*; D004279:DNA, Viral / Q000097:blood; D005434:Flow Cytometry; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D008253:Macaca mulatta; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology* / Q000821:virology; D015302:Simian Immunodeficiency Virus / Q000502:physiology*
chemical_list: D004279:DNA, Viral