title: Humoral and cellular immune responses in rhesus macaques infected with human immunodeficiency virus type 2.
abstract: Eighteen rhesus macaques were inoculated with either an infectious molecularly cloned human immunodeficiency virus type 2 (HIV-2)SBL/ISY, or with one of eight mutants defective in one or more accessory genes. The immune responses generated by the macaques were monitored for up to 2 years postinfection. All the macaques except those that received mutants lacking the vpr or vif genes demonstrated low to moderate antibody titers. Macaques inoculated with vpx- mutants exhibited a persistent serological response, suggesting continuous virus expression even in the absence of detectable virus in the peripheral blood mononuclear cells (PBMCs). Neutralizing antibodies developed in only four macaques. In general, low-level cytotoxic T lymphocyte (CTL) activity, not clearly HIV-2 specific, was detected in PBMCs. However, one virus-negative macaque exhibited significant HIV-2-specific CTL activity in an enriched CD8+ cell population from PBMCs, suggesting clearance of the viral infection. In addition, CTL activity against the Env and Gag/Pol epitopes of HIV-2 by CD8+ lymphocytes from the spleens and lymph nodes of two infected macaques, in one case requiring CD8+ T cell enrichment and in the other clearly evident in unfractionated tissue lymphocytes, was demonstrated for the first time. This sequestration of tissue CTLs occurred in the absence of significant levels of circulating CTLs in the blood. Our results suggest that routine monitoring of PBMCs may sometimes be inadequate for detecting cell-mediated immune responses. Elucidation of immune correlates of vaccine protection may therefore require sampling of lymphoid tissues and assessment of enriched CD8+ populations.
authors.affiliation: Laboratory of Tumor Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: A G
authors.initials: AG
authors.lastname: Abimiku
authors.forename: G
authors.initials: G
authors.lastname: Franchini
authors.forename: K
authors.initials: K
authors.lastname: Aldrich
authors.forename: M
authors.initials: M
authors.lastname: Myagkikh
authors.forename: P
authors.initials: P
authors.lastname: Markham
authors.forename: E
authors.initials: E
authors.lastname: Gard
authors.forename: R C
authors.initials: RC
authors.lastname: Gallo
authors.forename: M
authors.initials: M
authors.lastname: Robert-Guroff
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000097:blood / Q000276:immunology*; D000818:Animals; D000917:Antibody Formation; D003602:Cytotoxicity, Immunologic; D003673:Defective Viruses / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D017353:Gene Deletion; D005814:Genes, Viral; D015754:Genes, nef; D016341:Genes, vif; D016334:Genes, vpr; D015483:HIV Antibodies / Q000097:blood; D015498:HIV-2 / Q000235:genetics / Q000276:immunology*; D007111:Immunity, Cellular; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology / Q000821:virology; D008253:Macaca mulatta; D016296:Mutagenesis; D009500:Neutralization Tests; D013997:Time Factors
chemical_list: D015483:HIV Antibodies