title: Limited ability of humoral immune responses in control of viremia during infection with SIVsmmD215 strain.
abstract: We investigated the impact of rhesus macaque (RM) B-cell depletion before inoculation with the isolate SIVsmmD215. Seven RMs were treated every 3 weeks with 50 mg/kg of an anti-CD20 antibody (rituximab) starting 7 days before inoculation for 2 (n = 4) and 5 (n = 3) months. Four control animals received no antibody. Three animals were completely depleted of CD20(+) B cells, but 4 were only partially depleted of CD20 cells in the LNs and intestine. The decrease in antibody production was consistent with the efficacy of tissue CD20 depletion. Seroconversion and neutralizing antibody production was significantly delayed in animals showing complete tissue CD20 depletion and remained at low titers in all CD20-depleted RMs. Surprisingly, there was no significant difference in acute or chronic viral loads between CD20-depleted and control animal groups. There was a tendency for lower viral set points in CD20-depleted animals. At 6 weeks after inoculation, cellular immune responses were significantly stronger in CD20-depleted animals than in controls. There was no significant difference in survival between CD20-depleted and control animals. Our data suggest that a deficiency of Ab responses did not markedly affect viral replication or disease progression and that they may be compensated by more robust cellular responses.
authors.affiliation: Division of Microbiology, Tulane National Primate Research Center, Covington, LA 70433, USA.
authors.forename: Thaidra
authors.initials: T
authors.lastname: Gaufin
authors.forename: Rajeev
authors.initials: R
authors.lastname: Gautam
authors.forename: Melissa
authors.initials: M
authors.lastname: Kasheta
authors.forename: Ruy
authors.initials: R
authors.lastname: Ribeiro
authors.forename: Erin
authors.initials: E
authors.lastname: Ribka
authors.forename: Mary
authors.initials: M
authors.lastname: Barnes
authors.forename: Melissa
authors.initials: M
authors.lastname: Pattison
authors.forename: Coty
authors.initials: C
authors.lastname: Tatum
authors.forename: Jeanne
authors.initials: J
authors.lastname: MacFarland
authors.forename: David
authors.initials: D
authors.lastname: Montefiori
authors.forename: Amitinder
authors.initials: A
authors.lastname: Kaur
authors.forename: Ivona
authors.initials: I
authors.lastname: Pandrea
authors.forename: Cristian
authors.initials: C
authors.lastname: Apetrei
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D058846:Antibodies, Monoclonal, Murine-Derived; D000914:Antibodies, Viral / Q000276:immunology*; D000917:Antibody Formation / Q000502:physiology; D018951:Antigens, CD20 / Q000276:immunology; D001402:B-Lymphocytes / Q000502:physiology; D005434:Flow Cytometry; D007111:Immunity, Cellular; D007124:Immunoenzyme Techniques; D007155:Immunologic Factors / Q000494:pharmacology; D007422:Intestines / Q000276:immunology / Q000821:virology; D008213:Lymphocyte Activation / Q000187:drug effects; D008212:Lymphocyte Depletion; D008253:Macaca mulatta; D008297:Male; D000069283:Rituximab; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology*; D015302:Simian Immunodeficiency Virus / Q000472:pathogenicity*; D013601:T-Lymphocytes / Q000276:immunology; D019562:Viral Load; D014766:Viremia / Q000517:prevention & control*; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D000914:Antibodies, Viral; D018951:Antigens, CD20; D007155:Immunologic Factors; D000069283:Rituximab