Suppression of adaptive immune responses during primary SIV infection of sabaeus African green monkeys delays partial containment of viremia but does not induce disease.
One of the most puzzling observations in HIV research is the lack of pathogenicity in most nonhuman primate species that are natural hosts of simian immunodeficiency virus (SIV) infection. Despite this, natural hosts experience a level of viremia similar to humans infected with HIV or macaques infected with SIV. To determine the role of adaptive immune responses in viral containment and lack of disease, we delayed the generation of cellular and humoral immune responses by administering anti-CD8- and anti-CD20 lymphocyte-depleting antibodies to sabaeus African green monkeys (Chlorocebus sabaeus) before challenge with SIV(sab9315BR). In vivo lymphocyte depletion during primary infection resulted in a brief elevation of viremia but not in disease. Based on the magnitude and timing of SIV-specific CD8(+) T-cell responses in the lymphocyte-depleted animals, CD8(+) T-cell responses appear to contribute to viral containment in natural hosts. We found no evidence for a contribution of humoral immune responses in viral containment. These studies indicate that natural hosts have developed mechanisms in addition to classic adaptive immune responses to cope with this lentiviral infection. Thus, adaptive immune responses in natural hosts appear to be less critical for viral containment than in HIV infection.
Zahn
Roland C
RC
Division of Viral Pathogenesis, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
Rett
Melisa D
MD
Li
Ming
M
Tang
Haili
H
Korioth-Schmitz
Birgit
B
Balachandran
Harikrishnan
H
White
Robert
R
Pryputniewicz
Sarah
S
Letvin
Norman L
NL
Kaur
Amitinder
A
Montefiori
David C
DC
Carville
Angela
A
Hirsch
Vanessa M
VM
Allan
Jonathan S
JS
Schmitz
Jörn E
JE
D056704:Adaptive Immunity / Q000276:immunology*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000627:therapeutic use; D058846:Antibodies, Monoclonal, Murine-Derived; D057134:Antibodies, Neutralizing / Q000096:biosynthesis; D018951:Antigens, CD20 / Q000378:metabolism; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology / Q000821:virology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology / Q000821:virology; D002522:Chlorocebus aethiops / Q000276:immunology* / Q000821:virology*; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology; D056724:Immunity, Humoral / Q000276:immunology; D007156:Immunologic Memory / Q000276:immunology; D007165:Immunosuppression Therapy; D007371:Interferon-gamma / Q000276:immunology; D019394:Ki-67 Antigen / Q000378:metabolism; D008212:Lymphocyte Depletion; D008221:Lymphoid Tissue / Q000276:immunology; D000069283:Rituximab; D016097:Simian Acquired Immunodeficiency Syndrome / Q000188:drug therapy / Q000276:immunology* / Q000517:prevention & control / Q000821:virology*; D015302:Simian Immunodeficiency Virus; D013997:Time Factors; D014766:Viremia / Q000276:immunology / Q000517:prevention & control* / Q000821:virology
D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D057134:Antibodies, Neutralizing; D018951:Antigens, CD20; D019394:Ki-67 Antigen; D000069283:Rituximab; D007371:Interferon-gamma