Cytotoxic T-cell response and AIDS-free survival in simian immunodeficiency virus-infected macaques.
OBJECTIVE
To determine whether cytotoxic T lymphocytes have a beneficial effect during infection with the simian immunodeficiency virus (SIV) in macaques.


METHODS
We followed up 12 rhesus macaques experimentally infected with SIV. Cytotoxic T lymphocytes were detected in nine macaques, who were subdivided into a group of high responders (n = 6), with a sustained and polymorphic response directed against most SIV proteins, and a second group of weak responders (n = 3), in which the responses were only transient and directed against only a few proteins. A third group was characterized by the absence of any cytotoxic T-lymphocyte response (n = 3). Proliferative responses closely paralleled cytotoxic responses in intensity and evolution.


RESULTS
Clinical profiles and CD4 cell counts were markedly linked to cytotoxic activity; five out of six macaques that responded to multiple proteins were still healthy 2 years after SIV infection, with two of them presenting a decrease in circulating CD4 cells concomitant with the disappearance of the cytotoxic T-lymphocyte response. Conversely, five non-responder or weak-responder macaques developed overt disease after 4-21 months.


CONCLUSIONS
These data suggest that a cytotoxic response may predict a better clinical outcome.
Bourgault
I
I
Cochin Institute for Molecular Genetics (ICGM), INSERM U152, Cochin Hospital, Paris, France.
Villefroy
P
P
Beyer
C
C
Aubertin
A M
AM
Levy
J P
JP
Venet
A
A
D000818:Animals; D000956:Antigens, Viral / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016827:CD8 Antigens / Q000378:metabolism; D002460:Cell Line; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D008253:Macaca mulatta; D012191:Retroviridae Proteins / Q000276:immunology; D016097:Simian Acquired Immunodeficiency Syndrome / Q000097:blood / Q000276:immunology*; D015302:Simian Immunodeficiency Virus / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D013997:Time Factors
D000956:Antigens, Viral; D016827:CD8 Antigens; D012191:Retroviridae Proteins