Kinetics of T lymphocyte apoptosis and the cellular immune response in SIVmac239-infected rhesus macaques.
BACKGROUND
Although increased apoptosis is a central feature of AIDS, little is known about its kinetics or relationship to the early host response in acute HIV/SIV infection.


METHODS
Ex vivo apoptosis in freshly isolated peripheral blood and lymph node lymphocytes was monitored longitudinally in SIVmac239-infected rhesus macaques by flow-cytometric detection of active caspase-3, cleaved poly (ADP-ribose) polymerase, and fragmented DNA.


RESULTS
Increased apoptosis of multiple lymphocyte subsets was observed in the first 2 weeks following SIV infection. Apoptosis of CD4+ T lymphocytes was of low magnitude but peaked earlier than other T lymphocyte subsets. A 10- to 36-fold increase in CD8+ T lymphocyte apoptosis coincided temporally with onset of the SIV-specific cellular immune response and enrichment of caspase-3-positive cells within recently proliferating, activated CD8+ T lymphocytes.


CONCLUSIONS
The virus-specific T lymphocyte response to primary infection and generalized non-specific immune activation contribute to the pathogenesis of apoptosis in acute SIV infection.
Meythaler
Mareike
M
Division of Immunology, New England Primate Research Center, Harvard Medical School, Southborough, MA, USA.
Pryputniewicz
Sarah
S
Kaur
Amitinder
A
D000818:Animals; D017209:Apoptosis / Q000276:immunology*; D005434:Flow Cytometry; D007700:Kinetics; D008253:Macaca mulatta; D012367:RNA, Viral / Q000097:blood; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology*; D015302:Simian Immunodeficiency Virus / Q000276:immunology*; D018709:Statistics, Nonparametric; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*
D012367:RNA, Viral