Age-dependent changes in T cell homeostasis and SIV load in sooty mangabeys.
Sooty mangabeys (Cercocebus atys) showed age-dependent changes in T cell regeneration. Younger animals had a high percentage of CD4+ CD45RA + T cells and a high concentration of T cell receptor excisional circles (TRECs) in peripheral blood, which indicated active thymopoiesis. In contrast, older animals had an increased T cell turnover, which suggested that most T cell production occurred in the periphery. In addition, the number of peripheral CD4+ T cells naturally decreased with age. Non-pathogenic SIVsm infection did not significantly change the T cell proliferation rate or the TREC concentration, though it did cause a moderate loss of peripheral CD4 + T cells. The viral load correlated negatively with age, which could be accounted for by the reduced availability of CD4 + target cells in older mangabeys. Thus, the number of susceptible target cells may be a limiting factor in natural SIV infection.
Chakrabarti
L A
LA
Aaron Diamond AIDS Research Center, The Rockefeller University, New York, NY 10016, USA. chakra@adarc.org
Lewin
S R
SR
Zhang
L
L
Gettie
A
A
Luckay
A
A
Martin
L N
LN
Skulsky
E
E
Ho
D D
DD
Cheng-Mayer
C
C
Marx
P A
PA
D000375:Aging / Q000276:immunology*; D000818:Animals; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016665:Cercocebus atys; D006706:Homeostasis; D012367:RNA, Viral / Q000097:blood; D012044:Regression Analysis; D016097:Simian Acquired Immunodeficiency Syndrome / Q000097:blood / Q000276:immunology* / Q000503:physiopathology; D015302:Simian Immunodeficiency Virus / Q000302:isolation & purification / Q000502:physiology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D019562:Viral Load
D012367:RNA, Viral