title: Age-dependent changes in T cell homeostasis and SIV load in sooty mangabeys.
abstract: 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.
authors.affiliation: Aaron Diamond AIDS Research Center, The Rockefeller University, New York, NY 10016, USA. chakra@adarc.org
authors.forename: L A
authors.initials: LA
authors.lastname: Chakrabarti
authors.forename: S R
authors.initials: SR
authors.lastname: Lewin
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.forename: A
authors.initials: A
authors.lastname: Gettie
authors.forename: A
authors.initials: A
authors.lastname: Luckay
authors.forename: L N
authors.initials: LN
authors.lastname: Martin
authors.forename: E
authors.initials: E
authors.lastname: Skulsky
authors.forename: D D
authors.initials: DD
authors.lastname: Ho
authors.forename: C
authors.initials: C
authors.lastname: Cheng-Mayer
authors.forename: P A
authors.initials: PA
authors.lastname: Marx
mesh_terms: 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
chemical_list: D012367:RNA, Viral