title: In vivo effects of a bacterial superantigen on macaque TCR repertoires.
abstract: A macaque model was employed to explore staphylococcal enterotoxin B (SEB) superantigen-driven T lymphocyte responses. The SEB-reactive Vbeta+ cell subpopulations demonstrated a striking tri-phase response in rhesus monkeys following an SEB challenge in vivo. The hyperacute down-regulation, seen as early as 2 h through 2 days after SEB injection, was characterized by a disappearance of the reactive Vbeta-restricted PBL subpopulations from the circulation and decreased expression of these cell subpopulations in lymphoid tissues. Following this, a dominant expansion of reactive Vbeta-expressing CD4+ cell subpopulations occurred in lymph nodes and spleens, whereas in the peripheral blood a preferential expansion of reactive Vbeta-expressing CD8+ cell subpopulations was seen. An exhaustion of this response was then seen, with a prolonged decrease in the number of the reactive Vbeta+ CD4+ lymphocyte subpopulations. Interestingly, monoclonal or oligoclonal dominance was seen in the reactive Vbeta+ cell subpopulations in the period of the transition from the polyclonal cellular expansion to the exhaustion of the response, suggesting that some Vbeta+ cell clones may be more resistant than others to superantigen-mediated depletion. These results indicate that in vivo SEB superantigen-mediated effect on lymphocyte subpopulations in macaques is complex, suggesting that profound dynamics in the TCR repertoires may in part account for the susceptibility of higher primates to SEB-induced diseases.
authors.affiliation: Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA. zchen@bidmc.harvard.edu
authors.forename: Z C
authors.initials: ZC
authors.lastname: Kou
authors.forename: M
authors.initials: M
authors.lastname: Halloran
authors.forename: D
authors.initials: D
authors.lastname: Lee-Parritz
authors.forename: L
authors.initials: L
authors.lastname: Shen
authors.forename: M
authors.initials: M
authors.lastname: Simon
authors.forename: P K
authors.initials: PK
authors.lastname: Sehgal
authors.forename: Y
authors.initials: Y
authors.lastname: Shen
authors.forename: Z W
authors.initials: ZW
authors.lastname: Chen
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects*; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects*; D004768:Enterotoxins / Q000633:toxicity*; D008253:Macaca mulatta; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis / Q000235:genetics*; D013211:Staphylococcus aureus / Q000276:immunology*; D018089:Superantigens / Q000633:toxicity*
chemical_list: D004768:Enterotoxins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D018089:Superantigens; C031818:enterotoxin B, staphylococcal