title: Cutting edge: apoptosis of superantigen-activated T cells occurs preferentially after a discrete number of cell divisions in vivo.
abstract: Staphylococcal enterotoxins are bacterial products that display superantigen activity in vitro as well as in vivo. For instance, staphylococcal enterotoxin B (SEB) polyclonally activates T cells that bear the Vbeta8 gene segment of the TCR. SEB-activated T cells undergo a burst of proliferation that is followed by apoptosis. Using an in vivo adaptation of a fluorescent cell division monitoring technique, we show here that SEB-activated T cells divide asynchronously, and that apoptosis of superantigen-activated T cells is preferentially restricted to cells which have undergone a discrete number of cell divisions. Collectively, our data suggest that superantigen-activated T cells are programmed to undergo a fixed number of cell divisions before undergoing apoptosis. A delayed death program may provide a mechanistic compromise between effector functions and homeostasis of activated T cells.
authors.affiliation: Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, Epalinges, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Renno
authors.forename: A
authors.initials: A
authors.lastname: Attinger
authors.forename: S
authors.initials: S
authors.lastname: Locatelli
authors.forename: T
authors.initials: T
authors.lastname: Bakker
authors.forename: S
authors.initials: S
authors.lastname: Vacheron
authors.forename: H R
authors.initials: HR
authors.lastname: MacDonald
mesh_terms: D000818:Animals; D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002455:Cell Division / Q000276:immunology; D004768:Enterotoxins / Q000276:immunology; D005434:Flow Cytometry; D005452:Fluoresceins / Q000378:metabolism; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D051379:Mice; D008807:Mice, Inbred BALB C; D013211:Staphylococcus aureus / Q000276:immunology; D013388:Succinimides / Q000378:metabolism; D018089:Superantigens / Q000276:immunology*; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism
chemical_list: C087165:5-(6)-carboxyfluorescein diacetate succinimidyl ester; D017304:Annexin A5; D004768:Enterotoxins; D005452:Fluoresceins; D013388:Succinimides; D018089:Superantigens; C031818:enterotoxin B, staphylococcal