title: Apoptosis in thymus of adult Xenopus laevis.
abstract: Thymocyte apoptosis in adult Xenopus laevis is demonstrated on agarose gels and is quantified by propidium iodide incorporation using flow cytometry. Basal apoptotic levels are increased after in vitro exposure to a glucocorticoid, dexamethasone (DEX), and to the lectin, phytohemagglutinin (PHA). To determine the role that newly introduced antigenic determinants may play in this regard, a repertoire of altered-self antigens was created by exposing thymuses in vitro to trinitrobenzene sulfonic acid (TNBS) thereby derivatizing self-cells and proteins via 2,4,6-trinitrophenyl-acetic acid conjugation. An increase in apoptosis in TNBS-treated thymuses is observed. Thus, the thymocytes of adult Xenopus laevis are susceptible to apoptosis when induced by a glucocorticoid, a lectin, and by altered self, antigen activation.
authors.affiliation: Department of Biology, Reed College, Portland, OR 97202-8199.
authors.forename: L N
authors.initials: LN
authors.lastname: Ruben
authors.forename: D R
authors.initials: DR
authors.lastname: Buchholz
authors.forename: P
authors.initials: P
authors.lastname: Ahmadi
authors.forename: R O
authors.initials: RO
authors.lastname: Johnson
authors.forename: R H
authors.initials: RH
authors.lastname: Clothier
authors.forename: S
authors.initials: S
authors.lastname: Shiigi
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology*; D002478:Cells, Cultured; D004247:DNA / Q000032:analysis; D003907:Dexamethasone / Q000494:pharmacology; D004587:Electrophoresis, Agar Gel; D005434:Flow Cytometry; D010835:Phytohemagglutinins / Q000494:pharmacology; D017634:Self Tolerance; D013950:Thymus Gland / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D014302:Trinitrobenzenesulfonic Acid / Q000276:immunology; D014982:Xenopus laevis / Q000276:immunology*
chemical_list: D010835:Phytohemagglutinins; D003907:Dexamethasone; D014302:Trinitrobenzenesulfonic Acid; D004247:DNA