title: T cells of different developmental stages differ in sensitivity to apoptosis induced by extracellular NAD.
abstract: Extracellular nucleotides such as ATP and NAD can profoundly affect the functions of lymphocytes, macrophages, and other cells. We have recently shown that extracellular NAD induces rapid apoptosis in naive T cells by a mechanism involving the ADP-ribosylation of cell surface molecules. In the present paper, we describe that T cells of different developmental stages differ in their sensitivity to NAD-induced apoptosis. Thymocytes were less susceptible than peripheral lymph node T cells, and freshly activated cells were more resistant than resting cells. Sensitivity to NAD-induced apoptosis generally correlated with expression of the ADP-ribosyltransferase ART2.2, which is not expressed on thymocytes and shed from peripheral T cells upon activation. Our findings suggest that NAD-induced apoptosis does not play a role during thymic selection of T cells, but rather may play a role by preventing the activation of unwanted bystander T cells during an immune response, and thus may participate in the control of autoimmunity.
authors.affiliation: Institute of Immunology, University Hospital, Martinistr. 52, D-20246 Hamburg, Germany. haag@uke.uni-hamburg.de
authors.forename: Friedrich
authors.initials: F
authors.lastname: Haag
authors.forename: Dunja
authors.initials: D
authors.lastname: Freese
authors.forename: Felix
authors.initials: F
authors.lastname: Scheublein
authors.forename: Wiebke
authors.initials: W
authors.lastname: Ohlrogge
authors.forename: Sahil
authors.initials: S
authors.lastname: Adriouch
authors.forename: Michel
authors.initials: M
authors.lastname: Seman
authors.forename: Friedrich
authors.initials: F
authors.lastname: Koch-Nolte
mesh_terms: D036002:ADP Ribose Transferases / Q000096:biosynthesis; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology*; D015551:Autoimmunity; D002454:Cell Differentiation / Q000276:immunology*; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D009243:NAD / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology
chemical_list: D009243:NAD; D036002:ADP Ribose Transferases; C449339:Art2b protein, mouse