Administration to mouse of endotoxin from gram-negative bacteria leads to activation and apoptosis of T lymphocytes.
Lipopolysaccharide (LPS) from gramnegative bacteria is a well-known T cell-independent B lymphocyte mitogen and macrophage/monocyte activator. While the conventional view holds that LPS is ignored by T cells, we report here that administration of LPS to mice activates all B cells, but also engages most CD4 and CD8 T cells, as measured by the expression of the activation markers CD69 and CD25 and by size increase. T cells recruited in endotoxin-treated mice showed, following in vitro stimulation by concanavalin A, altered patterns of cytokine production. In vivo, massive T cell apoptosis was evidenced in the days following LPS exposure. The present observation may contribute novel insights into the mechanisms of endotoxin shock and of the immunological consequences of gram-negative infections.
Castro
A
A
Unité d'Immunobiologie, CNRS URA 1961, Institut Pasteur, Paris, France.
Bemer
V
V
Nóbrega
A
A
Coutinho
A
A
Truffa-Bachi
P
P
D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology*; D048429:Cell Size / Q000187:drug effects / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics; D004731:Endotoxins / Q000008:administration & dosage*; D007274:Injections, Intraperitoneal; D037181:Lectins, C-Type; D008213:Lymphocyte Activation / Q000187:drug effects* / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000235:genetics; D012486:Salmonella typhimurium / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D016207:Cytokines; D004731:Endotoxins; D037181:Lectins, C-Type; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2; D000099192:CD69 Antigens