Administration to mouse of endotoxin from gram-negative bacteria leads to activation and apoptosis of T lymphocytes |
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Authors: | Ana Castro,Veronique Bemer,Alberto Nó brega,Antó nio Coutinho,Paolo Truffa-Bachi |
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Abstract: | 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. |
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Keywords: | Endotoxin Polyclonal activation Apoptosis Lymphocyte Mouse |
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