T lymphocyte clonal anergy

T lymphocyte antigen receptor (TCI signalling in isolation is not sufficient to activate T lymphocytes, since purified T lymphocytes do not secrete IL-2 in response to mitogenic lectins or anti-TCR antibodies in the absence of viable accessory cells, despite the feet that under these conditions TCR-associated second 

Experiments investigating co-stimulation have been based on the premise that TCR-mediated and costimulatory signals could be provided by ligands present on different surfaces. For example, the TCR-mediated signal could be provided to the T lymphocyte by anti-TCR antibody immobilized on a plastic surface and the co-stimulatory signal by any accessory cell of interest. This approach has been used (Mueller et a.1., 1989) to identify several features of the co-stimulatory signal. 

It is delivered by T lymphocyte/accessory cell contact, not by soluble factors such as cytokines. 

It does not require MHC compatibility between the responding T lymphocyte and the co-stimulating accessory cell. 

It is provided most efficiently by dendritic cells, less effectively by macrophages and activated B lymphocytes, poorly by resting B lymphocytes, and not at all by T lymphocytes. 

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Schwartz. R.ll. "A Cell Culture Model for T Lymphocyte Clonal Anergy," Seieme. 1349 (June 15. 19911). 

Schwartz, R. H., A cell culture model for T lymphocyte clonal anergy. Science 248,1349—1356... 

O Hehir RE, Lamb JR Induction of specific clonal anergy in human T lymphocytes by Staphylococcus aureus enterotoxins. Proc Natl Acad Sci USA 1990 87 8884-8888. 

Rammensee HG, Kroschewski R, Frangoulis B Clonal anergy induced in mature V beta 6+ T lymphocytes on immunizing Mls-lb mice with Mls-la expressing cells. Nature 1989 339 541-544. 

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