Signal transduction in T helper cells: CD4 coreceptors exert complex regulatory effects on T cell activation and function.
Curr Issues Mol Biol
; 6(1): 1-15, 2004 Jan.
Article
em En
| MEDLINE
| ID: mdl-14632255
ABSTRACT
The immune system provides a highly sophisticated surveillance mechanism to detect diverse antigens and to protect the host organism from invading pathogens and altered cells (e.g., virus-infected and tumor cells). Adaptive immune responses depend on the recognition of antigen by specific antigen receptors that are expressed on the surface of T and B lymphocytes. Helper T cells provide regulatory functions and direct the adaptive immune system to respond appropriately to a particular antigen (i.e., cytotoxic T cell responses against viral infections and tumor cells, humoral responses against extracellular bacteria and parasitic worms). Helper T cells express CD4 coreceptors, which recognize conserved domains on proteins expressed by the class II major histocompatibility complex, the same proteins that present antigen to the T cell receptor. Recent progress in T cell biology has identified multiple regulatory functions of CD4 during thymocyte development and antigen stimulation of mature T helper cells. Signaling pathways induced by engagement of CD4 independently of T cell receptor signaling mediate these regulatory functions. In this review, we discuss the regulation of T cell signaling and emphasize the functional consequences of proper and improper CD4 coreceptor signaling.
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Base de dados:
MEDLINE
Assunto principal:
Ativação Linfocitária
/
Linfócitos T CD4-Positivos
/
Transdução de Sinais
/
Antígenos CD4
/
Subpopulações de Linfócitos T
/
Linfócitos T Auxiliares-Indutores
Limite:
Humans
Idioma:
En
Revista:
Curr Issues Mol Biol
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Estados Unidos