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T cell differentiation (view source)
Revision as of 08:06, 27 September 2010
, 08:06, 27 September 2010→T-Cell Activation
* CD4 binds MHC class II - [[T_cells#Helper_CD4.2B|CD4+ T-cells]] recognise antigen only in association with [[Major Histocompatability Complexes#MHC II|MHC class II]].
* CD4 binds MHC class II - [[T_cells#Helper_CD4.2B|CD4+ T-cells]] recognise antigen only in association with [[Major Histocompatability Complexes#MHC II|MHC class II]].
* CD8 binds MHC class I - [[T_cells#Cytotoxic_CD8.2B|CD8+ T-cells]] recognise antigen only in association with [[Major Histocompatability Complexes#MHC I|MHC class I]].
* CD8 binds MHC class I - [[T_cells#Cytotoxic_CD8.2B|CD8+ T-cells]] recognise antigen only in association with [[Major Histocompatability Complexes#MHC I|MHC class I]].
Activation of [[Lymphocytes#T cells|T cells]] requires two distinct signals:
Activation of T cells requires two distinct signals:
* '''Signal 1''' is the interaction of the TcR with the antigenic peptide/[[Major Histocompatability Complexes|MHC]] complex on the antigen presenting cell.
* '''Signal 1''' is the interaction of the TcR with the antigenic peptide/[[Major Histocompatability Complexes|MHC]] complex on the antigen presenting cell.
*'''Signal 2''' is the interaction of CD28 on the T cells with its ligand, CD80, on the antigen-presenting cell (APC). APC expression of CD80 only occurs after the engagement of pattern recognition on Fc receptors or activation by the cytokines Interferon, IL-1&beta or TNF&alpha.
*'''Signal 2''' is the interaction of CD28 on the T cells with its ligand, CD80, on the antigen-presenting cell (APC). APC expression of CD80 only occurs after the engagement of pattern recognition on Fc receptors or activation by the cytokines Interferon, IL-1&beta or TNF&alpha.