IMM2011 Lecture Notes - Lecture 17: Mhc Class Ii, Antigen-Presenting Cell, Innate Immune System
14 Jul 2018
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Document Summary
Delineate the mechanism of antigen recognition and b cell activation. On the surface of b cell there are multiple bcr expressed, these can be these only bind to extracellular short cytoplasmic domain which is unable to igd antibodies. However these have either igm or pathogen but undergo signal transduction. Receptors are non covalently associated with other proteins, igb. these have immunoreceptor tyrosine based activation motif (itams) When there is a pathogen ,this allows for cross linking of receptors when igm molecules of a b cell come together and bind to repeating adjacent epitopes of one antigen. This allows for antigen receptor mediated signal transduction. When two or more antigen receptors of b cell are clustered, the tyrosines in the itams of iga and igb are phosphorylated by kinase associated with bcr. Phosphotyrosine are fyn, lyn and blk and these recruit syk tyrosine kinase then phosphorylates tyrosine residues on adaptor protein.
