MIMM 214 Lecture Notes - Lecture 13: Protein Tyrosine Phosphatase, Ptprc, Immunological Synapse
5 Jan 2019
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Document Summary
Tcr recognize pmhc complex, cd3 + tcr signal to t-cell that will lead to activation of t-cells. 1 cell to thousands, different type of t-cells for different pathways. To ensure specificity in immune responses, there is a second signal that is conserved across all t-cells called costimulation. The main costimulatory molecule is cd28 that binds. Functions of the cd4 and cd8 co- receptors: bind mhc molecule and enhance the affinity of the tcr-pmhc interaction, initiation of signalling from the tcr. Co-receptor has a cytosolic domain that signals to lck thyrosine kinase that will phosphorylate thyrosine residues on platforms called itams of. When itams are phosphorylated, they attract zap-70 thyrosine kinase that reeves up downstream activation. Highly expressed in all nucleated hematopoietic cells under resting conditions (very abundant) Cd45 is expressed in multiple isoforms as a result of alternative splicing of variable cd45 exons: (history of t-cell) Cd45ro: memory cells (lost a, b, c epitopes)
