BIOM20002 Lecture Notes - Lecture 70: Autocrine Signalling, Interleukin 2, Nfat
Document Summary
T cell recognises foreign antigen via tcr, there is a tyrosine kinase phosphorylation pathway leading to an increase in intracellular calcium, which triggers a variety of responses. One upregulates il-2 gene: il-2 secreted and acts in autocrine fashion to cause t cell proliferation. Mechanism of action of cyclosporin and similar agents. Apc presents antigen to tcr which activatrs phospho-lipase c (plc) which causes increase in. Calcineurin is a phosphatase that removes phosphate from transcription factor (nfat nuclear factor of activated t cells) Nfat enters nucleus and drivrs a gene profile resulting in t cell proliferation. Cyclosporin binds to one type of immunophilin called cyclophilin. Tacrolimus binds to another called fk506 binding protein (fkbp) These drugs when bound to immunophilins inhibit clacineurin. Cyclosporin discovered, and used clinically, prior to comprehensive understanding of mechanism of action. (not uncommon) Furthered our understanding of the role of calcineurin in t-cell proliferation and revealed the importance of immunophilins in controlling its actions.
