MEDI7212 Lecture Notes - Lecture 94: Cathepsin, Superoxide, Elastase
Document Summary
Introduction aim of immune system is to protect host from external factors (microorganisms, toxins) and also prevent attacks from internal factors (tumours, autoimmune phenomena) Innate immune system: epithelial barriers, mucociliary clearance, phagocytic cells, complement proteins, adaptive immune system, cell mediated, antibody mediated. Langerhan cells, oligodendrocytes, kupffer cells: action, process and transport ag from skin/ respiratory/ gi surface -> regional lymphoid tissue. Introduction 70-80% circulating blood lymphocytes; cellular immune response: precursor t cell -> thymus for maturation -> peripheral lymphoid tissues. Cd4 helper t cell: amplify b cell production of ig and cd8 mediated toxicity, th1. Il12 induced development: produced by macrophages, cellular immune response against intracellular. Secrete ifny, tnf pathogens & type iv delayed hs: th2. Secrete il4 and il13 (ige production) & il5 (eosinophils production: humoral response against allergens and helminthes. Cd8 cytotoxic t cell: defence against intracellular pathogens (eg viruses), tumour immunity, organ graft rejection etc via osmotic lysis, secrete tnf or induce apoptosis.
