91401 Lecture Notes - Lecture 5: B-Cell Receptor, Fc Receptor, Fragment Crystallizable Region
Document Summary
Antibody isotypes 1: also known as immunoglobulins. Most common isotype found in serum approx. 80% of serum ab: long half life in serum (7-25 days, 3 heavy chain constant domains, monomer (2 binding sites, the fc portion of igg can: recruit complement via c1q or c3. Engage fc receptors on macrophages, dcs and neutrophils to enhance phagocytosis. Engage fc receptors on nk cells to induce target cell cytotoxicity. Enhancement of phagocytosis by igg graph flow chart: phagocyte opsonization of microbe by igg binding of opsonized microbes to phagocyte fc receptors (fc ri) Binding of opsonized microbes to phagocyte fc receptor signals activate phagocyte phagocytosis of microbe killing of ingested microbes. Complement dependent cytotoxicity (cdc: cdc initiated by c1q binding to fc region of igg, recruitment of the complement cascade that results in the lysis of the target cell. Binds fcr a/m on macrophages can enhance phagocytosis of microbes: high avidity, important in control of bloodstream infections.
