MIP 300 Lecture Notes - Immunoglobulin M, Opsonin, Streptococcus
Document Summary
How specific ones become plasma cells and make antibodies. Phagocytic cell eats antigen expresses antigens (with multiple epitopes) on cell surface with mhc class ii molecules. Immature th recognizes specific epitope on antigen/mhc ii complex phagocytic cell releases growth factors (interleukines and cytokines), th becomes mature, activated, divides. Create many mature th cells specific for the same epitope on the antigen. T-helper cell receptor protein binding of epitope similar to antibody: lock and key binding of correct shape. Antibodies will neutralize toxins, microbes, and viruses, induce opsonization and complement fixation. Memory cells would wait for future infections with the same microorganism. Th also activate immature ctls by producing growth factors after binding to ctls that have bound antigen ctls mature, divide, go kill virus infected cells, tumor cells, transplants. Memory cells live few years life time. Ctls kill cells expressing the correct epitope on an antigen for which they are specific.