PHGY 313 Lecture Notes - Lecture 15: Clonal Selection, Immunoglobulin M, B-Cell Receptor
24 May 2016
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Document Summary
Pro-b stage is when heavy chain is rearranged. Pre-b stage is when light chain is rearranged. Mature b cells have both igd and igm on surface, immature only has igm. Rag proteins are the key dna cutting enzymes responsible for recombination. When you don"t have rag, you cannot recombine stuck at pro-b cell stage no b cells! Ko of tdt would lead to b cells but less diversity! Thousands of receptors but all have the same antigen specificity in t and b cells. Clonal selection occurs when an antigen binds to a mature b cell (clonal expansion!!) Antibodies (especially igg) deal with ec forms of pathogens and toxic products. Igg is most abundant, they neutralize ec pathogens and their toxins. Antibodies have a few functions: opsonization, neutralization, complement activation (mediated by igm and igg) Constant region confers functional specialization and isotype of the antibody. Most of abs are distributed by diffusion from their site of synthesis.
