BIO SCI E124 Study Guide - Midterm Guide: Antigen-Presenting Cell, Histocompatibility, Thymus
Document Summary
=> huge amount of diversity due to many v,j,c combinations --> diversity. *when the join, imprcecise joining occurs at the edges--> influence specificity of antibody. Joining is not precise - generates alterations that promote diversity. B cells are diploid (material + paternal chromosomes) => rearrangement only happens on one of the chromosomes. Problem: 1 b cell with 2 different specificities (b cell must be specific to only one epitope). => during this process, somatic hypermutation and affinity maturation occurs. Dendritic cells takes up antigen from outside and displays it over the surface. B cells recognize antigen on surface of dendritic cells. Process of selection by dendritic cells is called affinity maturation. During initial immune response, igd function is lost, igm is maintained. => as immune responses continue, b cells can switch to expressing a different class. Td4 helper t cells that promote b cells which promote t killer cells. Helpder indpednent - not strong/can"t really clear infection.
