Transcript Document
Sections to Skip for Ch 2 Figure 2.3 - Enzyme digestion of Ab’s Monoclonal Antibodies Fig 2.12 & 2.13 Examples of Problematic Ab binding to various structures Pocket: Penicillin - antibiotic that IgE can bind to and initiate inflammatory response Groove: DNA - Systemic Lupus Erythematosus (Lupus) Extended Surface: Lysozyme - Hen egg component Questions From Class Is IgM only pentameric? IgM is made as a monomer in the cell and then assembled in the cell into a pentamer, with the help of the J chain. After assembly, it is secreted from the cell as a pentamer. Therefore, the secreted form of IgM is only present as a pentamer Why does a T helper cell (CD4 TH1 have to activate a macrophage after the same macrophage has already phagocytosed a pathogen? Macrophages have two main effector functions (see Fig 1.14): 1) phagocytosis and 2) effector signaling by secretion of cytokines. TH1 cells will themselves secrete cytokines to increase the overall effector activity of the macrophage including the secretion of cytokines from the same macrophage (Fig 1.27, 3.11 and 8.15). Questions From Class (continued) What does soma mean with respect to somatic recombination? Soma refers to all the cells of the body (soma is latin for body) except germ cells. Germline configuration refers to the arrangement of genes in all of the somatic cells and germ cells that do not undergo somatic recombination. In cells that have the unique capability to undergo somatic recombination, such as B and T cells, germline configuration refers to gene arrangement before those cells have undergone gene rearrangement (by the process of somatic recombination) A) Can the two types of light chain( and ) be made at the same time in the same B cell? B) How does that affect Ab diversity? A) No. One B cell only expresses one type of light chain. B) Please see the following slide for the correct calculation. Random Recombination of Gene segments is one factor contributing to diversity (200* + 120*) X 10,530 = 3,369,600 Ig molecules * Only one light chain loci gives rise to one functional polypeptide!