University:
York University
Course:
SC/BIOL 3120 | Immunobiology
Academic year:

2023
Views:

414

Pages:

2
Author:

Niklas

The Antibody Diversity Problem: approx 10-10 different lymphocyte receptors/lymphocytes exist in the body 100 million antibodies can be produced 5 antibody isotypes IgA, IgD, IgE.196.19M there are 20-25 thousand genes in the human genome The Problem (the antibody diversity problem) we need to make a lot of proteins (receptors), but we do not have the genes to do it →the gene for one protein DOESN'T WORK 50 these receplers ARE NOT germline encoded The Solution recombination arranging gene segnunta in various ways to create different results BAG 1/2 antigen receptor gene recombinase complex mediates DNA clearage directs epigentic targeting TdTterminal deaxyribonucleatidyl transferase adds non-templated (N) nucienides to V-D and D-J joints of ig heavy chain and all joints of TCR chains in a template independent manner Artemis phosphorylated by DNA-Pics opens hair pin on the coding end joint B-celis B-cell receptor membrane bound antibody antibody secreted from B-cell casentially same tructurm general disclaimer: BCRS and TCR -every 8-cell undergoes the process of antigen receptor genetics, So every B-cell has different antigen receptor random process -T-cell under goes similar process Generating Receptor Diversity: complementary determining regions highly diverse (hapervariable regions) -proteins that code are found in the variable region COD 000 4 mechanisms: Somatic recombination combinatorial diversity occurs during B. cell development in bone marroul BEFORE the coll encounters antigen junctional diversity Somatic hyper mutation occurs after development, during an immune response functional genes for antigen receptors do not exist until they are generated during the development of lymphocytes Ig bene Rearrangement variable region exons are formed by splicing igether segments of genes inherited through the germline →T-cells go through a similar process BUT use different gene segments recombination is a prerequisite for lymphocyte receptor expression Mechanism #1: Somatic Recombina Hon