BIOM Antigen Receptors and Lymphocyte Development 2024 PDF

Lymphocytes Development 12-10-2024 Shafik Habal, MD...

Lymphocytes Development 12-10-2024 Shafik Habal, MD Assistant Dean for Curriculum Management and Reporting Professor, Medical Microbiology and Immunology Philadelphia College of Osteopathic Medicine Georgia Campus Certain materials are included under the fair use exemption of the U.S. Copyright Law and have been prepared according to the fair use guidelines and are restricted from further use.  Learning Objectives 1. Recall the definition of an antigen and immunogenicity 2. Recognize the difference between formed and preformed antigen receptors and list examples of each type. 3. Describe the structure of a BCR 4. Describe the structure of a TCR 5. Discuss the events associated with the development and maturation of a B-cell 6. Discuss the events associated with the development and maturation of a T-cell 7. In relation to the stages of T-cell maturation, describe the concepts of single positive, double positive and double negative 8. Explain the difference between positive and negative selection during the development of T-cells. 9. Explain the concept of allelic exclusion 10. Define “somatic hypermutation” Reading Assignment: Cellular and Molecular Immunology 9th edition Chapter 7: Immune Receptors and Signal Transduction (Review) Chapter 8: Lymphocyte Development and Antigen Receptor Gene Rearrangement  w Re v i e The Immune System - Overview Physical barriers Skin Mucous membrane Innate Immune Response Phagocytes NK cells Humoral immunity Adaptive Immune Response Cellular Immunity  Lymphocytes Normal resting lymphocytes are small cells with condensed chromatin and a small amount of pale basophilic cytoplasm. The nucleus of a resting lymphocyte is just slightly larger than a red blood cell. https://imagebank.hematology.org/image/60511/lymphocyte  What is an Antigen? An antigen (Ag) is a molecule which specifically binding a T- cell receptor or an antibody site. An immunogen is any molecule that elicit an immune response by binding to a T- cell receptor or an antibody. All immunogens must be antigens Not all antigens are immunogens https://microbenotes.com/introduction-to-antigen/  Antigen Receptors Preformed Receptors: (Innate Immune Response) Pattern Recognition Receptors (PRR) Toll-like Receptors (TLR) Killer activation receptor (KAR) on NK cells Killer Immunoglobulin-like Receptor on NK cells Complement receptors (CR) FcR on phagocytes Generated Receptors: (Adaptive Immune Response) T- cell receptors (TCR) Specifi c B- cell receptors (BCR) **ITIM- Immunoreceptor tyrosine based inhibition motif.  T Cell Receptor - TCR 1. A heterodimer of two polypeptide chains α and β chains held together by disulfide bonds A small subset (