清华大学：《分子生物学》课程PPT教学课件（基因ene）第二十四章 免疫多样性（Immune diversity）

Chapter 24 Immune diversity 清莘大当

Chapter 24 Immune diversity

24.1 Introduction 24.2 Clonal selection amplifies lymphocytes that respond to individual antigens 24.3 Immunoglobulin genes are assembled from their parts in lymphocytes 24.4 Light chains are assembled by a single recombination 24.5 Heavy chains are assembled by two recombinations 24.6 Recombination generates extensive diversity 24.7 Avian immunoglobulins are assembled from pseudogenes 24.8 Immune recombination uses two types of consensus sequence 24.9 Recombination generates deletions or inversions 24.10 The RAG proteins catalyze breakage and reunion 24.11 Allelic exclusion is triggered by productive rearrangement 24.12 DNA recombination causes class switching 24.13 Early heavy chain expression can be changed by RNA processing 24.14 Somatic mutation generates additional diversity 24.15 B cell development and memory 24.16 T-cell receptors are related to immunoglobulins 24.17 The major histocompatibility locus codes for many genes of the immune system 清苇大当

24.1 Introduction 24.2 Clonal selection amplifies lymphocytes that respond to individual antigens 24.3 Immunoglobulin genes are assembled from their parts in lymphocytes 24.4 Light chains are assembled by a single recombination 24.5 Heavy chains are assembled by two recombinations 24.6 Recombination generates extensive diversity 24.7 Avian immunoglobulins are assembled from pseudogenes 24.8 Immune recombination uses two types of consensus sequence 24.9 Recombination generates deletions or inversions 24.10 The RAG proteins catalyze breakage and reunion 24.11 Allelic exclusion is triggered by productive rearrangement 24.12 DNA recombination causes class switching 24.13 Early heavy chain expression can be changed by RNA processing 24.14 Somatic mutation generates additional diversity 24.15 B cell development and memory 24.16 T-cell receptors are related to immunoglobulins 24.17 The major histocompatibility locus codes for many genes of the immune system

24.1 Introduction Antigen is any molecule whose entry into an organism provokes synthesis of an antibody (immunoglobulin) Superfamily is a set of genes all related by presumed descent from a common ancestor,but now showing considerable variation. T cells are lymphocytes of the T(thymic)lineage;may be subdivided into several functional types.They carry TcR(T-cell receptor)and are involved in the cell- mediated immune response. 清莘大当

Antigen is any molecule whose entry into an organism provokes synthesis of an antibody (immunoglobulin). Superfamily is a set of genes all related by presumed descent from a common ancestor, but now showing considerable variation. T cells are lymphocytes of the T (thymic) lineage; may be subdivided into several functional types. They carry TcR (T-cell receptor) and are involved in the cell￾mediated immune response. 24.1 Introduction

24.1 Introduction Secretion of antibodies by B cell requires helper T cells Figure 24.1 Humoral 人AA人 immunity is conferred by the Antibodies Antigen binding of free antibodies to antigens to form antigen- Antibody-antigen antibody complexes that are comple以 removed from the bloodstream by macrophages or that are attacked directly by the complement proteins. Macrophage 清菜大当 Complement

Figure 24.1 Humoral immunity is conferred by the binding of free antibodies to antigens to form antigen￾antibody complexes that are removed from the bloodstream by macrophages or that are attacked directly by the complement proteins. 24.1 Introduction

Infected target cell degrades antigen into fragments 24.1 Introduction Figure 24.2 In cell-mediated immunity,killer T cells use Killer T cell the T-cell receptor to recognize a fragment of the MHC "presents' -cell receptor antigen foreign antigen which is presented on the surface of the target cell by the MHC protein. Killer T cell h阁H7品90 情菜大当

Figure 24.2 In cell-mediated immunity, killer T cells use the T-cell receptor to recognize a fragment of the foreign antigen which is presented on the surface of the target cell by the MHC protein. 24.1 Introduction

24.2 Clonal selection amplifies lymphocytes that respond to individual antigens Hapten is a small molecule that acts as an antigen when conjugated to a protein. 清菜大当

Hapten is a small molecule that acts as an antigen when conjugated to a protein. 24.2 Clonal selection amplifies lymphocytes that respond to individual antigens

24.2 Clonal selection amplifies lymphocytes that respond to individual antigens Figure 24.3 The pool of immature lymphocytes contains B cells and T cells making antibodies and receptors antiger with a variety of specificities. Clonal Reaction with an antigen leads to expansion clonal expansion of the lymphocyte with the antibody (B cell)or receptor (T cell)that can recognize the antigen. 清華大当

Figure 24.3 The pool of immature lymphocytes contains B cells and T cells making antibodies and receptors with a variety of specificities. Reaction with an antigen leads to clonal expansion of the lymphocyte with the antibody (B cell) or receptor (T cell) that can recognize the antigen. 24.2 Clonal selection amplifies lymphocytes that respond to individual antigens

24.3 Immunoglobulin genes are assembled from their parts in lymphocytes C genes code for the constant regions of immunoglobulin protein chains. V gene is sequence coding for the major part of the variable (N-terminal) region of an immunoglobulin chain. 清菜大当

C genes code for the constant regions of immunoglobulin protein chains. V gene is sequence coding for the major part of the variable (N-terminal) region of an immunoglobulin chain. 24.3 Immunoglobulin genes are assembled from their parts in lymphocytes

24.3 Immunoglobulin V domain Antigen binding genes are assembled from their parts in lymphocytes CH1 Hinge 1 domair Figure 24.4 Heavy Light chain CH C2 domain and light chains combine to generate Effector functions an immunoglobulin CHS with several discrete C3 domain domains. Heavy chain 情菜大当

Figure 24.4 Heavy and light chains combine to generate an immunoglobulin with several discrete domains. 24.3 Immunoglobulin genes are assembled from their parts in lymphocytes

24.3 Immunoglobulin V domain Antigen binding genes are assembled from their parts in CH1 lymphocytes Hinge C C1 domair Figure 24.4 Heavy Light chain CH C2 domain and light chains combine to generate Effector functions an immunoglobulin with several discrete C3 domain domains. Heavy chain 清菜大当

Figure 24.4 Heavy and light chains combine to generate an immunoglobulin with several discrete domains. 24.3 Immunoglobulin genes are assembled from their parts in lymphocytes