医学免疫学英文版教学课件：Chapter 3 General introduction ofimmune system

1、 Chapter 3 General introduction of immune systemImmune SystemImmune organs and immune tissues bone marrow, thymus lymph nodes, spleen MALT,SALT Immune cells Lymphocytes(T,B cells and NK cells) APC(M,DC,B cells) Other cells(neutrophil,basophil,eosinophil etc.)Immune molecules Antibody,Complement,Cyto

2、kine CD and adhesion molecules,MHC molecules Immune organs Central immune organs or primary lymphoid organs： -The site that lymphocytes generate and mature into functional cells. Peripheral immune organs or secondary lymphoid organs and tissues: -The sites that T and B lymphocytes reside in and resp

3、ond to antigens. Section I Central immune organs Central immune organs: The site that lymphocytes generate and mature into functional cells. bone marrow thymusbursa of Fabricius ( only in birds) -The place where B cells matureI. Bone marrow 1. Bone marrow is the site of generation of all circulating

4、 blood cells in the adult, including immature lymphocytes.2. The bone marrow is the site of B cell maturation3. The sites that secondary humoral immunity carries through.II. Thymus Cortex outer cortex : immature T cells ( thymocytes) inter cortex : thymus epithelial cell, macrophage , DCMedulla Matu

5、re T cells , thymus epithelial cell, macrophage , DC 1. The structure of thymus 2. Cells in thymus and thymic microenvironment (1)Thymus stroma cells (TSC) Thymus epithelial cells(TEC), Macrophages, Dendritic cells(2)Thymocytes The cells migrate from the bone marrow to the thymus and then become thy

6、mocytes. 3. Function of ThymusDevelopment and differentiation of T lymphocytes in thymusPositive selection (MHC restriction)Negative selection (Self tolerance) (2) Immune regulation of the thymus Thymosin, thymulin-, thymopoietin(3) Barrier function of the thymus The immune organs /tissues or second

7、ary lymphoid organs/tissues are sites that T and B lymphocytes reside in and respond to antigens. spleen lymphoid nodes mucosal immune system Section II Peripheral Immune tissues and organs I. Spleen The spleen is the major site of immune responses to blood-borne antigens.White pulp Central arteriol

8、e peripheral lymphoid sheaths (PALS) Tcell area : around the central arteriole T cells , dendritic and macrophage B -cell area: lymphoid follicles B cells, macrophage and DCRed pulp cellular cord vascular sinusoid1. The Structure of spleen 2. Function of spleenThe site of T and B cells residence B c

9、ells : thymus-independent area T cells : Thymus dependent areaSite of immune response to antigens Synthesize some bioactive substance component of complement Filtering blood II. Lymphoid nodes1. Structure of Lymphoid nodeCortex :Outer cortex: B cell-rich area lymphoid follicle/lymphoid nodule : prim

10、ary lymphoid follicle : mature and nave B cells secondary lymphoid follicle :with germinal center Paracortex : T cell-rich area Medulla : DC, macrophages, T cells, plasma cells2. Function of lymphoid nodeThe site of T and B cells residence B cells : thymus-independent area T cells : Thymus dependent

11、 areaSite of immune response Recirculation of lymphocytesFiltering blood III. SALT (skin associated lymphoid tissue) The skin contains a specialized cutaneous immune system consisting of intraepidermal lymphocytes and APCs (such as Langerhans cell). Cellular components of the cutaneous immune system

12、IV. MALT (mucosal associated lymphoid tissue) The mucosal surfaces of the gastrointestinal and respiratory tracts,like the skin,are colonized by lymphocytes and APCs that initiate immune responses to ingested and inhaled antigens.scattered lymphoid tissue organized lymphoid tissue (Peyers patch),（I）

13、The constitution of MALT Gut-associated lymphoid tissue, GALTNasal-associated lymphoid tissue, NALT Bronchial-associated lymphoid tissue, BALT（II）The function and features of MALTFirst defense lineSite of immune responseSecrete sIgA Section III Lymphocytes homing and recirculation I. Lymphocyte homi

14、ng The process by which particular subsets of lymphocytes selectively enter some tissues but not others is called lymphocyte homing. The continuous movement of lymphocytes between blood stream and peripheral lymphoid tissues is called lymphocyte recirculation. II. Lymphocyte recirculation Significan

15、ce of lymphocyte recirculation Renew the lymphocytes in peripheral lymphoid organsMaximize the chances of specific encounter with antigen and initiation of adaptive immunity Enable lymphocytes to circulate throughout body and facilitate immune response to antigenII. Immunocytes Its refered to the ce

16、lls that participate in or are related to the immune response. lymphocytes :T, B, NK other Immunocytes III. Immune molecules Membrane moleculesSecretive moleculesMembrane molecules 1.Antigen receptors of lymphocyte (TCR, BCR) 2.CD ( cluster of differentiation ) a group antigens on immunocytes related to the cell differentiation 3. MHC (MHC I MHC II) Immune moleculesSecreted molecu