Chapter 2 Immune organs and tissues Immune organs

Chapter 2 Immune organs and tissues 第二章 免疫器官与组织

Immune organs is called lymphoid organs. Immune organs are divided into Central and peripheral immune organs 中枢与外周免疫器官 Central immune organs : thymus and bone marrow peripheral immune organs : spleen, lymphonodes and mucosal-associated lymphoid tissue

§ 1 Central Immune Organs 第一节 中枢免疫器官 Central immune organ are composed of Bone marrow（骨髓）and Thymus（胸腺） a place for generation, differentiation, development and maturation of immune cells(B T)

一、bone marrow （骨髓） （一）structure ：结构 1). Stromal cells （基质细胞）composed with microenvironment, HIM=Soil（土壤） 异常时可导致骨髓增生异常综合症（MDS） 2). Hematopoietic stem cell（造血干细胞）= Seed （种子） 异常时可导致白血病 (lymphoid stem cell and myeloid stem cell in the bone marrow）

(二) Differentiation of HSC and Immune cell form（ 造血干细胞与免疫细胞分化发育） 1、 Origin of HSC 造血干细胞分化发育 yolk sac fetal liver、 spleen bone marrow 起源于卵黄囊，途径肝脾，定位于骨髓 pluripotent hematopoietic stem cell ( self-renewing and differentiation) lymphoid progenitor and myeloid progenitor develop into Mature T cells in thymus, B cells in bone marrow

2、surface marker of HSC 造血干细胞的表面标志 1)、CD 34： CD 34 express in 1 -4% bone marrow cells ， and is a characteristic marker in HSC，but mature T cells CD 34－ Immune magnetic bead, IMB/ Fluores activated cell sorting, FACS 2)、CD 117（c-kit）：It is stem cell factor receptor (SCFR ) from c-kit gene. CD 117+ cells account for 14%, Ig. SF. 50 -70% CD 117+ cells express CD 34+，It is a characteristic marker in HSC 3)、Lin- cell：lineage negative cells, Lin-：non-marker early HSC。CD 2 CD 3/ T；CD 19、CD 24/B；CD 14/M； CD 16、56/NK；Antibody-A/RBC ---mixture antibody+IMB----HSC

（三）Function of bone marrow 骨髓的功能 1、generation place of various immunocytes 各类免疫细胞发生的场所

2、a place for human B NK cell development maturation B细胞、NK细胞分化发育成熟的部位 3、a place for secondary humoral immunoresponse. Bm 再次体液免疫应答的部位 multiple hematopoietic stem cells tratment leukemia，MDS and immunodeficiency

二、Thymus（胸腺） （一）Structure 结构: It are divided Cortex（皮质） and medulla（髓质）. Cortex is consisted of outer Cortex and inner cortex The cells is consisted of thymic stromal cell(胸腺基质细胞=土壤) and thymocytes（胸腺细胞=种子）

Thymus microenvironment （胸腺微环境） n TSC（胸腺基质细胞 ）include thymus epithelial cell, macrophage, dendritic cell with their unique microenvironment (cytokine , thmosin , extracelluar matrix)which is essential for the maturation of the functional T cells.

（二）Function of thymus 功能 In thymus, about 95% of the thymocytes will die, 5% are still alive, and the latter will proliferate and differentiate into mature TH and CTL, then migrate to lymphoid tissues out of thymus

1) a place of T cell differentiation and maturation T细胞分化发育成熟的部位 n CD 4 -CD 8→ CD 4+CD 8+ n (double negative) (double positive) n →CD 4+or CD 8+ →negative select (single positive) n → maturation T cell n

2) Immune regulation: CK , thmosin 免疫调节 3) Form of immune tolerance 免疫耐受 针对自身组织的T细胞凋 亡，从而诱导自身耐受

§ 2 Peripheral Immune Organs and Tissues 第二节 外周免疫器官与组织 Peripheral immune organs consist of lymphnode, spleen and mucous immune system，a place for mature T cell and B cell residence and, also a place for initiating adaptive immune response.

一、lymph nodes (500 -600个) （一）structure of lymph node 结构 Thymus-independent area---B Thymus dependent area-----T DC HEV

1)、cortex 皮质 深皮质—T cell 浅皮质--B cell 2)、medulla 髓质 B 、Plasma cell 、 T and MΦ

（二）function of lymph node 功能 1)、a place for T and B cell settle : T 75%，B 25% T细胞定居的场所 2)、a place for celluar immunoresponse: Ag+DC→Th → T → effect T cell → CMI T细胞发挥细胞免疫应答的部位 3)、 The functions as a physical and biologic filter 过滤作用 4)、Lymphocyte traffic and recirculation 参与淋巴细胞再循环。 借助淋巴细胞归巢受体（L选择素）与血管内皮细胞黏附 分子（addressing血管地址素）结合进行淋巴细胞归巢 及再循环

Function of recirculation: (1)Lymphocytes can survey the antigen and play immunity。 n 有利于淋巴细胞捕捉抗原 n (2)It help maintain a balance overall distribution of lymphocytes and more new lymphocyte in tissue n 有利于淋巴细胞合理分布和更新换代 (3) It is advantageous to the information transfer between immune cells n 有利于免疫细胞间信息传递 n

二、Spleen 脾脏 （一）Structure of spleen 结构 1)、white pulp 白髓 Lymphoid follicle –B ---germinal center ---Marginal zone--T、B 2)、red pulp 红髓 B and plasma cell、 MΦ and DC

（二）Function of spleen 脾脏的功能 1)、a place for T and B cell lying : B 60% B细胞定居场所 2)、a place for primary immunoresponse 初次体液免疫应答部位 3)、synthetize cytokine and complement 分泌细胞因子及补体 4)、The functions as a physical and biologic filter 过滤作用

三、Mucous immune system（MIS） 400 m 2 50%淋巴组织位于粘膜内—屏障 called the mucosa-associated lymphoid tissue，MALT(400 m 2) gut-associated lymphoid tissue, GALT <1>membranous epithelial cell, M cell: specialized antigen transporting cell <2>Intraepithelial lymphocyte, TEL 40% αβ+T, 60% +T, B cell

（2） Function and characteristics of MALT 粘膜相关淋巴组织的功能 （ 非包膜化淋巴组织） secretory Ig. A，s. Ig. A （分泌型Ig. A ） local immunoresponse 发挥粘膜局部免疫反应

Point 本章重点 The Functions and Compsing of Immun Tissues and Organs 各类免疫器官的功能 ２．Differentiation of HSC and Immune cell form ３．T Cell Develop Process in Thymus T细胞在胸腺内分化发育过程 4． The Meaning of Lymphocyte Recirculation 淋巴细胞再循环的意义 a.