B细胞激活 分化和效应功能中法班演示文稿.pptx

B细胞激活、分化和效应功能Activation and Differentiation of B cell;;;B细胞对抗原的识别; Overview of B-cell development. During the antigen-independent maturation phase, immuno-competent B cells expressing membrane IgM and IgD are generated in the bone marrow. Only about 10% of the potential B cells reach maturity and exit the bone marrow. Naive B cells in the periphery die within a few days unless they encounter soluble protein antigen and activated TH cells. Once activated, B cells proliferate within secondary lymphoid organs. Those bearing high-affinity mIg differentiate into plasma cells and memory B cells, which may express different isotypes because of class switching. The numbers cited refer to B-cell development in the mouse, but the overall principles apply to humans as well.;;;四、B细胞抗原识别信号的转导;;;;由BCR启动的信号转导途径及参与的相关分子 BLNK: B细胞连接蛋白，发挥平台蛋白（衔接蛋白）功能；GEF: 鸟苷酸置换因子； Btk：Bruton酪氨酸激酶，Tec PTK家族成员；Syk：Syk PTK家族成员； Blk,Fyn,Lyn：Src PTK家族成员。;类别 主要成分 T细胞 B细胞 跨膜分子 抗原受体 TCR BCR 带有ITAM的辅助分子 CD3 ζ链, γε链, δε链 Igα, Igβ 辅助受体 CD4/CD8 CD21, CD19, CD81 蛋白酪氨酸磷酸酶 CD45 CD45 蛋白酪氨酸激酶 受体关联性(Src家族) Lck, Fyn Lyn, Fyn, Blk, Lck 胞质游离性(Syk家族) ZAP-70 Syk 胞质游离性(Tec家族) Itk, Atk Btk, Atk 衔接蛋白 膜型衔接蛋白 LAT, SLP-76 BLNK(SLP-65) 游离衔接蛋白, Grb2, Gad Grb2 MAP激酶途径 鸟苷酸置换因子(GEF) Sos, Vav Vav, Sos 小G蛋白 Ras, Ras, Rac MAP激酶 Erk, Jnk Jnk, p38 第二信号 受体 CD28 CD40 配体 B7