醫(yī)學免疫學英文版課件：Chapter10 B Lymphocyte

1、 Chapter 10 B LymphocyteIntroductionSurface membrane molecules on B cellsSubgroups of B cellsFunctions of B cellsPart I Surface membrane molecules on B cellsAntigen receptor complex: recognizing antigenAccessory membrane molecules related to the activation of B cellsOther surface membrane moleculesI

2、. Antigen receptor complex-BCR and BCR complex1.BCRMembrane immunologlobulin on B cell, mIg: mIgM, mIgD -Bind antigen specifically2.BCR complex: BCR and 2 Ig-( heterodimer) Ig- (CD79a) , Ig- (CD79b) ITAM-bind to tyrosine kinase -transduct a activatory signalII. Accessory membrane molecules on B cell

3、s1. CD19, CD21, CD81, CD225(Leu-13) -co-receptorCD19: Transduct activatory signal into B cell CD21(CR2): receptor of C3dg,C3d and iC3b -Enhance the binding of BCR and antigen and pass activatory signal to CD19 -EB virus receptor2. CD40-co-stimulatory receptor CD40 on B cell binds to CD40L on activat

4、ed T cell -Transduct an important costimulatory signal to B cells 3. CD27 and CD704. CD80(B7-1) and CD86(B7-2)4. ICAM-1 and LFA-1III. Other surface membrane molecules1.Mitogen receptor: LPS-Activate B cell only2.MHC-I and MHC-3.Fc receptor (CD32-FcRII-b) -Related to immunological regulation Part II

5、Subgroups of B cellAccording to expression of CD5 or notB1 cell (CD5+) B2 cell (CD5-)Comparison of B1 and B2 cells B1 B2 Development early late BCR mIgM mIgM and mIgD CD5 + - Reproduction self-renewing from pre-B cell in BM Recognized Ag TI-Ag and auto-Ag TD-Ag Ab type IgM IgG IgG IgM Ab avidity low

6、 high Second IR - + Function innate immunity adaptive immunity Part III Function of B cellProduce the antibodyPresent antigen Participate in immunological regulationI. Produce the antibodyNeutrlization OpsonizationActivate complementADCCII. Present antigen III.Participate in immunological regulation Activated B cells secrete various cytokines to participate in immunological regulation.What you should know by the end of this lectureDefinition of BCR and BC