B CELL RECEPTOR final.pptx

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1. B CELL RECEPTOR BY: DR SADAF MOEEZ

2. B CELL RECEPTOR is a transmembrane protein on the surface of a B cell. A B cell receptor is composed of a membrane-bound immunoglobulin molecule  a signal transduction moiety.

3. B CELL RECEPTOR

4. STRUCTURE

5. STRUCTURE

6. STRUCTURE

7. B-cell receptor The B-cell receptor consists of an Ig molecule anchored to the cell’s surface. CH = heavy chain constant region; CL = light chain constant region; Fab = antigen-binding fragment; Fc =  crystallizable fragment; Ig = immunoglobulin; L-kappa ( κ) or lambda ( λ) = 2 types of light chains; VH = heavy chain variable region; VL = light chain variable region .

8. The B cell receptor (BCR) has two crucial functions upon interaction with the antigen . One function is signal transduction, involving changes in receptor oligomerization The second function is to mediate internalization for subsequent processing of the antigen and presentation of peptides to helper T cells.

9. B-cell co-receptor The B-cell co-receptor is expressed on mature B cells as  a complex of the cell-surface molecules CD19, CD21, and CD81.