*(L25) Humoral (B cell) Immune Response

Question 1

What surface molecules do B cells have?

L24 S9

Answer 1

BCR (IgM/IgD)
Igα and Igβ 
CD19, CD81, and CD21 (CR2)
MHC class II
CD40
CD20

Question 2

What are the types of B cells and where are they found?

L25 S7

Answer 2

B-1 cells:

• found in mucosa
• limited Ag specificity

B-2 cells:
-follicular B cells (majority)
—circulating B cells
-marginal B cells
—found in marginal zone of spleen
—secrete Abs for polysaccharides

Question 3

What causes B cells to migrate to the lymph follicles?

L25 S8

Answer 3

CXCR5 expressed on B cells and is a receptor for CXCL13, a chemotactic factor produced by the spleen and lymph nodes.