Question

Which of the following is a way in which follicular B cells can acquire antigen entering a lymph node via an afferent lymphatic?

A. Direct capture of whole antigen that directly enters the follicle by passing between sub-capsular sinus macrophages
B. Transfer of complement-bound antigen from surface receptors on sub-capsular sinus macrophages to B cells
C. Passage of antigen from sub-capsular sinus macrophages to follicular dendritic cells to B cells
D. Passage of antigen from DCs that reside near HEVs to B cells
E. All of the above are possible.

Answer 1

E. All of the above are possible. Follicular B cells can acquire antigens through direct capture, transfer from macrophages, interaction with follicular dendritic cells, or from dendritic cells near HEVs, leading to the conclusion that all the methods listed are possible ways for B cells to acquire antigens.

Step-by-step explanation:

Follicular B cells in lymph nodes can acquire antigens that enter through afferent lymphatic vessels in several ways. These antigens are initially gathered as lymph drains from tissues before they are filtered through the lymph nodes. The options provided enumerate the various ways B cells can acquire antigen:

1. Direct capture of whole antigen that enters the follicle by passing between sub-capsular sinus macrophages.
2. Transfer of complement-bound antigen from surface receptors on sub-capsular sinus macrophages to B cells.
3. Passage of antigen from sub-capsular sinus macrophages to follicular dendritic cells to B cells.
4. Passage of antigen from dendritic cells (DCs) that reside near high endothelial venules (HEVs) to B cells.

All of these possible methods indicate that the correct answer to the question is E. All of the above are possible.