Question

Macrophages have different roles based on if they bind a microbe surface antigen versus a soluble antigen/toxin. What are these different roles?

a) Binding microbe surface antigens activates phagocytosis, while binding soluble antigens/toxins triggers antibody production.

b) Binding microbe surface antigens triggers antibody production, while binding soluble antigens/toxins activates phagocytosis.

c) Macrophages exhibit the same roles regardless of the type of antigen they encounter.

d) Binding microbe surface antigens and soluble antigens/toxins both inhibit macrophage activity.

Answer 1

Macrophages activate phagocytosis when they bind microbe surface antigens and are involved in adaptive immunity processes, such as presenting antigens to T cells, when they bind soluble antigens. However, they do not directly trigger antibody production, as this is the role of B cells.

Step-by-step explanation:

The different roles of macrophages when they bind to microbe surface antigens versus soluble antigens/toxins are quite distinct. Binding microbe surface antigens activates phagocytosis, a process where macrophages engulf and digest the invading pathogens. In contrast, when macrophages bind to soluble antigens or toxins, they do not directly trigger antibody production; that is a role typically carried out by B cells after they process and present antigens to T cells. However, macrophages can stimulate T cells to release cytokines that enhance the macrophage's phagocytic capabilities and play roles in the adaptive immune response by presenting antigens to T cells in the context of MHC molecules.

Therefore, the correct answer to the student's question is (a): Binding microbe surface antigens activates phagocytosis, while binding soluble antigens/toxins triggers antibody production. Nevertheless, it is important to note that while macrophages do participate in these responses, the actual antibody production is a function of B cells.