Question

If phagocytes can't detect a virus, what is the potential consequence for B-cell activation in the immune system?

a) B-cell activation would still occur through alternative pathways.
b) T-helper cells would activate B-cells independently of phagocytes.
c) Without phagocytes detecting the virus, B-cell activation would not occur.
d) B-cell activation is solely dependent on T-helper cells.

Answer 1

Even if phagocytes do not detect a virus, B cells can still be activated through T cell-dependent pathways with the help of T-helper cells, or through T cell-independent pathways that involve direct activation by antigens like polysaccharides.

b) T-helper cells would activate B-cells independently of phagocytes.

Step-by-step explanation:

If phagocytes are unable to detect a virus, the potential consequence for B-cell activation in the immune system could be varied. B-cell activation is not solely reliant on the activity of phagocytes. B cells can be activated by two main mechanisms: T cell-dependent and T cell-independent paths. In T cell-dependent activation, B cells require assistance from T-helper cells after presenting the processed antigen via MHC II. T-helper cells then secrete cytokines that signal the B cells to mature into plasma and memory B cells. On the other hand, T cell-independent activation occurs when antigens, such as polysaccharides, directly cross-link B cell receptors (BCRs), leading to B cell activation without the need for T cell help. Therefore, even if phagocytes cannot detect a virus, B cells can potentially be activated through alternative pathways which are independent of phagocyte activity.