Question

1. Explain why the thymectomized mice had no humoral immune response (Hint: What role do T cells play in the process you outlined in C?) Humoral immune response involve T cells
2. Explain why the removal of the thymus improved the success of skin grafts (Hint: What role do T cells play in skin graph rejection?)

Answer 1

a)If the mice is thymectomized then the maturation of T-cells would not take place. Humoral immune response involve T cells hence that would also be hampered. The T cells helps B cells to secrete antibodies and for macrophages to phagocytize the pathogen. T helper cells release cytokine which mediate the humoral immunity so all in all due to Thymectomy no humoral immune response would be in existence.

b) The T cells plays two major central function in graft rejection -

1)Allorecognition - Identify foreign antigen and T cells gets activated for antigen-antibody reaction.

2) Orchestration and pro-inflammatory response - This causes organ damage.

Thymectomy causes inability of T cells to mature. Hence the graft rejection would not take place due to absence of T cells . Hence there would be success in skin grafts.