Question

MHC I & MHC II serve different purposes in the body. Discuss, in detail, what might go wrong if each system were to fail. In other words, list potential problems that may arise from failure of the MHC I system and compare/contrast that with the problems that would arise from failure of the MHC II system.

Answer 1

Compare :

• Since both MHC I and MHC II molecules help the acquired immune system to recognise the foreign particles and act accordingly ,failure of both the systems would lead to failure of activation of acquired immune system in presence of foreign particles.
• Since both MHC I and MHC II present antigens on their surface to be recognised by the specific T cells ,failure of both the system would not allow for activation of respective T cells in response of antigens and thus body would fail to induce an immune response.
• Failure of both the systems could lead to autoimmune diseases where the cells fails to recognise its own self antigen and cancer progression.
• Failure of both the systems would lead to failure in development immunological memory.

Contrast:

• Failure of MHC I system would lead to failure in indentification of endogenous antigens that MHC I molecules interact with while failure of MHC II system would lead to failure in indentification of exogenous antigens that MHCII interact with.
• Failure of MHC I system would fail to activate cytotoxic T cells,macrophages,natural killer cells while failure of MHCII system would fail to activate helper T cells and B cells to produce antibodies that act against antigen.
• Failure of MHC I system would lead to failure in activation of cellular immunity in which the process of apoptosis by cytotoxic T cells as well as macrophages and natural killer cells would be prevented while failure of MHC II system would lead to failure in activation of humoral immunity that produces antibody.
• Failure of MHC I system would lead to failure of development of immunological memory associated with effector cells while failure of MHC II system would lead to failure in development of immunological memory associated with T cells and B cells.