Question

Transplantation of tissues/organs to save certain patients often fails due to rejection of such tissues/organs by the patient. Which type of immune response is responsible for such rejections?

• A. cell-mediated immune response
• B. auto-immune response
  
• C. physiological immune response
  
• D. .humoral immune response
  

Answer 1

The correct option is A cell-mediated immune response

Auto-immune response:

Auto-immune response occurs when the immune system fails to recognise its own cells and starts producing antibodies against them.

Humoral immune response:

Humoral responses are mediated by the B lymphocytes which produce serum antibodies against the invading foreign antigens.

Physiological immune response:

Body secretions like the acid of the stomach, lysozymes in tears and saliva are a part of physiological barriers which protect the body from infections.

Cell-mediated immune response:

The body has the ability to differentiate between self and non-self antigens. The cell-mediated immune response mainly involves T cells which release cytokines in response to foreign objects (non-self cells). Rejection of the graft is due to cell-mediated immune responses which are mediated by the T lymphocytes.

Final answer d. cell-mediated immune response