Question

Meetu and her friends were discussing that the kids who already had chicken pox once in their lifetime will not have the disease again. This is a magical ability of our immune system. Which of the following ability of immune system prevents such diseases after first exposure?

• A. Memory cells generated from the first exposure
• B. Generating plasma B cells to fight against the pathogen
• C. Differentiate between self and non self
• D. Recognising MHC or receptor peptide on cell surface

Answer 1

The correct option is A Memory cells generated from the first exposure

Adaptive immunity is the ability of the body to fight against infection or pathogen encountered during life time of an individual. Hence, it is also known as acquired immunity.

It helps the body to fight against specific pathogen. Therefore, it is very specific.

The MHC (major histocompatibilty complex) or peptide receptor present on every cell helps the T cells of the body to recognise and differentiate self from non self. The ones which are foreign are attacked by immediate formation and multiplication of cells.

For this helper T cells plays an important role by activating other cells( cytotoxic T cell and naive B cells) so that they can fight and kill the pathogen.

Ctotoxic T cells are killer cells whereas naive B cells differentiate into types - plasma B cells which immediately start fighting with the infection or pathogen and memory B cells which are kept for future.

Memory lymphocytes (B and T cells) are specialized cells of the immune system that that are formed during the first attack or primary infection and are important in generating an accelerated and more robust antibody-mediated immune response in the case of re-infection (also known as a secondary immune response).

Therefore, if a kid had chicken pox once during the lifetime, the ability of the immune system to keep a memory of exposure prevents the infection for the next time.