Question

A researcher is studying immune response in mice. He removes the thymus from each mouse surgically when it is born to study the effect on immune cell maturation. Later, when he gives the mice a vaccine, he finds that they produce few or no antibodies in response to this immune challenge. Explain how the lack of a thymus led to this result.

Answer 1

Answer:

Thymus gland is a small bilobed endocrine gland which is located behind the sternum in the mediastinum region of the living vertebrate body.

The gland is categorized as an endocrine gland as it remains indulged in the release of a non nutrient substance called as hormone which brings about many physiological responses within the body.

The hormone released by the Thymus gland is the Thymosin and the hormone is required for the maturation of the B and T lymphocytes.

B lymphocytes are the class of the immune cells which are also called as the plasma cells and they are attributed towards the synthesis of the antibodies which are the proteins and they get bound with the foreign disease causing pathogen leading to their elimination.

Similarly, T lymphocytes are the class of the immune cells which are committed for the antigen presentation. The antigen could be of an endogenous origin or of an exogenous origin and thus there are two lineages of T cells; T Helper cells who present the foreign born antigens to the human body and the T cytotoxic cells which present the antigens of endogenous origin.

Administration of vaccines in the living body induces a severe immune response requiring the activation of B and T lymphocytes. However when the Thymus gland from the mice got removed, there were no formation of Thymosins due to which B and T lymphocytes did not attain their maturity and hence condition of few or no antibodies response was reported.