Question

The cells that have $C{ D }_{ 8 }$ markers of the cell membrane are
(a) B- lymphocytes
(b) Natural Killer cells
(c) T cytotoxic cells
(d) T helper cells

Answer 1

Hint: There are types of lymphocytes that function during any immune response in the body. These cells produce receptors which are present in the cell membrane and are produced in the Thymus gland of the body. The cells function to kill the cancer cells and viruses which enter the body.

Complete answer:
The T- cells having $C{ D }_{ 8 }$ receptors in their cell membrane have a quick response to the cell- mediated immune response. $C{ D }_{ 8 }$ receptor T- cells are cytotoxic in nature. They create toxicity in the mediated cell which causes the death of the cell in the region of the immune response. Also, they initiate another immune response if there is a need for other cells in that region. These cells can also attack viruses that enter the body. Hence they are known as ‘Killer cells’ of the body. They can detect cancer or tumor cells in the body and destroy the cells.
- $C{ D }_{ 8 }$ T- cells produce cytokines which are kind of proteins that produce an immune response in the body.
- These immune responses signal other effector cells such as macrophages and MHC cells in the site of infection and damage.
- These cells are used in defending the body from autoimmune diseases.
- B- lymphocytes produce proteins that identify the viruses and bacteria which enter the body. They attach to the foreign body and produce antibodies for it.
- T- helper cells have $C{ D }_{ 4 }$ receptors. They do not infect the viruses directly rather they signal the cytotoxic T- cells ($C{ D }_{ 8 }$) and macrophages to infect the viruses.

So, the correct answer is ‘(c) T cytotoxic cells’.

Note: Cell-mediated response refers to the immune response created by the own cells of the body due to some allergic reaction in the body. Cytotoxic means which is poisonous for the cells, which relates to the death of the cell. It can be imagined as phagocytosis too.