Q. Which one of the following statements best describes the role of B cells and T cells in the human body?
a) They protect the body from environmental allergens.
b) They alleviate the body’s pain and inflammation.
c) They act as immunosuppressants in the body.
d) They protect the body from the diseases caused by pathogens.
Correct Answer: d) They protect the body from the diseases caused by pathogens.
Question from UPSC Prelims 2022 GS Paper
Explanation :
B Cells in the Adaptive Immune System
B cells, or B lymphocytes, are white blood cells that play a key role in the humoral immune response. They are responsible for producing antibodies, which are specific proteins that bind to antigens on the surface of pathogens or infected cells. When B cells encounter an antigen that matches their specific antibody, they can differentiate into plasma cells that secrete large quantities of antibodies into the bloodstream. These antibodies neutralize pathogens by blocking their ability to infect cells, tagging them for destruction by other immune cells, or activating the complement system to destroy the pathogen.
T Cells in the Adaptive Immune System
T cells, or T lymphocytes, are another type of white blood cell that is essential for the adaptive immune response. There are several types of T cells, including helper T cells (CD4+ T cells) and cytotoxic T cells (CD8+ T cells).
Helper T Cells
Helper T cells assist in activating and directing other immune cells, including B cells and cytotoxic T cells. They release cytokines that help orchestrate the immune response.
Cytotoxic T Cells
Cytotoxic T cells directly kill infected cells by recognizing small fragments of antigens (peptides) presented on the surface of these cells by major histocompatibility complex (MHC) class I molecules.
Regulatory T Cells
Another subset of T cells, regulatory T cells (Tregs), help maintain immune tolerance and prevent autoimmune responses by suppressing the activity of other immune cells.
