Q. Which one of the following statements best describes the role of B cells and T cells in the human body?

• They protect the body from environmental allergens. 
• They alleviate the body’s pain and inflammation.
• They act as immunosuppressants in the body.
• They protect the body from the diseases caused by pathogens.

Answer: (d) They protect the body from the diseases caused by pathogens.

B cells and T cells

• A lymphocyte is a type of white blood cell that is part of the immune system. They play a critical role in keeping us healthy. Without them, we can’t survive.
• There are two main types of lymphocytes: B cells and T cells. The B cells produce antibodies that are used to attack invading bacteria, viruses, and toxins. The T cells destroy the body’s own cells that have themselves been taken over by viruses or become cancerous.
  • T cells protect us from infection. In our daily lives, we’re constantly exposed to pathogens, such as bacteria, viruses and fungi. Without T lymphocytes, also called T cells, every exposure could be life-threatening. T cells can wipe out infected or cancerous cells. They also direct the immune response by helping B lymphocytes to eliminate invading pathogens.
  • B lymphocytes, also called B cells, create a type of protein called an antibody. These antibodies bind to pathogens or to foreign substances, such as toxins, to neutralize them. For example, an antibody can bind to a virus, which prevents it from entering a normal cell and causing infection. B cells can also recruit other cells to help destroy an infected cell.
• Similarities Between B cells and T cells
  • Both B and T cells originate within the bone marrow.
  • These cells are involved in adaptive immunity.
  • They are a type of lymphocytes.
  • The cells are nucleated and motile.
  • Both protect the body’s immune system and help fight infections.
  • Both the cells are non-phagocytic and are a part of the lymphatic system.

Immune System

• The immune system is a collection of organs and cells that helps keep us healthy. It does this by distinguishing between what we refer to as self (our own normal cells and tissue) and things that make us sick, such as bacteria, viruses and fungi. We call those pathogens. The immune system can also sometimes recognize and destroy cancer.  
• Most cells that make up the immune system can be found within our bloodstream. Known as white blood cells, they travel to different areas of the body, depending on where they’re needed. They develop from hematopoietic stem cells, which are produced in our bone marrow.