Which of the following types of cells produce and release antibodies?
A.
Natural killer cells
B.
Cytotoxic T-cells
C.
Plasma B cells
D.
Helper T-cells
The Correct answer and Explanation is:
The correct answer is C. Plasma B cells.
Explanation:
Plasma B cells are a type of white blood cell that plays a crucial role in the adaptive immune response. Their primary function is to produce and secrete antibodies, which are also known as immunoglobulins. These antibodies are critical for identifying and neutralizing pathogens like bacteria and viruses.
Here’s a detailed look at how plasma B cells function:
- B Cell Development: B cells originate from hematopoietic stem cells in the bone marrow. They undergo a maturation process in the bone marrow where they develop specific receptors on their surface, known as B-cell receptors (BCRs), that recognize specific antigens.
- Activation: Once mature, B cells circulate through the blood and lymphatic system. When a B cell encounters an antigen that matches its specific BCR, it binds to this antigen. This antigen binding is often enhanced by help from helper T cells. Helper T cells (specifically CD4+ T cells) provide additional signals that are crucial for B cell activation.
- Differentiation: Upon activation, B cells undergo a process of proliferation and differentiation. They can differentiate into two main types: memory B cells and plasma B cells. Memory B cells persist long-term and provide rapid responses upon future exposure to the same antigen. Plasma B cells, on the other hand, are short-lived and focus on producing large quantities of antibodies.
- Antibody Production: Plasma B cells are the cells responsible for the actual production and secretion of antibodies. These antibodies are specific to the antigen that initially triggered the B cell response. The antibodies circulate throughout the body, binding to antigens and marking them for destruction by other immune cells or neutralizing their ability to infect cells.
- Antibody Function: Antibodies produced by plasma B cells can neutralize pathogens directly, opsonize them to enhance phagocytosis by other immune cells, or activate the complement system to help destroy pathogens.
In summary, plasma B cells are essential for the humoral immune response, producing antibodies that target specific antigens and facilitate their elimination from the body.