B cells, also known as B lymphocytes, are a type of white blood cell that plays a crucial role in the adaptive immune system, primarily responsible for humoral immunity. Their main functions include:
- Producing antibodies: B cells generate infection-fighting proteins called antibodies that specifically bind to antigens (foreign substances such as pathogens) to neutralize or mark them for destruction by other immune cells
- Memory formation: Some B cells become memory cells after activation, allowing the immune system to respond more rapidly and effectively if the same antigen is encountered again in the future
- Antigen presentation: B cells act as professional antigen-presenting cells (APCs). They internalize antigens via their B cell receptors (BCRs), process them, and present antigen fragments on their surface to T cells, helping to initiate and regulate T cell immune responses
- Cytokine secretion: B cells release cytokines, which influence other immune cells, regulate immune responses, and contribute to immune system homeostasis and inflammation control
- Development and location: B cells develop from hematopoietic stem cells in the bone marrow. Mature B cells then migrate to lymphoid organs such as the spleen and lymph nodes, where they participate in immune responses
In summary, B cells are essential for identifying specific pathogens, producing antibodies to fight them, remembering past infections for faster future responses, presenting antigens to T cells, and coordinating broader immune functions
