B Cells and Antibodies

Question: Write a lay summary of on B cells and antibodies in the immune system. Answer: The development of B cells begins when the lymphoid progenitor cells get the signals from the bone marrow for their development. The development of these cells, begins in the fetal liver and the development continues throughout the life of an individual in the bone marrow. When the B cells mature, they move towards the outer surface and can be activated by an antigen and become a memory B cell or antigen secreting plasma cell. The function of B cells in maintaining the immunity and the immune response is immense. B cells secrete antibodies that are responsible for flushing out the foreign antigens from the body (NIAID 2012). Each B cell is programmed in such a way that it prepares a specific antibody. For an instance, a single B cell may produce an antibody against the virus that causes common cold, while another B cell may produce an antibody that works against the bacteria responsible for causing pneumonia. During the initial stage of the development of the B cells, the antibody mo lecules are inserted into the plasma membrane and there they serve as the receptors or receivers for the antigen molecules. When the antigen binds to these receptors, a signal is triggered with the help of the helper T cells and the B cells start to proliferate into several other memory B cells or the antibody secreting effector cells. B cells can form different antibodies, each with a different sequence of amino acid and a different antigen binding site too. The antibodies so formed, are collectively termed as the Immuniglobins and are the most important protein component of the blood (Alberts B, Johnson A, Lewis J, et al. 2002). References Alberts B, Johnson A, Lewis J, et al., 2002, B cells and antibodies, Molecular biology of the cell, 4th Edn., Garland science, New York. National Institute of Allergy and Infectious Diseases (NIAID), 2012, B cells, viewed on 28th February 2015, https://www.niaid.nih.gov/topics/immunesystem/immunecells/Pages/bcells.aspx.