Describe the process of B-cell activation
What will be an ideal response?
Answer: B cells are produced in the bone marrow as stem cells, pass through a series of steps to become undifferentiated immature B cells, undergo genetic mutations, produce cell surface receptors encoded by Ig genes, and are then released from the bone marrow to circulate in the blood and lymph. Once they detect an antigen, they are activated, undergo a series of structural and genetic changes that depend on signals from other cells. Upon binding with an antigen on the APC (antigen-presenting cell), the final differentiated process is initiated. The activated B cells undergo monoclonal expansion, then hypermutation, and lastly differentiation. The hypermutation process results in binding antigens more efficiently. If the B cells don't bind to an antigen, programmed cell death will occur. This programmed cell death ensures that any cells with detrimental mutations will be destroyed. Cells that bind effectively continue replicating and differentiating. Encounter with helper T cells stimulates final maturation. Some cells differentiate into plasma cells, which produce antibodies, while other cells remain as memory B cells. Memory B cells provide our immune system with the memory that leads to effective immunization.
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