Final answer:
The commitment to the B cell lineage involves the differentiation of multipotent stem cells in the bone marrow into diverse clones of B cells, essential for the adaptive immune response. B cells mature into antibody-secreting plasma cells and memory B cells, contributing to potent immune responses during primary and secondary exposures.
Step-by-step explanation:
The commitment to the B cell lineage involves the differentiation of multipotent stem cells in the bone marrow into B cells. These stem cells have the potential to differentiate into various types of cells within a specific lineage, including red blood cells and white blood cells. Throughout B cell maturation in the bone marrow, a vast diversity of up to 100 trillion B cell clones is generated. This is essential for the diversity of antigen receptors that can be comparable to what is seen in T cells.
B cells complete their maturation in the bone marrow and differentiate into antibody-secreting plasma cells, which play a crucial role in the adaptive immune response. The process also involves the clonal selection of B cells, where B cells corresponding to one specific BCR (B cell receptor) variant are activated, followed by their proliferation. Naïve mature B cells express membrane-bound monomeric forms of IgD and IgM as their BCRs.
Furthermore, during a primary B cell immune response, both antibody-secreting plasma cells and memory B cells are produced. The presence of these memory cells aids in the differentiation of more plasma cells and memory B cells during secondary responses, strengthening the immune response upon subsequent encounters with the same antigen.