Final answer:
Assembly of the pre-B cell receptor prevents a B cell from continuing heavy chain recombination, protecting against the production of self-reactive B cells and reducing the risk of autoimmunity. The mechanisms of clonal deletion and clonal anergy ensure that only non-self-reactive B cells progress to full maturity and become active participants in the immune response.
Step-by-step explanation:
Assembly of the pre-B cell receptor prevents a B cell from undergoing further recombination events that would alter the specificity of the heavy chain of the immunoglobulin molecule. This checkpoint ensures that only B cells with a successfully rearranged heavy-chain gene progress in development. This process is critical as it prevents the further rearrangement of the heavy chain, which could potentially lead to the production of B cells with self-reactive receptors, thereby increasing the risk of autoimmunity. If these B cells were to mature and become activated, they could start producing antibodies against the body's own tissues. The negative selection mechanisms in place, including clonal deletion, clonal anergy, and receptor editing, work to remove or inactivate these self-reactive B cells.
The clonal deletion removes self-reactive B cells by inducing apoptosis, while the clonal anergy process renders B cells that react to soluble antigens in the bone marrow nonfunctional. Only those B cells that successfully pass these selection processes can proceed to the spleen for final maturation and differentiation into plasma cells upon activation. The mature B cells then participate in the adaptive immune response by producing and secreting antibodies specific to foreign antigens.