Which of the following descriptions about affinity maturation is correct?

Question

Quizplus · Accepted Answer

Affinity maturation is a process that occurs in the germinal centers of secondary lymphoid organs, such as the spleen and lymph nodes, during an immune response. This process refines the antibody response by increasing the affinity of antibodies for their specific antigens. The key mechanism behind affinity maturation is the somatic hypermutation (SHM) of immunoglobulin (Ig) variable (V) region genes in B cells. These mutations occur at a high rate and can lead to either an increase or decrease in the affinity of the antibody produced by the B cell for its antigen.
B cells that acquire mutations resulting in higher affinity antibodies are preferentially selected for survival and further proliferation. This positive selection occurs through interactions with antigen and helper T cells within the germinal center. B cells with low-affinity antibodies, or those that do not bind antigen, are typically eliminated through apoptosis, a process known as negative selection.
The other options mentioned do not directly describe the process of affinity maturation:
B. Negative selection does play a role in eliminating B cells that cannot bind antigen with high affinity, but the question specifically asks about the mechanism that leads to the production of high-affinity antibodies, which is somatic mutation of V genes.
C. While antigen processing and presentation by dendritic cells are essential for the activation of helper T cells, which in turn help B cells during the immune response, this is not the mechanism that directly leads to affinity maturation within the germinal center.
D. The autoimmune regulator (AIRE) gene is involved in the expression of peripheral tissue antigens in the thymus, which is important for the negative selection of T cells, not B cells, and is unrelated to the process of affinity maturation.
E. Somatic recombination of Ig V genes, also known as V(D)J recombination, is a process that occurs during early B cell development to generate the primary repertoire of antibody specificities. It is distinct from the somatic hypermutation that occurs during affinity maturation in the germinal center.
In summary, affinity maturation depends on the somatic mutation of V genes in B cells within the germinal center, leading to the production of antibodies with increased affinity for their antigen.

Which of the Following Descriptions About Affinity Maturation Is Correct