Answer :
Final answer:
To enhance interaction with CD4 T cells, B cells undergo clonal expansion, affinity maturation, and memory formation after encountering a protein antigen. These changes contribute to an effective immune response and the development of immunological memory.
Explanation:
When a protein antigen interacts with B cells, it leads to a multi-step process that enhances the B cells' interaction with CD4 T cells. This process includes several key changes within the B cells:
- Clonal Expansion: Naive B-lymphocytes that have encountered an antigen undergo proliferation upon receiving signals from cytokines produced by T4-helper lymphocytes. This results in the expansion of B cells with B-cell receptors (BCRs) specific to the antigen.
- Affinity Maturation: During clonal expansion, slight alterations called somatic hypermutations occur in the BCR genes. These mutations can increase the affinity of BCRs for the antigen, resulting in better immune response.
- Memory Formation: Some of the proliferated B cells differentiate into memory B cells, which can rapidly respond to future exposures to the same antigen.
These changes enable B cells to effectively present antigens to CD4 T cells, receive further activation signals, and differentiate into either plasma cells that produce antibodies (part of the humoral immune response) or memory B cells that contribute to immunological memory.
