Accelerating Antibody Maturation

Antibodies are the basis of humoral immunity, but in order to be protective they must mature into potent (high-affinity) antibodies. Germinal centers are the sites of antibody maturation and diversification. Because B cells express and ultimately produce antibodies, they often take center stage in our understanding of antibody affinity maturation. However, they do not work alone and must be selected by T follicular helper cells, which recognize and select B cells based on the affinity of their evolving antibodies. Therefore, T cells can also be seen as major protagonists in the antibody maturation process. Despite this, they have been comparatively understudied as a tool to modulate B cell antibody dynamics. Here, we examined how T cell sensitivity shapes selection thresholds for B cells carrying antibodies of different affinities. We find that more sensitive T cells can select antibodies with a broader range of affinities. These data establish a new conceptual framework for designing vaccines that can either focus or broaden B cell antibody responses by calibrating T cell help