Figure 2.

Functional Bifurcations Among CD4⁺ T Cells. Following activation, naïve cells are programmed to modulate central or peripheral processes. Similarly, activated cells either drive or suppress inflammation. These functional bifurcations are coincident and sufficiently independent to allow for the simultaneous generation of all four potential outcomes. Pro-inflammatory T follicular helper (Tfh) cells organize germinal center responses, while traditional non-Tfh effector subsets promote cellular responses at the site of inflammation. Both exist in mutual opposition with a suppressive counterpart. T follicular regulatory cells (Tfr) modify central events, while peripherally induced regulatory T cells (pTregs) suppress peripheral inflammation. The dynamic heterogeneity of CD4⁺ T cell responses may be due in part to plasticity between subsets (indicated by arrows). Created with BioRender.com.