Fig. 3

Stem-like CD4⁺ T cells serve as a reservoir for sustained effector differentiation. Following clonal selection by dendritic cells (DCs), naïve CD4⁺ T cells differentiate into a stem-like population that functions as a self-renewing reservoir. These stem-like cells maintain themselves while progressively giving rise to functionally distinct progeny. Over time, they differentiate into either terminal effector Th cells (e.g., Th1), which execute immune functions and ultimately undergo cell death, or follicular helper T (Tfh) cells, which support B-cell responses. This model highlights the central role of the stem-like CD4⁺ T-cell state in sustaining adaptive immunity through self-renewal and continuous output of effector Th and Tfh lineages. Created with BioRender.com