Fate of naive B cells dictated by IFN-g and TFH cell-derived IL-21 and according to T-bet expression: resting memory (RM) cells represent the self-renewal reservoir of B cell memory, activated memory (AM) cells are poised for differentiation into donor-specific antibody-producing plasma cells driven by IL-21, and tissue-like memory (TLM) cells in an inhibitory state driven by IFN-g signals. Plasticity between AM and TLM cell fate may exist. This figure was created with BioRender. Abbreviations: CD, cluster of differentiation; MHC, major histocompatibility complex; TCR, T cell receptor.