biostudies-literatureUnknown52(10)Marsman CHuman naïve B cells are notoriously difficult to differentiate into antibody-secreting cells (ASCs) in vitro while maintaining sufficient cell numbers to evaluate the differentiation process. B cells require T follicular helper (T_FH ) cell-derived signals like CD40L and IL-21 during germinal center (GC) responses to undergo differentiation into ASCs. Cognate interactions between B and T_FH cells are transient; after T_FH contact, B cells cycle between GC light and dark zones where T_FH contact is present and absent, respectively. Here, we elucidated that the efficacy of naïve B cells in ACS differentiation is dramatically enhanced by the release of CD40L stimulation. Multiparameter phospho-flow and transcription factor (TF)-flow cytometry revealed tEuropean journal of immunology1662-1675https://www.ebi.ac.uk/biostudies/studies/S-EPMC9825913biostudies-literatureTermination of CD40L co-stimulation promotes human B cell differentiation into antibody-secreting cells.PMC9825913Marsman CJorritsma TVerstegen NJTen Brinke Avan Ham SMBoon LStreutker MfalseTermination of CD40L co-stimulation promotes human B cell differentiation into antibody-secreting cells.Human naïve B cells are notoriously difficult to differentiate into antibody-secreting cells (ASCs) in vitro while maintaining sufficient cell numbers to evaluate the differentiation process. B cells require T follicular helper (T_FH ) cell-derived signals like CD40L and IL-21 during germinal center (GC) responses to undergo differentiation into ASCs. Cognate interactions between B and T_FH cells are transient; after T_FH contact, B cells cycle between GC light and dark zones where T_FH contact is present and absent, respectively. Here, we elucidated that the efficacy of naïve B cells in ACS differentiation is dramatically enhanced by the release of CD40L stimulation. Multiparameter phospho-flow and transcription factor (TF)-flow cytometry revealed t2022-01-01T00:00:00Z2022 Oct2025-04-21T14:19:52.261Z2025-04-21T14:19:52.261ZS-EPMC98259133607300910.1002/eji.202249972