Hepatitis B Vaccine Non-Responders Show Higher Frequencies of CD24highCD38high Regulatory B Cells and Lower Levels of IL-10 Expression Compared to Responders
Nina Körber, Laureen Pohl, Birgit Weinberger, Beatrix Grubeck‐Loebenstein, Andrea Wawer, Percy A. Knolle, Hedwig Roggendorf, Ulrike Protzer, Tanja Bauer
Abstract
Background The cellular mechanisms involved in the lack of protective antibody response after hepatitis B vaccination are still rather unclear. Regulatory B cells (Breg) known as modulators of B-and T-cell responses may contribute to poor vaccine responsiveness. The current study aimed to investigate the role of regulatory B cells (Breg) in hepatitis B vaccine non-responsiveness after immunization with second- or third-generation hepatitis B vaccines. Method We performed comparative phenotypic and frequency analysis of Breg subsets (CD24 + CD27 + and CD24 high CD38 high Breg) in second-generation hepatitis B vaccine non-responders (2 nd HBvac NR, n = 11) and responders (2 nd HBvac R, n = 8) before (d0), on day 7 (d7), and 28 (d28) after booster vaccination. Cryopreserved peripheral blood mononuclear cells were stimulated ex vivo with a combination of CpG, PMA, and Ionomycin (CpG+P/I) and analyzed for numbers and IL-10 expression levels of Breg by flow cytometry-based analyses. Results Flow cytometry-based analyses revealed elevated frequencies of CD24 + CD27 + Breg at all time points and significantly higher frequencies of CD24 high CD38 high Breg on d0 ( p = 0.004) and 28 ( p = 0.012) in 2 nd HBvac NR compared to 2 nd HBvac R. In parallel, we observed significantly lower levels of CpG+P/I-induced IL-10 expression levels of CD24 + CD27 + and CD24 high CD38 high Breg (d0: p < 0.0001; d7: p = 0.0004; d28: p = 0.0003 and d0: p = 0.016; d7: p = 0.016, respectively) in 2 nd HBvac NR compared to 2 nd HBvac R before and after booster immunization. Frequencies of CD24 + CD27 + and CD24 high CD38 high Breg significantly decreased after third-generation hepatitis B booster vaccination (d7: p = 0.014; d28: p = 0.032 and d7: p = 0.045, respectively), whereas IL-10 expression levels of both Breg subsets remained stable. Conclusion Here we report significantly higher frequencies of CD24 high CD38 high Breg in parallel with significantly lower IL-10 expression levels of CD24 + CD27 + and CD24 high CD38 high Breg in 2 nd HBvac NR compared to 2 nd HBvac R. Anti-HBs seroconversion accompanied by a decrease of Breg numbers after booster immunization with a third-generation hepatitis B vaccine could indicate a positive effect of third-generation hepatitis B vaccines on Breg-mediated immunomodulation in hepatitis B vaccine non-responders.