Responses of CD27(+)CD38(+) plasmablasts, and CD24(hi)CD27(hi) and CD24(hi)CD38(hi) regulatory B cells during primary dengue virus 2 infection

Background Humoral immunity is thought to play a central role in mediating the immunopathogenesis of dengue virus (DENV) infection; however, the B-cell responses elicited by primary DENV2 infection are incompletely understood. Follicular helper T cells (Tfh) are important to promote B-cell activation and differentiation. Methods The present study analyzed the detailed dynamic changes of circulating B-cell subsets and Tfh (cTfh) using flow cytometry to explore their responses to DENV2 infection. Results Thirty-six patients with DENV2 and 21 healthy individuals were included. The results showed that CD27(+)CD38(+) plasmablasts emerged after DENV2 infection, and correlated with CXCR5(+)PD-1(+) or CXCR5(+)ICOS(+)PD-1(+) cTfh, which increased after DENV2 infection, and correlated with DENV2 RNA viral loads. Significantly low levels of CD27(-) naive B cells, and CD24(hi)CD27(hi) and CD24(hi)CD38(hi) regulatory B cells (Breg) were observed after DENV2 infection, which correlated negatively with CXCR5(+)PD-1(+) or CXCR5(+)ICOS(+)PD-1(+) cTfh cells. Conclusion Overall, these results provide insights into the DENV2-elicited B-cell response and revealed previously unidentified CD24(hi)CD27(hi) and CD24(hi)CD38(hi) Breg responses to DENV2 infection.