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(−) naïve 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.