ABSTRACT
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 CD24hi CD27hi and CD24hi CD38hi 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 CD24hi CD27hi and CD24hi CD38hi Breg responses to DENV2 infection.
