Dengue virus-specific memory B cell subsets differ as a function of infection history

The four dengue virus serotypes (DENV1-4) cause the most prevalent human mosquito-borne viral disease. Dengue is a febrile disease that often results in debilitating body pain and can rapidly progress to severe disease involving shock. People are generally protected after multiple exposures to different serotypes. Memory B cells (MBCs) can contribute to lasting protection against subsequent dengue. To understand how these rare DENV-specific MBCs develop over multiple exposures, we compared samples from cases with primary versus secondary (i.e., multiple) DENV infections. We found that instead of a higher frequency of total DENV-specific MBCs, particular subsets of DENV-specific MBCs were higher and peaked later after multiple exposures. This suggests that a qualitative shift in DENV-specific MBCs may contribute to protective immunity.