Dengue virus (DENV) is the most prevalent mosquito-borne virus causing human disease. Of the 4 DENV serotypes, epidemiological data suggest that DENV-2 secondary infections are associated with more severe disease than DENV-4 infections. Mass cytometry by time-of-flight (CyTOF) was used to dissect immune changes induced by DENV-2 and DENV-4 in human DCs, the initial targets of primary infections that likely affect infection outcomes. Strikingly, DENV-4 replication peaked earlier and promoted stronger innate immune responses, with increased expression of DC activation and migration markers and increased cytokine production, compared with DENV-2. In addition, infected DCs produced higher levels of inflammatory cytokines compared with bystander DCs, which mainly produced IFN-induced cytokines. These high-dimensional analyses during DENV-2 and DENV-4 infections revealed distinct viral signatures marked by different replication strategies and antiviral innate immune induction in DCs, which may result in different viral fitness, transmission, and pathogenesis.
Rebecca E. Hamlin, Adeeb Rahman, Theodore R. Pak, Kevin Maringer, Ignacio Mena, Dabeiba Bernal-Rubio, Uma Potla, Ana M. Maestre, Anthony C. Fredericks, El-ad D. Amir, Andrew Kasarskis, Irene Ramos, Miriam Merad, Ana Fernandez-Sesma
DENV-4 infection of DCs induces greater cytokine and chemokine secretion compared with DENV-2 infection.
Levels of cytokine and chemokine secretion (as indicated) were measured by performing multiplex ELISA on supernatants of DC cultures infected with dengue virus 2 (DENV-2) or DENV-4 (MOI of 0.5) or mock-infected cultures. Sixteen donors are shown. Mean ± SEM is shown. Black asterisks represent statistical significance by the paired, 2-tailed Wilcoxon signed-rank test, comparing DENV-4 to DENV-2 at each time point. Red asterisks represent statistical significance for either DENV-2 or DENV-4 compared with mock-infected cells at each time point. The Benjamini-Hochberg procedure was performed within each time point to adjust the significance level for multiple comparisons (*