Dengue virus type-3 isolated from a fatal case with visceral complications induces potent inflammatory responses associated with apoptosis in human monocyte-derived dendritic cells

Dengue virus (DENV) infection is one of the most serious public health problems worldwide. A recent dengue outbreak in Paraguay (2007-2009) presented unusual manifestations such as hepatitis, encephalitis, pulmonary as well as cardiac disorders associated with 50% of deaths caused by dengue in the country. Despite the knowledge on inflammatory responses observed during the course of disease, the role of innate immune cells in the control of virus replication influencing clinical outcome is poorly defined. Using two clinical isolates of the virus, a non-fatal case of classical DF (DENV3/290) and a fatal case of DF with visceral complications (DENV3/5532), we sought to determine the profile of dengue infection in human dendritic cell, a major innate immune cell population. Compared to classical DENV3/290, the strain DENV3/5532 displayed higher replicative ability in mdDCs. In addition, DENV3/5532 was found to induce elevated production of pro-inflammatory cytokines associated with higher rates of programmed cell death. The observed phenotype was due to viral replication in mdDCs and TNF appeared to display a protective effect on virus-induced mdDCs apoptosis. These results suggest that the fatal case DENV3/5532 isolate modulates dendritic cell survival as well as inflammatory mediators synthesis.

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Silveira GF, Meyer F, Delfraro A, Mosimann AL, Coluchi N, Vasquez C, Probst CM, Báfica A, Bordignon J, Dos Santos CN