Dengue virus infects macrophages and dendritic cells in a mouse model of infection

Dengue fever is a mosquitoborne viral illness caused by 4 dengue viruses (DENV-1-4). The cellular tropism of DENV has not been definitively determined, despite its importance for understanding viral pathogenesis and identifying therapeutic targets. To define DENV cellular tropism in a small animal model, 129/Pas mice lacking interferon-alpha/beta and/or gamma receptors were infected with DENV via a subcutaneous route. During the first week after infection, virus was present in lymph nodes, spleen, bone marrow, and circulating white blood cells. F4/80(+)CD11b(+) macrophages and CD11c(+) dendritic cells were demonstrated to be targets for DENV-2 infection in the spleen by flow cytometry directed to structural and nonstructural DENV proteins and by magnetic bead separation followed by strand-specific reverse-transcriptase polymerase chain reaction. We find that the initial cellular tropism of DENV in mice is similar to that reported in humans, thereby paving the way for investigation of cellular tropism and pathogenesis of DENV in primary and secondary infections.