Comparison of dengue infection in human mononuclear leukocytes with mosquito C6/36 and mammalian vero cells using flow cytometry to detect virus antigen

Fluorescent activated cell sorter (FACS) analysis is useful for the detecti on of cellular surface antigens and intracellular proteins. We used this me thodology in or-der to detect and quantify dengue antigens in highly suscep tible cells such as clone C6/36 (Aedes albopictus) and Vero cells (green mo nkey kidney). Additionally lye analyzed the infection in vitro of human per ipheral blood mononuclear leukocytes (PBML). FACS analysis turned out to be a reliable technique to quantify virus growt h in traditional cell cultures of C6/36 as well as Vero cells. High rates o f infection were achieved with a good statistical correlation between the v irus amount used in infection and the percentage of dengue antigen containi ng cells detected in infected cultures. We also showed that human monocytes (CD14+) are preferred target cells for in vitro dengue infection among PBML. Monocytes were much less susceptible to vii us infection than cell lines but they displayed dengue antigens dete cted by FACS five days after infection. rn contrast, lymphocytes showed no differences in their profile for dengue specific immunofluorescence. Without an animal model to reproduce dengue disease, alternative assays hav e been sought to correlate viral virulence with clinical manifestations and disease severity. Study of in vitro interaction of virus and host cells ma y highlight this relationship.