US EPA

1687824 

Journal Article 

Interaction of dengue virus with human Kupffer cells in vitro 

Marianneau, P; Steffan, AM; Royer, C; Drouet, MT; Jaeck, D; Kirn, A; Deubel, V 

1999 

207-210 

WOS:000085097400069 

The hepatic lesions in dengue fever consist generally of central and paracentral focal necrosis, the presence of sinusoidal acidophilic bodies, hypertrophy of Kupffer cells in which viral antigens are occasionally found, mild fatty changes and patchy portal mononuclear cell infiltration. The role of the Kupffer cells and the nature of their interactions with dengue virus in the course of the disease are not well known. In this study we have infected primary cultures of human Kupffer cells with dengue virus and examined the production of infectious particles, the synthesis of intracellular viral antigens and the induction of the cell death by apoptosis. In a parallel study, the penetration of the virus into the cells and its cytopathic effect have been examined by electron microscopy. Finally, we have followed the production of several cytokines and nitric oxide (NO) by infected Kupffer cells.



Our results show that viral particles are taken up by Kupffer cells mainly by phagocytosis and, less frequently, by receptor-mediated endocytosis in clathrin-coated pits. Several pictures suggested a process of fusion. No infectious dengue particles were released from Kupffer cells. Viral proteins were synthesized in about 10% of the cells, 24 hours after infection. The pattern of the immunofluorescence was either speckled or concentrated in huge patches. Viral antigen-containing cells disappeared from the culture 72 hours after infection. Apoptotic cells could be detected by TUNEL assay and electron microscopy; and these were phagocytosed and degraded by neighouring Kupffer cells. Viral particles were occasionnally found associated with the cells being degraded in phagosomes.



Production of IL1-alpha, IL1-beta and IFN-gamma could not be revealed. However infected Kupffer I:ells synthetized TNF-alpha, IFN-alpha and NO as early as 6 hours after infection, and IL-6 after 24 hours.



In conclusion, our results show that Kupffer cells are not permissive for dengue virus. In a low number of cells an abortive infection resulting in apoptotic: cell death was observed. dengue virus induces Kupffer cell activation, as demonstrated by IL-6, TNF-alpha, IFN-alpha and NO production. Viral particles as well as viral antigen-containing cells were rapidly taken up and degraded.