Effect of chlordane on influenza type a virus and herpes simplex type 1 virus replication in vitro

Abstract

The effect of chlordane on the susceptibility of Madin‐Darby canine kidney cells and African Green monkey kidney cells to infection with influenza type A/PR/8/34 (HON1) virus and herpes simplex type 1 virus was determined. Exposure of both cell lines to various concentrations of chlordane for 24 h at 37° C (acute exposure) effected a marked reduction in the efficiency of influenza type A virus infection, except at a dose of 0.025 ppm. Acute exposure of the monkey cells did not alter their susceptibility to herpes simplex virus infection. Viral adsorption studies at 4 and 37° C revealed a marked reduction in (he attachment of influenza type A virus to both cell lines following acute exposure to 10 ppm chlordane. Viral inactivation studies carried out at 4 and 37°C failed to reveal differences in the level of influenza type A virus inactivation in the presence or absence of chlordane. Madin‐Darby canine kidney cells, exposed to 70 ppm chlordane for 60 d (chronic exposure) manifested a decrease in the efficiency of influenza type A virus infection, whereas cells chronically exposed to 0.025 ppm chlordane manifested an increase in the efficiency of influenza type A virus infection relative to mock‐treated control cells. When chronically exposed cells were passaged six times in the absence of chlordane, these effects were reversed. Viral adsorption studies carried out at 4 and 37°C on cells chronically exposed to 10 ppm chlordane revealed a decrease in the adsorption of influenza type A virus. Quantitation of the levels of cell‐surface sialic acid, the essential terminal sugar on the receptor for influenza type A virus, indicated that the reduced adsorption of influenza type A virus to Madin‐Darby canine kidney cells was not due to a loss of cell‐surface sialic acid. Our findings indicate that chlordane alters the susceptibility of cells to infection with influenza type A virus but not to herpes simplex type 1 virus.