Inhibition of phagocytosis and superoxide production by pentachlorophenol in two leukocyte subpopulations from Fundulus heteroclitus

Abstract

The effect of pentachlorophenol (PCP) on non-specific immune function was studied in two phagocytic cell populations isolated from the pronephros of an estuarine fish, Fundulus heteroclitus. Macrophages and eosinophils were exposed to sublethal doses of PCP in vitro, then assayed for phagocytic activity and superoxide (O − 2) generation. Phagocytic activity was determined with a fluorescence concentration analyzer following incubation of the cells with FITC-conjugated yeast particles. Lucigenin-dependent chemiluminescence (CL) was used to measure superoxide production. Phagocytosis by both leukocyte populations was significantly inhibited at concentrations of PCP greater than 5 mg/liter; the production of O − 2 was significantly inhibited at PCP concentrations of 10 mg/liter or more. These two leukocyte populations play primary roles in cellular microbicidal and antiparasitic activities; therefore, the immunosuppression seen in these experiments suggests that exposure to sublethal levels of PCP could result in increased disease susceptibility.