Asbestos-induced chemiluminescence response of human polymorphonuclear leukocytes

Abstract

Products of the oxidative metabolism of polymorphonuclear leukocytes (PMN), namely hydrogen peroxide and superoxide, may play a role in tissue injury at sites of inflammation. Oxidant production by PMN was measured by the luminol-enhanced chemiluminescence (CL) of cells exposed in vitro to asbestos fibers. Human peripheral blood PMN were incubated with 1–1000 μg/ml of UICC chrysotile B asbestos fibers opsonized with either normal or heat-inactivated human serum. CL was measured over 210 min and revealed a peak response at 45 min; this response was delayed in comparison to control CL induced by Staphylococcus aureus (5–10 min) and represented approximately 50% of that of the latter. Although maximal CL was generated by asbestos concentrations of 100–500 μg/ml, significant CL was observed at concentrations as low as 0.5–1 μg/ml. Opsonization of asbestos fibers with heat-inactivated serum markedly depressed CL responses, suggesting that complement activation by asbestos fibers may be important in the generation of CL by PMN. In view of the previously reported accumulation of PMN in the lungs of asbestos-exposed animals, this study suggests that oxidant production by PMN may mediate some of the pathological effects of asbestos fibers.