Decreases in ATP levels of human natural killer cells induced by exposure to Pentachlorophenol.

Abstract

Pentachlorophenol (PCP) is an organochlorine compound that has been used as wood preservative for power‐line poles and fence poles. Pentachlorophenol (PCP) has been detected in human tissues. Human natural killer (NK) cells play a central role in immune defense against viral infection and tumor development. In previous studies we have shown that exposure to10–0.5μM PCP decreases the tumor‐killing (lytic) function of NK cells. The purpose of the study was to examine whether there was an association between loss of lytic function and decreased ATP levels. The ability of antioxidants to prevent any PCP‐induced decreases in either ATP levels or lytic function was also examined. NK cells were exposed to PCP at concentrations ranging from 10 to 0.5 μM for 24 and 48 h. ATP levels were decreased by 15% in NK cells exposed to 10 μM PCP for 24 h. There was no decrease in ATP levels at 5 μM PCP. Exposure of NK cells to 5 and 2.5 μM PCP for 48 h decreased ATP by 32% and 12%, respectively. Exposure to 10 μM PCP for 24 h decreased lytic function by 69%, while exposure to 5μM PCP for 24 h decreased lytic function by about 45% and by 90% after 48 h. These data indicate that PCP exposure is able to decrease ATP levels in NK cells but that significant decreases in cytotoxic function occur even when there is no decrease in ATP levels. The addition of 1 mM antioxidant was unable to prevent the PCP‐induced decreases in ATP levels or lytic function.