INVITRO EFFECT OF ACTINOMYCIN-D ON HUMAN NEUTROPHIL FUNCTION

The effect of actinomycin D (ACT-D) on human neutrophil chemo-taxis, chemiluminescence (CL), superoxide (O2−) production, phagocytic uptake, and intracellular bacterial killing has been examined. The viability of the ACT-D-treated neutrophils was 98% even at a concentration of 10 μg/ml for 4 hr. Using fMLP as the chemotactic factor, depressed chemotaxis was demonstrated following ACT-D (1—10 μg/ml) pretreatment of neutrophils as compared with the non-treated controls. Similar ACT-D pretreatment produced the depressed responses in phorbol myristate acetate-induced CL and superoxide production by neutrophils. Moreover, using heat-inactivated human serum as an opsonin for Salmonella enteritidis (NCTC 6676), there was a significant difference in intracellular killing (P<0.01) but no difference in phagocytic uptake between ACT-D-treated and non-treated neutrophils. These studies indicate that ACT-D profoundly impairs both intracellular bacterial killing by human neutrophil through an effect on respiratory burst activity and directed cell migration of human neutrophils. © 1990, Center For Academic Publications Japan. All rights reserved.