Abstract
The effect of various antigens of Leishmania major promastigotes on the function of human polymorphonuclear leucocytes (PMNLs) was examined. Different concentrations of L. major antigens were incubated with isolated PMNLs for various periods and the respiratory burst was assessed by Luminol-dependent chemiluminescence. All the Leishmania antigens employed inhibited the PMNL respiratory burst by 35-64%. PMNL viability was not affected either by the concentrations or type of the parasite antigen. Oxygen free radical scavengers enhanced the action of the antigens on the PMNL respiratory burst.