Effect of entamoeba histolytica toxins on isolated human polymorphonuclear leukocytes' phagocytic function

ABSTRACT

This study was undertaken to investigate the effect of Entamoeba histolytica toxin [Ehp/t] obtained from HM1IMSS strain on human polymorphonuclear leukocytes [PMN[s]] phagocytic function. A less virulent strain, i.e., NIH200 was also used in this study for comparison. The results revealed that the toxin obtained from the strain HM1 IMSS inhibited the phagocytic activity of PMN[s] as measured by yeast uptake or chemiluminescence response while the toxin of strain NIH200 did not show any significant effect. On the other hand, washing of PMN[s] that had been pre-exposed to the toxin of strain HM1IMSS failed to reverse the effect of the toxin on PMN[s]. Heat inactivation of the toxin failed to alter its effect on PMN[s]. Addition of N-acetyl-D-galactosamine [GalNA[c]] to the PMN[s] did not alter the activity of Ehp/t toxin. These findings suggested that Ehp/t toxin might induce similar effect on PMN[s] of patients infected with ameba