Abstract
The adherence of polymorphonuclear leukocytes (PMNs) to eight pathogenic and nine nonpathogenic strains ofEntamoeba histolytica was examined. No difference between pathogenic and nonpathogenic strains was found. The addition of different carbohydrates confirmed the importance of the 170-kDa lectin ofE. histolytica in binding to PMNs, corroborated by the finding that treatment of PMNs with galactosidase inhibited adherence. Inhibition of the microfilament system ofE. histolytica using cytochalasin B resulted in a loss of adherence to PMNs. Inhibition of the microtubule system using nocodazole did not affect adherence. Preincubation of the trophozoites with serum resulted in enbanced adherence, but the serum factor responsible for this effect could not be identified. Fibronectin, vitronectin, integrins (CD11/CD18 molecules), complement, and mannose-binding protein did not seem to mediate adherence betweenE. histolytica and PMNs. In summary, these results indicate that defective adherence mechanisms are not a common feature of nonpathogenicE. histolytica strains.