951 AHTIAMOEBIC PROPERTIES OF HUMAN COLOSTRAL MACROPHAGES

Abstract

A number of specific and non-specific soluble and cellular antimicrobial factors have been demonstrated in human colostrum. Although macrophages are the most abundant cellular elements in human colostrum, the role of these cells against intestinal parasites has not been explored. Ve assesed the activity of human colostral macrophages against trophozoites of axenically cultured Entamoeba histolytica. Colostrum samples from 50 Mexican women were obtained by manual expresion into sterile plastic tubes. Macrophages were isolated, washed in HBSS and adjusted to 2×106 cells/ml in RPMI containing 20% fetal calf serum. 1 ml of this cell suspension was dispensed onto sterile coverslips and incubated at 37°C in 5% CO2 for 24 hrs and then washed 2X with HBSS and observed for viability. Monolayers of adherent cells were then overlayed with trophozoites of E. histolytica to give a macrophage to amoeba ratio of 30:1 and incubated at 37°C in 5% CO2 and examined by light microscopy at 15′, 30′, 1 hr, and 3 hr intervals. A progressive diminution in the number of tropiiozoites was observed when compared to control coverslips containing trophozoites alone. These findings suggest that colostral macrophages and/or their secretagogues are cytotoxic for trophozoites of E. histolytica.