LIPOPHOSPHOGLYCAN IS PRESENT IN DISTINCTLY DIFFERENT FORM IN DIFFERENT ENTAMOEBA-HISTOLYTICA STRAINS AND ABSENT IN ENTAMOEBA-MOSHKOVSKII AND ENTAMOEBA-INVADENS

Lipophosphoglycan has recently been demonstrated on the cell surface o f Entamoeba histolytica strain HM-1:IMSS. A monoclonal antibody agains t this molecule had failed to react with some other strains of E. hist olytica, including the strain Rahman. To determine if a structurally d istinct lipophosphoglycan existed in Rahman, [H-3]galactose-labeled gl ycoconjugates were electrophoresed through sodium dodecyl sulfate poly acrylamide gel electrophoresis. The electrophoretic pattern in Rahman was very different compared to that obtained with strains HM-1:IMSS an d 200:NIH. A number of experiments including sensitivity to mild acid, nitrous acid and phosphoinositol-specific phospholipase C suggest tha t the Rahman glycoconjugate is indeed a lipophosphogylcan-like molecul e but distinctly different from that of HM-1:IMSS. Mild acid-treated g lycoconjugates from Rahman and HM-1:IMSS revealed the presence of neut ral trisaccharides and monosaccharides in Rahman but not in HM-1:IMSS. Human immune sera from amoebiasis patients and a polyclonal antibody against HM-1:IMSS liphophosphoglycan both recognized Rahman glycoconju gate. Thus, while lipophosphoglycan molecules from the two strains sha re common epitopes, they are clearly distinct from each other. Molecul es bearing resemblance to lipophosphoglycan could not be detected in o ther Entamoeba species, namely Entamoeba invadens and Entamoeba moshko vskii.