Parasitology


Research Article

Virulent and avirulent Entamoeba histolytica and E. dispar differ in their cell surface phosphorylated glycolipids


S. MOODY a1 , S. BECKER a1 , Y. NUCHAMOWITZ a1 and D. MIRELMAN a1
a1 Department of Membrane Research and Biophysics, Weizmann Institute of Science, Rehovot 76100, Israel

Abstract

Virulent strains of Entamoeba histolytica have been reported to produce a mixture of phosphoglycoconjugates that share some structural features with the lipophosphoglycans (LPGs) of Leishmania. Purification of these glycoconjugates is essential to their precise structural characterization. In this study we have extracted ‘LPG-like’ molecules from various virulent E. histolytica strains and purified on the basis of charge differences, 2 apparently related glycoconjugates a ‘LPG’ and a ‘lipophosphopeptidoglycan (LPPG)’. In marked contrast to the abundance of these ‘LPG’ and ‘LPPG’ molecules in the virulent strains, avirulent E. histolytica and E. dispar strains produce either very low, or no detectable levels of LPG, and either low levels or modified forms of ‘LPPG’. Monospecific polyclonal antibodies prepared against that ‘LPG’ of the virulent strain HM-1: IMSS cl6 identified epitopes shared between both the ‘LPG’ and the ‘LPPG’ of this and other virulent strains, using Western blot analysis. Flow cytometric analysis of a range of strains using these antibodies identified a surface distribution of these molecules and confirmed a correlation between surface exposure of epitopes bound by these antibodies and parasite virulence.

(Received April 2 1996)
(Revised July 31 1996)
(Accepted August 16 1996)

Key Words: Entamoeba histolytica; Entamoeba dispar; lipophosphoglycan; lipophosphopeptidoglycan; virulence.

Correspondence:

Corresponding author. Tel: +972 8934 3160. Fax: +972 89468256. E-mail: bfmirelm@weizmann.weizmann.ac.il.



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