Cell surface composition of promastigote and opisthomorph forms of Herpetomonas roitmani (Kinetoplastida: Trypanosomatidae)

Abstract

Cell surface saccharide composition and surface charge of promastigote (PRO) and opisthomorph (OPM) forms of Herpetomonas roitmani were analyzed using labeled lectins and flow cytometry and cell electrophoresis. The FITC signals for concanavalin A, Helix pomatia agglutinin and wheat germ agglutinin were stronger in PRO forms, whereas for Limulus polyphemus agglutinin (LPA) and Wisteria floribunda agglutinin they were stronger in OPM forms. Prior treatment of the cells with neuraminidase decreased the FITC signal for LPA in OPM but not in PRO forms. Furthermore OPMs displayed a high negative charge (-15.45+/-1.10 mV) than PROs (-9.47+/-1.01 mV). Neuraminidase and phospholipase C treatment of the parasites significantly reduced the surface charge, especially in OPM forms. TLC analysis of the acidic components of H. roitmani showed the presence of N-acetyl-neuraminic acid. The results presented in this work indicate that changes in exposed cell surface components occur between PRO and OPM forms of H. roitmani obtained by growing the cells under different conditions.

Differential lectin recognition of glycoproteins in choanomastigote-shaped trypanosomatids: taxonomic implications

“…The occurrence of sialic acid in trypanosomatids has been reported in a broad range of trypanosomatids, including Trypanosoma , Crithidia , Herpetomonas and Phytomonas [4,7,13–21]. Sialic acids are a family of carboxylated nine‐carbon sugars found in glycoproteins and glycolipids at the non‐reducing end of oligosaccharides forming α2,3 and α2,6 linkages to galactose and N ‐acetyl‐ d ‐galactosamine.…”

Leptomonas wallacei Shows Distinct Morphology and Surface Carbohydrates Composition Along the Intestinal Tract of Its Host Oncopeltus fasciatus (Hemiptera: Lygaeidae) and in Axenic Culture

“…The cell surface carbohydrates of different monoxenic trypa‐nosomatids have been characterized by lectins (Esteves et al 1982, 1987, 1988; Faria‐e‐Silva 1999; Gazzinelli et al 1991; Motta et al 1991; Valle‐Matta et al 1999). However, the genus Leptomonas has been neglected.…”

“…In trypanosomatids, morphological changes are accompanied by variations in surface molecules, mainly in sugar residues (De Souza 1989, 1995). Studies of the cell surface carbohydrates have been done for monoxenic trypanosomatids of the genera Crithidia (Esteves et al 1982, 1987; Gazzinelli et al 1991; Motta et al 1991), Herpetomonas (Faria‐e‐Silva et al 1999; Gazzinelli et al 1991), and Phytomonas (Esteves et al 1988). However, these analyses were made on axenically cultivated cells where there is a considerable influence of the composition of the culture medium on cell surface properties (Chatterjee et al 2003).…”

The surface charge of trypanosomatids

“…Treatment of C. deanei with neuraminidase reduced in about 45% the EPM of the protozoan, irrespective of the presence of the endosymbiote (Oda et al 1984). Parasites of the genus Herpetomonas have been used to analyze changes on cell surface during the process of differentiation in vitro, since the composition of the plasma membrane and the surface coat are of primary importance in cell response to environmental stimuli and in the interaction of parasites with their hosts (Soares et al 1988, Lopes et al 1989, Faria-e-Silva et al 1999. Besides these aspects, Herpetomonas sp presents four developmental stages (promastigotes, paramastigotes, opisthomastigotes and opisthomorphs), are non pathogenic for men and show close antigenic similarities to Trypanosoma cruzi Roitman 1971, Souza et al 1974).…”

“…Prior incubation of cells in the presence of neuraminidase from Clostridium perfringens reduced the fluorescence intensity in OPM but not in PRO forms. Thin-layer chromatography analysis of H. roitmani showed the presence of N -acetyl-neuraminic acid (Faria-e-Silva et al 1999). …”