Np. Kock et al., RECEPTORS FOR CARBOHYDRATE LIGANDS INCLUDING HEPARIN ON THE CELL-SURFACE OF LEISHMANIA AND OTHER TRYPANOSOMATIDS, TM & IH. Tropical medicine & international health, 2(9), 1997, pp. 863-874
By employing neoglycoproteins (NGP) and glycosaminoglycans, the detect
ion of endogenous glycoligand-binding sites has become possible. Monit
oring specific binding of 11 of these sugar receptor-specific tools, 1
3 trypanosomatids of monogenetic genera Blastocrithidia, Crithidia, He
rpetomonas, and Leptomonas and digenetic genera Endotrypanum, Leishman
ia, and Sauroleishmania were analysed by agglutination and fluorescenc
e assays. NGP showed agglutination reactions only with the digenetic b
ur not with the monogenetic species. Sensitive flow cytofluorimetric i
nvestigations revealed that the apparently different reactivity to NGP
is due to a pronounced quantitative difference in expression of bindi
ng sites between mono-and digenetic flagellates. Moreover, flow cytofl
uorimetry was used to demonstrate the occurrence of receptor sites for
heparin on the cell surfaces of all trypanosomatids. An indication fo
r a correlation of the binding capacity for the NGP N-acetyl-beta-D-gl
ucosamine and heparin to differences in the pathogenicity of parasites
was observed for Leishmania donovani as well as Leishmania enriettii.
Infective populations of these species contained a significantly high
er number of cells which had bound N-acetyl-beta-D-glucosamine and hep
arin than noninfective (long-term in vitro-cultured) populations. The
results of the present report additionally support the hypothesis that
lectin-carbohydrate interactions with neutral sugar moieties and hepa
rin or heparin-like molecules participate in the interactions between
trypanosomatids and host (cells), and that the detected binding sires
for carbohydrates and heparin may thus be referred to as potential vir
ulence factors.