Carbohydrates Detection in the Hepatic Egg - Granuloma System Using Lectin Histochemistry

Abstract

MELO-JÚNIOR, M. R.; CAVALCANTI, C. L. B.; DE PONTES-FILHO, N. T.; DE CARVALHO JR, L. B. & BELTRÃO, E. I. C.Carbohydrates detection in the hepatic egg-granuloma system using lectin histochemistry. Int. J. Morphol.,26(4):967-972, 2008. SUMMARY:This study aims to evaluate the egg-granuloma system in hepatic tissues using lectin histochemistry in experimental Schistosomiasis. Eight Swiss mice were infected with a local strain of Schistosoma mansoni, being submitted forty days later to a perfusion after which slices of liver (4µ m) were prepared. The tissue samples were incubated with the following peroxidase conjugated lectins: Peanut agglutinin (PNA), Wheat Germ agglutinin (WGA), and Concanavalin A (Con A). All lectins recognized the glycoconjugates in the adult worm tegument. In the hepatic tissue, WGA presented the highest staining followed by PNA and Con A. The PNA presented the most intense staining of the egg-granuloma system while WGA stained the hepatic sinusoid cells and Con A bound preferentially the fibrosis rings of granuloma and the surrounding hepatic parenquima. WGA and PNA indicated the presence of residues of N-acetyl-glucosamine and galactose in the surface of Schistosoma mansoni eggs in the hepatic granulomas. In conclusion, using PNA, Con A and WGA our study presented different aspects of the egg-granuloma and Tegument of Schistosoma mansoni as well as indicated differences in the peri-ovular granulomas indicating alterations in the cellular mechanism of expression of surface carbohydrates during progression of the Schistosomiasis.

Evaluation of WGA and Concanavalin A (Con A) lectin as biomarkers of hepatosplenic schistosomiasis in human biopsies with no evidence of egg-granuloma system

“…Lectin histochemistry with different carbohydrate specificities can provide a sensitive detection system linked to different labels, such as peroxidase and acridinium ster 15 for changes in glycosylation and carbohydrate expression that may occur during embryogenesis, growth and disease 2 . Among lectins, we can highlight Con A, since the schistosoma egg-granuloma surface system was evidenced by this lectin 11 and the high pattern of WGA staining in pathologic disorders 16 . Besides this, lectin probe analyses on Schistosoma mansoni tegumental surface glycopeptides showed high levels of surface polypeptides reacting with horseradish peroxidase-labelled Canavalia ensiformis (Con A), Erythrina corallodendron (ECA), Glycine max (SBA) and Triticum vulgaris (WGA), indicating that carbohydrates associated with the tegumental primary sporocyst may act as receptors, mediating recognition by the internal defense system of the molluscan host, Biomphalaria glabrata 8 .…”