Glycobiology of schistosomiasis

Schistosomiasis is a helminthic parasitic disease that results in a wide-ranging pathology in the approximately 200 million infected people worldwide. Much of the immunity to the parasite is directed against carbohydrate determinants in both glycoproteins and glycolipids from the adult worms and their eggs. Circulating glycoproteins derived from the parasite may be diagnostic for the disease. Recent studies of the structures of schistosome-derived glycoconjugates reveal that they exhibit several interesting and novel motifs. Many schistosome glycans are rich in fucose and devoid of sialic acid. It is surprising that some of the fucosylated schistosome glycans contain the Lewis x (Le(x)) antigen that is also found on human leukocytes and other tissues. These Le(x)-containing glycans elicit autoantibodies, and the glycans may affect lymphocyte functions. This review highlights recent progress in schistosome research in terms of structure, function, and biosynthesis of glycoconjugates. It is hoped that the deeper understanding being gained about glycoconjugates will foster innovative new strategies for lessening the mortality and morbidity caused by these parasites.