Defense mechanisms against trematode-associated fucosylated glycoproteins in rock and mud dwelling snails inhabiting Kuwait bay

Wild, rock-dwelling Turbo coronatus and mud-dwelling Cerithidea cingulata snails were compared in terms of hemocyte subpopulations inhabiting the hemolymph and their capacity to mount defense reactions towards target erythrocytes, which were either control-coated (BSA-SRBCs) or coated with a specified fraction of larval trematode glycoproteins expressing fucosyllactose determinants (Sm-SRBCs). Based on time-dependent rosette-forming cell and phagocytosis assays, hemocytes derived from both groups of snails exhibited comparable efficiency in selectively binding Sm-SRBCs compared to BSA-SRBCs. However, a higher anti-trematode phagocytic response was only evident among hemocytes derived from Turbo coronatus. Two-dimensional polyacrylamide gel electrophoresis indicated that Turbo coronatus and Cerithidea cingulata were distinct in constituent hemolymph proteins, particularly in the group of polypeptides that correspond to lectin subunits specific to the trematode fucosyllactose determinant. This was reflected in the higher anti-trematode glycan agglutination titres selectively observed in the hemolymph of Turbo coronatus compared to Cerithidea cingulata. The possible implication of trematode glycan-specific lectins, in both the cellular and humoral aspects of snails resistance or susceptibility to infection, is discussed