Effects of plant lectins on cellular defense reactions of ascidian hemocytes

Abstract

Abstract. The effects of plant lectins on the three cellular defense reactions of hemocytes of the solitary ascidian, Halocynthia roretzi (hemocyte aggregation, phagocytosis, and an allogenic reaction), were investigated. Concanavalin A inhibited aggregation, while wheat germ agglutinin and ricin inhibited the allogenic reaction. Neither of the lectins showed inhibitory effects on phagocytosis, but ricin promoted phagocytosis. These effects of the lectins were diminished by the addition of sugars specific for the respective lectins. These results strongly suggest that different surface carbohydrates are involved in the recognition mechanisms of three H. roretzi cellular defense reactions.