Determinants of snail-trematode associations

点击翻译按钮获取中文摘要

Snails serve as intermediate hosts supporting the larval development of almost every one of the 10,000 described species of digenetic trematodes. The majority of these infections result in diseases of humans or animals that cause profound medical and agriculture burdens. Snails place significant selective pressure on tremaotdes, acting as a filter for those that they encounter. In many cases, only a single species of snail is suitable as a host for a trematode species. A result of this specificity is that the geographic distribution of the human and animal diseases caused by adult trematodes is defined by the presence of susceptible snail hosts. Immunological factors play a central role in determining compatibility between snails and trematodes. Snails have both cellular and circulating components to their immune response, both of which must function properly if a snail is to successfully defend against trematode challenge. Advancing our understanding of the immunological determinants of snail resistance to trematode infection is the primary focus of my NSERC Discovery Grant. The specific objectives proposed address two essential aspects of the snail defence response against trematodes. The first objective aims to further characterize a critical group of immunological molecules in the snail: the fibrinogen related proteins (FREPs). We know that FREPs are important mediators of the snail immune response, however we know very little about how they function to coordinate parasite defence and clearance. The second objective aims to improve our understanding about snail immune cells (hemocytes), including how their development is regulated, and what the specific functions of each hemocyte type is. We know that hemocytes are essential for killing invading trematodes, however we remain ignorant regarding how they are recruited and what roles they play in defence. This NSERC DG will advance our understanding of a host-parasite relationship that has significant impact on human and animal health. Resulting in the development of novel disease control strategies focused on breaking the intimate bond between snails and trematodes, thereby preventing trematode disease transmission.