The snail Biomphalaria glabrata as a model to interrogate the molecular basis of complex human diseases

Schistosomiasis is considered the most important of the helminth diseases of humanity in terms of morbidity and mortality [1]. Although advances have been made in controlling the disease, long-term reduction remains elusive [2–5]. Schistosomiasis has re-emerged in southern Europe [6] where it had not been seen in recent times, unlike in more tropical endemic countries, including sub-Saharan Africa, the Maghreb, Egypt, and Brazil (http://www.thiswormyworld.org/worms/global-burden). These recent cases of schistosomiasis in higher latitudes suggest that global warming could influence the geographical range and snail susceptibility to infection as climate temperature increases.The freshwater snail Biomphalaria glabrata has been studied for several years at the molecular level, mainly within the context of its interaction with the trematode Schistosoma mansoni for which it serves as the obligate intermediate host for asexual development of larval stages of the parasite. The genome sequence of B. glabrata has been reported [7], which reveals deep insights into the compatibility of this snail as a host for parasitism by S. mansoni. Analysis of the snail can be expected to further illuminate more deeply those molecular determinants of the snail that should give us insight into molecular interactions underlying the evolutionary success of this ancient relationship between the snail and schistosomes. Studies of comparative immunology relating to innate immunity have helped identify elements of invertebrate immunity that might also shape innate immunity in mammals. Hannington and colleagues recently reviewed this topic [8]. Here, we focus on aspects of the snail/schistosome relationship that could elucidate common pathways that enable both snails and humans to accommodate parasitism by schistosomes in the face of physiological and immunological environments.