Hemocyte production in Biomphalaria glabrata snails after exposure to different Schistosoma mansoni infection protocols

The objective of this work was to determine the profile of the cellular defense system during mansonic infection. Specifically, this study assessed the number of hemocytes that were produced and released into the hemolymph in response to the parasitic infection. The quantification of the Biomphalaria glabrata hemocytes was performed on groups of snails at 1, 5, 10, 15, 20 and 30 days post-infection that had been individually infected with 5, 10, 15 or 30 Schistosoma mansoni miracidia. The results revealed that B. glabrata possesses a cellular defense mechanism that is characterized by the release of hemocytes into the hemolymph. The maximum peak of cellular production occurred 24 hours after infection, and there was a significant reduction in the hemocyte concentration over the following 10 days. However, at 15 days post-infection, there was a second increase in the cellular hemocyte production, although this was not as strong as the primary peak. At 30 days post-infection, there was another moderate rise in the cellular hemocyte production. Based on this cellular response profile, the defense system of the snail appears to be effective immediately following infection, but the response does not ensure the destruction of all parasites during the course of the infection.