Detection of proteins induced in the haemolymph of biomphalaria pfeifferi infected with schistosoma Mansoni.

Abstract

Schistosomiasis is a parasitic disease caused by a blood fluke of the genus Schistosoma. The disease is often associated with water resource development projects such as dams and irrigation schemes, where the snail intermediate host breeds. Snail-schistosome interactions in relation to immunological, and biochemical changes induced in the host’s tissues by the developing intramolluscan stages of the parasite form an integral part in understanding the biology of infection. This study focused on determining whether there are induced proteins in an infected snail haemolymph and to determine the cross reactivity of the proteins with antibodies raised against the cercariae and worm antigens. Snail haemolymph of the infected and uninfected host were obtained. Proteomic analysis which included treatment of snail hemolymph to SDS-PAGE, 2D electrophoresis, western blotting and analysis of differentially expressed proteins were carried out. The protein profiles in SDS-PAGE revealed a complex mixture polypetides some of which were being regulated by induction or suppression on specific days during the infection period. In addition the separation of haemolymph proteins by two dimensional gel analyses revealed no distinct spot pattern but most of the proteins were acid with a high molecular weight with very few proteins on the basic end. Finally haemolymph proteins from infected snails and the control (uninfected) snails were not recognized by antibodies raised against S. mansoni antigens namely Soluble Worm Antigen (SWAP) and Soluble Cercariae Antigen (SCA) and therefore could not be used as immunogens for vaccine design. There is need for an integrated approach to schistosomiasis control as the search for new vaccine candidates is ongoing.