Control of schistosomiasis pathology by combination of Sm28GST DNA immunization and praziquantel treatment

Today the control of schistosomiasis infection relies only on the use of pr aziquantel (PZQ) chemotherapy. However, PZQ treatment cannot prevent reinfe ction and progressive development of the pathology, We assessed in a mouse model the efficiency of a combined therapy, based on the combination of PZQ chemotherapy with Schistosoma mansoni 28-kDa glutathion S-transferase (Sm2 8GST) DNA vaccination, designed to limit the pathology. Following this comb ined therapy, the long-term survival of the mice was significantly enhanced in comparison with the survival of mice either vaccinated only or treated with PZQ only. In addition, the development of the pathology observed in th e control groups was almost completely prevented in the vaccinated-PZQ-trea ted mice and was associated with a dramatic reduction of egg deposition in the tissues. We showed that PZQ treatment induced the unmasking of the nati ve GST enzyme at the surface of the worms, thus permitting its neutralizati on by the antibodies raised by DNA immunization, This study provides insigh ts into the synergistic mechanisms involved in an immunointervention strate gy associated with chemotherapy for the control of a chronic infection and its associated pathology.