Application of adult worm and lung-stage antigens to immunize against schistosoma mansoni using cytokines as adjuvants

Different Schistosoma mansoni antigens; adult worm antigen [SWAP] and lung-stage antigen [SLAP] together with different cytokine adjuvants [Interferon-gamma and Interleukin-4] were used to immunize mice against. S. mansoni. Immunization program was directed towards the production of an intense immune response together with balanced T-helper1 and T-helper2 immune responses. The goal of immunization was not only to protect from infection but also to modulate the pathology inflicted by the parasite. Parameters like adult load, egg counts, anti-Schistosoma antibody titers and liver pathology were used to evaluate the different immunization scheme. SLAP antigen has proven to be a better antigen not only in protection but also in pathology modulation. SLAP plus IFN-gamma as an adjuvant was the best immunization regimen with almost 50% protection and a remarkable resolving of parasite pathology. Unexpectedly, IL- 4 had a weak but observed adjuvant protective effect. The results is a step in the path for a Schistosoma vaccine that guides the immune system towards a balanced response targeting the pathology induced by the parasite rather than the parasite itself

Heterologous antigens of toxoplasma gondii and salmonella typhimurium as adjuvants in an immunization program against schistosoma mansoni

Different bacterial and parasitic heterologous antigens were evaluated as adjuvants in a cocktail vaccine against Schistosoma mansoni. Killed Salmonella typhimurium and Toxoplasma gondii soluble antigens were used [each or both] combined with S. mansoni adult worm antigen [SWAP] to immunize against S. mansoni in murine models. Adult worm load, egg counts, anti-Schistosoma antibody titers and liver histopathology were used as measured parameters to evaluate the different study groups. Each of the used heterologous antigens has proven to be a beneficial adjuvant effect not only in protection but also in pathology modulation. Killed S. typhimurium was more efficient than T gondii soluble antigens. The most remarkable protective and pathology modulating effect was observed in the study group where both antigens were combined with SWAP in an immunization scheme indicating an additive response. Thus, the results of the current study proves that heterologous bacterial or parasitic antigens could be beneficial adjuvants helping to direct the immune response, to another parasite, towards a direction that confers both protection and pathology modulating effect