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

ABSTRACT

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