Immune Responses of Mice Immunized with Active Recombinant Shiga Toxin and Its Derivatives

Bacterial protein toxins have been exploited as therapeutic agents and as vaccines. an issueof deserving interest is development of new generations of vaccines and immune adjuvants.in this study an active assembled recombinant shiga toxin of escherichia coli (rstxl) and itsderivatives, recombinant a and b subunits (stxl-a and stxl-b), were used to immunizemice. the elicited antibody responses were compared with and without using adjuvant.protection against intraperitoneal lethal dose of rstx challenge was observed byimmunization with sublethal dose of rstxl, rstx-a and rstx-b subunits.the immunological studies on toxin subunits can be used for immunization againstsystemic shiga toxin mediated disease and also subunits as a vector for antigen presentation inimmunotherapeutic approaches. in our experiment, while stimulation of the immune system bya and b subunits were different, both subunits produced neutralizing antibodies. regarding bsubunit the amount of specific igg i/igg2a antibody ratio was higher than a subunit.in addition b subunit stimulated proliferation of immune cells with ifny production thesame as rstxl, suggesting that b subunit can be used as an immunomodulator to stimulatethe immune response in conjunction with other recombinant proteins