evaluation and comparison of immunization level between recombinant proteins of binding subunit of entrotoxigenic escherichia coli and botulinum toxin

background and aims: among the bacterial agents, the most common cause of diarrheal disease is entrotoxigenic escherichia coli. letal toxin b (ltb) subunit of lt toxin could induce six-month immunity. clostridium botulinum causes botulism disease. bont/a-hc toxin subunit could induce two years immunity against this disease. it seems that the immunogenicity potency of these two subunits may influence on the memory longevity. the aim of this study is the assessment of ltb and bont/a-hc immunogenicity and investigation of their relations to immunological memory longevity. methods: in this experimental study the transgenic e. coli blde3 with pet28a vector, containing recombinant ltb and bont/a-hc genes separately were used for expression of recombinant proteins. ltb and bont/a-hc expressed as insoluble and soluble forms respectively and their purity were confirmed on sds-page gels. finally, mice immunization were carried out and antibody titration of both recombinant proteins were evaluated and compared using t-test in spss software. results: after immunization the mice, a difference in antibody titer was observed between two proteins i.e. bont/a-hc and ltb (p<0.01). conclusion: there was a significant difference of antibody titration between ltb and bont/a-hc proteins. that can represent a strong adjuvanticity of ltb and almost the same immunogenicity in a limited time.