Objectives: Typhoid fever is caused by Salmonella enterica serovar Typhi. OmpC, OmpF and OmpA, the
three major outer membrane proteins (OMPs), could serve as vaccine candidates.
Methods: The porins antigenicity was predicted in silico. The OMP genes were amplified, cloned and
expressed. Sero-reactivities of the recombinant proteins purified by denaturing method were assayed by
ELISA. BALB/c mice were immunized with the recombinant porins followed by bacterial challenge.
Results: Bacterial challenge of the animal model brought about antibody triggering efficacy of the antigen
in OmpF > OmpC > OmpA order. Experimental findings validated the in silico results. None of the antigens
had synergic or antagonistic effects on each other from immune system induction points of view.
Despite their high immunogenicity, none of the antigens was protective. However, administration of two
or three antigens simultaneously resulted in retardation of lethal effect. Porins, in addition to their
specific functions, share common functions. Hence, they can compensate for each other’s functions.
Conclusions: The produced antibodies could not eliminate the pathogenicity by blockade of one or some
of the antigens. Porin antigens are not suitable vaccine candidates alone or in denatured forms. Native
forms of the antigens maybe studied for protective immunogenicity.?>