Immunogenicity Response of Mus musculus var. Balb/C after Immunization using Flagellin Salmonella typhi Serovar Semarang.

<b>Background and

Objective

</b> The flagellin of <i>Salmonella typhi</i> is potentially developed as an identifying antigen in a rapid diagnostic test instrument that may be more accurate than conventional serological tests. Therefore, this study aims to analyze the immunogenicity of flagellin <i>S. typhi</i> as the basis for developing a typhoid fever diagnostic. <b>Materials and

Methods

</b> Flagellin was isolated from the bacterial culture of <i>S. typhi</i> serovar Semarang and used as the primary antigen for vaccine assembly. Native flagellin antigen was immunized in Balb/C mice with injection doses of 2, 3, 4, 5 and 6 g/100 L in each group (K0-K5), respectively, via intraperitoneal cavity. Blood serum was collected to ELISA based-measurement for IL-6 and TNF-a titers. Then, specific immunoglobulin (Ig) of anti-flagellin was detected using in-house ELISA and western blotting. <b>

Results

</b> The findings in this study showed that immunization at the dose of 4-5 g/100 L significantly decreased the IL-6 titer, i.e., 8.33±0.87 pg mL<sup>1</sup>, compared to control. The antibody titer test analysis showed the highest Ig-G anti-flagellin was found in K4 mice after immunization using a dose of 5 g/100 L with an average absorbance of Ig-G reaching 1.19 ±0.32. <b>

Conclusion

</b> The results indicated that the flagellin protein of <i>S. typhi</i> serovar Semarang induces adaptive immune responses and produces specific antibodies against flagellin. The immunogenic properties of the flagellin protein of <i>S. typhi</i> serovar Semarang potentially developed as a specific diagnostic marker. Further research may also focus on a beneficial feature of flagellin as a vaccine candidate.