An efficient mucosal adjuvant is a double-mutant heat-labile toxin of enterotoxigenic Escherichia coli (ETEC). Recent research has demonstrated that dmLT has adjuvanticity for antigens given parenterally. In this work, researchers vaccinated mice subcutaneously (SC) with the ETEC adhesin-based vaccine, CFA/I/II/IV MEFA (multi epitope fusion antigen), adjuvanted with dmLT, and investigated the effect of dmLT on antibody responses specific to the vaccine’s seven adhesins. To test the possible dmLT dosage response relationship, mice were vaccinated with a fixed dose of CFA/I/II/IV MEFA and escalating doses of dmLT adjuvant.
Data indicated that dmLT increased systemic antibody responses to all seven MEFA-targeted antigens (CFA/I, CS1-CS6) in a dose-dependent manner. The adjuvant effect of dmLT on the MEFA construct reached a peak at 0.1 g. The results also showed that dmLT is an efficient parenteral adjuvant when used in conjunction with the ETEC adhesin MEFA vaccination via the SC route, and that antibody augmentation was obtained with very modest dosages. These findings point to the potential use of dmLT for parenteral ETEC vaccine candidates, as well as vaccinations against other infections.
Reference: https://www.tandfonline.com/doi/full/10.1080/21645515.2019.1649555
