An efficacious tuberculosis (TB) vaccine is required for both veterinary and human use. Traditional approaches to vaccine development have failed to identify better vaccines to replace or supplement BCG for the control of TB. Subunit vaccines offer a safer and more reproducible alternative for the prevention of disease.
In this study, the immunogenicity of bacterially derived polyester beads displaying three different Rv antigens of Mycobacterium tuberculosis was evaluated. Polyester beads displaying the antigens Rv1626, Rv2032, Rv1789 were produced in an endotoxin-free Escherichia coli strain, Clearcoli®. Beads were purified, formulated with adjuvant dimethyldioctadecylammonium bromide (DDA) and used to vaccinate C57BL/6 mice 3 times at 2 weekly intervals. Immunological responses were measured 3 weeks after the final vaccination.
Results showed that mice vaccinated with beads displaying Rv1626 had significantly greater IgG1 responses compared to all the other vaccinated groups (p<0.05). Immunoblotting of antisera from these mice indicated the antibody responses were Rv1626 antigen-specific and there was no detectable immune response to the polyester component of the vaccine.
Overall, this study suggested that selected TB antigens derived from reverse vaccinology approaches can be displayed on polyester beads to produce antigen-specific immune responses potentially relevant to the prevention of TB in both animals and humans.