Immunological Characterization of Leptospiral Outer Membrane Protein Loa۲۲ in Mice

BACKGROUND AND ABJECTIVELeptospirosis is a worldwide zoonotic disease caused by pathogenic Leptospira, which often occurs in tropical and subtropical regions. Focusing on development of rapid diagnostic methods to facilitate early diagnosis and development of a universal vaccine are the main key issues to overcome the disease burden of leptospirosis.MATERIALS AND METHODSIn the present study, we have studied the immunogenic potential of prepared rLoa۲۲ protein of local pathogenic Leptospira species in a murine model and its ability to induce humoral and cellular immunity was further evaluated by analyzing the IgG subclasses and cytokines produced through immunization.RESULTS AND DISCUSSIONBased on the results, mice immunized with rLoa۲۲/adjuvant and a trivalent vaccine induced high titers of total IgG antibodies. All immunized groups were able to increase IgG۱ subclass at almost the same level, but in the case of IgG۲a subclass, the antibody levels was significantly higher in the vaccine and rLoa۲۲/adjuvant groups than rLoa۲۲ alone.The animals immunized by the vaccine produced more IL-۴ compared to the recombinant groups and also the group that received the rLoa۲۲/adjuvant was higher than rLoa۲۲ alone. The level of IFN-γ showed a slight but significant increase in the rLoa۲۲ with and without adjuvant groups. Our results also demonstrated the rLoa۲۲ protein in indirect ELISA, was able to detect the presence of anti-Leptospira antibodies in mice serum.CONCLUSIONTherefore, the protein can be used either alone or in combination with other leptospiral antigens as a marker in assessing the seroprevalence of leptospirosis and also in development of an effective vaccine against leptospirosis.

کلیدواژه ها:

Pathogenic Leptospirosis ، Recombinant Loa۲۲ Protein ، Immune Responses