Immunoprotection studies using Leptospiral recombinant proteins from L. interrogans Icterohaemorrhagiae in hamster models : A synergistic approach

Major immune-dominant proteins of Leptospira interrogans Icterohaemorrhagiae were cloned, expressed in prokaryotic system was purified and confirmed by western blot. The protective efficacy of purified recombinant proteins was assayed synergistically with adjuvant in hamster models. Three combination were assessed for homologous protection (i.e, rLipL41, rOmpL1, rHapI and rSphH; rLipL41, rOmpL1, rLigA and rLigB; rLigA, rLigB, rHapI and rSphH) each protein at 25 μg and 37.5 μg concentration. Among the combinations tested combination of immunoglobulin’s (rLigA and rLigB) with hemolysins (rHapI and rSphH) conferred 100% protection in both the concentration tested that is evident through the elevated elicited antibody levels. The combination of outer membrane proteins and the immunoglobulin’s stands next which is comparable with the former combination. The blend of recombinant outer membrane proteins and hemolysins did effect protection which is lesser than the coalescence of immunoglobulin’s and hemolysins. Membrane fractions of E. coli harboring pET15b used as internal control showed neither homologous protection nor enhanced antibody levels used to compare the experimental proteins over hamster models. Placebo controls receiving PBS showed similar results as that of internal controls.