Immunodominance of LipL3293–272 peptides revealed by leptospirosis sera and therapeutic monoclonal antibodies

Abstract

Background/Purpose: Leptospirosis is a neglected zoonosis, imposing significant human and veterinary public health burdens. In this study, recombinant LipL3293–147 and LipL32148–184 middle domain of LipL3293–184, and LipL32171–214, and LipL32215–272 of c-terminal LipL32171–272 truncations were defined for immunodominance of the molecule during Leptospira infections revealed by leptospirosis sera. Results: IgM-dominant was directed to highly surface accessible LipL32148–184 and Lipl32171–214. IgG dominance of LipL32148–184 revealed by rabbit anti-Leptospira sera and convalescent leptospirosis paired sera were mapped to highly accessible surface of middle LipL32148–184 truncation whereas two LipL32148–184 and LipL32215–272 truncations were IgG-dominant when revealed by single leptospirosis sera. The IgM-dominant of LipL32148–214 and IgG-dominant LipL32148–184 peptides have highly conserved amino acids of 70% identity among pathogenic and intermediate Leptospira species and were mapped to the highly surface accessible area of LipL32 molecule that mediated interaction of host components. IgG dominance of two therapeutic epitopes located at LipL32243–253 and LipL32122–130 of mAbLPF1 and mAbLPF2, respectively has been shown less IgG-dominant (<30%), located outside IgG-dominant regions characterized by leptospirosis paired sera. Conclusion: The IgM- and IgG-dominant LipL32 could be further perspectives for immunodominant LipL32-based serodiagnosis and LipL32 epitope-based vaccine. Keywords: Leptospira spp., LipL32, IgM-dominant LipL32 peptide, IgG-dominant LipL32 peptide, Therapeutic LipL32 epitopes