Outer membrane protein LipL21 as a potential candidate against Leptospira interrogans: An in silico prediction.

abstractLeptospirosis is one of the most widespread zoonotic diseases caused by Leptospira interrogans, characterized by mild febrile illness to severe multiorgan failure. The conventional vaccines against Leptospira have several drawbacks, including short-term immunity and serovar-based protection. The current study focuses on determining the most effective outer membrane protein (OMP) as a potential antigen using various computational approaches in providing protection against leptospirosis, as they are conserved within pathogenic serovars. Out of OmpL1, LipL21, LipL32, and LipL41, the VaxiJen analysis revealed LipL21 to be the most antigenic with a score of 0.7848. The antigenic epitopes of LipL21 were further analyzed using BCPred and MHCPred. It is conserved among all the pathogenic serovars while being absent in nonpathogenic. LipL21 had both B-cell and T-cell epitopes, suggesting that it is immunogenic. The VaxiJen score, localization of protein, Clustal Omega, and confirmational analysis of B-cell epitopes were studied for defining a better immunogenic and conserved OMP. This study holds importance as the surface proteins are a potential vaccine candidate for the development of new and effective vaccines in the prevention of leptospirosis hold. An ideal protein, which has its entire conserved immunogenic domain, would confer cross-protection against heterologous serovars. Thus, using bioinformatic approaches, we for the first time predict that LipL21 is a promising, effective vaccine candidate in providing protection against Leptospira.