A key peptide that can be used to develop a new preventive vaccine against leptospirosis has been successfully identified by researchers from the Gujarat Biotechnology Research Centre, Gandhinagar.
Leptospirosis is an emerging tropical infectious disease, and currently, there is no preventive vaccine for humans that is available in the market. The researchers used computer-based analysis to study the whole protein set of the bacteria Leptospira interrogans and narrowed the search down to one effective immunogenic protein. This protein was found to be present in almost all the serovars (different types within a species) of the bacteria and can be an effective vaccine candidate against most serovars.
According to a paper published in 2015, leptospirosis causes almost 60,000 deaths every year, globally. The bacteria can be transmitted via exposure to contaminated water or soil or direct contact with reservoirs hosts like wild or domestic animals.
Among these proteins, the researchers further searched to identify the outer membrane proteins as these are known to play important roles in the interaction between the bacteria and their host. Further computational modeling and simulation helped the researchers narrow it to one specific protein. The protein was chosen as the candidate immunogen once the physicochemical and structural studies were carried out.
The researchers then looked for sites on human T cells and B cells where the antigen could bind. Identification of target sites is a key step in vaccine design.