Abstract
The zoonotic parasite Ascaris is estimated to infect over 700 million people worldwide while concomitantly remaining one of the most common helminth infections in pigs. The use of anthelmintic drugs remains the most frequent control method in both human and pigs. There has been an increased interest regarding alternative control methods due to the possibility of the development of resistance to anthelmintic drugs.
This study used a reverse vaccinology approach to identify potential vaccination targets against ascariasis present in Ascaris proteomes. Due to the zoonotic nature of the parasite, this was done using both A. lumbricoides and A. suum proteomes. Four proteins, a cadherin, a Piezo channel, and two calcium channels (T-type and L-type), were identified as putative vaccination targets and predicted to bind to both B-cells and T-cells.
A multi-epitope vaccine polypeptide was designed using an in silico methodology. This polypeptide was designed with epitopes from the four proteins identified through the reverse vaccinology approach alongside epitopes from the established targets As14, As16 and As37. Immune simulations predicted a beneficial immune response with the potential to control Ascaris infections.
Based on whole-genome sequence data, the vaccine targets integrated in the multi-epitope vaccine had a low variation rate in Ascaris samples from the Philippines. Nevertheless, some targets had mutations that require further research due to potential protein truncation, making them unviable as vaccine targets in this population. Furthermore, mitochondrial genome phylogenetic analysis highlighted the similarities between Ascaris strains from humans and pigs from geographically distinct parts of the world.
The research presented in this work has identified additional potential Ascaris antigens for vaccine development and highlights the benefits of incorporating these antigen epitopes into a single polypeptide to enhance vaccine efficacy. This will open further research venues and reinforces reverse vaccinology as a useful tool for vaccine development in Ascaris.