Identifying New T-Cell Epitopes for Babesia bovis: A Pump Priming Grant Success Story

Research supported by the International Veterinary Vaccinology Network (IVVN) Pump Priming Grant has led to promising advances in the search for a new generation of vaccines against Babesia bovis, a parasite responsible for significant economic losses in cattle production worldwide.

The project, led by Dr Silvina Elizabeth Wilkowsky of the Institute of Agricultural Biotechnology and Molecular Biology (Argentina), brought together a collaborative team of researchers from Argentina and the United Kingdom. The team included Dr Nicola Ternette (University of Oxford), Magali Valenzano (National Agricultural Technology Institute, Argentina), and Professor Morten Nielsen (University of San Martín, Argentina).

Their findings were recently published in the journal Vaccine, in a paper titled: “Identification of T-cell epitopes of the intracellular parasite Babesia bovis by immunopeptidomic analysis of BoLA-II presented peptides.”

Tackling a Complex Parasite with New Tools

Babesia bovis is an intracellular parasite transmitted by ticks, affecting cattle in tropical and subtropical regions. While live attenuated vaccines are currently used to prevent severe disease, these vaccines have several limitations - including the risk of reversion to virulence, restrictions on use in adult cattle, and cold chain dependency.

The goal of this project was to identify novel T-cell epitopes that could be used to inform the development of recombinant subunit vaccines - a safer and more stable alternative to live vaccines.

A Novel Approach Using Immunopeptidomics

Using liquid chromatography–mass spectrometry (LC-MS), the researchers analysed the peptides presented by bovine leukocyte antigen (BoLA) class II molecules in primary bovine macrophages that had been exposed to Babesia bovis-infected erythrocytes. This model aimed to closely mimic the natural antigen presentation process that occurs following infection.

Through this immunopeptidomic approach, the team successfully identified 28 previously uncharacterised BoLA-II presented peptides from B. bovis. One of these peptides - derived from glyceraldehyde-3-phosphate dehydrogenase - was validated in vitro and shown to elicit interferon-gamma (IFN-γ) responses from CD4+ T cells in infected cattle.

Implications for Future Vaccine Design

This study marks the first characterisation of the Babesia bovis BoLA-II immunopeptidome, offering valuable insights into the parasite’s interaction with the host immune system. The identified T-cell epitopes represent promising candidates for future recombinant vaccine development, and the peptide dataset generated could also help refine bioinformatic tools used for predicting antigens in other intracellular pathogens affecting livestock.

About the IVVN Pump Priming Grant

This research was made possible through IVVN Pump Priming Grant funding, awarded to Dr Wilkowsky and the team as part of the 2020 round. The funding is designed to enable IVVN members to accelerate their vaccine research, with the aim of advancing vaccine development for livestock and zoonotic diseases in low- and middle-income countries (LMICs).

We have so far funded 17 exciting projects through our pump-priming catalyst funding scheme - you can explore them here.