MAIT cells play a role in protecting cattle against bacterial infections

In a collaborative study, researchers at the Roslin Institute, The Pirbright Institute, the Universities of Oxford, Ultrech and Queensland, the University of Melbourne’s Doherty Institute, and the Animal and Plant Health Agency have identified new immune cells in cattle, called mucosal-associated invariant T (MAIT) cells.

Human MAIT cells have been shown to tackle bacterial and viral infections, as well as playing a role in wound healing and vaccine response. This is the first time that they have been characterised in cattle.

Human MAIT cells are activated by various environmental signals which can trigger them to either promote antimicrobial activity or tissue repair. They are known to be involved in the immune response against various bacteria and viruses like influenza, HIV and hepatitis C, where they activate other immune cells which then kill infected cells.

In their study, published in Frontiers in Immunology, scientists demonstrated that cattle MAIT cells were extremely similar to human MAIT cells. They were mainly located in mucosal tissues as well as in the lymph nodes. The team also showed that cattle MAIT cells can be activated by bacteria in vitro and that MAIT cells respond in the context of mastitis and Mycobacterium bovis infection in cattle, suggestive of a role for MAIT cells in these diseases.

Dr Elma Tchilian, Head of the Mucosal Immunology group at Pirbright, said: “The highly conserved nature of MAIT cells demonstrated in this study suggests that they may well have an important function in protection against infection. This work was made possible because of truly international collaboration.”

The work was funded by the Biotechnology and Biological Sciences Research Council, part of UK Research and Innovation, the Department for Environment, Food and Rural Affairs, and the Australian Research Council.

Article: Edmans, M. D., Connelley, T. K., Jayaraman, S., Vrettou, C., Vordermeier, M., Mak, J., Liu, L., Fairlie, D. P., Maze, E. A., Chrun, T., Klenerman, P., Eckle, S., Tchilian, E., Benedictus, L. (2021). Identification and Phenotype of MAIT Cells in Cattle and Their Response to Bacterial Infections. Frontiers in Immunology, 12:627173, doi: 10.3389/fimmu.2021.627173

[SOURCE: Pirbright Institute/Roslin Institute]