Key drivers of the immune response of wild animals
Scientists identified the most important factors in allowing an animal to withstand infection and disease.
Researchers are investigating what factors affect the immune system of wild animals so they can understand how infection and disease affects the animals.
By looking at the biology of the germs or pathogens that infect animals, scientists can understand how germs are passed from one species to another, including to humans.
Many factors, individually, have been shown to constrain or to promote immune responses. These factors include age, sex, infection status, and body condition. However, the extent to which these different factors actually affect how animals recognise and defend themselves against bacteria, viruses and other infections is relatively unknown.
In the new study led by the University of Bristol’s School of Biological Science, in collaboration with The Roslin Institute and the London School of Hygiene and Tropical Medicine, the team investigated the immune ecology of wild house mice – the same species as the laboratory mouse – as an example of a wild mammal, characterising their adaptive humoral, adaptive cellular and innate immune state.
They first found that neighbouring populations of wild mice – on different farms, for example – were often in a very different immune state. This was the first time that this has been seen.
Secondly, they identified the main factors that underlie the immunological differences among individual mice, showing that mice with good body condition had enhanced immune responses. In general, older mice had a poorer immune state but older animals also had better body condition, allowing them to partially resist the effects of their older age on their immune systems.
By applying a multifactorial analysis to an immune system-wide analysis, our results bring a new and unified understanding of the immunobiology of a wild mammal.
Understanding which of many key drivers of the immune response are actually most important in allowing an individual animal to withstand infection is crucial to understanding how infections move among and between populations, how epidemics spread or can be contained, and how infections can jump species barriers to cause disease in new host populations.
The research is published in the journal PLoS Biology.