Social association predicts immunological similarity in rewilded mice

Abstract

Environmental influences on immune phenotypes are well-documented, but our understanding of which elements of the environment affect immune systems, and how, remains vague. Behaviors, including socializing with others, are central to an individual's interaction with its environment. We tracked behavior of rewilded laboratory mice of three inbred strains in outdoor enclosures and examined contributions of behavior, including social associations, to immune phenotypes. We found that the more associated two individuals were, the more similar their immune phenotypes were. Social association was particularly predictive of similar memory T and B cell profiles and was more influential than sibling relationships or worm infection status. These results highlight the importance of social networks for immune phenotype and reveal important immunological correlates of social life.

Genetic and Environmental interactions contribute to immune variation in rewilded mice

“…While we previously proposed that the immune cell composition for an individual is shaped by the environment (20), we find here that immune composition in the peripheral blood is shaped by interactions between genetics and the environment and those in the mesenteric lymph node is shaped by interactions between genetics, environment and ongoing infection. We further find that phenotypic variation is influenced by social associations among pairs of rewilded mice (22). This complexity has important ramifications for the course of natural selection on the immune system and diversity in immune genotypes.…”

“…We have taken a decidedly different approach of using an outdoor enclosure system to introduce laboratory mice of different genotypes into a natural environment that we term "rewilding" (21). We track behavior outdoors (22), recover the mice for analysis, and then investigate genetic and environmental contributions to immune phenotypes (20,21,23). For example, using mice with mutant alleles in inflammatory bowel disease susceptibility genes (Nod2 and Atg16l1), we found that the genetic mutations affected the production of cytokines in response to microbial stimulation, whereas immune cell composition was more influenced by environment (20,23).…”