Abstract
Despite millions of years of evolution of mammals in symbiosis with their microbiota, our knowledge about the immune system largely derives from highly inbred mice kept under extremely hygienic conditions. In spite of this, the immune system of free-living mice has rarely been studied. We here present the first study of natural killer (NK) cells in wild-caught mice, revealing a significant activation and quicker responsivity of these cells, as compared to C57BL/6 (lab) mice raised under standard Specific Pathogen-Free conditions. Furthermore, we present some preliminary observations of differences in the architecture of the intestinal immune tissues.
NK cells have been regarded as typical innate immune cells, acting as "foot soldiers" to eliminate cancer and infected cells. However, much of this understanding is built on mice models, and recent hypotheses have launched a more central regulating role for these cells. Our findings cohere with recent reports that NK cells need to be primed by microbial stimuli in order to reach full maturity, whereupon they enter lymph nodes and regulate adaptive immune responses.
Thus, studies in wild rodents suggest that immunological properties may be significantly altered in lab mouse models removed from their natural environmental conditions, with the ensuing risk of misleading or undiscovered results in studies like vaccine or drug discovery. At this seminar, we also wish to propose a model which may distinguish whether the observed differences are rooted in environmental vs. genetic factors.
Preben Boysen, Anne K. Storset
Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, Oslo
References
BOYSEN, P., EIDE, D. M. and STORSET, A. K. (2011), Natural killer cells in free-living Mus musculus have a primed phenotype. Molecular Ecology, 20: 5103–5110. doi: 10.1111/j.1365-294X.2011.05269.x
RILEY, E. M. and VINEY, M. E. (2011), Wild mice provide insights into natural killer cell maturation and memory. Molecular Ecology, 20: 4827–4829. doi: 10.1111/j.1365-294X.2011.05315.x