Of Creatures Great and Small: The Advantages of Farm Animal Models in Immunology Research

host-pathogen interactions that occur in outbred populations. A fundamental point in the development of new and improved intervention strategies is the understanding of host differences in the innate immune response, which primes the subsequent adaptive immune response. Although the innate immune system has been largely conserved during evolution, marked variations and diversity exist between different mammalian species within PatternRecognition-Receptor (PRR) structure (Jungi et al., 2011). These differences are based on evolutionary pressure within the innate immune system, potentially reflecting the specific threats encountered by each species (Zhang et al., 2010). This selective pressure appears to be absent in the available murine sequences (Werling et al., 2009). The similarity between human and farm animal PRR (Jungi et al., 2011) is further supported by their similar response to ligands (Kapetanovic et al., 2012), in contrast to murine PRR (Hajjar et al., 2002; Grabiec et al., 2004; Farhat et al., 2010). Since recognition by PRR is associated with adaptive immunity by providing optimal immunostimulation, learning more about these key molecules in farm animals might inform us about their adjuvant effect in vaccines for use in these animals as well as humans. Given the size and blood volumes of farm animals, there are also greater opportunities to repeatedly access to different cell types – an asset which would facilitate the assessment of cell specific effects of such immunomodulatory agents on autologous cells (Hein and Griebel, 2003). Farm animal models do have their disadvantages such as dedicated housing, biosecurity, and the confinement of infected animals. However, it is misleading to rely on murine Of creatures great and small: the advantages of farm animal models in immunology research