The Immune System Of Lagomorphs

The order Lagomorpha is composed of two families. Ochotonidae consist of a single genus Ochotona (Pikas) and Leporidae include 11 genera. Studies of Leporidae have made and continue to make major contributions to knowledge of immunobiology and evolution. Comparisons between immune systems of several mammals revealed that the European rabbit (Oryctolagus cuniculus) has unique features including a single IgG, 13 IgA, and a duplication of the IGK locus. The importance of gut microflora and gut-associated lymphoid tissues for the primary antibody diversification process was recognized in rabbit before current popular recognition of the importance of the gut microbiome. Comparisons of adaptive immune system genes in leporids showed that they are evolving under positive selection and that the divergences of both IGHV and MHC DQA alleles preceded the split of Leporid genera. Myxomatosis and rabbit hemorrhagic viral diseases that are nonpathogenic for other leporids affect the European rabbit. We discuss evolutionary and genetic aspects of important host candidate genes of the innate immune system that might explain the virus susceptibility versus resistance and highlight the roles of the European rabbit as an important model for autoimmune and infectious diseases and for the development and testing of therapeutics and preclinical investigations.