. Author manuscript; available in PMC: 2012 Sep 1.
Published in final edited form as: Mucosal Immunol. 2011 Nov 16;5(2):121–128. doi: 10.1038/mi.2011.56
Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:http://www.nature.com/authors/editorial_policies/license.html#terms