Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON L8N 3Z5, Canada; McMaster Immunology Research Centre, McMaster University, Hamilton, ON L8N 3Z5, Canada; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON L8N 3Z5, Canada. Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON L8N 3Z5, Canada; Department of Biochemistry & Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada; Department of Medicine, McMaster University, Hamilton, ON L8N 3Z5, Canada; Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON L8N 3Z5, Canada. Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON L8N 3Z5, Canada; McMaster Immunology Research Centre, McMaster University, Hamilton, ON L8N 3Z5, Canada; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON L8N 3Z5, Canada. Electronic address: bowdish@mcmaster.ca.