Macpherson, A. J.Martinic, M. M.Harris, N.2010-01-072010-01-072010-01-07200210.1007/s000180200009https://infoscience.epfl.ch/handle/20.500.14299/45118There is an immense load of non-pathogenic commensal bacteria in the distal small intestine and the colon of mammals. The physical barrier that prevents penetration (translocation) of these organisms into the body is a simple epithelium comprised of the single enterocyte/colonocyte cell layer with its overlying mucus. In this review, we discuss the roles of intestinal T cells in initiating and regulating innate and adaptive mucosal immune responses of the mucosal immune system that avoid or limit penetration of the commensal intestinal bacteria.intraepithelial lymphocytelamina propria lymphocyteigacommensal bacteriamacrophageintestinal mucosagerm-free miceintraepithelial lymphocytesbacterial translocationmicrobial colonizationinterferon-gammaimmune-responselamina propriadeficient miceiga responsescholera-toxintext::journal::journal article::review article