Abstract.
There 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.
Keywords: Key words. Intraepithelial lymphocyte; lamina propria lymphocyte; IgA; commensal bacteria: macrophage: intestinal mucosa.
Footnotes
Received 9 August 2002; accepted 9 September 2002
RID="*"
ID="*"Corresponding author.