Immunology of the gut and oral tolerance
نویسنده
چکیده
The gastrointestinal tract has developed a unique immunological system because of its close proximity to the intestinal contents. The system has evolved in such a way that it does not respond to the presence of beneficial microbes, but retains the ability to react quickly to the presence of harmful organisms. The challenge faced by the mucosal immune system is to generate an immune response of appropriate magnitude to control the microbial invasion while maintaining the integrity of the epithelial barrier. An imbalanced or improper immune response can result in a variety of inflammatory disorders of the gut.
منابع مشابه
Oral tolerance for delayed type hypersensitivity contribution of local and peripheral mechanisms
Oral tolerance is a physiological immune mechanism, which controls the outcome of deleterious hypersensitivity reactions to environmental antigens absorbed through the gastrointestinal tract, and maintains homeostasis. Using a mouse model of oral tolerance of delayed type hypersensitivity to contact allergens, i.e. haptens, we have examined the mechanisms involved in the induction of oral toler...
متن کاملLack of local suppression in orally tolerant CD8-deficient mice reveals a critical regulatory role of CD8+ T cells in the normal gut mucosa.
We found that feeding keyhole limpet hemocyanin (KLH) to CD8-deficient (CD8-/-) mice induced oral tolerance that was comparable in both magnitude and quality to that induced in wild-type (wt) mice. The tolerance was dose dependent, and only higher doses of KLH caused significant reduction in specific Ab and T cell responses. Both Th1 and Th2 CD4+ T cell functions were affected. Feeding KLH toge...
متن کاملT-cell Tolerance Following Bacterial Glutamic Acid Decarboxylase (GAD) Feeding in Streptozotocin-induced Diabetes
Background: Autoimmune type 1 diabetes mellitus is caused by T-cell mediated immune destruction of the insulin-producing β-cell in pancreatic islets of Langerhans. Specificity of the auto-antibodies and of the auto-reactive T-cells has been investigated, in which several auto-antigens were proposed. Objective: To determine whether glutamic acid decarboxylase (GAD) feeding would induce oral tol...
متن کاملThe role of dendritic cells, B cells, and M cells in gut-oriented immune responses.
Although induction of T cell responses to fed Ag (oral tolerance) is thought to happen within the organized lymphoid tissue of the gut, we found that mice lacking Peyer's patches, B cells, and the specialized Ag-handling M cells had no defect in the induction of T cell responses to fed Ag, whether assayed in vitro by T cell proliferation or cytokine production, or in vivo by delayed-type hypers...
متن کاملIn situ immune response in gut-associated lymphoid tissue (GALT) following oral antigen in TCR-transgenic mice.
Oral administration of Ag results in systemic hyporesponsiveness termed oral tolerance. The regulatory cells induced by oral Ag are effective in the suppression of Th1-type autoimmune diseases. We examined the cytokine microenvironment in gut-associated lymphoid tissue in response to orally administered OVA in OVA TCR-transgenic mice. Mice were fed a low (0.5 mg) or high (500 mg) dose of OVA on...
متن کاملTeleost intestinal immunology.
Teleosts clearly have a more diffuse gut associated lymphoid system, which is morphological and functional clearly different from the mammalian GALT. All immune cells necessary for a local immune response are abundantly present in the gut mucosa of the species studied and local immune responses can be monitored after intestinal immunization. Fish do not produce IgA, but a special mucosal IgM is...
متن کامل