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Jefferson Adams posted an article in Diabetes and Celiac DiseaseCeliac.com 10/29/2018 - Researchers Emma L. Smith with UCB Pharma Ltd., Slough, United Kingdom, and Mark Peakman from the Department of Immunobiology, King’s College London, London, United Kingdom recently set out to catalog clinical advances in peptide immunotherapy for Type 1 diabetes. Autoimmune and allergic diseases occur when a person’s body has an incorrect immune response to an antigen from the person’s own body, or to an innocuous antigen from outside the body. This triggers a pathogenic T-cell response which causes damage to certain tissues and organs. In Type 1 diabetes, this process results in the destruction of the insulin-secreting β cells, which leads to permanent need for recombinant insulin to make up for the loss. The best way to restore immune homeostasis and prevent further tissue damage is to reduce or cease the pathogenic T-cell response by using antigen-specific peptide immunotherapy. Smith and Peakman found that recent clinical advances with peptide therapy approaches in both Type 1 diabetes and other diseases are beginning to show encouraging results. New treatments that target peptides specific to certain cell types are also moving from the development stages into clinical use. Drug developers still face numerous hurdles in reaching full clinical use, including determining optimal dose and dosing frequency, but peptide immunotherapy for Type 1 diabetes is clearly becoming a very active field of drug development. Read their full report: Front Immunol. 2018; 9: 392.Published online 2018 Feb 28. doi: 10.3389/fimmu.2018.00392PMCID: PMC5836708PMID: 29541078
Celiac.com 12/05/2012 - Regulatory T cells (Tregs) are play a pivotal role in helping our bodies tolerate self-antigens and dietary proteins. Interleukin (IL)-15 is a cytokine that is overly present in the intestines of patients with celiac disease. Studies have shown that Interleukin (IL)-15 does not interfere with the generation of functional Tregs, but causes human T cells to resist Treg suppression. To better understand how control of effector T cells by regulatory T cells is inhibited, a team of researchers compared Treg numbers and responses of intestinal and peripheral T lymphocytes to suppression by Tregs in celiac disease patients and in a control group. The research team included N.B. Hmida, M. Ben Ahmed, A. Moussa, M.B. Rejeb, Y. Said, N. Kourda, B. Meresse, M. Abdeladhim, H. Louzir, and N. Cerf-Bensussan. They are affiliated with the Department of Clinical Immunology and the Institut Pasteur de Tunis in Tunis, Tunisia. For their study, the team isolated intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs) from duodenal biopsy specimens of patients with celiac disease and in a control group. The team then purified CD4+CD25+ T lymphocytes (Tregs) from blood. By analyzing anti-CD3-induced proliferation and interferon (IFN)-γ production in the presence or absence of peripheral Tregs, they were able to test responses of IELs, of LPLs, and peripheral lymphocytes (PBLs) to suppression by Tregs. The team used flow cytometry to measure lamina propria and peripheral CD4+CD25+FOXP3+ T cells. They found that, although patients with active celiac disease showed significantly increased percentages of CD4+CD25+FOXP3+ LPLs, they also showed less inhibited proliferation and IFN-γ production of intestinal T lymphocytes by autologous or heterologous Tregs (P < 0.01). IEL for subjects with celiac disease showed no response to Tregs. Also, the team noted resistance of LPLs and PBLs to Treg suppression in patients with villous atrophy who had substantially higher blood levels of IL-15 compared with patients without villous atrophy and controls. From their results, the research team concludes that effector T lymphocytes in people with active celiac disease become resistant to suppression by Tregs. This resistance may result in loss of tolerance to gluten, and to self-antigens. Source: Am J Gastroenterol. 2012 Apr;107(4):604-11. doi: 10.1038/ajg.2011.397. Epub 2011 Nov 22.
Celiac.com 09/15/2009 - Active delivery of recombinant autoantigens or allergens to intestinal mucosa by genetically modified Lactococcus lactis (LL) offers a unique therapeutic approach for the induction of tolerance to gluten proteins. A team of researchers recently set out to determine whether oral administration of LL-delivered DQ8-specific gliadin epitope induces Ag-specific tolerance. The research team was made up of Inge L. Huibregtse, Eric V. Marietta, Shadi Rashtak, Frits Koning, Pieter Rottiers, Chella S. David; Sander J. H. van Deventer, and Joseph A. Murray under the auspices of the Center for Experimental and Molecular Medicine of the Academic Medical Center of the University of Amsterdam in the Netherlands. Celiac disease is associated with either HLA-DQ2- or HLA-DQ8-restricted responses to specific antigenic epitopes of gliadin, and may be treated by induction of Ag-specific tolerance. The research team engineered LL to secrete a deamidated DQ8 gliadin epitope (LL-eDQ8d) and then observed the induction of Ag-specific tolerance in NOD AB degrees DQ8 transgenic mice. The team measured tolerance by delayed-type hypersensitivity reaction, cytokine measurements, eDQ8d-specific proliferation, and regulatory T cell analysis. Oral administration of LL-eDQ8d induced suppression of local and systemic DQ8-restricted T cell responses in NOD AB degrees DQ8 transgenic mice. Result was an Ag-specific decrease of the proliferative capacity of inguinal lymph node (ILN) cells and lamina propria cells. Production of IL-10 and TGF-beta and a significant induction of Foxp3(+) regulatory T cells were associated with the eDQ8d-specific suppression induced by LL-eDQ8d. These results support the development of orally administered Ag-secreting LL to treat gluten-sensitive disorders. Such treatments may be effective even in cases of established hypersensitivity. Journal of immunology (Baltimore, Md. : 1950) 2009;183(4):2390-6