Characterisation of tissue transglutaminase-reactive T cells from patients with coeliac disease and healthy controls

• tTG-specific T cells can be detected in patients with CD and healthy controls.
• T cell proliferation in response to tTG was HLA-DR and HLA-DQ-restricted.
• T-cell lines specific for tTG can be generated from both CD and healthy responders.
• tTG-specific T cells are characterised by the production of large amounts of IFN-γ.

Previous studies have shown evidence for T lymphocytes specific for tissue transglutaminase (tTG) in the periphery of coeliac disease (CD) patients. These cells could play a role in disease pathogenesis and may be involved in providing help for the production of anti-tTG autoantibodies. The objective of this study was to further investigate the presence of tTG-specific T cells in patients with treated and untreated CD, and normal controls. Positive proliferative responses to three different commercial tTG antigens were detected in all groups tested, occurring more frequently and at higher levels in untreated CD patients. The addition of antibodies to HLA-DQ and HLA-DR caused a significant reduction in the proliferative response to tTG. T cell lines specific for tTG and composed predominantly of CD4-positive T cells were generated from responsive CD and control individuals, and were found to produce large amounts of interferon-γ, as well as interleukins 10, 17A, and 21.