In future, the ability of other groups to perform assays developed in other laboratories needs to be addressed; an assay is of little value if it cannot be performed by scientists worldwide. Combinations of the different approaches described here also deserve testing. For example, it may be that stimulating cells with nitrocellulose-bound islet antigens followed by tetramer analysis of the responding population, detected by CFSE dilution, will be more informative than any of these assays alone. The ability to measure mRNA transcripts readily from antigen-stimulated PBMCs adds another weapon to the arsenal. Molecular approaches are well suited to broad screening of many transcripts, potentially giving

a detailed picture of how cells are responding to islet and control antigens. Again, these approaches may be combined with current assays such as ELISPOT to confirm JQ1 datasheet that induction of a transcript correlates with protein secretion. Currently, none of the methods can measure directly the activation and function of islet-antigen specific regulatory T cells. ELISPOT

assays for IL-10 have been used successfully to detect IL-10 secretion following in vitro stimulation with islet antigen-derived BIBW2992 peptides [28,58]. While IL-10 is clearly secreted by some human regulatory T cells [59,60], it is not the only cytokine or cellular pathway used by regulatory T cells [61]. Hence, a more direct measure of regulatory T cell function would be a useful tool. T cell responses measured by an in vitro assay are the outcome of complex interactions between antigen-presenting

cells, effector and regulatory T cell subsets, antigen and components of the innate immune system. Many of these components are yet to be delineated clearly, but measuring the outcome of these interactions will help to dissect the contributing events. Despite the challenges inherent in the detection and analysis of human islet autoantigen-specific T cells, several methods have been developed. The assays on this ‘short-list’ Gefitinib clinical trial are currently being tested and optimized and will aid greatly in the development of immune therapies for T1D and other immune-based diseases. The T-cell Workshop Committee of the Immunology of Diabetes Society (IDS) is generously supported by the Juvenile Diabetes Research Foundation (JDRF grant no. 5-2009-413). We thank members of the IDS Council for critical reading of the manuscript. The authors have no conflicts of interest to declare. Members of the T-Cell Workshop Committee of the Immunology of Diabetes Society: Barbara M. Brooks-Worrell, Veterans Affairs Puget Sound Health Care System, University of Washington, Seattle, WA, USA; Corrado M. Cilio, Lund University, Department. of Clinical Sciences, Cellular Autoimmunity Unit, Malmö, Sweden; Ivana Durinovic-Bellò, Benaroya Research Institute, Seattle, WA, USA; Peter A.