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Naturally Arising Human CD4 T-Cells That Recognize Islet Autoantigens and Secrete Interleukin-10 Regulate Proinflammatory T-Cell Responses via Linked Suppression

OBJECTIVE: Regulatory T-cells (Tregs) recognizing islet autoantigens are proposed as a key mechanism in the maintenance of self-tolerance and protection from type 1 diabetes. To date, however, detailed information on such cells in humans, and insight into their mechanisms of action, has been lacking...

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Detalles Bibliográficos
Autores principales: Tree, Timothy I.M., Lawson, Jennifer, Edwards, Hannah, Skowera, Ania, Arif, Sefina, Roep, Bart O., Peakman, Mark
Formato: Texto
Lenguaje:English
Publicado: American Diabetes Association 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2874706/
https://www.ncbi.nlm.nih.gov/pubmed/20299476
http://dx.doi.org/10.2337/db09-0503
Descripción
Sumario:OBJECTIVE: Regulatory T-cells (Tregs) recognizing islet autoantigens are proposed as a key mechanism in the maintenance of self-tolerance and protection from type 1 diabetes. To date, however, detailed information on such cells in humans, and insight into their mechanisms of action, has been lacking. We previously reported that a subset of CD4 T-cells secreting high levels of the immunosuppressive cytokine interleukin-10 (IL-10) is significantly associated with late onset of type 1 diabetes and is constitutively present in a majority of nondiabetic individuals. Here, we test the hypothesis that these T-cells represent a naturally generated population of Tregs capable of suppressing proinflammatory T-cell responses. RESEARCH DESIGN AND METHODS: We isolated and cloned islet-specific IL-10–secreting CD4(+) T-cells from nondiabetic individuals after brief ex vivo exposure to islet autoantigens using cytokine capture technology and examined their phenotype and regulatory potential. RESULTS: Islet-specific IL-10(+) CD4 T-cells are potent suppressors of Th1 effector cells, operating through a linked suppression mechanism in which there is an absolute requirement for the cognate antigen of both the regulatory and effector T-cells to be presented by the same antigen-presenting cell (APC). The regulatory T-cells secrete perforin and granzymes, and suppression is associated with the specific killing of APCs presenting antigen to effector T-cells. CONCLUSIONS: This hitherto undescribed population of islet autoantigen–specific Tregs displays unique characteristics that offer exquisite specificity and control over the potential for pathological autoreactivity and may provide a suitable target with which to strengthen β-cell–specific tolerance.