Expression of PD-1 Molecule on Regulatory T Lymphocytes in Patients with Insulin-Dependent Diabetes Mellitus

International Journal of Molecular Sciences

Valentina Perri⁴  Benedetta Russo⁴  Antonino Crinò¹  Riccardo Schiaffini¹  Ezio Giorda²  Marco Cappa¹  Maria Manuela Rosado³  Alessandra Fierabracci⁴ 

[1]Division of Endocrinology, Children’s Hospital Bambino Gesù, Piazza S. Onofrio 4, 00165 Rome, Italy

[2] E-Mails:

[3]Research Laboratories, Children’s Hospital Bambino Gesù, Viale S. Paolo 15, 00146 Rome, Italy

[4] E-Mail:

[5]Consultant in Immunology, 00100 Rome, Italy

[6] E-Mail:

[7]Immunology and Pharmacotherapy Area, Children’s Hospital Bambino Gesù, Viale S. Paolo 15, 00146 Rome, Italy

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关键词: type 1 diabetes;    T regulatory cells;    programmed cell death 1-programmed cell death ligand 1;   

DOI  :  10.3390/ijms160922584

来源: mdpi

【 摘 要 】

Type 1 diabetes is caused by autoreactive T cells that destroy pancreatic beta cells. Animal models suggested that a CD4⁺CD25⁺ population has a regulatory function capable of preventing activation and effector functions of autoreactive T cells. However, the role of CD4⁺CD25^high T cells in autoimmunity and their molecular mechanisms remain the subject of investigation. We therefore evaluated T regulatory cell frequencies and their PD-1 expression in the peripheral blood of long-standing diabetics under basal conditions and after CD3/CD28 stimulation. Under basal conditions, the percentages of T regulatory cells were significantly higher while that of T effector cells were significantly lower in patients than in controls. The ratio of regulatory to effector T cells was higher in patients than that in controls, suggesting that T regulatory cells were functional in patients. Percentages of total PD-1⁺, PD-1^low and PD-1^high expressing T regulatory cells did not change in patients and in controls. After stimulation, a defect in T regulatory cell proliferation was observed in diabetics and the percentages of total PD-1⁺, PD-1^low and PD-1^high expressing cells were lower in patients. Our data suggest a defective activation of T regulatory cells in long-standing diabetics due to a lower expression of PD-1 on their surface.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.