ABSTRACT
Background: Type 1 diabetes [T1D] is a T cell mediated autoimmune disease targetingthe insulin-producing beta cells within pancreatic islets. Autoimmune diseases maydevelop as a consequence of altered balance between regulatory [Tregs] andautoreactive T cells
Objectives: To evaluate Treg cells frequency and suppressivefunction in the peripheral blood of newly diagnosed T1D patients in comparison withhealthy controls
Methods: Fifteen new cases of T1D patients and 15 age- and sexmatchedhealthy controls were recruited to this study. Their peripheral bloodmononuclear cells [PBMCs] were isolated and CD4[+]CD25[+]FoxP3[+]CD127[-/low] Treg cellswere studied by flowcytometry technique. Thereafter, Tregs were isolated by Magnetic-Activated Cell Separation [MACS] technology and by using CFSE [carboxyfluoresceinsuccinimidyl ester] dilution assay, their suppressive activity was evaluated in thecoculture of CD4[+]CD25[-] T responder cells with Treg cells
Results: The percentage ofCD4[+]CD25[+]FoxP3[+]CD127[-/low] Tregs did not differ between T1D patients and healthycontrols but the MFI [mean fluorescence intensity] of transcription factor FoxP3[forkhead box protein P3] was significantly decreased in T1D patients [20.03 +/- 1.4 vs.31.33 +/- 2.95, p=0.0017]. Moreover, the suppressive function of CD4[+]CD25[+]CD127[-/low]Treg cells was significantly diminished in T1D patients in comparison with controlgroup [35.16 +/- 4.93% vs. 60.45 +/- 5.26%, respectively, p=0.0015]
Conclusion: Presentstudy indicates an impaired immune regulation among T1D patients, characterized bydefects in suppressive function and expression of FoxP3 in Treg cells without anysignificant decrease in their frequency in peripheral blood