ABSTRACT
Objective To investigate the changes in nunmber and function of natural killer ( NK ) cells in patients with newly-diagnosed type 1 diabetes mellitus.Methods Cell courning was performed in peripheral blood mononuclear cell ( PBMC ) subsets in 43 cases with newly diagnosed type 1 diabetes ( T1D ),14 cases with newly diagnosed type 2 diabetes( T2D ) and 21 cases of normal controls by flow cytometry sorting.And then,isolating and collecting NK cells were performed in T1D patients and normal controls.Real time PCR was performed to evaluate the mRNA expression levels of NK cell activity related genes IFN-γ,perforin,NKp46,and NKp30 in NK cells.Results Compared to normal controls,both the proportion and the absolute counting of NK cells in PBMC from patients with T1D were significantly decreased [( 102±86 )/μl vs ( 355±264 )/μ1,P＜0.01],while only the proportion of CD4+ cell were slightly increased( P＜0.05 ).No statistical difference was observed regarding CD8+ T cells ( P＞0.05 ).mRNA expression levels of NK cell activity related genes perforin and NKp46 in NK cells were remarkably down-regulated ( P＜0.05 ),while IFN-γ and NKp30 were not changed compared with normal controls.Conclusions The reduced number and functional deficiency of NK cells may lead to the immune dysfunction in T1D and play an important role in the development of T1D.