Changes of expression levels of NK,NKT cells and their receptors in peripheral blood of human and its correlation with rheumatoid arthritis / 中国免疫学杂志

ABSTRACT

Objective:To explore the changes of NK and NKT cells and the expression levels of their activated, inhibitory receptors in the peripheral blood of patients with newly diagnosed rheumatoid arthritis ( RA), and to reveal the potiential role of NK and NKT cells played in the pathogenesis of RA.Methods:32 patients with new onset RA and 15 healthy controls were recruited.Activated and inhibitory NK and NKT cells in peripheral blood were quantified by flow cytometry.The frequency of spontaneous and stimulated IFN-γ+NK and NKT cells and CD107aγ+NK cells were examined.Finally,the potential relationship between the frequency of NK and NKT cells subsets and clinical indexes were analyzed.Results:The frequencies of NK cells in peripheral blood in RA patients were sig-nificantly lower than those in the controls ( P=0.026 ).The frequencies of NKG2D+, NKP46+activated NK cells and NKG2C+, NKG2D+,NKP46+activated NKT cells in RA patients were significantly higher than those in the controls (P=0.011,P=0.010,and P<0.001,P=0.032,P=0.001,respectively),whereas the frequencies of KIR2DL3+,KIR3DL1+and NKG2A+inhibitory NK cells and KIR2DL3+,NKG2A+inhibitory NKT cells in RA patients were significantly lower (P=0.002,P=0.002,P=0.014,and P=0.027,P=0.002,respectively).Moreover, the frequencies of stimulated IFN-γ+NK cells and IFN-γ+NKT cells, spontaneous and stimulated CD107 aγ+NK cells in RA patients were significantly higher than that in the controls ( P=0.037, P=0.004 and P=0.001, P=0.001, respectively).Furthermore,the frequencies of NK cells,NKG2Aγ+and KIR2DL3γ+inhibitory NK cells were correlated significantly with the values of DAS28 in RA patients (r=0.357,P=0.045;r=0.399,P=0.024;r=0.468,P=0.021,respectively).Conclusion:Lower frequencies of NK cells, higher frequencies of activated NK cells and activated NKT cells, lower frequencies of inhibitory NK cells and inhibitory NKT cells, and higher NK cell activity may induce the autoimmune reaction involved in the pathogenesis of RA.