The Alteration Of The Phenotype And Function Of Regulatory T Cells In Peripheral Blood Of Asthmatic Patients

Background: Asthma is a global healthy issue and all ages are affected.Recently,the prevalence of asthma is increasing in many countries.The previous studies have revealed that Th2 cells play a predominant role in the development of asthma.Regulatory T cells(Treg)also have an effect on the pathogenesis of asthma through acting on Th2 cells.We investigate the change of regulatory T cells in the peripheral blood of asthmatic patients,thus further reveal the important role of regulatory T cells in the mechanism of asthma.Method: 33 asthmatic patients were recruited for our experiments,then,we assessed asthmatic patients by ACQ questionnaire and collected the peripheral blood of asthmatic patients.After separating the peripheral blood monouclear cells,the percentage of Treg cells were assessed by Fluorescence Activating Cell Sorter.In the meantime,the phenotypic marker Neuropilin-1(Nrp1),the proliferation associated factor Ki67,the function associated factors of Treg cells--cytotoxic T-lymphocyte associated protein 4(CTLA4),glucocorticoid-induced tumor necrosis factor receptor(GITR)and specific transcription factor--forkhead box P3(FOXP3),GATA binding 3(GATA3)were analyzed by Fluorescence Activating Cell Sorter.The amount of Ig E,TGF-?and IL-10 in the serum were analyzed by ELISA.What's more,we also analyzed the expression level of interleukin 4 and interferon-? in Treg cells after stimulation for 4 hours by ionomycin and PMA.22 sex-and age-matched healthy persons were recruited as control.Results: Consistent with the previous studies,the percentage of Treg cells decreased in asthmatic group.Most importantly,the expression of Nrp1,Ki67,CTLA-4 and GITR F in Treg cells also decreased in asthmatic group.The amount of TGF-?and IL-10 is fewer in the asthmatic group than the control group.What's more,in the asthmatic group,Treg cells express higher level of FOXP3 and GATA3 compared with the control.There is also a significant difference in the FOXP3/GATA3 between the control group and asthmatic group.The level of Il-4 expressed by Treg cells increased in asthmatic group,on the contrary,the expression of IFN-? has no difference in these two groups.The expressions of FOXP3,GATA3 and the ratio of FOXP3 and GATA3 have no correlation with FEV1%.Conclusion: We have found that the percentage of Treg cells decreased and their function impaired in the peripheral blood of asthmatic patients,which may be the result of the imbalance of FOXP3 and GATA3,and this imbalance leads to the changes of Treg cells.However,the mechanism of imbalance of FOXP3 and GATA3 needs further study.