Feasibility of up-regulating CD4(+)CD25(+) Tregs by IFN-γ in myasthenia gravis patients.
BACKGROUND
In myasthenia gravis (MG) patients, the dysfunction of CD4(+)CD25(+) regulatory T cells (CD4(+)CD25(+) Tregs) may be one of the important pathogenesis of MG. Currently, the role of IFN-γ in autoimmune diseases is still controversial and needs further exploration. In this study, whether IFN-γ can induce CD4(+)CD25(-) T cells into CD4(+)CD25(+) Tregs in MG in vitro was investigated systematically.


METHODS
Flow cytometry was used to analyze the number of CD4(+)CD25(+) Tregs in MG patients and healthy controls (HCs). CD4(+)CD25(-) T cells were separated from the peripheral blood mononuclear cells of MG patients and HCs, and the CD4(+)CD25(+) Tregs were separated from HCs by Magnetic cell sorting (MACS). IFN-γ with different concentrations was used to stimulate CD4(+)CD25(-) T cells. The percentages of the induced CD4(+)CD25(+) T cells were detected by flow cytometry. The FoxP3 expression of the induced CD4(+)CD25(+) T cells in MG patients was detected by real-time PCR at mRNA level. The induced CD4(+)CD25(+) T cells were co-cultured with autologous CD4(+)CD25(-) T cells to estimate the suppressive ability of the induced CD4(+)CD25(+) T cells to CD4(+)CD25(-) T cells.


RESULTS
It shows the percentages of CD4(+)CD25(+) T cells among CD4(+) T cells have no significant difference in MG patients compared with those in HCs. There is also merely no difference in the percentages of CD4(+)CD25(+) T cells between thymectomized and non-thymectomized MG patients. CD4(+)CD25(-) T cells can be induced to CD4(+)CD25(+) T cells after applying IFN-γ in MG patients and HCs. The proportion and FoxP3 expression of the induced CD4(+)CD25(+) T cells are the highest at the level of 40 ng/ml IFN-γ, and the suppressive function of the CD4(+)CD25(+) T cells induced by 40 ng/ml IFN-γ is the strongest in MG patients.


CONCLUSIONS
This subject will further reveal the role of IFN-γ in the pathogenesis of MG from a new perspective. It will also provide the scientific basis for the clinical targeted therapy of MG.
Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, 150080, P.R. China. cecile_huang@163.com.
Shuo
S
Huang
Department of Neurology, The Second Affiliated Hospital of Harbin Medical University, Harbin, 150086, P.R. China. wangweizhi@163.com.
Weizhi
W
Wang
Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, 150080, P.R. China. clj3757@yahoo.com.cn.
Lijun
L
Chi
D000328:Adult; D000368:Aged; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism*; D016022:Case-Control Studies; D002469:Cell Separation; D005240:Feasibility Studies; D005260:Female; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000276:immunology* / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000378:metabolism*; D015854:Up-Regulation; D055815:Young Adult
C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit; D007371:Interferon-gamma