A Preliminary Study: Effect And Mechanism Of Adipose Tissue-derived Stem Cells On T Cell Subsets In Patients With Acute Graft-versus-host Disease In Vitro

Objective:To explore the effect of adipose tissue-derived stem cells(ADSCs)on T cell function and its mechanism in patients with acute graft-versus-host disease(aGVHD).Methods:The adipose derived stem cells of healthy human body were isolated and cultured,and the cellular morphology was observed.The cells were cultured to the third generation,and the surface markers were identified by flow cytometry.Adipogenic differentiation and osteogenic differentiation were identified.Patients with aGVHD who underwent hematopoietic stem cell transplantation in the Hematology Center of the First Affiliated Hospital of Xinjiang Medical University were selected as the experimental group,and healthy subjects were selected as the control group.Peripheral blood mononuclear cells(PBMC)were isolated,and phytohemagglutinin was added to induce the proliferation of PBMC.The PBMC and ADSCs were co-cultured for 3 days(PBMC:ADSCs=10:1),which were divided into three groups:(1)PBMC of patients with aGVHD and ADSCs were co-cultured,(2)PBMC of healthy people and ADSCs were co-culture,(3)PBMC was cultured separately.In the co-culture group,the expression levels of specific transcription factors of Th1 and Th2 subsets and the changes of HES-1 gene expression were detected by PCR,and the changes of Th1 and Th2 subsets in the three groups were detected by flow cytometry.Results :(1)ADSCs obtained by liposuction showed multidirectional differentiation potential,expressing CD29 、 CD105 and CD44,while CD31 、 CD34 and CD34 was weakly expressed.(2)The proportion of Th1 subsets in CD4+T cells in aGVHD patients was higher than that in the control group by flow cytometry,and the difference was statistically significant.After co-culture with ADSCs,Th1 subsets show a decreasing trend and Th2 subsets show an increasing trend,but there was no statistical significance.(3)After co-culture with ADSC,the expression of TH1 transcription factor was decreased,the expression of TH2 transcription factor was increased,and the expression level of HES-1 was decreased.CONCLUSIONS: There is a Th subset imbalance in patients with aGVHD,mainly manifested as Th1 deviation.ADSCs may correct immune imbalance by reducing Th1 cell differentiation,promoting Th2 cell differentiation,and down-regulating Notch signaling pathway.