ABSTRACT
BACKGROUND: House dust mite (Dermataphagoides pteronyssinus) is a widespread risk factor in the development of asthma. CD4+ T lymphocytes have an important role in the pathogenesis of allergic asthma by polarizing to Th2 cells. OBJECTIVE: We aimed to evaluate the immunoregulatory effects of dental follicle mesenchymal stem cells with and without IFN-γ stimulation on peripheral blood mononuclear cells of house dust mite sensitive asthmatic patients, and compared those with Dexamethasone as a systemic steroid. MATERIAL AND METHODS: PBMC of asthmatic patients and healthy individuals separately cultured with or without DF-MSCs in the presence and absence of IFN-γ or Der p1 or Dexamethasone for 72h. CD4+ T proliferation, cell viability, CD4+CD25+FoxP3+ Treg cell frequency and cytokine profiles of PBMC were evaluated via flow cytometry. RESULTS: DF-MSCs suppressed proliferation of CD4+ T lymphocytes (pCDmix<0.01, pDerp1<0.01, pIFN<0.005) by increasing the number of FoxP3 expressing CD4+CD25+ T regulatory cells (pCDmix<0.005, pDerp1<0.01, pIFN<0.001) and suppressed lymphocyte apoptosis (pCDmix<0.05, pDerp1<0.05, pIFN<0.05), while Dexamethasone increased the apoptosis and decreased Treg cell frequency in asthmatic patients. IFN-γ stimulation increased the suppressive effect of DF-MSCs and also enhanced the frequency of FoxP3 expressing CD4+CD25+ T regulatory cells. The cytokine levels were regulated by DF-MSCs by reducing IL-4 cytokine levels (pCDmix<0.01, pDerp1<0.05, pIFN<0.05) and upregulating IFN-γ levels (pCDmix<0.01, pDerp1<0.05, pIFN<0.005) in asthmatic patients. CONCLUSION: IFN-γ stimulated DF-MSCs were found to have a high modulatory effect on CD4+ T cell responses, while Dexamethasone had an apoptotic effect on CD4+ T cells in asthmatic patients. DF-MSCs may be a new cell-based therapy option for allergic diseases including asthma.
