Immune Modulation in Peripheral Blood of Cystic Fibrosis Patients Following Ex Vivo Co-Culture with Mesenchymal Stem Cells

Background: Cystic fibrosis (CF) is an inherited multisystemic disease. Despite advances in treatment, many patients still experience progressive lung dysfunction. Dental follicle-derived mesenchymal stem cells (DF-MSCs) possess significant immunomodulatory potential in inflammatory airway diseases. We evaluated the effects of DF-MSCs on lymphocyte proliferation, CD4+CD25+FoxP3+ regulatory T cell (Treg) frequency, and cytokine responses in peripheral blood mononuclear cells (PBMCs) from CF patients. Methods: PBMCs from 20 CF patients and 20 matched healthy controls were isolated by density gradient centrifugation, stimulated with a CD3/CD28 T-cell-activating antibody cocktail (CD-mix), and co-cultured ex vivo with cryopreserved DF-MSCs. Lymphocyte proliferation was assessed by carboxyfluorescein succinimidyl ester (CFSE)-based flow cytometry, and Tregs were analyzed by flow cytometry. Cytokine levels in culture supernatants were quantified using a multiplex immunoassay. Results: DF-MSC co-culture significantly suppressed lymphocyte proliferation in CF PBMCs. Treg frequency significantly increased in the stimulated CF samples following MSC co-culture. Following co-culture, levels of tumor necrosis factor-alpha (TNF-α), interleukin-8 (IL-8), and IL-23 decreased. In CF samples, levels of interferon-alpha 2 (IFN-α2), monocyte chemotactic protein-1 (MCP-1), interleukin-12 (IL-12), interleukin-18 (IL-18), and interleukin-33 (IL-33) were elevated. Conclusions: DF-MSCs reduced lymphocyte proliferation, increased Treg frequency, and regulated cytokine levels in CF, supporting their potential to restore immune balance.