Cell Journal (Jan 2010)
Induction of Specific T-Cell Response Following In Vivo Treatment of Dendritic Cells by 1,25-Dihydroxycholecalciferol
Abstract
Objective: Dendritic cells (DCs), as the managers of the immune response, have a crucialrole in forming the direction and nature of the immune response. Some compoundssuch as 1,25-dihydroxycholecalciferol affect the function of DCs and can be used toshift the immune functions toward favorite directions. The aim of this study was to investigatethe in vivo effects of 1, 25- dihydroxycholecalciferol on DCs surface markers,their potential to induce specific T-cell responses and the cytokines profile.Materials and Methods: 1, 25-dihidroxycholecolciferol was regularly injected intraperitonealinto C57BL/6 mice. DCs were separated from the spleens of calciferol treatedand non-treated mice using magnetic beads. The expression of DCs surface markerswas investigated by flow cytometric analysis. The separated cells were pulsed by myelinoligodendrocyte glycoprotein (MOG) and injected subcutaneously into front footpadsof syngeneic mice. After five days, the lymphocytes from regional lymph nodes wereseparated and used for the lymphocyte transformation test (LTT) and determination ofthe interferon gamma/interleukin 4 (IFNγ/IL-4) ratio by ELISA technique.Results: Statistical analysis of the obtained results showed reduced expression ofmaturation markers and co-stimulatory molecules by cholecalciferol treated DCs. Thespecific T-cell stimulation potential of treated DCs as well as the induced IFNγ/IL-4 ratiowas also down-regulated compared to non-treated cells (p value<0.05).Conclusion: It seems that 1,25-dihydroxycholecolciferol can regulate the DCs functionand maturation state in vivo. The T-cell stimulation rate and Th1/Th2 cytokines ratio alsochanges following interaction with cholecalciferol treated DCs.
