Maturation State and Function of Monocyte Derived Dendritic Cells in Liver Transplant Recipients

Background: Dendritic cells (DCs) are potent antigen presenting cells for triggering of the immune reaction post transplantation. These cells are centrally involved in the initiation of T cell-dependent immune responses. Objective: To compare the level of DC maturation and function in liver transplant recipients with healthy controls. Methods: In this study, twelve peripheral blood samples were selected from six liver transplant patients and six healthy controls. After the generation of DCs from monocytes, expression levels and mean fluorescent intensity (MFI) of several DC maturation markers were evaluated using flowcytometry. Secretion of IL-6, IL-12 and IL-23 proinflammatory cytokines was determined using ELISA. Gene expressions of TLR-2, TLR-4 and IL-23 were analyzed using real-time PCR. Results: DC expression markers including CD83 (p=0.007) and CD86 (p=0.02), as well as secretion of IL-6 (p=0.02) and IL-12 (p=0.007) by DCs were significantly increased in liver transplant patients compared with healthy controls. The MFI of CD86 (p=0.009) and HLA-DR (p= 0.005) expression on DCs was also higher in patients. The expression of TLR-2 transcripts in DCs of patients was higher than that of the controls (p=0.03). Conclusion: Based on these findings, increased frequency of DCs expressing CD83 and CD86, higher expression of CD86, HLA-DR, and TLR-2 as well as elevated secretion of proinflammatory cytokines in DCs of liver transplant recipient's point to the more mature phenotype and active function of DCs in patients compared with controls.