[Effect of CD86 Gene Modified Recipient Dendritic Cell on Mix Cultured Donor-derived Islet with Recipient-derived Lymphocyte in vitro].

Objective: To investigate the effect of CD86 gene modified recipient dendritic cell (DC) on mix cultured donor-derived islet with recipient-derived lymphocyte in vitro.
Methods: DCs were separated from bone marrow of BALB/c mice and identified by flow cytometry. Chemically synthesized CD86 siRNA was transferred into DC. Donor islets were separated from the pancreas of SD rats. Acridine orange (AO)/Propidium iodide (PI) staining was conducted to assess the viability of islets. Lymphocytes were collected from the spleen of SD rats and then co-cultured with CD86 gene modified recipient DCs. CD86 gene modified recipient DC, donor-derived islet (400 IEQ) and recipient-derived lymphocyte (1 x 10(6)) were mix cultured in vitro. Four groups were set: blank group (islets of SD rat only), control 1 group (islets of SD rat with splenic lymphocyte of BALB/c mice) , control 2 group (islets of SD rat, splenic lymphocyte of BALB/c mice with normal recipient DC) and experimental group (islets of rat, splenic lymphocyte of BALB/c mice with CD86 gene modified recipient DC). After 3 days culture, the cellular morphology of culture was observed with light inverted microscope. The levels of IL-2, IL-4, IL-10 and IFN-γ in the culture supernatant were tested, and islets viability was assessed by AO/PI staining. GSIS was conducted and stimulation index (SD was calculated.
Results: Typical DC morphology was found from the collected cells. The positive rates of CD1lc, CD80 and CD86 protein expression on DCs were 86.26% ± 9.73%, 72.64% ± 8.55% and 77.18% ± 10.23%, respectively. The positive rate of CD86 protein expression on DCs after transfection was 23.64% ± 5.25%. The viability of islets was over 95%. After 3 days culture, the level of IL-10 increased significantly and the levels of IL-2 and INF-γ decreased significantly in experimental group (vs. control 1 and control 2 groups, P < 0.05). The level of IL-4 was similar in control 1, control 2 and experimental groups, but the proliferation rate of lymphocyte in the experimental group was the lowest one, the viability of islets in the experimental group was the best and the SI was the highest. The levels of IL-2, IL-4, IL-10 and IFN-γ in the experimental group were higher than those in the blank group.
Conclusion: CD86 gene modified recipient DC loaded with donor-derived antigen could protect the islet function in vitro to some extent.