The therapeutic effect and its mechanism of dendritic cells overexpressed suppressors of cytokine signaling 1 on acute liver failure in mice / 中华传染病杂志

ABSTRACT

Objective To investigate the impact of suppressor of cytokine signaling 1 (SOCS1) overexpression on dendritic cells (DC) functions and its therapeutic effect on acute liver failure (ALF) in mice.Methods Bone marrow derived dendritic cells (BMDC) from C57BL/6 mice were transfected with lentivirus encoding SOCS1 and negative control lentivirus at a MOI=50, and labeled as DC-SOCS1and DC-VNG, respectively after 96 hours of successful transduction.Then DCs were stimulated with lipopolysaccharides(LPS)1 mg/L and collected for flow cytometry analysis of surface costimulatory molecules, allogeneic mixed lymphocyte reaction (MLR) and western blot test of Janus kinase (JAK)/signaling transducers and activators of transcription (STAT) pathway.Afterwards, 90 mice were randomly assigned into 4 groups including 12 in normal control group, 26 in ALF group, 26 in treatment groups with DC-SOCS1 and 26 with the treatment of DC-VNG.All were received tail vein injection with normal saline, modified DC-VNG and DC-SOCS1 suspended in normal saline, respectively.Twelve hours after injection, LPS (10 μg/kg)/D-GaIN (600 mg/kg) were injected intraperitoneally to induce ALF model.The mortality, serum levels of alanine aminotransferase (ALT) and aspartate transaminase (AST), liver pathology and proportion of splenic regulatory T cells of each group were observed.Means in different groups were compared with one-way ANOVA analysis.Categorical variables were analyzed with x2 test.Variables were examined with normality test and homogeneity of variance with LSD test.Results The results of mixed lymphocyte reaction (MLR) revealed that T cell proliferation ratio in DC-SOCS1 group with mixture ratio of 100∶1 were (25.87±0.38)%, which was lower than that of mixture ratio of 10∶1 in the mDC group ([84.29±3.25]%) with statistical significance (x2=49.821, P<0.01);interleukin (IL)-10 concentration was higher than that in mDC group with mixture ratio of 10∶1 with statistical significance (F=20.112, P<0.05);IL-6 concentration was also lower with statistical significance (F=47.718, P<0.05).Compared to imDC, expression of JAK2 (t=0.525,0.523 and 0.489, respectively, all P<0.01), signal transduction factors and activation of transcription factors-1 (STAT1) (t=0.442,0.400 and 0.402, respectively, all P<0.01) and SOCS1 (t=0.322,0.363 and 1.090, respectively, all P<0.01) of mDC, DC-VNG and DC-SOCS1 after LPS stimulation increased significantly.Furthermore, the expressions of phosphorylated STAT1 (p-STAT1) and phosphorylated JAK2 (p-JAK2) of DC-SOCS1 were much lower than those of the mDC, with statistically significant difference (t=-3.840 and 0.254, respectively, both P<0.01).Pathological analysis revealed that there existed moderate hepatic cells necrosis and less immune cell infiltration in DC-SOCS1 group accompanied with higher regulatory T lymphocytes proportion than those in ALF group and DC-VNG group.Survival rate of ALF with DC-SOCS1 treatment group was significantly higher than that of ALF group with statistical difference (x2=12.87, P<0.05).Conclusions DC-SOCS1could sustain an immature state and exhibit as regulatory DC through negative regulation of JAK2/STAT1 pathway with overexpression of SOCS1.Infusion of DC-SOCS1 could ameliorate ALF by inhibiting aggressive inflammation response with increased proportion of regulatory T cells in mice, which shows good therapeutic effect for ALF mice.