The Change Of T Cells In Non-myeloablative GVHD Mice And Research On The Intervention Mechanism Of Arsenic Trioxide

ObjectiveStudying the change of T cells in peripheral blood with non-myeloablative GVHD mice model of different irradiation dose and intervening GVHD mice model with arsenic trioxide,then observe the effect of arsenic trioxide on survival,clinical symptoms of GVHD mice,change of peripheral blood T cells,cytokine serum concentrations and Nrf2/OH-1 signal pathway.Methods1.The change of T cells in peripheral blood of non-myeloablative GVHD mice50 BALB/C mice were randomly divided into 5 groups?10 mice/group?:7.5GyIRD group?irradiation group?,8GyIRD group,7.5GyGVHD group,8GyGVHD group and control group^[15].7.5GyIRD group and 8GyIRD group were treated with7.5GyTBI?total body irradiation?and 8GyTBI^[15];7.5GyGVHD group and8GyGVHD group were implanted with donor?C57BL/6?1*10⁷ bone marrow cells and 2.5*10⁷ spleen cells within 24h after received 7.5GyTBI and 8GyTBI respectively^[15];The control group received no treatment^[15].Observe the clinical symptoms of 7.5GyGVHD group and 8GyGVHD group after transplantation,the pathological changes of liver,lung and intestinal tissue and the rate of chimerism and the change of T cell subsets in peripheral blood by flow cytometry^[15].2.Reseach on the intervention mechanism of arsenic trioxide on non-myeloablative GVHD mice30 BALB/C mice were randomly divided into GVHD+ATO group,GVHD+PBS group,BMT group.GVHD+ATO group:BALB/C mice were implanted with donor?C57BL/6?1.5*10⁷ bone marrow cells and 5*10⁷ spleen cells within 24h after8GyTBI,and treated with intraperitoneal injection of 1ug/g d^-1 ATO for 14 days;GVHD+PBS group:BALB/C mice were implanted with donor?C57BL/6?1.5*10⁷bone marrow cells and 5*10⁷ spleen cells within 24h after 8GyTBI,and treated with intraperitoneal injection of PBS?same volume to ATO?for 14 days;BMT Group:BALB/C mice were implanted with donor?C57BL/6?1.5*10⁷ bone marrow cells within 24h after 8GyTBI.Observe the GVHD clinical symptoms and the pathological changes of liver,lung and intestinal tissue,the proportion of T cells in peripheral blood and cytokine serum concentrations changes by flow cytometry and Nrf2 protein and HO-1 protein level of Nrf2/HO-1 signal pathway in liver through Western blot.Results1.The change of T cells in peripheral blood of non-myeloablative GVHD miceAllogeneic H-2d positive cells proportion was higher than 90%in both7.5GyGVHD group and 8GyGVHD group after transplantation^[15].The CD4+/CD8+ratio decreased first,then increased positively correlated with the clinical scores of GVHD in both two GVHD groups;The CD4+/CD8+ratio in 8GyGVHD group with severe symptoms was higher than 7.5GyGVHD group,the difference between the two groups was statistically significant in the 10th,17th and 24th day after transplantation?p<0.05?^[15].As time prolonged,the CD4+CD25+T cell proportion decreased to the minimum gradually in both two GVHD groups;the percentage of CD4+CD25+T cell in 8GyGVHD group decreased more slowly than 7.5GyGVHD group,implied that the decline was negatively correlated with the irradiation dose^[15].2.Reseach on the intervention mechanism of arsenic trioxide on non-myeloablative GVHD miceThe survival time of GVHD+ATO group was longer than that of GVHD+PBS group?p<0.05?,the clinical symptoms were relieved and the GVHD score was decreased?p<0.05?.The ratio of CD4+/CD8+in the 5th,10th and 15th day in GVHD+ATO group was lower than that of GVHD+PBS group and was statistically significant difference in the 10th and 15th day?p<0.05?.Lower serum cytokine concentrations of TNF-a and IFN-r in GVHD+ATO group compared with GVHD+PBS group?p<0.05?and other cytokines IL-2,IL-4,IL-5,IL-6,IL-10,IL-13didn't show the significant difference?p>0.05?.The results of Weston blot showed that the expression of Nrf2 protein and HO-1 protein in GVHD+ATO group was significantly higher than that in GVHD+PBS group?p<0.05?.Conclusion1.The high ratio of CD4+/CD8+in peripheral blood of 8GyGVHD group with severe GVHD symptoms.2.Arsenic trioxide can reduce the CD4+/CD8+ratio in peripheral blood of GVHD mice.3.Arsenic trioxide can reduce the serum levels of TNF-a and IFN-r,activate the Nrf2/HO-1 signaling pathway,prolong the survival time of GVHD mice,and relieve the symptoms of GVHD.