Objective Thermal injury causes pulmonary edema, which may lead to acute respiratory distress syndrome, sepsis, multiorgan failure and even death. The article aimed to study the mechanism of curcumin pretreatment on inflammatory factors in lung tissues and serum endotoxin of rats with dry-heat environment.Methods A total of 50 SD rats were randomly divided into 5 groups (n=10): normal control group, dry heat control group, low concentraion group (50mg/kg curcumin pretreatment group), middle concentraion group (100mg/kg curcumin pretreatment group), and high concentration group (200mg/kg curcumin pretreatment group). Rats in normal control group and dry heat control group were given normal saline by gavage, while rats in 3 curcumin pretreatment groups were given curcumin of different concentrations (50 mg/kg, 100 mg/kg, 200 mg/kg) by gavage once a day for 7 consecutive days. At 8d, all the other 4 groups except normal control group were transferred to the climate cabin (The Simulated Climate Cabin for Special Environment of Northwest of China) with the condition of (41±0.5)℃, (10±1)% relative humidity.The rats were put in the dry-heat environment for 150min, then they were anaesthetized and sacrificed at 150min to collect the blood, lung tissues for further analysis. Observation was made on the pathological changes of lung tissues of rats in each group and the changes of inflammatory factors such as IL-1β, IL-6, TNF-α and LPS.Results Compared with dry heat control group, the concentrations of IL-1β, IL-6, TNF-α and LPS in normal control group, curcumin pretreatment groups with low concentration, middle concentration and high concentration were significantly higher(P<0.01). The concentrations of IL-1β, IL-6, TNF-α and LPS in curcumin pretreatment group with low concentration were significantly lower than those curcumin pretreatment groups with middle concentration and high concentration(P<0.05). Compared with curcumin pretreatment group with middle concentration, LPS concentration of curcumin pretreatment group with high concentration decreased significantly (P<0.01). Pearson correlation analysis showed that there was a positive correlation between the plasma of LPS and inflammatory cytokines of IL-1β, IL-6, and TNF-α in lung tissues (correlation coefficient r=0.866, r=0.900, r=0.885, P=0.000).Conclusion Curcumin inhibits bacterial endotoxin in blood, reduces the expression of inflammatory factors, and plays an important role in alleviating secondary multiple organ damage, which means curcumin pretreatment can relieve lung damage caused by heatstroke and reduce the mortality of heatstroke.

Objective To observe the function of immature CD8α+ dentritic cells (DCs) in vitro. Methods The bone marrow and spleen of C57BL/6(H-2b) and Balb/c (H-2d) mice were got to prepare immature CD8α+ DCs and spleen lymphocytes,and treated by mytomycin. MTT test was used.MLR group, MLR plus variable density syngeneic CD8α+ DC group, MLR plus variable density allogeneic CD8α+ DC group,MLR plus variable density CD8α+ DC supernatant group,CD8α+ DC plus syngeneic T cell group and negative control group were established. MLR group was set up by responder cell ratio of 0.2,0.5,0.8,1.0,to build the MLR plus syngeneic and allogeneic CD8α+ DC experimental groups. Culture supernatant from different density (1 × 105/ml - 5 × 106/ml) of CD8α+DCs was added into MLR to build CD8α+ DC supernatant group. CD8α+ DCs were co-cultured with syngeneic T cells to build CD8α+ DCs plus syngeneic T cells group. 2 × 105/well responder cells served as the negative control group. ELISA was used to detect the concentrations of IFN-γ and IL-10 in the DCs could both suppress MLR (P＜0. 05), and the difference was not statistically significant (P＞0. 05). When CD8α+ DCs were increased, the suppressive effect was enhanced. When CD8α+ DC/responder cell ratio ＞0. 2, the inhibitory effect could be observed, and this effect reached the peak when the ratio was 1.0. The CD8α+ DCs had weak ability to stimulate syngeneic lymphocyte proliferation in vitro, and certain stimulating effect could be seen only when CD8α+ DC/responder cell ratio ＞2 (P＜0. 05). Its culture supernatant also showed suppressive effect (P＜0. 05), and the supernatant with a cell density of 5 × 105/ml showed the maximum effect. IL-10 concentration in the concentration was 1.0 ± 1.2 pg/ml. Conclusion The in vitro function of immature CD8α+ DCs was immunosuppression/tolerance,and they could secret high level of IL-10. The CD8α+ DCs and their culture supernatant could suppress MLR in vitro.

Objective To construct the murine allogeneic acute GVHD model.Methods C57BL/6 (H-2b) mice were used as the donors and Balb/c (H-2d) mice as the recipients in allogeneic bone marrow transplantation (BMT).Groups were set as total body radiation (TBI) control group (n =4),GVHD group (n =10),simple BM transplantation group (n =10) and normal control group (n =4).For TBI control group,mice were subjected to TBI but did not receive BMT after radiation.For GVHD group,5 days before TBI,gentamycin (320 mg/L) and erythromycin (250 mg/L) were added into the drinking water,and on the day of transplantation,mice received one total dose of 8.0 Gy 60Coγ TBI,and within 5 h,2 × 106 C57BL/6 BM cells and 1 × 107 C57BL/6 spleen cells were transfused per mouse via the tail vein.For simple BMT group,the pretreatment was the same as GVHD group,and mice received only 2 × 106 C57BL/6 BM cells per mouse via the tail vein.The mental status,activity,posture,fur,weight,and stool were observed after transplantation.Survival time of each mouse was recorded,survival rate was calculated,and survival curve was drawn.Pathological examination was done for the liver,skin,small intestine and BM on the brink of death.Results The median survival time (MST) in TBI control group,GVHD group and BMT group was (9.0 ± 0.7),(32.0 ± 3.2) and ( 17.5 ± 1.6) days respectively,and there was significant difference between every two groups (P ＜ 0.01 ).Pathological examination in TBI control group showedhematopoiesis exhaustion.GVHD group showed acute GVHD symptoms 10-13 days after allo-BMT,and the pathological changes of the skin,liver and small intestine corresponded to those of Ⅰ to Ⅱ degree of GVHD.Simple BMT group also showed acute GVHD symptoms 10-13 days after alloBMT,but their GVHD manifestation and histological changes were less serious and only 0 to Ⅰ degree of GVHD could be seen.ConclusionStable acute GVHD model can be constructed by transfusion of allogeneic BM cells and spleen cells into Balb/c mice after lethal TBI.

The graft-versus-tumor (GVT) effect of T cells induced by tumor antigen-pulsed CD8α+dendritic cells (DCs) in vitro was investigated in this study.Immature CD8α+ DCs were prepared from C57BL/6 (H-2b) bone marrow cells by using a cytokine cocktail.On the 3rd day of culture,CD8α- DCs were pulsed by allogeneic (Balb/c,H-2d) EL9611 leukemia antigen,or RM-1 syngeneic prostate cancer antigen,with the concentration series of 0,2.5,5.0,10.0,20.0 μg/mL,respectively,then antigen-loaded immature CD8α+ DCs were co-cultured with syngeneic T cells according to the DC/T ratio of 1∶1,2∶1and 4∶1.T cell proliferation was measured by MTT assay.Cytokines including interferon gamma (IFN-γ)and interleukin-10 (IL-10) in CD8α+ DCs and T co-culture supernatant were detected by using ELISA.Cytotoxic effect of antigen-specific T cells was tested by LDH release assay.Conventional mature DCs　(mDCs) induced from C57BL/6 (H-2b) bone marrow cells by using granulocyte-macrophage colony　stimulating factor (GM-CSF) and interleukin-4 (IL-4) served as a control.The results showed that the　proliferative activity of T cells stimulated by CD8α+ DCs loaded with allogeneic or syngeneic tumor antigen was augmented with the CD8α+ DC/T ratio increased (P＜0.05).When antigen concentration ≤ 5μg/mL and CD8α+ DC/T ratio ≤ 2∶1,the ability of CD8α+ DCs to stimulate T cell proliferation was　higher than mDC control in allogeneic tumor antigen-pulsed groups (P＜0.05),but not in syngeneic tumor antigen-pulsed groups (P＞0.05).The level of IFN-γ and IL-10 in CD8α+DCs and T cell co-culture　supernatant were increased in both allogeneic and syngeneic antigen-pulsed groups (P＜0.05),and the　cytokine level was higher in allogeneic antigen-pulsed groups than in syngeneic antigen groups when　the CD8α+DC/T was 1∶1 or 2∶1 (P＜0.05).There existed a negative correlation between the level of　IL-10 and T cell proliferation.T cell cytotoxicity assay showed that when CD8α+ DCs were pulsed with　allogeneic tumor antigen,the maximal T cell killing efficiency could reach (100±7.7)％,whereas syngeneic tumor antigen-pulsed group had only (65.0±3.4)％.It was concluded that syngeneic and allogeneic tumor antigen-pulsed immature CD8α+ DCs could stimulate T cells to exert the GVT effect in vitro,and the GVT effect was more obvious with allogeneic tumor antigen than with syngeneic tumor antigen.The optimal condition was low allogeneic tumor antigen pulsation (≤ 5 μg/mL) and low CD8α+ DC/T　ratio (1∶1 and 2∶1).

The graft-versus-tumor (GVT) effect of T cells induced by tumor antigen-pulsed CD8α(+) dendritic cells (DCs) in vitro was investigated in this study. Immature CD8α(+) DCs were prepared from C57BL/6 (H-2(b)) bone marrow cells by using a cytokine cocktail. On the 3rd day of culture, CD8α(+) DCs were pulsed by allogeneic (Balb/c, H-2(d)) EL9611 leukemia antigen, or RM-1 syngeneic prostate cancer antigen, with the concentration series of 0, 2.5, 5.0, 10.0, 20.0 μg/mL, respectively, then antigen-loaded immature CD8α(+) DCs were co-cultured with syngeneic T cells according to the DC/T ratio of 1:1, 2:1 and 4:1. T cell proliferation was measured by MTT assay. Cytokines including interferon gamma (IFN-γ) and interleukin-10 (IL-10) in CD8α(+) DCs and T co-culture supernatant were detected by using ELISA. Cytotoxic effect of antigen-specific T cells was tested by LDH release assay. Conventional mature DCs (mDCs) induced from C57BL/6 (H-2(b)) bone marrow cells by using granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4) served as a control. The results showed that the proliferative activity of T cells stimulated by CD8α(+) DCs loaded with allogeneic or syngeneic tumor antigen was augmented with the CD8α(+) DC/T ratio increased (P<0.05). When antigen concentration ≤ 5 μg/mL and CD8α(+) DC/T ratio ≤ 2:1, the ability of CD8α(+) DCs to stimulate T cell proliferation was higher than mDC control in allogeneic tumor antigen-pulsed groups (P<0.05), but not in syngeneic tumor antigen-pulsed groups (P>0.05). The level of IFN-γ and IL-10 in CD8α(+) DCs and T cell co-culture supernatant were increased in both allogeneic and syngeneic antigen-pulsed groups (P<0.05), and the cytokine level was higher in allogeneic antigen-pulsed groups than in syngeneic antigen groups when the CD8α(+) DC/T was 1:1 or 2:1 (P<0.05). There existed a negative correlation between the level of IL-10 and T cell proliferation. T cell cytotoxicity assay showed that when CD8α(+) DCs were pulsed with allogeneic tumor antigen, the maximal T cell killing efficiency could reach (100±7.7)%, whereas syngeneic tumor antigen-pulsed group had only (65.0±3.4)%. It was concluded that syngeneic and allogeneic tumor antigen-pulsed immature CD8α(+) DCs could stimulate T cells to exert the GVT effect in vitro, and the GVT effect was more obvious with allogeneic tumor antigen than with syngeneic tumor antigen. The optimal condition was low allogeneic tumor antigen pulsation (≤ 5 μg/mL) and low CD8α(+) DC/T ratio (1:1 and 2:1).