There are multiple types of inhibitory immune cells in tumor. Among these cells, Treg (regulatory T cell) plays an extremely important role in tumor development and progression. Treg exihibits potent inhibitory effects on effector cells by a variety of mechanisms, which might be the the key factor for tumor immune escape. These mechanisms include inhibiting the effector cell function by inhibitory cytokines, killing effector cells by granzyme and profrin, interfering effector cell metabolism, and affecting Treg differentiation and proliferation by regulating the function of dendrtic cells, etc. The research on Treg has provided new strategies for tumor immunotherapy. Tumor immunotherapies targeting Treg and related immunosuppressive factors, such as deleting Treg nonsepcificlly or sepcificlly controling the numbers and functions of Treg, might have a bright future in clinical application.keyword regulatory T cell(Treg); neoplasms; immune escape; immunotherapy

The Renca-bearing mice were treated by combined fibroblast-mediated IL-2 and G-CSF gene therapy. The survival periods of Renca-bearing mice were prolonged markedly and 75% of Renca-bearing mice were cured. The spleens of Renca-bearing mice treated by fibroblast-mediated G-CSF gene therapy were larger than the spleens of other mice. Histologic analysis of tumor showed that there were a number of infiltrating eosinophils. The NK, LAK and CTL activity induced from the splenocytes of the tumor-bearing mice increased siginificantly when the mice were treated by fibroblast-mediated IL-2 gene therapy and the cytotoxicity of macrophages also increased. The results demonstrated that the and - tumor responses might be induced more significantly by combined fibroblast-mediated IL-2 and G-CSF gene therapy and better antitumor effect may be achieved.

Dendritic cells (DC) are antigen presenting cells (APC) that play critical roles in the initiation of T cell response and development of T cell-dependent antibodies in vivo. CD34_+ hematopoietic progenitor cells of bone marrow and peripheral blood can differentiate into DC when cultured with GM-CSF and TNF-? in vitro. In the present study, we cultured monocytes isolated from human peripheral blood with 100ng/ml hGM-CSF and 500U/ml hIL-4 for one week, and then found that a large number of DC with high purity were gengerated. DC expressed MHC I , MHC II and costimuladng moleculers highly on cell surface and cound stimulate proliferation of allogeneic T lymphocytes. Self serum or fetal calf serum are best for generation of DC. When hGM-CSF was used alone, the monocytes differentiated into macrophages but not to DC. TNF-? could induce further maturation of DC when added in late period of the culture. Generation of DC from human peripheral blood may facilitate further studies on DC and their clinical applications.

A main complication of chemotherapy in cancer patients is hematopoiesis suppression. Microenviroment transplantation using bone marrow stromal cells (BMSCs) has been demonstrated to be a potent method in recovery of hematopoiesis in animal models. Based on hematopoiesis-supportive ability of BMSCs and high potency of IL-3 in hematopoiesis stimulation, BMSCs were studied as a cellular delivery system for IL-3 gene transfection to promote hematopoiesis recovery of mice after high dose chemotherapy. BMSCs were transfected with recombinant adenovirous containing murine IL-3 gene(MOI = 10), the level of mIL-3 secreted by gene-modified BMSCs was 110U/ml/10~6 cells/ 24h in vitro. The mice were injected with high dose cyclophosphamide(200mg/kg) i.p. and after 24 hours the IL-3 gene-modified BMSCs(2 x 10~6/mouse) were transplanted intrasplenically. White blood cell counts in peripheral blood of mice received intrasplenic injection of IL-3-BMSCs were kept at a high level within two weeks after chemotherapy. The pathological sections of spleens and bone marrow showed significant recovery of hematopoiesis, compared with that of mice received chemotherapy only. The data indicated the feasibility of IL-3 gene-modified BMSCs transplantation in the acceleration of hematopoiesis recovery after chemotherapy.

After murine fetal liver cells (FLC) were transfected with granulocyte-macrophage colony-stimulating factor (GM-CSF) gene by recombinant adenovirus and intrasplenically transplanted into allogeneic mice, the effects of GM-CSF gene-transfected FLC on the recovery of immune response inhibited by chemotherapy were observed. The number of CD4 + cells and the ratio of CD4 + /CDS + cells from peripheral blood lymphocytes increased significantly. The cytotoxicity of the NK cells and the proliferation response of splenocytes to ConA, LPS elevated markedly, but the same results were not from bone marrow. These data demonstrated that intrasplenic transplantation of GM-CSF gene-transfected FLC could effectively accelerate the recovery of immune response after high-dose chemotherapy.

A geometrical model of L4-L5 lumbar segment was constructed using a three-dimensional graphics software. Four conditions of the degenerated discs, i. e. light degeneration, moderate degeneration, severe degeneration and complete excision degeneration, were simulated with loading situations using finite element method under the condition of appropriate computational accuracy. By applying a vertical load of 378.93 N on L4 vertebral plate, stress nephograms on joint isthmus under four different working conditions were obtained. The results showed that the contacted area of facet joint was influenced by the degree of intervertebral disc degeneration level, which influenced the mises stress on joint isthmus. It was proved that joint isthmus was the important pressure-proof structure of the back of lumbar vertebra, and the stress values and distribution were related to structural stiffness of the back of lumbar vertebra as well as the contact area of facet joint. The conclusion could be the theoretical reference for the analysis of spinal biomechanics and artificial disc replacement as well.
Biomechanical Phenomena ; Finite Element Analysis ; Humans ; Intervertebral Disc ; pathology ; Intervertebral Disc Degeneration ; Lumbar Vertebrae ; physiopathology ; Models, Anatomic ; Pressure ; Zygapophyseal Joint

Objective: To study the treatment of experimental lung metastasis by intratracheal injection of IL 18 gene recombinant adenovirus. Methods: (1)The mouse IL 18 mRNA was detected by RT PCR, the concentrations of IL 18, associated cytokines in lung lavage and blood were determined by ELISA at different times after intratracheal injection of IL 18 recombinant adenovirus. (2)The lung metastasis nodes, mouse survival period, survival rates were investigated in the treatment of experimental lung metastasis in C57BL/6 mouse model. The NK activity and CTL activity were determined by 51 Cr 4 h release method. Results: (1)The IL 18 mRNA could be detected in lung tissue 6 h after intratracheal use of IL 18 recombinant adenovirus, and the concentrations of IL 18 in lung lavage was higher than that of peripheral blood, and both IL 18 mRNA and IL 18 could not be detected in control groups. (2)Intratracheal use of IL 18 recombinant adenovirus had significant therapeutic effect on experimental lung metastasis with the results of increased CTL and NK activity, and with longer survival period and higher survival rates compared with the control groups. Conclusion: Intratracheal usage of adenovirus vector containing IL 18 gene has therapeutic effect on the lung metastasis, denoting that gene therapy of lung diseases can be done through airway directly with recombinant adenovirus.

Objective To investigate the mechanisms of tacrolimus on the migration of Langerhans′ cells. Methods The concentration of MCP-1 in the cultured supernatants of HaCaT cell treated with tacrolimus was determined by ELISA. The expression level of MCP-1 mRNA in HaCaT cell treated with tacrolimus was studied by RT-PCR method. Results The concentration of MCP-1 in HaCaT cell treated with 625 ～ 5 000 ng/mL of tacrolimus was significantly decreased. The expression level of MCP-1 mRNA was also markedly decreased. Conclusions Tacrolimus may probably decrease the expression of MCP-1 in keratinocytes and suppress the chemotactic ability of Langerhans′ cells precursor and Langerhans′ cells, thus inhibiting or diminishing certain local immunoreaction.

To investigate effects of rhIL-17 on growth and development of mouse bone marrow progenitors andhuman cord blood LD34~+ stem cells. Methods: Mouse bone marrow progenitors were isolated by routine protocol, and CD34~+ stem cells were isolated from normal human cord blood by Mini-MACS, then cultured with rhIL-17 and/or GM-CSF/IL-4. The phenotypes of the cells were analyzed by FACS, IL-12 level was analyzed by ELISA and T cell stimulating activity in allo-MLR was determined by [~3H]-TdR incorporation. Results: Expression of MHC class II molecules and B7-2 on the surface of immature DC derived from mouse bone marrow progenitors was up-regulated by IL-17. The capacity of the cells to secrete IL-12 and their T cell stimulating activity were also enhanced. The cells showed the characteristics of mature DC. After cultured with IL-17 for 9 days, the number of CD34~+ stem cells increased by 2 times. The phenotypes of some cells were CDla~(high), B7-2~(high), and HLA-DR~(lwo). The cells could stimulate allo geneic T cells to proliferate but their capacity was lower than that of the cells cultured with IL-17 combined with GM-CSF. The cells cultured with IL-17 and GM-CSF proliferated markedly and the rate of CDla~+ and B7-2~+ cells increased significantly. The T cell stimulating activity of cells was also augmented. Conclusion: IL-17 could promote DC derived from mouse bone marrow progenitors to mature. When combined with GM-CSF, IL-17 could induce human CD34~+ stem cells not only to proliferate markedly but also to show characteristics of DC, indicating that CD34~+ stem cells might differentiate to DC by IL-17.

Interleukin-6 (IL-6) is a pleiotropic cytokine which has antitumor activity. In the present study, a model for fibroblasts-mediated IL-6 gene therapy and its immune regulation are described. Human IL-6 cDNA was inserted into plasmid vector BCMGNeo containing a neomycin resistance gene. BCMGNeo-IL-6 was transferred into NIH3T3 fibroblasts by calcium phosphate coprecipitation method. A fibroblast clone (T6.6) secreting 1L-6 at highest level was selected by G418 resistance selection and limiting dilution. When T6.6 was implanted i.p. into mice, IL-6 could be detected in serum after 12 h. Even after 96 h, serum IL-6 still maintained at high level. Lymphocyte proliferation and IL-2 production could be enhanced significantly after in vivo implantation of T6.6. These results demonstrate that fibroblasts -mediated IL-6 gene therapy could augment immune function efficiently and outline a novel strategy for cancer treatment.