The Regulation of Reactive Oxygen Species on Dendritic Cells / 中国生物化学与分子生物学报

Dendritic cells (DCs) are specialized antigen-presenting cells. Immature dendritic cells can be activated into mature dendritic cells by recognizing antigens, then the antigens are processed and pres-ented to T lymphocytes. DCs play a vital role in initiating immune response, regulating immune response and maintaining immune tolerance. Therefore, regulating the immune function of DCs can be used to treat diseases such as autoimmune diseases and tumors. With the deepening of research on the regulation of DCs, people have gradually realized that the existence of reactive oxygen species (ROS) in DCs is of great significance. ROS is a term of strong oxidizing reactive species, and the dynamic balance of its pro-duction and removal is the key to maintaining cell redox homeostasis. ROS of physiological level is an im-portant molecule involved in a variety of signal pathways, which can regulate cell growth, differentiation and different physiological and biochemical reactions. The changes in the level of ROS affect the state and function of cells. In addition, because there are many ways to produce ROS in the cell, the effects of dif-ferent sources of ROS on DCs are not usually the same; and even the same source of ROS may have dif-ferent effects when cells are in different states. This article summarized the influence of intracellular ROS changes and different sources of ROS on the differentiation, maturation and function of DCs, aiming to re-veal how ROS plays an important role in regulating the immune function of DCs. At the same time, this article also showed the urgent need for the in-depth study of ROS regulating the function of DCs, which may help the application of DCs immune regulation to a wider range of disease treatments.

Long-term efficacy of dendritic cell vaccines combined with cytokine-induced killer cells in the treatment of metastatic renal cell carcinoma / 中国肿瘤生物治疗杂志

@# Objective: To evaluate the long-term clinical efficacy and follow-up of dendritic cell (DC) vaccines in combination with cytokine-induced killer cell (CIK) treatment in metastatic renal cell carcinoma. Methods: From January 2011 to December 2013, 29 patients with metastatic renal cell carcinoma (pathologically confirmed as renal clear cell carcinoma) were treated by DC vaccines-CIK at the Department of Hematopoietic Stem Cell Transplantation, the Fifth Medical Center of Chinese PLA General Hospital. The 29 patients included 24 male and 5 female, with a median age of 57(32-81) years old. Mature DC vaccine was obtained by gene transfection technology and CIK cells were obtained by i n v i t r o culture; and DC vaccine-CIK was infused back to patients through lymphatic drainage area and vein by each course. Twelve patients received first line treatment, 6 patients received second line treatment after the disease progression by targeted drug therapy or cytokine therapy, and 11 patients received third-linetreatment or above. The long-term clinical efficacy and overall survival rate were evaluated. Results: The median follow-up time was 5 (1-7) years. Treatment cycle was over 2 (2-23) cycles. One case (3.4%) achieved complete remission, 9 cases (31%) achieved partial responses, 13 cases (44.8%) demonstrated stable disease over 3 months and 6 patients (20.7%) developed progressive disease. The objective response rate was 34.4%,and the disease control rate was 79.2%. Stable disease for more than one year realized in 19 cases (65.5%). The 1-, 3- and 5-year survival rates were 93.1% (27/29), 65.5% (20/29) and 51.7% (15 / 29), respectively. Neither the median progression-free survival (PFS) nor the median survival time was achieved. No adverse reactions above grade 3 were observed during treatment. Conclusion: DC vaccines-CIK therapy for the treatment of metastatic renal cell carcinoma is affirmative; it achieved good disease control and long-term survival with controllable safety, and prolonged the survival time for advanced renal cell carcinoma patients.

Inhibitory effects of DC vaccine sensitized with MAGE-3 combined with CpG ODN on bladder cancer BIU-87 cells / 中国肿瘤生物治疗杂志

@#Objective: To investigate the role of CpG ODN (CpG oligodeoxynucleotide) adjuvant in enhancing the anti-bladder cancer response induced by MAGE-3 (melanoma antigen gene -3) antigen and its molecular mechanism. Methods: Mononuclear cells were isolated from HLA-A2 type peripheral blood of healthy donors by Ficoll method to prepare mature DC by conventional means. DC surface markers were detected by flow cytometry. MTT assay was used to detect the promotion effect of DCs sensitized by different means (MAGE-3, CpGODN, MAGE-3+CpG ODN, irrelevant control antigen) on the proliferation of T lymphocytes and the killing effect of CTL on BIU-87 tumor cells. The tumor mass of nude mice bearing BIU-87 bladder cell xenograft were examined on Day 7 and 11 after CpG ODN+MAGE-3 sensitized DC treatment. The expression of Bcl-2/Bax protein was detected by Western blotting while the proliferation level of xenograft cells was detected by MTT assay. Results: DCs sensitized by CpG ODN combined with MAGE-3 antigenic peptides could promote the proliferation of T lymphocytes and significantly enhance the killing effect of CTLon target BIU-87 cells (P< 0.05). Compared with other sensitized DCs, in vivo experiments showed that 7 and 11 days after treatment, both the tumor volume and weight were significantly reduced (all P<0.05), and the proliferation ability of xenograft tumor was decreased (P<0.05). Compared with other sensitization means, CpG ODN+MAGE-3 especially exhibited obvious inhibitive effect on tumor growth on Day 11, and significantly promoted the proliferation of splenic monocytes of tumor bearing mice (P<0.01); moreover, Bcl-2 expression in xenograft tissues significantly decreased（P<0.01）while Bax expression significantly increased（P<0.05 or P<0.01）on Day 3 after treatment. Conclusion: CpG ODN can promote the inhibitory effect of MAGE-3 sensitized DC on bladder cancer BIU-87 cells, which will provide experimental basis for clinical application of DC vaccine in bladder cancer treatment.

Effect of PvMSP1 on differentiation,maturation and function of dendritic cells / 中国血吸虫病防治杂志

Objective To investigate the effects of Plasmodium vivax merozoite surface protein 1(PvMSP1)on differentia-tion,maturation and function of dendritic cells(DC)and the mechanisms of PvMSP1 on the activation of DC via toll like receptors (TLR). Methods DCs were incubated with different doses of PvMSP1(1.0,10.0,100.0μg/ml)in vitro. The changes of CD83, CD86,and HLA-DR on DC were detected by flow cytometry(FCM);the expressions of cytokine IL-10 and IL-12 of DC were mea-sured by ELISA;the expressions of TLR4 and TLR9 mRNA of DC were measured by RT-PCR;the proliferation induction to autol-ogous lymphocytes of DC was measured by MTT. Meanwhile,the untreated DC and LPS inducing DC were as the negative control and positive control,respectively. All the data were analyzed statistically. Results Compared with the untreated DC,the propor-tions of CD83,CD86 and HLA-DR on DC induced by LPS and PvMSP1 increased significantly(all P0.05). In the PvMSP1-treated group,the DC TLR4 mRNA production increased(P0.05);DC stimulated the proliferation of autologous lympho-cytes. Conclusion PvMSP1 enhances DC differentiation and maturation,and the mature DC induced by PvMSP1 has the ability of antigen presenting. The route for PvMSP1 inducing DC maturation might be TLR4 pathway rather than TLR9 pathway.

Enhanced CEA-specific Immune Responses by Tat-LLO Fusion Protein

BACKGROUND: Carcinoembryonic antigen (CEA) is well-known soluble tumor marker frequently detectable in peripheral blood of carcinoma patients and considered as good target for antigen-specific immunotherapy. However, it is known that the induction of immune response to CEA is very difficult because CEA is a self-antigen expressed in fetal cells and weakly expressed in normal colorectal epithelial cells. To enhance anti-tumor immunity specific for CEA, recombinant CEA protein was modified using listeriolysin O (LLO) for endosomal lysis and transactivator of transcription (Tat) domain for transducing extracellular proteins into cytoplasm. METHODS: After immunization using dendritic cells pulsed with Tat-CEA, both Tat-CEA and LLO, and both Tat-CEA and Tat-LLO, antibody titer to CEA and LLO, cytotoxic T lymphocyte activity and the frequency of IFN-gamma producing T lymphocytes were measured. RESULTS: Immunization using DC pulsed with both Tat-CEA and Tat-LLO protein showed the increasement of production of CEA-specific antibody in serum, cytotoxic T lymphocyte activity, the frequency of IFN-gamma secreting T cells, compared with DC pulsed with both Tat-CEA and LLO. Furthermore the ratio of CD8+ T cell to CD4+ T cell among CEA-specific T cells was increased in group pulsed with both Tat-CEA and Tat-LLO. CONCLUSION: These results suggested that DC vaccine using Tat-LLO could be used for the development of effective immunotherapy for the treatment of tumor.

Induction of CEA-specific Cytotoxic T Lymphocytes by Murine Dendritic Cells Expressing CEA

BACKGROUND: Carcinoembryonic antigen (CEA) is well-known soluble tumor marker frequently detectable in peripheral blood of carcinoma patients and considered as good target for antigen-specific immunotherapy. In this study, we used a replication-deficient adenovirus containing CEA to study CTL induction in vitro after adenovirus-mediated gene transfer into DC. METHODS: DC were obtained from mouse bone marrow and cultured with IL-4 and GM-CSF. For measuring CTL activity, splenocytes were harvested from the mice, which were immunized with DC that had been infected AdV-CEA or pulsed with CEA peptide. Untreated DC was used as a control. Splenocytes were re-stimulated in vitro with DC pulsed with CEA peptide for 7 days and CTL activity with CEA peptide-pulsed EL-4 cells were assessed in a standard 51Cr-release assay. The frequencies of antigen-specific cytokine-secreting T cell were determined with mIFN-gamma ELISPOT. RESULTS: DC infected with recombinant adenovirus expressing CEA induced CEA-specific CTL responses in vivo. Splenocyte induced from mice immunized with AdV-CEA-infected DC increase in the number of IFN-gamma secreting T cells compared with those from mice immunized with CEA peptide-pulsed DC. CONCLUSION: These results suggested that DC infected with recombinant adenovirus has advantages over other forms of vaccination and could provide an alternative approach vaccination therapies.

Enhanced Induction of CEA Specific Tumor Immunity by TatCEA Fusion Protein

PURPOSE: The human carcinoembryonic antigen (CEA) is expressed in several tumor types, including colorectal cancer, and is a tumor-associated antigen used as a target for antigen-specific immunotheraphy. CEA is a self-antigen associated with development, expressed in fetal cells and rarely expressed in normal colorectal epithelial cells. The induction of immune response to CEA is very difficult. In this study, we attempted to increase the tumor immunity specific to CEA by using dendritic cells pulsed with fusion proteins of CEA and Tat (transactivator of transcription), which transduces extracellular proteins into cytoplasm and causes antigens to be presented with MHC class I pathway. METHODS: The Tat gene was amplified in the PNL4-3 HIV plasmid and then inserted into PCEP4 plasmid vector. The CEA gene was cloned from cDNA from LoVo human colorectal cell line and then amplified through polymerase chain reaction method. After cloning of PCEP4 plasmid vector, the dendritic cell was sensitized and internalized with CEA and Tat-CEA protein. Then the Western blot analysis of the expression of CEA in the gene-modified dendritic cell and the immunofluorescent staining of the expression of CEA in CEA or Tat-CEA-pulsed dendritic cell were performed. A detection of IFN-gamma-releasing CD8 cell and a cytotoxicity of T-cell were was assesed using ELISPOT assay. The Immunoglobulin (Ig) G isotypes were analyzed with enzyme-linked immunosorbent assay. The statistical significance was assessed using Students t-test. RESULTS: CEA pulsed in dendritic cells was distributed over the cell surface and TatCEA was observed in the cytoplasm. The cellular immune responses by immunization with dendritic cells pulsed with TatCEA (322/10(4) lymphocytes) were significantly increased compared with those with CEA (244/10(4) lymphocytes) by IFN-gamma ELISPOT assay (P<0.05). The cytotoxic T lymphocyte (CTL) activity using mouse T-cell, EL-4 pulsed peptide (EAQNTTYL) as target cells was 23.3+/-2.75% (E:T=1:100) in the CEA group and 22.9+/-2.23% (E:T=1:100) in the TatCEA group. In ELISA analysis of the IgG isotype, the titer of IgG2a and IgG3, representing Th1 immune response, was lower than that of IgG1, representing Th2 immune response, in both the CEA group and the TatCEA group. CONCLUSIONS: These results suggest that TatCEA could be used for the development of a tumor vaccine and cellular immunotherapy using CTLs induced in vitro.

Induction,proliferation and functional study of specific anti-acute myeloid leukemia(AML) T cells / 中国免疫学杂志

Objective:To develop specific anti-AML T cells in vitro,and to study their biological characteristics and functions.Methods:Peripheral blood or bone marrow mononuclear cells (MNCs) were isolated from 12 patients with AML,and co-cultured with cytokine combinations in 96 well plates to be induced into dendritic cells (DCs).Cell morphology was observed under an inverted microscope during the first week and immunophenotype was detected by flow cytometry at day 7.Cytokine combination was replaced with high dose IL-2 at day 7 to promote specific anti-AML T cells.T cell phenotype was detected after 4 to 5 weeks.Lactate dehydrogenase (LDH) release assay was used to determine T cell killing activity.Results:After being cultured with cytokine combinations,the typical dendritic appearance with delicate membrane projections was observed.CD80,CD86 and HLA-DR markers were significantly upregulated(P

The effect of PA on the proliferation and maturation of cord blood derived DC in vitro / 中国药理学通报

Aim To study the effect of PA on the proliferation and maturation of cord blood derived DC in vitro. Methods The monocytes were isolated from human umbilical cord blood and cultured with PA, GM-CSF+IL-4+TNF-?(GTI), GTI+PA (GTIP), respectively. On day 7 of cultivation, the CD1a, CD83,HLA-DR and CD34 antigens expression of cells were analyzed by immunohistochemistry. Result The cells with typical morphological properties of DC can be observed with electron microscope among PA, GTI and GTIP groups. The CD1a and CD83 positive rates of PA group increased significantly, reaching 19.63%?3.61% and 14.52%?5.79% respectively, much higher than that of the control. In addition, compared with GIT group, the positive rate in GTIP group has increased remarkably. Conclusion PA does not only promote the proliferation and maturation of cord blood derived DC, but also cooperate with GTI to enhance the production of DC. PA is a useful activator of DC.

Enhancement of the cytotoxic effect of cytokine induced killers by dendritic cells pulsed with astragalus polysaccharides / 中国免疫学杂志

Objective:To observe the effects of Astragalus polysaccharides on antigen presentation of dendritic cells(DC).Methods:DC and CIK cells were generated by culturing PBMC of healthy blood donor.The typical DC and DC pulsed by Astragalus polysaccharides were co-cultured with CIK cells,respectively.Then the changes in the phenotypes of the DCs pulsed with Astragalus polysaccharides were determined.Cell surface markers were analysed by FACS method.IFN-? and IL-12 secreted by co-cultured cells were detected by ELISA.The cytotoxicity of effector cells on A549 cells in vitro were measured by MTT assays.Results:Astragalus polysaccharides could increase the expression of CD40,CD80 and HLA-DR on DC surface.The Astragalus polysaccharides pulsed DC-CIK cells resulted in an enhanced killing activity to A549 cells than that of unpulsd DC-CIK cells(P