OBJECTIVETo investigate the mechanisms underlying the ability ofheparin-treated dendritic cells (DCs) to promote Th0 to Th1 differentiation in chronic hepatitis B (CHB).

METHODSPeripheral blood mononuclear cells (PBMCs) were isolated from CHB patients and cultured in RPMI-1640 with recombinant GM-CSF and IL-4 with or without heparin to obtain DCs for study. The levels of Toll-like receptors (TLRs) on the DCs were measured using FACS and qPCR techniques.DC subsets with high expression of TLRs were selected for analysis of functional changes by treatment with the corresponding TLR-siRNA. The CD4+ T cell subpopulation was purified from peripheral blood by Dynal immunomagnetic beads, and then the production of IL-12 by DCs in the presence of poly(I:C) or R848 and ofIFN and IL-4 by Th cells co-cultured with DCs was evaluated by ELISA. The t-test was used for statistical analysis.

RESULTSTLR3 expression, and not expression of TLR 7 or TLR8,was significantly increased in heparin-treated DCs as compared to levels detected in the DCs without heparin treatment (t =2.849,P less than 0.05;t =3.027,P less than 0.05). The level of IL-12 produced by heparin-treated DCs stimulated with poly(I:C) was obviously higher than that produced by DCs without heparin treatment and stimulated with poly(I: C) (t =8.68,P less than 0.01) or with R848 (t =19.01,P less than 0.01). However, the IL-12 production by TLR3-siRNA transfected-DCs was significantly reduced (t =31.49, P less than 0.01).When Th cells from allogenic patients with CHB were co-cultured with the TLR3-siRNA transfectedDCs, the frequency ofCD4+ IFN+ cells was significantly reduced (1.64+/-0.57% vs.6.31+/-0.88%,P less than 0.01),as was the capability of Thl to generate IFNg (t =20.83,Pless than 0.01).

CONCLUSIONHeparin may have up-regulated the TLR3 expression level of DCs, and sequentially promoted Th0 to Th1 differentiation.

CD4-Positive T-Lymphocytes ; cytology ; Cell Differentiation ; Coculture Techniques ; Dendritic Cells ; cytology ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; Heparin ; pharmacology ; Hepatitis B, Chronic ; immunology ; Humans ; Interferon-gamma ; metabolism ; Interleukin-12 ; metabolism ; Interleukin-4 ; pharmacology ; Monocytes ; cytology ; Recombinant Proteins ; pharmacology ; Toll-Like Receptor 3 ; metabolism

Although mesenchymal stem cells (MSCs) are increasingly used to treat graft-versus-host disease (GVHD), their immune regulatory mechanism in the process is elusive. The present study aimed to investigate the curative effect of third-party umbilical cord blood-derived human MSCs (UCB-hMSCs) on GVHD patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and their immune regulatory mechanism. Twenty-four refractory GVHD patients after allo-HSCT were treated with UCB-hMSCs. Immune cells including T lymphocyte subsets, NK cells, Treg cells and dendritic cells (DCs) and cytokines including interleukin-17 (IL-17) and tumor necrosis factor-alpha (TNF-α) were monitored before and after MSCs transfusion. The results showed that the symptoms of GVHD were alleviated significantly without increased relapse of primary disease and transplant-related complications after MSCs transfusion. The number of CD3(+), CD3(+)CD4(+) and CD3(+)CD8(+) cells decreased significantly, and that of NK cells remained unchanged, whereas the number of CD4(+) and CD8(+) Tregs increased and reached a peak at 4 weeks; the number of mature DCs, and the levels of TNF-α and IL-17 decreased and reached a trough at 2 weeks. It was concluded that MSCs ameliorate GVHD and spare GVL effect via immunoregulations.
Adolescent ; Adult ; Cord Blood Stem Cell Transplantation ; methods ; Cytokines ; metabolism ; Dendritic Cells ; metabolism ; Female ; Graft vs Host Disease ; immunology ; therapy ; Hematopoietic Stem Cell Transplantation ; adverse effects ; Humans ; Immunomodulation ; Killer Cells, Natural ; metabolism ; Male ; T-Lymphocyte Subsets ; metabolism ; Transplantation, Homologous ; adverse effects ; Young Adult

OBJECTIVETo investigate the effects of anti-infection treatment on the expressions of antigen-presenting-related membrane-surface molecules HLA-DR and CD86 in dendritic cells (DCs) in rabbit buccal VX2 squamous cell carcinoma tissue complicated with local inflammation.

METHODSRabbit buccal VX2 squamous cell carcinoma with local inflammation models that were established by inflammation was induced by inoculation VX2 tumor, mechanical trauma, and drinking of milk with high sugar viscosity. The animals were divided into four groups. Group A (n=12): rabbit buccal VX2 squamous cell carcinoma with local inflammation, procaine penicillin was intramuscularly given, and tinidazole tablets were given by gavage for three consecutive days. Group B (n = 12): rabbit buccal VX2 squamous cell carcinoma with local inflammation, normal saline was intramuscularly given, and aspirin were given by gavage for three consecutive days. Group C (n = 12): rabbit buccal VX2 squamous cell carcinoma with local inflammation, normal saline was given intramuscularly and by gavage for three consecutive days. Group D (n = 10): rabbit buccal VX2 squamous cell carcinoma, normal saline was given intramuscularly and by gavage for three consecutive days. All the rabbits were sacrificed for collection of tumor specimens, and the expression levels of membrane-surface HLA-DR and CD86 in DCs of tumor specimens were detected viaflow cytometry.

RESULTSThe positive expression rate of HLA-DR and the double positive expression rate of HLA-DR and CD86 were group A > group D > group B > group C. The positive expression rate of CD86 were group A > group D > group B and group C (P < 0.05).

CONCLUSIONAnti-infection treatment significantly increased the expressions of HLA-DR and CD86 in DCs of rabbit buccal VX2 squamous cell carcinoma tissue complicated with local inflammation.

Animals ; Carcinoma, Squamous Cell ; immunology ; Dendritic Cells ; HLA-DR Antigens ; metabolism ; Inflammation ; Rabbits

Dendritic cells (DCs) comprise two functionally distinct subsets: plasmacytoid DCs (pDCs) and myeloid DCs (mDCs). pDCs are specialized in rapid and massive secretion of type I interferon (IFN-I) in response to nucleic acids through Toll like receptor (TLR)-7 or TLR-9. In this report, we characterized a CD56(+) DC population that express typical pDC markers including CD123 and BDCA2 but produce much less IFN-I comparing with pDCs. In addition, CD56(+) DCs cluster together with mDCs but not pDCs by genome-wide transcriptional profiling. Accordingly, CD56(+) DCs functionally resemble mDCs by producing IL-12 upon TLR4 stimulation and priming naïve T cells without prior activation. These data suggest that the CD56(+) DCs represent a novel mDC subset mixed with some pDC features. A CD4(+)CD56(+) hematological malignancy was classified as blastic plasmacytoid dendritic cell neoplasm (BPDCN) due to its expression of characteristic molecules of pDCs. However, we demonstrated that BPDCN is closer to CD56(+) DCs than pDCs by global gene-expression profiling. Thus, we propose that the CD4(+)CD56(+) neoplasm may be a tumor counterpart of CD56(+) mDCs but not pDCs.
Biomarkers ; metabolism ; CD56 Antigen ; genetics ; immunology ; Cell Lineage ; genetics ; immunology ; Dendritic Cells ; immunology ; metabolism ; pathology ; Gene Expression ; Hematologic Neoplasms ; genetics ; immunology ; pathology ; Humans ; Immunophenotyping ; Interferon Type I ; biosynthesis ; metabolism ; Interleukin-12 ; biosynthesis ; metabolism ; Interleukin-3 Receptor alpha Subunit ; genetics ; immunology ; Lectins, C-Type ; genetics ; immunology ; Membrane Glycoproteins ; genetics ; immunology ; Myeloid Cells ; immunology ; metabolism ; pathology ; Receptors, Immunologic ; genetics ; immunology ; Terminology as Topic ; Toll-Like Receptor 4 ; genetics ; immunology ; Toll-Like Receptor 7 ; genetics ; immunology ; Toll-Like Receptor 9 ; genetics ; immunology

OBJECTIVETo explore the anti-tumor effect and its mechanism of Sendai virus Tianjin strain defective interfering particles (DIP) on mouse models of colon carcinoma.

METHODSCT26 cells (5×10(6)/0.1 ml) were subcutaneously injected into the back of Bal B/c mice to establish murine colon carcinoma model. After the tumors reached 5 mm in diameter, the mice were randomly divided into Tianjin strain DIP group and saline control group. The former was intratumorally injected with Tianjin strain DIP (0.1 ml) once a day on day 4, 7, 10 and 13 after CT26 cell inoculation. The latter was intratumorally injected with the same volume of saline. Tumor volume and survival rate of the mice were calculated to confirm the anti-tumor effect of DIP. Flow cytometry and ELISA were used to examine the maturation and release of cytokines IL-6, IFN-α and TNF-α from murine myeloid dendritic cells (DCs) induced by Tianjin strain DIP. Moreover, real-time RT-PCR and immunohistochemistry were performed to identify whether the Tianjin strain DIP could induce infiltration of CD11c(+) DCs, CD4(+) and CD8(+) T cells in the tumors.

RESULTSOn day 22 after CT26 cell inoculation, the average tumor volume of the Tianjin strain DIP group was (33.2 ± 2.0) mm(3), significantly smaller than that of the control group [(2 376.0 ± 130.8)mm(3), P < 0.01]. On day 50 after CT26 cell inoculation, the survival rate of mice was 90.0% in the Tianjin strain DIP group, much higher than that of the control group (30.0%, P < 0.01). Flow cytometry analysis showed that the expression of markers of DCs maturation, including CD40, CD80 and CD86, was dose-dependently increased by DIP or intact virus. No statistically significant difference was found betweent the DIP and intact virus groups. ELISA results showed that DIP could stimulate the secretion of IL-6, IFN-α and TNF-α from mouse DCs. The secretion of all of the cytokines was dose-dependently increased by DIP or intact virus. Real-time RT-PCR revealed that the expression of CD4, CD8 and CD11c mRNAs was increased in tumors treated with DIP compared with that of the saline group at all time points. Moreover, the expression level of all of them remained maximal at 120 h after the last treatment. Immunohistochemical staining revealed that the ratios of CD4(+), CD8(+) T cells or CD11c(+) DCs to total cells were (21.60 ± 1.49)%, (22.12 ± 2.84)% and (23.05 ± 2.91)%, respectively, in the DIP-treated tumors. In the tumors treated by saline, the ratios were (2.62 ± 0.60)%, (4.05 ± 0.12)% and (3.10 ± 0.09)%, respectively. The difference between experimental group and control group had statistical significance.

CONCLUSIONSTianjin strain DIP may exert anti-tumor effect on tumor-bearing mice. The mechanism is related with the antitumor immunity induced by DCs and T cells.

Animals ; Cell Line, Tumor ; Colonic Neoplasms ; metabolism ; pathology ; Cytokines ; metabolism ; Defective Viruses ; immunology ; Dendritic Cells ; metabolism ; Female ; Interferon-alpha ; metabolism ; Interleukin-6 ; metabolism ; Mice ; Mice, Inbred BALB C ; Neoplasm Transplantation ; Random Allocation ; Sendai virus ; immunology ; T-Lymphocytes ; metabolism ; Tumor Burden ; Tumor Necrosis Factor-alpha ; metabolism

Dendritic cells (DCs) are key modulators that shape the immune system. In mucosal tissues, DCs act as surveillance systems to sense infection and also function as professional antigen-presenting cells that stimulate the differentiation of naive T and B cells. On the basis of their molecular expression, DCs can be divided into several subsets with unique functions. In this review, we focus on intestinal DC subsets and their function in bridging the innate signaling and adaptive immune systems to maintain the homeostasis of the intestinal immune environment. We also review the current strategies for manipulating mucosal DCs for the development of efficient mucosal vaccines to protect against infectious diseases.
Animals ; Dendritic Cells/*immunology/metabolism ; Humans ; Immunity, Mucosal ; Intestinal Mucosa/cytology/*immunology ; T-Lymphocytes, Helper-Inducer/immunology

Dendritic cells (DCs), which are regarded as the most potent antigen-presenting cells, are involved in innate and adaptive immunity. Upon uptake of pathogens, DCs express cell surface markers and secrete cytokines. In this study, we analyzed production of cytokines and found that interleukin (IL)-10 and transforming growth factor (TGF)-beta production significantly increased in bone marrow-derived DCs and a mouse DC line, DC2.4, after treatment with crude antigen (CA) from liver fluke, Clonorchis sinensis. However, expression patterns of several activation molecules did not change. In addition, following treatment of DC2.4 cells with antigen from the lung fluke, Paragonimus westermani, production of IL-10 and TGF-beta significantly increased compared with groups treated with other parasite antigens, Spirometra erinacei plerocercoid CA and Echinococcus granulosus hydatid cystic fluid. We also found that treatment of DC2.4 cells with C. sinensis CA resulted in rapid and significant phosphorylation of extracellular signal-regulated kinase 1/2, a mitogen-activated protein kinase. Following treatment of DC2.4 cells with C. sinensis CA, treatment with an inhibitor specific to an extracellular signal-regulated kinase inhibited production of IL-10 and TGF-beta. Our results suggest that CA from C. sinensis has a role in the anti-inflammatory function of DC cells by inducing IL-10 and TGF-beta through activation of extracellular signal-regulated kinase 1/2.
Animals ; Antigens, Helminth/*pharmacology ; Cells, Cultured ; Clonorchis sinensis/*immunology ; Dendritic Cells/drug effects/*metabolism ; Interleukin-10/genetics/*metabolism ; MAP Kinase Signaling System ; Mice ; Transforming Growth Factor beta/genetics/*metabolism

OBJECTIVEAntigen-presenting cells such as monocytes and dendritic cells (DCs) stimulate T-cell proliferation and activation during adaptive immunity. This cellular interaction plays a role in the growth of atherosclerotic plaques. Tanshinone II A (TSN) had been shown to decrease the growth of atherosclerotic lesions. We therefore investigated the ability of TSN to inhibit human monocyte-derived DCs and their T-cellstimulatory capacity.

METHODSDCs derived from human monocytes cultured with recombinant human interleukin (IL)-4 and recombinant human granulocyte-macrophage colony-stimulating factor were co-cultured with TSN and lipopolysaccharide for 48 h. Phosphate-buffered saline was used as a negative control. Activation markers and the capacity of DCs for endocytosis were measured by flow cytometry, and proinflammatory cytokines were measured by enzyme-linked immunosorbent assays. DCs were co-cultured with lymphocytes to measure T-cell proliferation and IL-2 secretion by mixed lymphocyte reactions.

RESULTSTSN dose-dependently attenuated DC expression of costimulatory molecules (CD86), and decreased expression of major histocompatibility complex class II (human loukocyte antigen-DR) and adhesion molecules (CD54). Moreover, TSN reduced secretion of the proinflammatory cytokines IL-12 and IL-1 by human DCs, and restored the capacity for endocytosis. Finally, TSN-preincubated DCs showed a reduced capacity to stimulate T-cell proliferation and cytokine secretion.

CONCLUSIONSTSN inhibits DC maturation and decreases the expression of proinflammatory cytokines, while impairing their capacity to stimulate T-cell proliferation and cytokine secretion. These effects may contribute to the influence of TSN on the progression of atherosclerotic lesions.

Antigen-Presenting Cells ; drug effects ; Atherosclerosis ; immunology ; pathology ; B7-2 Antigen ; metabolism ; Cell Membrane ; drug effects ; metabolism ; Cytokines ; secretion ; Dendritic Cells ; drug effects ; immunology ; secretion ; Diterpenes, Abietane ; pharmacology ; Endocytosis ; drug effects ; Flow Cytometry ; Humans ; Immunity, Cellular ; drug effects ; Inflammation Mediators ; metabolism ; Lymphocyte Activation ; drug effects

OBJECTIVETo investigate the mechanism of Mycobacterium tuberculosis invasion to mouse dendritic cells (DC).

METHODSMycobacterium tuberculosis strain H37Rv was co-cultured with mouse DC2.4 cells.The mRNA expression of Toll-like receptor 2/4(TLR2/4) in DC2.4 cells was detected by fluorescent quantitative real-time PCR and the protein expression of nuclear factor κB(NF-κB) was assessed by Western blotting.The extracellular concentration of tumor necrosis factor α(TNF-α) was measured by ELISA methods during Mycobacterium Tuberculosis invasion.Indirect immunofluorescent staining and flow cytometry assay were used to detect the expression of CD80 and CD86 on DC2.4 cells before and after invasion.

RESULTSThe invasion of Mycobacterium tuberculosis in DC2.4 cells was observed after 2 h of co-incubation.The rates of invasion were (37.9±5.6)%,(51.2±7.6)%,(57.2±8.9)% and(63.9±6.8)% at 6,8,10 and 12 h after co-incubation,respectively.The mRNA expression level of TLR2 /4 was significantly increased at 6 h but decreased at 10 h after co-incubation.The expressions of NF-κB p65 and TNF-α were higher in DC2.4 cells after being invaded by 6,8,and 10 h and then gradually decreased.CD80 and CD86 expression were increased on DC2.4 at 6 h after co-incubation.

CONCLUSIONInvasion of Mycobacterium tuberculosis strain H37Rv to DC might enhance its antigen-presenting function through activation of TLR2/4-NF-kB signaling pathway.

Animals ; B7-1 Antigen ; metabolism ; B7-2 Antigen ; metabolism ; Cells, Cultured ; Dendritic Cells ; immunology ; metabolism ; Mice ; Mycobacterium tuberculosis ; NF-kappa B ; metabolism ; Signal Transduction ; Toll-Like Receptor 2 ; metabolism ; Toll-Like Receptor 4 ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

BACKGROUNDDendritic cells (DCs) can recognize the pathogen-associated molecular patterns (PAMP) of Aspergillus fumigatus (A. fumigatus), activating the immune response. During A. fumigatus infection, a Th and Treg response induced in the fungi-pulsed DCs is not yet well understood.

METHODSIn this study, bone marrow-derived dendritic cells (BMDCs) were separated and proliferated from C57BL/6 mice. A. fumigatus pulsed DCs were generated and cultured with CD4(+) T cells derived from the spleen of C57BL/6 mice in vitro. CD4(+) T cells differentiation after co-culture were analyzed by flow cytometry, ELISA, and real-time PCR analysis.

RESULTSThe A. fumigatus pulsed DCs exhibited increased Th1 and Treg frequency, Th1-related cytokines (IFN-γ and IL-12), Treg-related cytokines (TGF-β) and T-bet, and Foxp3 mRNA levels compared with the control group. There was no significant difference between A. fumigatus pulsed DCs group and the control group about Th17 and Th2 frequency.

CONCLUSIONSThe inactivated conidia of A. fumigatus were able to activate BMDCs and made them capable of triggering T cell responses in vitro. A. fumigatus loaded DCs was a weak inducer of Th17 and Th2, but induced a strong Th1 and Treg response.

Animals ; Aspergillus fumigatus ; pathogenicity ; Cytokines ; metabolism ; Dendritic Cells ; immunology ; microbiology ; Forkhead Transcription Factors ; metabolism ; Interleukin-12 ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; T-Lymphocytes, Helper-Inducer ; immunology ; T-Lymphocytes, Regulatory ; immunology ; Th1 Cells ; immunology ; Transforming Growth Factor beta ; metabolism