Cutaneous dendritic cells (DCs), Langerhans cells (LCs) and dermal dendritic cells (DDCs), are present in an immature state. The maturation of DCs is crucial for initiating an immune response. Since HLA-DM has an important role for antigen presentation, an increase in HLA-DM expression according to the maturation of blood monocyte-derived dendritic cells (MoDCs), which have similar characteristics with DDCs, is expected. Therefore, the aim of this study was to determine whether or not HLA-DM expression in MoDCs is related to maturation at each culture day (from day 0 to day 13) by flow cytometry. This was compared with the functional changes related to the maturation of MoDCs. MoDCs were generated by culturing human peripheral blood monocytes in the presence of GM-CSF and IL-4 for 7 days, which were followed by subsequent treatment with a cytokine cocktail (GM-CSF, IL-4, IL-1beta, TNF-alpha, IL-6 and PGE2) for the maturation of MoDCs. The intracellular HLA-DM was expressed in the immature MoDC. A sudden 3 to 8 fold increase in the intracellular HLA-DM expression was observed after treatment with a cytokine cocktail. HLA-DM was weakly expressed on the surface of the immature MoDC, but it seemed to be decreased with maturation. This study indicated that the intracellular HLA-DM expression increased, but not on the MoDC surface during maturation. This was despite the fact that HLA-DM expression was noted not only on the surface but also in the intracellular in the MoDC.
Dendritic Cells/*immunology/physiology ; Endocytosis ; Flow Cytometry ; HLA-D Antigens/*analysis ; Human ; Monocytes/*physiology

Dendritic cells(DC) are specialized antigen-presenting cells that prime naive T cells to induce initial immune responses. The immature DC capture and process antigens in the periphery, then emigrate to lymphoid organs. There they complete their maturation by upregulating HLA-I, II molecules, costimulatory molecules (eg. CD80, CD86) and adhesive molecules (eg. CD50, CD54, CD58). More studies showed that in vitro only interferons type I (IFN-alpha, beta) accelerate DC maturation in a dose-dependent manner. The DC induced by IFN type I highly express HLA-A, B, C, HLA-DR, costimulatory molecules and adhesive molecules, and they express enhancing effect of T-cells stimulatory activity in vitro. Progress of research in this field was summarized in this paper.
Cells, Cultured ; Dendritic Cells ; drug effects ; immunology ; physiology ; Humans ; Immunophenotyping ; Interferon Type I ; pharmacology

As a member of the HSP90 family, heat shock protein (HSP) Gp96 is one of the most abundant proteins in the endoplasmic reticulum (ER), which displayed important molecular chaperones function in cells. Gp96 can stimulate the production of cytokines by activating the antigen presentation cells (such as dendritic cell, et al) in innate immunity. It is capable of eliciting an antigen-specific cytotoxic T lymphocyte (CTL) immune response to eliminate pathogens and tumors by facilitating antigen cross-presentation in adaptive immunity. Gp96 is also an ideal adjuvant in many recent researches. Here, we review the progress that addresses the role of biological characteristics, immunogenic mechanism that may be involved in the induction of anti-infection immune response and antitumor immunity, which may guide the new vaccine strategies with the knowledge of Gp96-antigen complexes.
Adjuvants, Immunologic ; genetics ; metabolism ; Antigen-Presenting Cells ; physiology ; Communicable Diseases ; immunology ; Dendritic Cells ; immunology ; Endoplasmic Reticulum ; immunology ; Humans ; Membrane Glycoproteins ; immunology ; Neoplasms ; immunology ; T-Lymphocytes, Cytotoxic ; immunology

Interleukin-21 (IL-21) is a new member of the interleukin-2 family. It is mainly synthesized and secreted by the activated of CD4(+) T cells and natural killer T cells. IL-21 receptor (IL-21R) is mainly expressed in T cells, B cells, and natural killer (NK) cells. After binding to its receptor, IL-21 can regulate the activation and proliferation of T cells, B cells, and NK cells through activating JAKs-STATs signaling pathways. As a new immunoregulatory factor, IL-21 and its receptor play important roles in the development and progression of various autoimmune diseases. Regulation of the expression levels of IL-21 and IL-21R and blocking of their signal transduction pathways with blockers may be new treatment options for autoimmune diseases.
Animals ; Autoimmune Diseases ; etiology ; immunology ; Dendritic Cells ; immunology ; Humans ; Interleukins ; physiology ; Killer Cells, Natural ; immunology ; Lymphocytes ; immunology ; Receptors, Interleukin-21 ; physiology

The aim of this study was to investigate the immune regulatory effect of dendritic cells phagocytosing photochemotherapy-treated allogeneic spleen lymphocytes on syngeneic T cells. DA rat spleen lymphocytes were treated with 8-methoxypsoralen plus UVA irradiation (PUVA). LEW rat bone marrow-derived DCs were co-cultured with PUVA-treated DA spleen lymphocytes (PUVA-SP), and the surface markers (MHC-II, CD86 and CD40) of treated DC were detected by flow cytometry. CFSE-labeled PUVA SP were incubated with LEW DCs and the phagocytosis of DCs on PUVA-SP was observed by using fluorescent microscope. The ability of DC phagocytosing allogeneic PUVA-SP (PUVA-SP DC) to stimulate the proliferation of LEW T cells was analyzed by mixed leukocyte reactions (MLR). The production of IL-4, IL-10, IL-2, IFN-gamma in MLR culture supernatant was determined by luminex method. The results indicated that the PUVA treatment effectively induced early apoptosis of DA rat spleen lymphocytes. After co-culture, DC efficiently phagocytosed allogeneic PUVA-SP and still maintained an immature phenotype with low levels of MHC II, CD40 and CD86. PUVA-SP DC induced LEW T cell hyporesponsiveness to DA rat antigen, and led to skewing of T cell cytokine expression toward Th2 (IL-10 and IL-4). It is concluded that the PUVA-SP DC effectively down-regulate T cell response to alloantigen and induce Th2 immune deviation in vitro.
Animals ; Dendritic Cells ; cytology ; immunology ; physiology ; Flow Cytometry ; Isoantigens ; Phagocytosis ; immunology ; Photochemistry ; Rats ; Rats, Inbred Lew ; T-Lymphocytes ; immunology

OBJECTIVETo investigate the role of CD40 ligand (CD40L) in dendritic cells (DC) of CEA transgenic mice and to evaluate the specific cellular immunity induced by activated DC.

METHODSBone marrow cells of the CEA transgenic mice were used to generate immature dendritic cells under the condition of GM-CSF and IL-4. CD40L was added to activate dendritic cells into mature phenotype. Dendritic cells cancer vaccine was pulsed with CEA526-533 peptide which made the vaccine specific for cancer immunity. The immunophenotype molecules were identified by flow cytometry. The cytokines produced by cells were determined by ELISA. T cells proliferation was measured by (3)H-thymidine essays.

RESULTSImmunophenotype molecules expressions of CD40L-activated dendritic cells were significantly higher than those in control group. IL-12 secretion by CD40L-activated dendritic cells was (937.81+/-51.99) pg/10(6) DC, significantly higher than that in control group [(83.06+/-8.58) pg/10(6) DC, P<0.01]. CD8(+) T cells proliferation induced by CD40 L-activated dendritic cells was stronger as compared to control group (P<0.05), and the secretion of IFN-gamma was(33.900+/-4.550) ng/L, significantly higher than that in control group [(5.226+/-0.460) ng/L, P<0.01]. Splenocytes proliferation induced by CD40 L-activated dendritic cells was stronger as compared to control group (P<0.01), and the secretion of IFN-gamma was (69.802+/-11.407) ng/L, significantly higher than that in control group [(2.912+/-0.562) ng/L, P<0.01].

CONCLUSIONThe method of using CD40L to stimulate bone marrow-delivered dendritic cells promotes the maturation and activation of dendritic cells, which enhances the cellular immunity in CEA transgenic mice.

Animals ; CD40 Ligand ; immunology ; physiology ; Dendritic Cells ; cytology ; immunology ; metabolism ; Immunity, Cellular ; immunology ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic

OBJECTIVETo identify the frequency and interferon (IFN)-alpha-producing ability of circulating type 2 pre-dendritic cells (pDC2) and evaluate its role in liver cirrhotic patients with chronic HBV infection.

METHODS27 liver cirrhotic patients were included in our study and 25 patients with chronic hepatitis B and 25 healthy individuals were enrolled as controls. The numbers of circulating pDC2 and lymphocytes including CD4+ T cells, CD8+ T cells, NK cells as well as B cells were analyzed by flow cytometry. The IFN-alpha-producing function of peripheral blood mononuclear cells (PBMCs) representing the circulating pDC2 was determined by ELISA assay after stimulated by ultraviolet-inactivated herpes simplex virus-1 (UV-HSV-1).

RESULTSThe number of pDC2 were (7.21+/-2.38)*10(6)/L, (4.49+/-3.08) *10(6)/L and (2.89+/-1.17) *10(6)/L for healthy control, chronic hepatitis B and cirrhotic patients respectively. Both the number and IFN-alpha-producing function of circulating pDC2 in liver cirrhotic patients significantly lower than that in healthy subjects. There was a correlated simultaneous decrease numbers of circulating CD8+ T cells, NK cells in HBV-infected cirrhotic patients. Furthermore, cirrhotic patients with opportunistic infections have lower numbers of pDC2, CD8+ T cells and NK cells compared to those without opportunistic infections.

CONCLUSIONSLiver cirrhotic patients with chronic HBV infection have a significant decrease of circulating pDC2 level and IFN-alpha-producing function. The decreased number and function of pDC2, together with the lower number of CD8+ T cells and NK cells may result in the decline of host immune response, which may partially contribute to the disease progression of HBV infection and opportunistic infections.

Cell Count ; Dendritic Cells ; physiology ; Hepatitis B, Chronic ; immunology ; Humans ; Interferon-alpha ; biosynthesis ; Liver Cirrhosis ; immunology ; T-Lymphocyte Subsets ; immunology

OBJECTIVETo study the role of dendritic cells (DCs) and macrophages, differentiated from the same individual peripheral blood monocytes, in tumor antigen- presenting.

METHODSDCs and macrophages were differentiated from human peripheral blood monocytes by adding both Granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) or GM-CSF only. Then they were loaded with tumor antigen at different concentrations and cocultured with autologous T cells in 96-well flat-bottomed microtiter plates for five days at 37 degrees C, 5% CO(2). (3)H-thymine was added before the culture terminated, and twelve hours later, the cells were gathered to test the cpm value.

RESULTSBoth DCs and macrophages chased with tumor antigen could strongly stimulate the proliferation of autologous T cells, especially DCs. The stimulation effect with 20 microl/ml antigen was the most remarkable and the cmp values were 11,950.3 +/-1621.8, 8,708.5 +/-176.1, 402.5+/-43.1 in DCs group, Macrophages group, and lymphocytes group, respectively.

CONCLUSIONThe antigen presenting role of DCs is stronger than that of macrophages from the same individual.

Antigen Presentation ; immunology ; Antigen-Presenting Cells ; immunology ; physiology ; Antigens, Neoplasm ; immunology ; Carcinoma, Hepatocellular ; immunology ; Dendritic Cells ; immunology ; physiology ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; Humans ; Liver Neoplasms ; immunology ; Macrophages ; immunology ; physiology ; Tumor Cells, Cultured

Dendritic cells (DCs), the most potent antigen-presenting cells, recognize pathogen by Toll-like receptors (TLRs) and serve as the bridge between the innate and the adaptive immune responses. TLRs-mediated signal transduction plays a crucial role in the functional maturation of DCs. This review summarizes the research progress on the expression and function of TLRs in DCs.
Dendritic Cells ; immunology ; metabolism ; Humans ; Immunity, Innate ; Signal Transduction ; Toll-Like Receptors ; metabolism ; physiology

Current therapies for autoimmune diseases are not cures but merely palliatives, aimed at reducing symptoms. For the most part, these treatments provide nonspecific suppression of the immune system and thus do not distinguish between a pathogenic autoimmune response and a protective immune response. Recently emerging evidence not only has indicated the involvement of members of the TNF receptor/ligand superfamilies but also has revealed exciting innovative strategies for the treatment of autoimmune diseases and other chronic inflammatory diseases without depressing the immune response in general. In this review, we will discuss the regulatory mechanisms of TNF receptor/ligand family members, such as HVEM/ LIGHT, 4-1BB/4-1BBL, and GITR/GITRL that regulate T and B cell functions and participate in the process of inflammatory diseases. We will also discuss how intervening in the costimulatory pathways mediated by these molecules might have some potential as a therapeutic approach to immune disorders.
Animals ; Apoptosis ; Autoimmune Diseases/immunology/metabolism/pathology ; B-Lymphocytes/immunology/physiology ; Dendritic Cells/physiology ; Human ; Inflammation/*immunology ; Lymphocyte Activation/immunology ; Models, Biological ; Receptors, Tumor Necrosis Factor/*physiology ; T-Lymphocytes/immunology/physiology ; Tumor Necrosis Factor/immunology/*physiology