Atherosclerosis ; pathology ; C-Reactive Protein ; metabolism ; Dendritic Cells ; metabolism ; Glycation End Products, Advanced ; metabolism ; Humans ; Inflammation

The pathways leading to the development of different dendritic cell (DC) subsets have long been unclear. In recent years, a number of precursors on the route to DC development, both under steady state and inflammatory conditions, have been described, and the nature of these pathways is becoming clearer. In addition, the development of various knockout mouse models and an in vitro system modelling DC development have revealed the role of numerous cytokines and transcription factors that influence DC development. Here, we review recent findings on the factors important in DC development in the context of the developmental pathways that have been described.
Animals ; Cytokines ; metabolism ; Dendritic Cells ; metabolism ; Humans ; Signal Transduction ; physiology ; Transcription Factors ; metabolism

MicroRNAs (miRNAs) are small, single-stranded and noncoding RNA molecules of about 22 nucleotides (nt) in length that regulate mRNA by binding to 3' untranslated regions (3'UTR) of target mRNA, inducing digestion, degradation and/or translational repression of the latter. Posttranscriptional regulation of gene expression by miRNA is critical for a wide range of physiologic and pathologic processes, including cell proliferation, differentiation, apoptosis, development and oncogenesis. Dendritic cells (DC) are professional antigen presenting cells that have a pivotal role in controlling immune responses. The latest studies indicated that miRNA are indispensable in regulation of development, differentiation and functions of DC. This review discusses the latest studies of miRNA controlling DC biological properties in order to deep understand the regulatory mechanism of DC, therefore, provide a new thinking for the therapeutic strategies of DC-associated immunological disorders.
Animals ; Cell Differentiation ; Cell Proliferation ; Dendritic Cells ; cytology ; metabolism ; Humans ; MicroRNAs ; metabolism

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

Considering the substantial role played by dendritic cells (DCs) in the immune system to bridge innate and adaptive immunity, studies on DC-mediated immunity toward biomaterials principally center on their adjuvant effects in facilitating the adaptive immunity of codelivered antigens. However, the effect of the intrinsic properties of biomaterials on dendritic cells has not been clarified. Recently, researchers have begun to investigate and found that biomaterials that are nonadjuvant could also regulate the immune function of DCs and thus affect subsequent tissue regeneration. In the case of proteins adsorbed onto biomaterial surfaces, their intrinsic properties can direct their orientation and conformation, forming "biomaterial-associated molecular patterns (BAMPs)". Thus, in this review, we focused on the intrinsic physiochemical properties of biomaterials in the absence of antigens that affect DC immune function and summarized the underlying signaling pathways. Moreover, we preliminarily clarified the specific composition of BAMPs and the interplay between some key molecules and DCs, such as heat shock proteins (HSPs) and high mobility group box 1 (HMGB1). This review provides a new direction for future biomaterial design, through which modulation of host immune responses is applicable to tissue engineering and immunotherapy.
Biocompatible Materials/metabolism* ; Dendritic Cells/metabolism* ; Tissue Engineering ; Immunomodulation ; Adaptive Immunity

Bone substitute material implantation has become an important treatment strategy for the repair of oral and maxillofacial bone defects. Recent studies have shown that appropriate inflammatory and immune cells are essential factors in the process of osteoinduction of bone substitute materials. Previous studies have mainly focused on innate immune cells such as macrophages. In our previous work, we found that T lymphocytes, as adaptive immune cells, are also essential in the osteoinduction procedure. As the most important antigen-presenting cell, whether dendritic cells (DCs) can recognize non-antigen biomaterials and participate in osteoinduction was still unclear. In this study, we found that surgical trauma associated with materials implantation induces necrocytosis, and this causes the release of high mobility group protein-1 (HMGB1), which is adsorbed on the surface of bone substitute materials. Subsequently, HMGB1-adsorbed materials were recognized by the TLR4-MYD88-NFκB signal axis of dendritic cells, and the inflammatory response was activated. Finally, activated DCs release regeneration-related chemokines, recruit mesenchymal stem cells, and initiate the osteoinduction process. This study sheds light on the immune-regeneration process after bone substitute materials implantation, points out a potential direction for the development of bone substitute materials, and provides guidance for the development of clinical surgical methods.
Biocompatible Materials/metabolism* ; HMGB1 Protein/metabolism* ; Myeloid Differentiation Factor 88/metabolism* ; Bone Substitutes/metabolism* ; Dendritic Cells/metabolism*

OBJECTIVETo investigate the effects of Mycobacterium tuberculosis on apoptosis of mouse dendritic cells (DC 2. 4) and the activation of caspase-3, caspase-8.

METHODSMycobacterium tuberculosis H37Rv strain was co-cultured with DC 2. 4 cells. The morphological changes of DC 2. 4 cells were observed with fluorescence microscope after DAPI staining and transmission electron microscope. The apoptosis of DC 2. 4 cells were examined by DNA agarose gel electrophoresis. The activities of caspase-3 and caspase-8 were detected by colorimetric assay.

RESULTSBacterial invasion was observed while DC 2. 4 cells and H37Rv were co-cultured for 2 h; and the rates of invasion were (16.1 ± 4.3)%, (35.8 ± 5.1)%, (50.2 ± 5.7)%, (58.3 ± 6.2)% and(65.9 ± 6.9)% at 4, 6, 8,10, 12 h, respectively. The phenomenon of nuclear condensation and marginalization were shown by DAPI staining and transmission electron microscope in DC 2. 4 cells at 6 h of co-cultivation with H37Rv. The characteristic bands of apoptosis by DNA electrophoresis were detected. The activities of caspase-3 and caspase-8 were increased in a time-dependent manner. The rates of DC 2. 4 cell apoptosis were (6.4 ± 2.5)%, (11.8 ± 5.3)% and (31.1 ± 8.7)% at 6 h,12 h and 24 h after co-cultivation with H37Rv, respectively. The maximal activities of intracellular caspase-3 and caspase-8 at 10 h and 6 h were (2.01 ± 0.09) U/μg and (2.40 ± 0.07)U/μg, respectively, which was significantly different compared with the control groups(P<0.05). The activation of caspase-8 was earlier than that of caspase-3.

CONCLUSIONMycobacterium tuberculosis can induce the apoptosis of DC 2. 4 cells, which is associated with the activation of intracellular caspase-3 and caspase-8.

Animals ; Apoptosis ; physiology ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Cells, Cultured ; Dendritic Cells ; metabolism ; pathology ; Mice ; Mycobacterium tuberculosis

OBJECTIVETo study the effects of Lipopolysaccharide (LPS) on the maturation and secretion of human peripheral dendritic cells (DCs).

METHODSDCs from healthy human peripheral monocytes (PBMCs) were induced in vitro with rhGM-CSF, rhIL-4, Flt3-L and TNFalpha. The subjects were divided into 3 groups: the long-term group stimulated with LPS 1 microg/ml at day 1, 4, 7, 9 post culture; the short-term group stimulated with LPS 1 microg/ml at day 7 and 8 post culture, and the DCs without LPS stimulation was control group. After 10 days of culture, the morphologic features of DCs were observed by light and electron microscopes, the phenotypic patterns were characterized by flow cytometry, the proliferation of T cell were evaluated with mixed leukocytes reaction (MLR) and the levels of IL-12 and IFNgamma produced by DCs were analyzed with ELISA.

RESULTSCompared with the short-term group, the expressions of HLA-DR (65.81%+/-10.96%), CD86 (48.81%+/-18.13%), CD80 (13.56%+/-5.48%), CD83 (11.52%+/-5.09%), the secretions of IFNgamma(15.60+/-5.83 pg/ml) and IL-12 (51.77+/-11.02 pg/ml) by the DCs in long-term group were decreased obviously (P is less than 0.05) and the proliferation of homogenic lymphocyte cells (1.548+/-0.365) stimulated by DCs was also impaired (P < 0.05).

CONCLUSIONLong-term LPS stimulation can suppress the maturation and secretion of DCs, which might be the reason of poor immunity in the patients with intestinal endotoxemia.

Cells, Cultured ; Dendritic Cells ; cytology ; drug effects ; metabolism ; Humans ; Interleukin-12 ; biosynthesis ; Lipopolysaccharides ; pharmacology ; Monocytes ; cytology ; metabolism

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

OBJECTIVETo detect the expressions of CCR5 and CCR7 on dendritic cells (DCs) in patients with rheumatoid arthritis (RA) in different phases of disease activity, and explore the relationship between the disease activity and the expression of chemokine receptors.

METHODSTwenty-eight patients with low, moderate and high disease activity and 10 normal control subjects were enrolled in this study. Peripheral blood was obtained from the subjects and the DCs were isolated. The expression of CCR5 and CCR7 on DCs were detected by flow cytometry, and the serum levels of rheumatoid factor (RF), C-reactive protein (CRP) and anti-CCP antibody (ACPA) were assessed. The correlation of the expressions of CCR5 and CCR7 to serum RF, CRP, and ACPA levels of the RA patients were analyzed.

RESULTSCompared to the normal control group, RA patients showed enhanced expressions of CCR5 and CCR7 on the DCs. A linear correlation was noted between CCR5 and CCR7 expressions on the DCs and the serum levels of RF and CRP, but not ACPA, in the RA patients.

CONCLUSIONThe expressions of CCR5 and CCR7 on the DCs may correlate to the disease activity of RA, and may serve as valuable indices in monitoring the disease activity and the efficacy of the treatment.

Adult ; Arthritis, Rheumatoid ; blood ; immunology ; Dendritic Cells ; metabolism ; Female ; Humans ; Male ; Middle Aged ; Receptors, CCR5 ; metabolism ; Receptors, CCR7 ; metabolism