Dendritic cells (DCs) are professional antigen-presenting cells that sample their environment and present antigens to naive T lymphocytes for the subsequent antigen-specific immune responses. DCs exist in a range of distinct subpopulations including plasmacytoid DCs (pDCs) and classical DCs (cDCs), with the latter consisting of the cDC1 and cDC2 lineages. Although the roles of DC-specific transcription factors across the DC subsets have become understood, the posttranscriptional mechanisms that regulate DC development are yet to be elucidated. MicroRNAs (miRNAs) are pivotal posttranscriptional regulators of gene expression in a myriad of biological processes, but their contribution to the immune system is just beginning to surface. In this study, our in-house probe collection was screened to identify miRNAs possibly involved in DC development and function by targeting the transcripts of relevant mouse transcription factors. Examination of DC subsets from the culture of mouse bone marrow with Flt3 ligand identified high expression of miR-124 which was able to target the transcript of TCF4, a transcription factor critical for the development and homeostasis of pDCs. Further expression profiling of mouse DC subsets isolated from in vitro culture as well as via ex vivo purification demonstrated that miR-124 was outstandingly expressed in CD24+ cDC1 cells compared to in pDCs and CD172alpha+ cDC2 cells. These results imply that miR-124 is likely involved in the processes of DC subset development by posttranscriptional regulation of a transcription factor(s).
Animals ; Antigen-Presenting Cells ; Biological Processes ; Bone Marrow ; Dendritic Cells* ; Gene Expression ; Homeostasis ; Immune System ; Mice ; MicroRNAs ; RNA Interference ; T-Lymphocytes ; Transcription Factors

A mysterious puzzle in immunology is how the immune system decides what types of immune response to initiate against various stimuli. Although much is known about control of T helper 1 (Th1) and Th17 responses, the mechanisms that initiate Th2 responses remain obscure. Antigen-presenting cells, particularly dendritic cells (DCs), are mandatory for the induction of a Th cell response. Numerous studies have documented the organizing role of DCs in this process. The present review summarizes the fundamental roles of DCs in inducing Th2 responses.
Allergy and Immunology ; Antigen-Presenting Cells ; Dendritic Cells* ; Immune System

INTRODUCTION: The ABX Pentra DX 120 (Pentra DX 120, ABX Diagnostics, Montpellier, France) adopted new technologies to perform differential leukocyte and erythroblast counts. The double matrix can discriminate Large Immature Cell (LIC), Immature Granulocyte (IMG), Immature Monocyte (IMM), Immature Lymphocyte (IML), and Atypical lymphocyte (ALY) in addition to a routine 5-differential count. For erythroblast (ERB), a fluorescence method is employed. In this study, we evaluated the performance of the Pentra DX 120 in the performance of differential leukocyte and erythroblast counts. METHODS: Precision was evaluated using 3-level control materials. Comparison analysis was performed on 200 samples: 100 normal and 100 abnormal samples. We evaluated the 5 part differential count, LIC, IMG, IMM, IML, ALY, and ERB. These parameters were analyzed in comparison with the results from the reference method, manual differential count. RESULTS: The coefficients of variation (CVs) of precision were <5% for neutrophils and lymphocytes, <15% for eosinophils and basophils and <7% for erythroblasts. The correlation coefficients (r) were >0.9 except monocytes and basophils. IMG, ALY and erythroblasts were also well correlated with manual count (r=0.8315, 0.5602, 0.8144, respectively). The efficiency of flagging system was 84% for LIC, 80% for ALY, and 78.0% for increased ERB (>2/100WBCs). CONCLUSIONS: The Pentra DX 120 performed reliable differential leukocyte and IMG, ALY, and ERB results demonstrated comparable performance to manual count. And, the flagging system was efficient for detecting each abnormal cell population. We expect the Pentra DX 120 double matrix and erythroblast count can reduce microscopic review rate in routine laboratory and promote laboratory efficiency.
Basophils ; Eosinophils ; Erythroblasts ; Fluorescence ; Granulocytes ; Leukocytes ; Lymphocytes ; Monocytes ; Neutrophils

Dendritic cells (DCs) are professional antigen presenting cells, and play an important role in the induction of antigen-specific adaptive immunity. However, some DC populations are involved in immune regulation and immune tolerance. These DC populations are believed to take part in the control of immune exaggeration and immune disorder, and maintain immune homeostasis in the body. Tolerogenic DCs (tolDCs) can be generated in vitro by genetic or pharmacological modification or by controlling the maturation stages of cytokine-derived DCs. These tolDCs have been investigated for the treatment of rheumatoid arthritis (RA) in experimental animal models. In the last decade, several in vitro and in vivo approaches have been translated into clinical trials. As of 2015, three tolDC trials for RA are on the list of ClinicalTrial.gov (www.clinicaltrials.gov). Other trials for RA are in progress and will be listed soon. In this review, we discuss the evolution of tolDC-based immunotherapy for RA and its limitations and future prospects.
Adaptive Immunity ; Antigen-Presenting Cells ; Arthritis, Rheumatoid* ; Dendritic Cells ; Homeostasis ; Immune System Diseases ; Immune Tolerance ; Immunotherapy* ; Models, Animal

B cells play a role in graft rejection via several mechanisms. Specifically, B cells produce high-affinity antibodies to alloantigens including allogeneic major histocompatibility complex (MHC) with the help of follicular helper T cells. B cells also function as antigen-presenting cells for alloreactive T cells, resulting in the activation of alloreactive T cells. Conversely, the frequency of regulatory B cells increases under inflammatory conditions and suppresses the rejection process. Here, the differential roles of the major B cell subpopulations (B-1, follicular B, marginal zone B, and regulatory B cells) involved in transplantation rejection are discussed together with their interaction with T cells.
Antibodies ; Antibody Diversity ; Antigen-Presenting Cells ; B-Lymphocytes* ; B-Lymphocytes, Regulatory ; Graft Rejection* ; Isoantigens ; Major Histocompatibility Complex ; T-Lymphocytes ; T-Lymphocytes, Helper-Inducer

BACKGROUND: Paeonia j ap onica Miyabe is a medicinal plant which has been widely used as a component of blood-building decoctions (Chinese medicinal concept : Bu-Xie). The immunopharmacological characteristics of the extract of Paeonia j ap onica (PJ) were investigated. METHODS: The effects of fractions of PJ extract on lymphocyte proliferation were measured by H3 -thymidine incorporation assay . The proliferated lymphocyte subsets were analyzed in flow cytometry . The subset cell populations of spleen cells were separated by magnetic cell separation system, and their proliferation by the extract were investigated. The effect of the extract on antibody production was determined in mice challenged with sheep red blood cells (SRBC) using hemolytic plaque forming cell assay. RESULTS: Spleen cells were proliferated by water extract of PJ. Polysaccharide fraction (PJ-P) of the extract was most active in the proliferation. It was found in flow cytometry that the lymphocyte subset proliferated by PJ-P was B cell population. Among the separated subset cell populations, T cell-depleted cell population and macrophage-depleted cell population were most proliferated by PJ-P. However, positively selected populations of B cells and T cells were not proliferated by PJ-P. These result s indicate that B cell proliferation by PJ-P may require the assistance of macrophages or T cells. These result s suggest that firstly PJ-P may stimulate macrophages or T cells, and then B cells are activated. The number of antibody-secreting cells was increased by administration of PJ-P in mice immunized with SRBC as a T-dependent antigen. CONCLUSION: These result s suggest that macrophages and accessory cells are directly activated by PJ-P and then helper T cells and B cells are indirectly activated. As the results, immune responses might be coordinately improved. In conclusion, PJ-P, a polysaccharide of P. j ap onica, may be a characteristic immunostimulator, which is analogous to polysaccharides such as lentinan, PSK and ginsan.
Animals ; Antibody Formation ; Antibody-Producing Cells ; B-Lymphocytes ; Cell Proliferation* ; Cell Separation ; Erythrocytes ; Flow Cytometry ; Lentinan ; Lymphocyte Subsets ; Lymphocytes ; Macrophages ; Mice ; Paeonia* ; Plants, Medicinal ; Polysaccharides ; Sheep ; Spleen ; T-Lymphocytes ; T-Lymphocytes, Helper-Inducer ; Water

BACKGROUND: Dendritic cells (DC) are professional antigen-presenting cells in the immune system and can induce T cell response against virus infections, microbial pathogens, and tumors. Therefore, immunization using DC loaded with tumor-associated antigens (TAAs) is a powerful method of inducing anti-tumor immunity. For induction of effective antitumor immunity, antigens should be efficiently introduced into DC and presented on MHC class I molecules at high levels to activate antigen-specific CD8+ T cells. We have been exploring methods for loading exogenous antigens into APC with high efficiency of Ag presentation. In this study, we tested the effect of the cationic liposome (Lipofectin) for transferring and loading exogenous model antigen (OVA protein) into BM-DC. METHODS: Bone marrow-derived DC (BM-DC) were incubated with OVA-Lipofectin complexes and then co-cultured with B3Z cells. B3Z activation, which is expressed as the amount of beta-galactosidase induced by TCR stimulation, was determined by an enzymatic assay using beta-gal assay system. C57BL/6 mice were immunized with OVA-pulsed DC to monitor the in vivo vaccination effect. After vaccination, mice were inoculated with EG7-OVA tumor cells. RESULTS: BM-DC pulsed with OVA-Lipofectin complexes showed more efficient presentation of OVA-peptide on MHC class I molecules than soluble OVA-pulsed DC. OVA-Lipofectin complexes-pulsed DC pretreated with an inhibitor of MHC class I-mediated antigen presentation, brefeldin A, showed reduced ability in presenting OVA peptide on their surface MHC class I molecules. Finally, immunization of OVA-Lipofectin complexes-pulsed DC protected mice against subsequent tumor challenge. CONCLUSION: Our data provide evidence that antigen-loading into DC using Lipofectin can promote MHC class I-restricted antigen presentation. Therefore, antigen-loading into DC using Lipofectin can be one of several useful tools for achieving efficient induction of antigen-specific immunity in DC-based immunotherapy.
Animals ; Antigen Presentation ; Antigen-Presenting Cells ; beta-Galactosidase ; Brefeldin A ; Dendritic Cells* ; Enzyme Assays ; Immune System ; Immunization ; Immunotherapy ; Liposomes ; Mice ; Ovum ; T-Lymphocytes ; Vaccination

CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although alpha-galactosylceramide (alpha-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1-skewed NKT cell response, which means a increased level of IFN-gamma by NKT cells, concomitant with a decreased level of IL-4, in the circumstance of co-culture of DCs and B Cells. Remarkably, the response promoted by B cells was dependent on CD1d expression of B cells.
Antigen-Presenting Cells ; B-Lymphocytes* ; Coculture Techniques ; Dendritic Cells ; Galactosylceramides ; Interleukin-4 ; Natural Killer T-Cells*

End-stage renal disease (ESRD) with immune disorder involves complex interactions between the innate and adaptive immune responses. ESRD is associated with various alterations in immune function such as a reduction in polymorphonuclear leukocyte bactericidal activity, a suppression of lymphocyte proliferative response to stimuli, and a malfunction of cell-mediated immunity at the molecular level. ESRD also increases patients' propensity for infections and malignancies as well as causing a diminished response to vaccination. Several factors influence the immunodeficiency in patients with ESRD, including uremic toxins, malnutrition, chronic inflammation, and the therapeutic dialysis modality. The alteration of T-cell function in ESRD has been considered to be a major factor underlying the impaired adaptive cellular immunity in these patients. However, cumulative evidence has suggested that the immune defect in ESRD can be caused by an Ag-presenting dendritic cell (DC) dysfunction in addition to a T-cell defect. It has been reported that ESRD has a deleterious effect on DCs both in terms of their number and function, although the precise mechanism by which DC function becomes altered in these patients is unclear. In this review, we discuss the effects of ESRD on the number and function of DCs and propose a possible molecular mechanism for DC dysfunction. We also address therapeutic approaches to improve immune function by optimally activating DCs in patients with ESRD.
Antigen-Presenting Cells ; Dendritic Cells* ; Dialysis ; Humans ; Immune System Diseases ; Immunity, Cellular ; Inflammation ; Kidney Failure, Chronic* ; Lymphocytes ; Malnutrition ; Neutrophils ; T-Lymphocytes ; Vaccination

Ginsan, a Panax ginseng polysaccharide that contains glucopyranoside and fructofuranoside, has immunomodulatory effects. Although several biologic studies of ginsan have been performed, its effects on dendritic cells (DCs), which are antigen-presenting cells of the immune system, have not been studied. We investigated the immunomodulatory effects of ginsan on DCs. Ginsan had little effect on DC viability, even when used at high concentrations. Ginsan markedly increased the levels of production by DCs of IL-12 and TNF-alpha, as measured by ELISA. To examine the maturation-inducing activity of ginsan, we measured the surface expression levels of the maturation markers MHC class II and CD86 (B7.2) on DCs. It is interesting that ginsan profoundly enhanced the expression of CD86 on DC surfaces, whereas it increased that of MHC class II only marginally. In 3H-thymidine incorporation assays, ginsan-treated DCs stimulated significantly higher proliferation of allogeneic CD4+ T lymphocytes than did medium-treated DCs. Taken together, our data demonstrate that ginsan stimulates DCs by inducing maturation. Because DCs are critical antigen-presenting cells in immune responses, this study provides valuable information on the activities of ginsan.
Antigen-Presenting Cells ; Dendritic Cells ; Enzyme-Linked Immunosorbent Assay ; Immune System ; Immunomodulation ; Interleukin-12 ; Panax ; Polysaccharides ; T-Lymphocytes ; Tumor Necrosis Factor-alpha