Atherosclerosis ; immunology ; Dendritic Cells ; immunology ; Humans

Dendritic cells (DC) play an important roles in the maintenance of central immune tolerance and peripheral immune tolerance. DC can be involved in formation of autoimmune tolerance by many mechanisms and demonstrate strong plasticity, so that DC become hot issue in the research of transplantation tolerance recently. In this article the DC typing and its role, the indirect pathway of DC-inducing immune tolerance, the F1t3L and apoptotic cell role, the modified DC by genetic engineering and the immune inhibitors were summarized.
Dendritic Cells ; immunology ; Humans ; Immune Tolerance ; Transplantation Tolerance ; immunology

Dendritic cells can be derived from leukemia cells and normal precursor cells in the patients with acute myeloid leukemia (AML). Dendritic cells may capture leukemia antigen in bone marrow or lymph nodes, and present leukemia common antigen to stimulate proliferation of specific CD8(+) T cells, playing anti-leukemia effect. Dendritic cells for clinical and experimental use are transformed from leukemia cells and peripheral blood mononuclear cells and loaded in vitro with leukemia -specific or tumor common antigen, play a therapeutic role after reinfusion. This article reviews dendritic cells in the immunotherapy of AML.
Dendritic Cells ; immunology ; Humans ; Immunotherapy ; Leukemia, Myeloid, Acute ; immunology ; therapy

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

Mesenchymal stem cells (MSCs) can inhibit T cell proliferation, the effects of MSCs on various T cell subsets have showed different immune regulatory reactions, and their mechanisms mainly include cell-cell contact and mediation by cytokines secreted from MSCs. Encouragingly, recent studies have showed that the effects of MSCs on T-cell response to pathogens is not significant, but can obviously suppress T cell response to allogeneic antigens. In addition, MSCs can regulate the proliferation, survival, antibody secretion and differentiation of B cells, inhibit the production, proliferation, migration and antigen-presentation of DCs, and modulate the differentiation and maturation of DCs, and regulate the proliferation, cell toxicity and cytokine secretion of NK cells. In this review, the research advances on immunomodulatory effects of MSCs on various immune cells including T-lymphocytes, B-lymphocytes, NK cells and DCs are summarized with emphasis on the immunoregulatory effects of MSCs on T-lymphocytes.
B-Lymphocytes ; immunology ; Dendritic Cells ; immunology ; Humans ; Killer Cells, Natural ; immunology ; Mesenchymal Stromal Cells ; cytology ; immunology ; T-Lymphocytes ; immunology

A new approach to enhancing the effectiveness of vaccines is to deliver antigens selectively to dendritic cells (DC) in situ, via monoclonal antibodies specific for particular DC surface molecules. This can markedly enhance CTL responses and, via helper T cells, also enhance antibody responses. DC activation agents or adjuvants must also be administered for effective CTL responses, but in some cases good antibody responses can be obtained without adjuvants. Here we review the role of different DC subsets and different DC target molecules in obtaining enhanced immune responses.
Antibodies, Monoclonal/immunology ; Antibody Formation ; Antigens/*administration & dosage/immunology ; Dendritic Cells/cytology/*immunology ; Humans ; Vaccines/*immunology

A new approach to enhancing the effectiveness of vaccines is to deliver antigens selectively to dendritic cells (DC) in situ, via monoclonal antibodies specific for particular DC surface molecules. This can markedly enhance CTL responses and, via helper T cells, also enhance antibody responses. DC activation agents or adjuvants must also be administered for effective CTL responses, but in some cases good antibody responses can be obtained without adjuvants. Here we review the role of different DC subsets and different DC target molecules in obtaining enhanced immune responses.
Antibodies, Monoclonal/immunology ; Antibody Formation ; Antigens/*administration & dosage/immunology ; Dendritic Cells/cytology/*immunology ; Humans ; Vaccines/*immunology

OBJECTIVETo review the development of T follicular helper (TFH) cells and their role in systemic lupus erythematosus (SLE) pathogenesis, the effect of dendritic cells (DCs) on TFH cells in SLE, as well as the potential use of TFH cells as a new therapeutic target in clinical practice.

DATA SOURCESThe data used in this review were retrieved mainly from the PubMed database (1989-2013). The terms used in the literature search were "T follicular helper cells," "systemic lupus erythematosus," and "dendritic cells."

STUDY SELECTIONRelevant publications about the TFH cells development, the interaction between the TFH cells and the DCs, and the clinical applications of TFH cells were identified, retrieved, and reviewed.

RESULTSTFH cells, a novel distinct CD4+ T cell subset, are specialized in providing help to B cells in the formation of germinal centers (GCs) and long-term protective humoral immune responses. The development of TFH cells from naïve CD4+ T cell is a multistep process. As the pivot of immunoregulation, DCs are indispensable for TFH cells generation. In addition to receptor-ligand interactions between TFH cells and DCs, the cytokines secreted by DCs are also necessary for TFH cell generation. TFH cell dysregulation has been implicated in the development of SLE. More evidence from animal models of SLE and SLE patients suggests that TFH cells are necessary for pathogenic autoantibody production. Therefore, therapeutically targeting TFH cells can be a promising approach to treat antibody-mediated autoimmune diseases including SLE.

CONCLUSIONTFH cells play a critical role in the pathogenesis of SLE, making them attractive therapeutic targets in clinical practice.

Autoantibodies ; immunology ; Dendritic Cells ; immunology ; Humans ; Lupus Erythematosus, Systemic ; immunology ; T-Lymphocytes, Helper-Inducer ; immunology

OBJECTIVETo study the effects of hemorrhage combined with closed fracture on delayed type hypersensitivity (DTH) responses in mice and to explore the relevant mechanisms.

METHODSDTH responses were induced with 2, 4-dinitro-1-fluorobenzene (DNFB) or fluorescein isothiocyanate (FITC) skin painting after injury, and single cell suspensions from pooled inguinal lymph nodes were analyzed by flow cytometry for FITC+ cells and dendritic cells (DC). The ability of cells from pooled inguinal lymph nodes was tested 24 hours after skin painting with DNFB in transferring sensitization for DTH to DNFB.

RESULTSThe DTH responses after injury decreased significantly compared with that of sham-injured mice (P<0.01). Flow cytometry showed that FITC+ cells, FITC+/CD11c+ cells, and FITC+/CD11c+ / major histocompatibility complex II+ cells were all significantly decreased after trauma (P<0.01). The ability of cells to transfer sensitization for DTH to DNFB also declined (P<0.01).

CONCLUSIONHemorrhage combined with closed fracture decreases the DTH responses in mice, which may be attributed to the reduced antigen-presenting capacity of DC in the injured mice.

Animals ; Dendritic Cells ; immunology ; Fractures, Closed ; complications ; immunology ; Hemorrhage ; complications ; immunology ; Hypersensitivity, Delayed ; immunology ; Mice

Dendritic cells (DCs) play a pivotal role in T cell-mediated immunity and have been shown to induce strong antitumor immune responses in vitro and in vivo. Various approaches utilizing different vaccine cell formats, cell numbers, vaccination schedule, site of vaccination and maturation stages of DCs were investigated worldwide. While clinical trials have demonstrated the safety of such strategies, the clinical outcome was less than expected in most cases. This is due to in part host immunodeficiency imposed by tumors and immunoediting of tumor cells. To overcome these obstacles, new approaches to improve DC-mediated immunotherapeutic strategies are under investigation. First, functional enhancement of monocyte-derived DCs can be generated with using flt3-ligand (FL). Second, diverse antigenic determinants from heat shock-treated tumor cells may improve the immunogenicity of DC-based vaccines. Third, inclusion of ex vivo expanded NK/NKT cells in DC-based vaccines could be beneficial since the bidirectional interaction of these two cell types are known to enhance NK cell effector function and to induce DC maturation. Application of these approaches may induce a broadened antitumor immune response and thereby promote the elimination of tumor antigen-negative variant clones that had escaped immunosurveillance or undergone immunoediting. We are currently examining the feasibility of these immunotherapeutic approaches using a murine pancreatic cancer model system.
Animals ; Dendritic Cells/*immunology ; Humans ; Immunotherapy/*methods/*standards ; Neoplasms/*therapy