scholarly journals Dendritic cells and isolevuglandins in immunity, inflammation, and hypertension

2017 ◽  
Vol 312 (3) ◽  
pp. H368-H374 ◽  
Author(s):  
Kala B. Dixon ◽  
Sean S. Davies ◽  
Annet Kirabo
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Protein Modification ◽  
Vascular Dysfunction ◽  
Organ Damage ◽  
Activated T Cells ◽  
Adaptive Immune ◽  
The Past ◽  
Antigen Presenting

Hypertension is the major risk factor for morbidity and mortality from myocardial infarction, stroke, heart failure, and chronic kidney disease. Despite its importance, the pathogenesis of essential hypertension is poorly understood. During the past several years, it has become evident that T cells contribute to hypertension. Activated T cells accumulate in the perivascular space and the kidney and release cytokines that promote vascular dysfunction and end-organ damage. Although dendritic cells play a pivotal role in initiating adaptive immune responses, T cells have taken center stage in studies implicating the immune system in the genesis of hypertension. The mechanisms by which T cells are activated and the antigens involved are poorly understood. We recently showed that hypertension is associated with increased dendritic cell production of the TH17 polarizing cytokines, IL-6, IL-1β, and IL-23. This occurs in part by increased superoxide production via NADPH oxidase and protein modification by highly reactive isolevuglandins (IsoLGs). IsoLGs are produced via the isoprostane pathway of free radical-mediated lipid peroxidation and, when adducted to proteins, have the potential to act as neoantigens. In this review, we discuss recent advances in our understanding of the role of antigen-presenting dendritic cells in the pathophysiology of hypertension and highlight potential neoantigens that may contribute to this disease.

scholarly journals SHP-1 Acts as a Key Regulator of Alloresponses by Modulating LFA-1-Mediated Adhesion in Primary Murine T Cells

2016 ◽  
Vol 36 (24) ◽  
pp. 3113-3127 ◽  
Author(s):  
Martin G. Sauer ◽  
Jessica Herbst ◽  
Ulf Diekmann ◽  
Christopher E. Rudd ◽  
Christian Kardinal
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tyrosine Phosphatase ◽  
Activated T Cells ◽  
Sirna Knockdown ◽  
Antigen Presenting ◽  
Pharmaceutical Agents ◽  
Interfering Rna ◽  
Clinical Potential

The clinical potential of transplantation is often reduced by T cell-mediated alloresponses that cause graft rejection or graft-versus-host disease. Integrin-mediated adhesion between alloreactive T cells and antigen-presenting cells is essential for allorejection. The identity of the signaling events needed for the activation of integrins such as LFA-1 is poorly understood. Here, we identified a novel role of the protein tyrosine phosphatase SHP-1 in the regulation of murine LFA-1-mediated adhesion in an allograft setting. Upon alloactivation, SHP-1 activity is reduced, resulting in an increase in LFA-1 adhesion compared to that for syngeneically activated T cells. The importance of these differential activation properties was further indicated by small interfering RNA (siRNA) knockdown of SHP-1 in syngeneically and allogeneically stimulated T cells. Mechanistically, SHP-1 modulated the binding of SLP-76 to ADAP by dephosphorylation of the YDGI tyrosine motif of ADAP, a known docking site for the Src family kinase Fyn. This novel key role of SHP-1 in the regulation of LFA-1-mediated adhesion may provide a new insight into T cell-mediated alloresponses and may pave the way to the development of new immunosuppressive pharmaceutical agents.

scholarly journals A subclass of dendritic cells kills CD4 T cells via Fas/Fas-ligand-induced apoptosis.

1996 ◽  
Vol 183 (4) ◽  
pp. 1789-1796 ◽  
Author(s):  
G Süss ◽  
K Shortman
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Cd4 T Cells ◽  
Fas Ligand ◽  
Activated T Cells ◽  
T Cell Apoptosis ◽  
Peripheral T Cells ◽  
Surface Staining ◽  
Induced Apoptosis ◽  
Antigen Presenting

Dendritic cells (DC), the most efficient antigen-presenting cells, are well equipped for activation of naive CD4+ T cells by their expression of high levels of major histocompatibility complex and costimulator molecules. We now demonstrate that some DC are equally well equipped for killing these same T cells. Murine splenic DC consist of both conventional CD8alpha- DC and a major population of CD8alpha+ DC. Whereas CD8- DC induce a vigorous proliferative response in CD4 T cells, CD8+ DC induce a lesser response that is associated with marked T cell apoptosis. By using various mixtures of T cells and DC from Fas-mutant lpr/lpr mice and Fas-ligand (FasL) mutant gld/gld mice, we show this death is due to interaction of Fas on activated T cells with FasL on CD8+ DC. Furthermore, we show by direct surface staining that CD8+ DC, but not CD8- DC, express FasL at high levels. These findings indicate that FasL+ CD8+ DC are a specialized subgroup of DC with a role in the regulation of the response of primary peripheral T cells.

Dendritic cells and T cells in rheumatoid arthritis

2020 ◽  
pp. 73-84
Author(s):  
Soi-Cheng Law ◽  
Pascale Wehr ◽  
Harriet Purvis ◽  
Ranjeny Thomas
Keyword(s):  
Rheumatoid Arthritis ◽  
T Cells ◽  
Dendritic Cells ◽  
Autoimmune Response ◽  
Immune Effector ◽  
Effector Functions ◽  
Adaptive Immune ◽  
Cell Antibody ◽  
Innate Immune Effector ◽  
Antigen Presenting

Dendritic cells (DCs) are specialized antigen-presenting cells which link the innate and adaptive immune responses, activating and priming effector CD4+ T cells, cross-presenting antigen to CD8+ T cells, and promoting B-cell antibody production. DCs also play important roles in the maintenance of immune tolerance. DCs and T cells underpin the basis of the autoimmune response in rheumatoid arthritis. In this chapter we describe the function of DCs and the response of T cells in rheumatoid arthritis pathogenesis, introduce the DC and T-cell players and their function in the immune system, then review the evidence for their involvement in the pathogenesis of rheumatoid arthritis (RA), particularly through the presentation of antigen that triggers the differentiation of autoreactive T cells, as well as innate immune effector functions. Finally, the emerging prospects for DC targeting for immunotherapy are covered.

scholarly journals Application of two-color immunofluorescence staining to demonstration of T-cells and HLA-DR-bearing cells in rheumatoid synovitis.

1992 ◽  
Vol 40 (11) ◽  
pp. 1675-1683 ◽  
Author(s):  
J Itoh ◽  
K Kinjoh ◽  
A Ohyama ◽  
M Nose ◽  
M Kyogoku
Keyword(s):  
T Cells ◽  
Inflammatory Lesion ◽  
Immunofluorescent Staining ◽  
Synovial Lining ◽  
High Endothelial Venules ◽  
Activated T Cells ◽  
Lymphoid Follicles ◽  
Hla Dr ◽  
Antigen Presenting

We studied the localization of T-cells and HLA-DR antigen-bearing (DR+) cells in rheumatoid synovitis by employing an improved two-color immunofluorescent staining (TCIF) technique. With this technique we have successfully identified DR+ activated T-cells in the inflammatory synovium. T-cells expressed HLA-DR antigen when they were in contact with DR+ antigen-presenting cells (APC). In addition, activated T-cells showed characteristic distribution within the synovium: they were found around high endothelial venules, within lymphoid follicles, and in hyperplastic synovial lining, suggesting their involvement in the development of rheumatoid synovial lesions via interaction with synovial DR+ APC lineage cells. These findings may contribute to better understanding of the role of activated T-cells in the histogenesis of rheumatoid synovitis, a typical chronic inflammatory lesion.

scholarly journals Lymph Node-Targeted Synthetically Glycosylated Antigen Leads to Antigen-Specific Immunological Tolerance

2021 ◽  
Vol 12 ◽  
Author(s):  
Chitavi D. Maulloo ◽  
Shijie Cao ◽  
Elyse A. Watkins ◽  
Michal M. Raczy ◽  
Ani. S. Solanki ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Lymph Node ◽  
Subcutaneous Administration ◽  
Immunological Tolerance ◽  
T Cell Tolerance ◽  
Clonal Deletion ◽  
Activated T Cells ◽  
Cellular Target ◽  
Antigen Presenting

Inverse vaccines that tolerogenically target antigens to antigen-presenting cells (APCs) offer promise in prevention of immunity to allergens and protein drugs and treatment of autoimmunity. We have previously shown that targeting hepatic APCs through intravenous injection of synthetically glycosylated antigen leads to effective induction of antigen-specific immunological tolerance. Here, we demonstrate that targeting these glycoconjugates to lymph node (LN) APCs under homeostatic conditions leads to local and increased accumulation in the LNs compared to unmodified antigen and induces a tolerogenic state both locally and systemically. Subcutaneous administration directs the polymeric glycoconjugate to the draining LN, where the glycoconjugated antigen generates robust antigen-specific CD4+ and CD8+ T cell tolerance and hypo-responsiveness to antigenic challenge via a number of mechanisms, including clonal deletion, anergy of activated T cells, and expansion of regulatory T cells. Lag-3 up-regulation on CD4+ and CD8+ T cells represents an essential mechanism of suppression. Additionally, presentation of antigen released from the glycoconjugate to naïve T cells is mediated mainly by LN-resident CD8+ and CD11b+ dendritic cells. Thus, here we demonstrate that antigen targeting via synthetic glycosylation to impart affinity for APC scavenger receptors generates tolerance when LN dendritic cells are the cellular target.

scholarly journals Mycobacterium leprae Infection in Monocyte-Derived Dendritic Cells and Its Influence on Antigen-Presenting Function

2002 ◽  
Vol 70 (9) ◽  
pp. 5167-5176 ◽  
Author(s):  
Ken Hashimoto ◽  
Yumi Maeda ◽  
Hiroaki Kimura ◽  
Koichi Suzuki ◽  
Akihiro Masuda ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Cytotoxic T Cells ◽  
Mycobacterium Leprae ◽  
T Cell Subsets ◽  
Cell Immunity ◽  
Ifn Γ ◽  
Antigen Presenting

ABSTRACT Host defense against Mycobacterium leprae infection is chiefly mediated by gamma interferon (IFN-γ)-secreting cytotoxic T cells. Since which antigen-presenting cell populations act to stimulate these T cells is not fully understood, we addressed the role of monocyte-derived dendritic cells (DCs). The DCs phagocytosed M. leprae and expressed bacterially derived antigens (Ags), such as phenolic glycolipid 1 (PGL-1), in the cytoplasm, as well as on the cell surface. The expression of HLA-ABC and -DR Ags on DCs was down-regulated by M. leprae infection, and that of CD86 was up-regulated, but not as fully as by Mycobacterium bovis BCG infection. Induction of CD83 expression required a large number of M. leprae cells. When a multiplicity of infection of >40 was used, the DCs induced a significant proliferative and IFN-γ-producing response in autologous T cells. However, these responses were significantly lower than those induced by BCG- or Mycobacterium avium-infected DCs. A CD40-mediated signaling in M. leprae-infected DCs up-regulated the expression of HLA Ags, CD86, and CD83 but did not enhance T-cell-stimulating ability. Therefore, M. leprae-infected DCs are less efficient at inducing T-cell responses. However, when the surface PGL-1 on M. leprae-infected DCs was masked by a monoclonal antibody, the DCs induced enhanced responses in both CD4+- and CD8+-T-cell subsets. M. leprae is a unique pathogen which remains resistant to DC-mediated T-cell immunity, at least in the early stages of infection.

scholarly journals Distinct mechanisms of neonatal tolerance induced by dendritic cells and thymic B cells.

1991 ◽  
Vol 173 (3) ◽  
pp. 549-559 ◽  
Author(s):  
M Inaba ◽  
K Inaba ◽  
M Hosono ◽  
T Kumamoto ◽  
T Ishida ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
B Cells ◽  
Cell Types ◽  
Cell Sorter ◽  
Histocompatibility Complex ◽  
Different Types ◽  
Induced Tolerance ◽  
Antigen Presenting

To assess the role of different types of antigen-presenting cells (APC) in the induction of tolerance, we isolated B cells, macrophages, and dendritic cells from thymus and spleen, and injected these into neonatal BALB/c mice across an Mls-1 antigenic barrier. One week after injection of APC from Mls-1-incompatible mice or from control syngeneic mice, we measured the number of thymic, Mls-1a-reactive, V beta 6+ T cells and the capacity of thymocytes to induce a graft-vs.-host (GVH) reaction in popliteal lymph nodes of Mls-1a mice. Injection of thymic but not spleen B cells deleted thymic, Mls-1a-reactive V beta 6+ T cells and induced tolerance in the GVH assay. The thymic B cells were primarily of the CD5+ type, and fluorescence-activated cell sorter-purified CD5+ thymic B cells were active. Injection of dendritic cells from spleen or thymus also induced tolerance, but the V beta 6 cells were anergized rather than deleted. Macrophages from thymus did not induce tolerance. Dendritic cells and thymic B cells were also effective in inducing tolerance even when injected into Mls-, major histocompatibility complex-incompatible, I-E- mice, but only thymic B cells depleted V beta 6-expressing T cells. Therefore, different types of bone marrow-derived APC have different capacities for inducing tolerance, and the active cell types (dendritic cells and CD5+ thymic B cells) can act by distinct mechanisms.

scholarly journals Regulation of Murine Dendritic Cell Immune Responses by Helicobacter felis Antigen

2006 ◽  
Vol 74 (8) ◽  
pp. 4624-4633 ◽  
Author(s):  
Maureen L. Drakes ◽  
Steven J. Czinn ◽  
Thomas G. Blanchard
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Dendritic Cell ◽  
Immune Responses ◽  
Lamina Propria ◽  
Adaptive Immune Responses ◽  
Helicobacter Felis ◽  
Adaptive Immune ◽  
Pulsed Dc ◽  
Antigen Presenting

ABSTRACT Helicobacter infections are present in approximately 50% of humans, causing severe illnesses such as gastritis and malignancies. Dendritic cells (DC) are critical antigen-presenting cells which link innate and adaptive immune responses. The mechanism of dendritic cell regulation in Helicobacter-induced gastritis is poorly understood. These studies characterized DC isolated from the lamina propria of Helicobacter-infected mice and analyzed innate and adaptive immune responses elicited by Helicobacter antigen (Ag)-pulsed DC. The presence of DC was elevated in the gastric lamina propria infiltrate of infected mice in comparison with controls. After treatment with Helicobacter felis Ag, DC were polarized to secrete interleukin-6 as the dominant cytokine. In the presence of DC and Helicobacter Ag, responder allogeneic T cells in culture exhibited limited cell division. We suggest that the response of DC and T cells to Helicobacter Ag is critical to the chronic persistence of Helicobacter-induced gastritis.

scholarly journals Overview of Bovine Dendritic Cells

2018 ◽  
Vol 66 (3) ◽  
pp. 815-821 ◽  
Author(s):  
Lucie Kratochvílová ◽  
Petr Sláma
Keyword(s):  
Dendritic Cells ◽  
Immune System ◽  
Volume Ratio ◽  
The Body ◽  
Adaptive Immune ◽  
Prevention And Treatment ◽  
Bone Marrow Derived Cells ◽  
Antigen Presenting ◽  
Adaptive Immune Systems

This article is an overview of dendritic cells (DCs) in cattle. The understanding of the immune system and the role of DCs in many ways can contribute to their use in the prevention and treatment of many infectious and autoimmune diseases. DCs are bone marrow-derived cells that function as professional antigen presenting cells. They act as messengers between the innate and the adaptive immune systems. The morphology of DCs results in a very large surface to volume ratio. That is, the DCs have a very large surface area compared to the overall cell volume. Currently, most dendritic cells research occurs in the human and mice. There is a lack of studies in cattle describing DCs. DCs survey the body and collect information relevant to the immune system. They are then able to instruct and direct the adaptive arms to respond to challenges.

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