scholarly journals Impaired Dendritic Cell Homing in COVID-19

2021 ◽  
Vol 8 ◽  
Author(s):  
Lukas Borcherding ◽  
Alime Sema Teksen ◽  
Bianca Grosser ◽  
Tina Schaller ◽  
Klaus Hirschbühl ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Lymph Nodes ◽  
Diffuse Alveolar Damage ◽  
Antigen Presenting Cells ◽  
High Viral Load ◽  
T Cell Response ◽  
Myeloid Dendritic Cells ◽  
Peripheral Cell ◽  
Antigen Presenting ◽  
The Impact

The high mortality of COVID-19 is mostly attributed to acute respiratory distress syndrome (ARDS), whose histopathological correlate is diffuse alveolar damage (DAD). Furthermore, severe COVID-19 is often accompanied by a cytokine storm and a disrupted response of the adaptive immune system. Studies aiming to depict this dysregulation have mostly investigated the peripheral cell count as well as the functionality of immune cells. We investigated the impact of SARS-CoV-2 on antigen-presenting cells using multiplexed immunofluorescence. Similar to MERS-CoV and SARS-CoV, SARS-CoV-2 appears to be impairing the maturation of dendritic cells (DCs). DC maturation involves a switch in surface antigen expression, which enables the cells' homing to lymph nodes and the subsequent activation of T-cells. As quantitative descriptions of the local inflammatory infiltrate are still scarce, we compared the cell population of professional antigen-presenting cells (APC) in the lungs of COVID-19 autopsy cases in different stages of DAD. We found an increased count of myeloid dendritic cells (mDCs) in later stages. Interestingly, mDCs also showed no significant upregulation of maturation markers in DAD-specimens with high viral load. Accumulation of immature mDCs, which are unable to home to lymph nodes, ultimately results in an inadequate T-cell response.

scholarly journals Impairments of Antigen-Presenting Cells in Pulmonary Tuberculosis

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Ludmila V. Sakhno ◽  
Ekaterina Ya. Shevela ◽  
Marina A. Tikhonova ◽  
Sergey D. Nikonov ◽  
Alexandr A. Ostanin ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Pulmonary Tuberculosis ◽  
Peripheral Blood ◽  
Antigen Presenting Cells ◽  
T Cell Response ◽  
Blood Monocytes ◽  
Peripheral Blood Monocytes ◽  
Gm Csf ◽  
Antigen Presenting

The phenotype and functional properties of antigen-presenting cells (APC), that is, circulating monocytes and generatedin vitromacrophages and dendritic cells, were investigated in the patients with pulmonary tuberculosis (TB) differing in lymphocyte reactivity toM. tuberculosisantigens (PPD-reactive versus PPD-anergic patients). We revealed the distinct impairments in patient APC functions. For example, the monocyte dysfunctions were displayed by low CD86 and HLA-DR expression, 2-fold increase in CD14+CD16+expression, the high numbers of IL-10-producing cells, and enhanced IL-10 and IL-6 production upon LPS-stimulation. The macrophages which werein vitrogenerated from peripheral blood monocytes under GM-CSF were characterized by Th1/Th2-balance shifting (downproduction of IFN-γcoupled with upproduction of IL-10) and by reducing of allostimulatory activity in mixed lymphocyte culture. The dendritic cells (generatedin vitrofrom peripheral blood monocytes upon GM-CSF + IFN-α) were characterized by impaired maturation/activation, a lower level of IFN-γproduction in conjunction with an enhanced capacity to produce IL-10 and IL-6, and a profound reduction of allostimulatory activity. The APC dysfunctions were found to be most prominent in PPD-anergic patients. The possible role of APC impairments in reducing the antigen-specific T-cell response toM. tuberculosiswas discussed.

scholarly journals Soluble HLA-G Inhibits Myeloid Dendritic Cell Function in HIV-1 Infection by Interacting with Leukocyte Immunoglobulin-Like Receptor B2

2010 ◽  
Vol 84 (20) ◽  
pp. 10784-10791 ◽  
Author(s):  
Jinghe Huang ◽  
Patrick Burke ◽  
Yue Yang ◽  
Katherine Seiss ◽  
Jill Beamon ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Cell Function ◽  
Critical Role ◽  
Antigen Presenting Cells ◽  
Hla Class I ◽  
Elite Controllers ◽  
Myeloid Dendritic Cells ◽  
Soluble Hla ◽  
Antigen Presenting ◽  
Hiv 1

ABSTRACT Dendritic cells represent a specialized class of professional antigen-presenting cells that are responsible for priming and maintaining antigen-specific effector cell responses and regulating immune activation by cytokine secretion. In HIV-1 infection, myeloid dendritic cells are highly dysfunctional, but mechanisms contributing to their functional alterations are not well defined. Here, we show that soluble molecules of the nonclassical major histocompatibility complex class Ib (MHC-Ib) antigen HLA-G are highly upregulated in the plasma during progressive HIV-1 infection, while levels of membrane-bound HLA-G surface expression on dendritic cells, monocytes, and T cells only slightly differ among HIV-1 progressors, HIV-1 elite controllers, and HIV-1-negative persons. These elevated levels of soluble HLA-G in progressive HIV-1 infection likely result from increased secretion of intracellularly stored HLA-G molecules in monocytes and dendritic cells and contribute to a functional disarray of dendritic cells by inhibiting their antigen-presenting properties, while simultaneously enhancing their secretion of proinflammatory cytokines. Interestingly, we observed that these immunoregulatory effects of soluble HLA-G were mainly mediated by interactions with the myelomonocytic HLA class I receptor leukocyte immunoglobulin-like receptor B2 (LILRB2; ILT4), while binding of soluble HLA-G to its alternative high-affinity receptor, LILRB1 (ILT2), appeared to be less relevant for its immunomodulatory functions on dendritic cells. Overall, these results demonstrate a critical role for soluble HLA-G in modulating the functional characteristics of professional antigen-presenting cells in progressive HIV-1 infection and suggest that soluble HLA-G might represent a possible target for immunotherapeutic interventions in HIV-1-infected persons.

Levels of plasmacytoid dendritic cells and type-2 myeloid dendritic cells are reduced in peripheral blood of patients with primary Sjögren's syndrome

2009 ◽  
Vol 69 (6) ◽  
pp. 1235-1238 ◽  
Author(s):  
Petra Vogelsang ◽  
Johan G Brun ◽  
Gunnvor Øijordsbakken ◽  
Kathrine Skarstein ◽  
Roland Jonsson ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Sjögren’S Syndrome ◽  
Peripheral Blood ◽  
Sjögren's Syndrome ◽  
Sjogren’S Syndrome ◽  
Sjogren's Syndrome ◽  
Healthy Controls ◽  
Myeloid Dendritic Cells ◽  
Antigen Presenting ◽  
Sjögren‘S Syndrome

ObjectiveSjögren's syndrome (SS) is a lymphoproliferative autoimmune disease, characterised by dryness of the mouth and eyes. Dendritic cells (DC) are potent antigen-presenting cells crucial for initiating and maintaining primary immune responses. This study quantified interferon-producing plasmacytoid DC (pDC) and two myeloid DC subsets (mDC1 and mDC2) in peripheral blood (PB) from primary SS (pSS) patients and healthy controls.MethodsBlood samples from 31 pSS patients and 28 gender and age-matched healthy controls were analysed by flow cytometry using the Miltenyi Blood DC enumeration kit. The presence of pDC in salivary glands (SG) from pSS patients was analysed by immunohistochemistry.ResultsPatients with pSS had significantly less pDC and mDC2 in PB compared with healthy controls. Moreover, pDC are present in SG from patients with pSS.ConclusionPatients with pSS have alterations among DC populations in PB, and pDC are present in the SG, suggesting a potential role of these cells in SS.

scholarly journals O-Linked glycans control glycoprotein processing by antigen-presenting cells: a biochemical approach to the molecular aspects of MUC1 processing by dendritic cells

2003 ◽  
Vol 33 (12) ◽  
pp. 3242-3254 ◽  
Author(s):  
Franz-Georg Hanisch ◽  
Tilo Schwientek ◽  
Michael S. Von Bergwelt-Baildon ◽  
Joachim L. Schultze ◽  
Olivera Finn
Keyword(s):  
Dendritic Cells ◽  
Antigen Presenting Cells ◽  
Glycoprotein Processing ◽  
Biochemical Approach ◽  
Molecular Aspects ◽  
Antigen Presenting

scholarly journals Follicular dendritic cells help resting B cells to become effective antigen-presenting cells: induction of B7/BB1 and upregulation of major histocompatibility complex class II molecules.

1993 ◽  
Vol 178 (6) ◽  
pp. 2055-2066 ◽  
Author(s):  
M H Kosco-Vilbois ◽  
D Gray ◽  
D Scheidegger ◽  
M Julius
Keyword(s):  
Dendritic Cells ◽  
Major Histocompatibility Complex ◽  
B Cells ◽  
Major Histocompatibility Complex Class ◽  
B Cell ◽  
Antigen Presenting Cells ◽  
Follicular Dendritic Cells ◽  
Complex Class ◽  
Histocompatibility Complex ◽  
Antigen Presenting

This study was designed to investigate whether follicular dendritic cells (FDC) can activate B cells to a state in which they can function as effective antigen-presenting cells (APC). High buoyant density (i.e., resting) B cells specific for 2,4-dinitro-fluorobenzene (DNP) were incubated with DNP-ovalbumin (OVA) bearing FDC, after which their capacity to process and present to an OVA-specific T cell clone was assessed. The efficacies of alternative sources of antigen and activation signals in the induction of B cell APC function were compared with those provided by FDC. Only FDC and Sepharose beads coated with anti-immunoglobulin (Ig)kappa monoclonal antibody provided the necessary stimulus. FDC carrying inappropriate antigens also induced B cell APC function in the presence of exogenous DNP-OVA. However, in circumstances where soluble DNP-OVA was limiting, FDC bearing complexes containing DNP, which could crosslink B cell Ig receptors, induced the most potent APC function. Analysis by flow cytometry revealed that within 24 h of coculture with FDC, a significant percentage of B cells increased in size and expressed higher levels of major histocompatibility complex class II. By 48 h, an upregulation of the costimulatory molecule, B7/BB1, occurred, but only when exposed to the FDC bearing DNP. Taken together, the results demonstrate that FDC have the capacity to activate resting B cells to a state in which they can function as APC for T cells. The stimuli that FDC provide may include: (a) an antigen-dependent signal that influences the upregulation of B7/BB1; and (b) possibly a signal independent of crosslinking mIg that results in Ig internalization. The relevance of these findings to the formation of germinal centers and maintenance of the humoral response is discussed.

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