scholarly journals Lymphatic exosomes promote dendritic cell migration along guidance cues

2018 ◽  
Vol 217 (6) ◽  
pp. 2205-2221 ◽  
Author(s):  
Markus Brown ◽  
Louise A. Johnson ◽  
Dario A. Leone ◽  
Peter Majek ◽  
Kari Vaahtomeri ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Ex Vivo ◽  
Inflammatory Diseases ◽  
Lymphatic Vessels ◽  
Guidance Cues ◽  
Cargo Proteins ◽  
Dendritic Cell Migration ◽  
Human Dendritic Cells ◽  
Cellular Protrusion

Lymphatic endothelial cells (LECs) release extracellular chemokines to guide the migration of dendritic cells. In this study, we report that LECs also release basolateral exosome-rich endothelial vesicles (EEVs) that are secreted in greater numbers in the presence of inflammatory cytokines and accumulate in the perivascular stroma of small lymphatic vessels in human chronic inflammatory diseases. Proteomic analyses of EEV fractions identified >1,700 cargo proteins and revealed a dominant motility-promoting protein signature. In vitro and ex vivo EEV fractions augmented cellular protrusion formation in a CX3CL1/fractalkine-dependent fashion and enhanced the directional migratory response of human dendritic cells along guidance cues. We conclude that perilymphatic LEC exosomes enhance exploratory behavior and thus promote directional migration of CX3CR1-expressing cells in complex tissue environments.

scholarly journals CD14 Expressing Precursors Give Rise to Highly Functional Conventional Dendritic Cells for Use as Dendritic Cell Vaccine

Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3818
Author(s):  
Maud Plantinga ◽  
Denise A. M. H. van den Beemt ◽  
Ester Dünnebach ◽  
Stefan Nierkens
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Cord Blood ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ex Vivo ◽  
Dendritic Cell Vaccine ◽  
Cell Vaccine ◽  
Activated T Cells

Induction of long-lasting immunity by dendritic cells (DCs) makes them attractive candidates for anti-tumor vaccination. Although DC vaccinations are generally considered safe, clinical responses remain inconsistent in clinical trials. This initiated studies to identify subsets of DCs with superior capabilities to induce effective and memory anti-tumor responses. The use of primary DCs has been suggested to overcome the functional limitations of ex vivo monocyte-derived DCs (moDC). The ontogeny of primary DCs has recently been revised by the introduction of DC3, which phenotypically resembles conventional (c)DC2 as well as moDC. Previously, we developed a protocol to generate cDC2s from cord blood (CB)-derived stem cells via a CD115-expressing precursor. Here, we performed index sorting and single-cell RNA-sequencing to define the heterogeneity of in vitro developed DC precursors and identified CD14+CD115+ expressing cells that develop into CD1c++DCs and the remainder cells brought about CD123+DCs, as well as assessed their potency. The maturation status and T-cell activation potential were assessed using flow cytometry. CD123+DCs were specifically prone to take up antigens but only modestly activated T-cells. In contrast, CD1c++ are highly mature and specialized in both naïve as well as antigen-experienced T-cell activation. These findings show in vitro functional diversity between cord blood stem cell-derived CD123+DC and CD1c++DCs and may advance the efficiency of DC-based vaccines.

scholarly journals Effects of Staphylococcus aureus Bacteriophage K on Expression of Cytokines and Activation Markers by Human Dendritic Cells In Vitro

Viruses ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 617 ◽  
Author(s):  
Helen Freyberger ◽  
Yunxiu He ◽  
Amanda Roth ◽  
Mikeljon Nikolich ◽  
Andrey Filippov
Keyword(s):  
Staphylococcus Aureus ◽  
Dendritic Cells ◽  
Inflammatory Response ◽  
Adaptive Immune Response ◽  
Human Monocyte ◽  
Activation Markers ◽  
Mhc I ◽  
Adaptive Immune ◽  
Human Dendritic Cells

A potential concern with bacteriophage (phage) therapeutics is a host-versus-phage response in which the immune system may neutralize or destroy phage particles and thus impair therapeutic efficacy, or a strong inflammatory response to repeated phage exposure might endanger the patient. Current literature is discrepant with regard to the nature and magnitude of innate and adaptive immune response to phages. The purpose of this work was to study the potential effects of Staphylococcus aureus phage K on the activation of human monocyte-derived dendritic cells. Since phage K acquired from ATCC was isolated around 90 years ago, we first tested its activity against a panel of 36 diverse S. aureus clinical isolates from military patients and found that it was lytic against 30/36 (83%) of strains. Human monocyte-derived dendritic cells were used to test for an in vitro phage-specific inflammatory response. Repeated experiments demonstrated that phage K had little impact on the expression of pro- and anti-inflammatory cytokines, or on MHC-I/II and CD80/CD86 protein expression. Given that dendritic cells are potent antigen-presenting cells and messengers between the innate and the adaptive immune systems, our results suggest that phage K does not independently affect cellular immunity or has a very limited impact on it.

Regulatory perspective on in vitro potency assays for human dendritic cells used in anti-tumor immunotherapy

Cytotherapy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 1289-1308 ◽  
Author(s):  
CHARLOTTE DE Wolf ◽  
MARJA VAN DE BOVENKAMP ◽  
MARCEL HOEFNAGEL
Keyword(s):  
Dendritic Cells ◽  
Tumor Immunotherapy ◽  
Regulatory Perspective ◽  
Human Dendritic Cells

scholarly journals In Vivo Role of Dendritic Cells in a Murine Model of Pulmonary Cryptococcosis

2006 ◽  
Vol 74 (7) ◽  
pp. 3817-3824 ◽  
Author(s):  
Karen L. Wozniak ◽  
Jatin M. Vyas ◽  
Stuart M. Levitz
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ex Vivo ◽  
Interleukin 2 ◽  
Mouse Lung

ABSTRACT Dendritic cells (DC) have been shown to phagocytose and kill Cryptococcus neoformans in vitro and are believed to be important for inducing protective immunity against this organism. Exposure to C. neoformans occurs mainly by inhalation, and in this study we examined the in vivo interactions of C. neoformans with DC in the lung. Fluorescently labeled live C. neoformans and heat-killed C. neoformans were administered intranasally to C57BL/6 mice. At specific times postinoculation, mice were sacrificed, and lungs were removed. Single-cell suspensions of lung cells were prepared, stained, and analyzed by microscopy and flow cytometry. Within 2 h postinoculation, fluorescently labeled C. neoformans had been internalized by DC, macrophages, and neutrophils in the mouse lung. Additionally, lung DC from mice infected for 7 days showed increased expression of the maturation markers CD80, CD86, and major histocompatibility complex class II. Finally, ex vivo incubation of lung DC from infected mice with Cryptococcus-specific T cells resulted in increased interleukin-2 production compared to the production by DC from naïve mice, suggesting that there was antigen-specific T-cell activation. This study demonstrated that DC in the lung are capable of phagocytosing Cryptococcus in vivo and presenting antigen to C. neoformans-specific T cells ex vivo, suggesting that these cells have roles in innate and adaptive pulmonary defenses against cryptococcosis.

scholarly journals C5a and C5aR1 are key drivers of microvascular platelet aggregation in clinical entities spanning from aHUS to COVID-19

2021 ◽  
Author(s):  
Sistiana Aiello ◽  
Sara Gastoldi ◽  
Miriam Galbusera ◽  
Piero Luigi Ruggenenti ◽  
Valentina Portalupi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Bacterial Infections ◽  
Viral Infections ◽  
Ex Vivo ◽  
Inflammatory Diseases ◽  
Thrombus Formation ◽  
Alternative Pathway ◽  
Atypical Hemolytic Uremic Syndrome ◽  
Uremic Syndrome

Unrestrained activation of the complement system till the terminal products, C5a and C5b-9, plays a pathogenetic role in acute and chronic inflammatory diseases. In endothelial cells, complement hyperactivation may translate into cell dysfunction, favoring thrombus formation. The aim of this study was to investigate the role of the C5a/C5aR1 axis as opposite to C5b-9 in inducing endothelial dysfunction and loss of anti-thrombogenic properties. In vitro and ex vivo assays with serum from patients with atypical hemolytic uremic syndrome (aHUS) -a prototype rare disease of complement-mediated microvascular thrombosis due to genetically determined alternative pathway dysregulation- and cultured microvascular endothelial cells, demonstrated that the C5a/C5aR1 axis is a key player of endothelial thromboresistance loss. C5a added to normal human serum, fully recapitulated the pro-thrombotic effects of aHUS serum. Mechanistic studies showed that C5a caused RalA-mediated exocytosis of vWF and P-selectin from Weibel-Palade bodies, which favored further vWF binding on the endothelium and platelet adhesion and aggregation. In patients with severe COVID-19 -who suffered from acute activation of complement triggered by SARS-CoV-2 infection- we found the same C5a-dependent pathogenic mechanisms. These results highlight C5a/C5aR1 as a common pro-thrombogenic effector spanning from genetic rare diseases to viral infections, and may have clinical implications. Selective C5a/C5aR1 blockade could have advantages over C5 inhibition, since the former preserves the formation of C5b-9 that is critical to control bacterial infections that often develop as comorbidities in severely ill patients. (Clinicaltrials.gov identifier NCT02464891)

scholarly journals Inflammatory Mediators and Gut Microbial Toxins Drive Colon Tumorigenesis by IL-23 Dependent Mechanism

Cancers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 5159
Author(s):  
Janani Panneerselvam ◽  
Venkateshwar Madka ◽  
Rajani Rai ◽  
Katherine T. Morris ◽  
Courtney W. Houchen ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Dendritic Cells ◽  
Tumor Progression ◽  
Inflammatory Mediators ◽  
Ex Vivo ◽  
Colon Tumor ◽  
Colonic Tumor ◽  
Colon Tumorigenesis ◽  
Microbial Toxins

Obesity-associated chronic inflammation predisposes colon cancer risk development. Interleukin-23 (IL-23) is a potential inflammatory mediator linking obesity to chronic colonic inflammation, altered gut microbiome, and colon carcinogenesis. We aimed to elucidate the role of pro-inflammatory eicosanoids and gut bacterial toxins in priming dendritic cells and macrophages for IL-23 secretion to promote colon tumor progression. To investigate the association of IL-23 with obesity and colon tumorigenesis, we utilized TCGA data set and colonic tumors from humans and preclinical models. To understand IL-23 production by inflammatory mediators and gut microbial toxins, we performed several in vitro mechanistic studies to mimic the tumor microenvironment. Colonic tumors were utilized to perform the ex vivo experiments. Our findings showed that IL-23 is elevated in obese individuals, colonic tumors and correlated with reduced disease-free survival. In vitro studies showed that IL-23 treatment increased the colon tumor cell self-renewal, migration, and invasion while disrupting epithelial barrier permeability. Co-culture experiments of educated dendritic cells/macrophages with colon cancer cells significantly increased the tumor aggression by increasing the secretory levels of IL-23, and these observations are further supported by ex vivo rat colonic tumor organotypic experiments. Our results demonstrate gut microbe toxins and eicosanoids facilitate IL-23 production, which plays an important role in obesity-associated colonic tumor progression. This newly identified nexus represents a potential target for the prevention and treatment of obesity-associated colon cancer.

The novel adjuvant CoVaccineHT™ increases the immunogenicity of cell-culture derived influenza A/H5N1 vaccine and induces the maturation of murine and human dendritic cells in vitro

Vaccine ◽  
2009 ◽  
Vol 27 (49) ◽  
pp. 6833-6839 ◽  
Author(s):  
R. Bodewes ◽  
M.M. Geelhoed-Mieras ◽  
J.G.M. Heldens ◽  
J. Glover ◽  
B.N. Lambrecht ◽  
...  
Keyword(s):  
Cell Culture ◽  
Dendritic Cells ◽  
Influenza A ◽  
The Novel ◽  
Human Dendritic Cells ◽  
H5n1 Vaccine

HIV gp120 receptors on human dendritic cells

Blood ◽  
2001 ◽  
Vol 98 (8) ◽  
pp. 2482-2488 ◽  
Author(s):  
Stuart G. Turville ◽  
Jim Arthos ◽  
Kelli Mac Donald ◽  
Garry Lynch ◽  
Hassan Naif ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Ex Vivo ◽  
Mannose Receptor ◽  
Lectin Receptor ◽  
Immunodeficiency Virus ◽  
Processing Pathways ◽  
Human Dendritic Cells ◽  
Hiv Gp120 ◽  
Hiv Envelope ◽  
Transfer Mechanisms

Abstract Dendritic cells (DCs) are important targets for human immunodeficiency virus (HIV) because of their roles during transmission and also maintenance of immune competence. Furthermore, DCs are a key cell in the development of HIV vaccines. In both these settings the mechanism of binding of the HIV envelope protein gp120 to DCs is of importance. Recently a single C-type lectin receptor (CLR), DC-SIGN, has been reported to be the predominant receptor on monocyte-derived DCs (MDDCs) rather than CD4. In this study a novel biotinylated gp120 assay was used to determine whether CLR or CD4 were predominant receptors on MDDCs and ex vivo blood DCs. CLR bound more than 80% of gp120 on MDDCs, with residual binding attributable to CD4, reconfirming that CLRs were the major receptors for gp120 on MDDCs. However, in contrast to recent reports, gp120 binding to at least 3 CLRs was observed: DC-SIGN, mannose receptor, and unidentified trypsin resistant CLR(s). In marked contrast, freshly isolated and cultured CD11c+ve and CD11c−ve blood DCs only bound gp120 via CD4. In view of these marked differences between MDDCs and blood DCs, HIV capture by DCs and transfer mechanisms to T cells as well as potential antigenic processing pathways will need to be determined for each DC phenotype.

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