scholarly journals VISTA is an activating receptor in human monocytes

2021 ◽  
Vol 218 (8) ◽  
Author(s):  
Bryan M. Rogers ◽  
Laura Smith ◽  
Zoltan Dezso ◽  
Xu Shi ◽  
Enrico DiGiammarino ◽  
...  
Keyword(s):  
T Cell Activation ◽  
Cell Biology ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
Human Peripheral Blood ◽  
Proteoglycan Synthesis ◽  
Future Research ◽  
Inhibitory Protein ◽  
Functional Changes

As indicated by its name, V-domain Ig suppressor of T cell activation (VISTA) is thought to serve primarily as an inhibitory protein that limits immune responses. VISTA antibodies can dampen the effects of several concomitantly elicited activation signals, including TCR and TLR activation, but it is currently unclear if VISTA agonism could singly affect immune cell biology. In this study, we discovered two novel VISTA antibodies and characterized their effects on human peripheral blood mononuclear cells by scRNA/CITE-seq. Both antibodies appeared to agonize VISTA in an Fc-functional manner to elicit transcriptional and functional changes in monocytes consistent with activation. We also used pentameric VISTA to identify Syndecan-2 and several heparan sulfate proteoglycan synthesis genes as novel regulators of VISTA interactions with monocytic cells, adding further evidence of bidirectional signaling. Together, our study highlights several novel aspects of VISTA biology that have yet to be uncovered in myeloid cells and serves as a foundation for future research.

scholarly journals Endogenous retrovirus-encoded Syncytin-2 contributes to exosome-mediated immunosuppression of T cells†

2019 ◽  
Author(s):  
Adjimon G Lokossou ◽  
Caroline Toudic ◽  
Phuong Trang Nguyen ◽  
Xavier Elisseeff ◽  
Amandine Vargas ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell Activation ◽  
Map Kinases ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
Endogenous Retrovirus ◽  
Jurkat Cells ◽  
Peripheral Blood Mononuclear ◽  
Interfering Rna

Abstract Modulation of the activation status of immune cell populations during pregnancy depends on placental villous cytotrophoblast (VCT) cells and the syncytiotrophoblast (STB). Failure in the establishment of this immunoregulatory function leads to pregnancy complications. Our laboratory has been studying Syncytin-2 (Syn-2), an endogenous retroviral protein expressed in placenta and on the surface of placental exosomes. This protein plays an important role not only in STB formation through its fusogenic properties, but also through its immunosuppressive domain (ISD). Considering that Syn-2 expression is importantly reduced in preeclamptic placentas, we were interested in addressing its possible immunoregulatory effects on T cells. Activated Jurkat T cells and peripheral blood mononuclear cells (PBMCs) were treated with monomeric or dimerized version of a control or a Syn-2 ISD peptide. Change in phosphorylation levels of ERK1/2 MAP kinases was selectively noted in Jurkat cells treated with the dimerized ISD peptide. Upon incubation with the dimerized Syn-2 ISD peptide, significant reduction in Th1 cytokine production was further demonstrated by ELISA and Human Th1/Th2 Panel Multi-Analyte Flow Assay. To determine if exosome-associated Syn-2 could also be immunosuppressive placental exosomes were incubated with activated Jurkat and PBMCs. Quantification of Th1 cytokines in the supernatants revealed severe reduction in T cell activation. Interestingly, exosomes from Syn-2-silenced VCT incubated with PBMCs were less suppressive when compared with exosome derived from VCT transfected with control small interfering RNA (siRNA). Our results suggest that Syn-2 is an important immune regulator both locally and systemically, via its association with placental exosomes.

PBMC-07- Stimulation of human peripheral blood mononuclear cells with immobilized anti-CD3 and soluble anti-CD28 antibodies. v1

2021 ◽  
Author(s):  
Alessia Furgiuele ◽  
Massimilano Legnaro ◽  
Alessandra Luini ◽  
Marco Ferrari ◽  
Emanuela Rasini ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Functional Responses ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells

This protocol was designed to activate the lymphocytes T of a population of peripheral blood mononuclear cells (PBMCs), simulating their physiological response to antigen/MHC complex acting on T Cell Receptors-TCR , in order to test their functional responses including cell proliferation and cytokine production. The co-stimulation protocol include: i)anti-CD3 antibody a polyclonal activator specific for invariant framework epitopes on TCR complex (in particular, we use UCHT1 clone an anti-human CD3 antibody that recognizes the ε-chain of CD3 which is used for immobilized option of activation) (http://static.bdbiosciences.com/documents/BD_Tcell_Human_CD3_Activation_Protocol.pdf) ii) anti-CD28 antibody used to cooperate with TCR signals promoting activation of T cells The procedure has been reproduced following the indications contained in the protocol of "EBiooscience" (https://tools.thermofisher.com/content/sfs/manuals/t-cell-activation-in-vitro.pdf). Pilot experiments on PBMC were carried out to determine the best concentrations of anti-CD3 and anti-CD28 to induce optimal proliferation of PBMC and production of cytokines TNF-α and IFN-γ. We found a dose dependent correlation between immobilized anti-CD3 and cells functional responses. The selected amount was 2 µg/mL for both anti-CD3 and anti-CD28 that was the concentration below the maximum response which allows also to test possible modulations by therapeutic agents. References http://static.bdbiosciences.com/documents/BD_Tcell_Human_CD3_Activation_Protocol.pdf https://tools.thermofisher.com/content/sfs/manuals/t-cell-activation-in-vitro.pdf https://www.bdbiosciences.com/ds/pm/tds/555330.pdf https://www.bdbiosciences.com/ds/pm/tds/555726.pdf BEFORE STARTING with this procedure Moreover, work under laminar flow hood when you are processing samples from the beginning to the end of the culture. Make sure you are using,sterile culture mediumand sterile plastic disposable as well.

Inactivation of Human Leukocytes in Platelet Products After Pathogen Reduction Technology Treatment in the Presence of Platelet Additive Solution.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2116-2116
Author(s):  
Loren D. Fast ◽  
Susanne Marschner ◽  
Gilbert DiLeone ◽  
Raymond Goodrich
Keyword(s):  
T Cell Activation ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Uv Light ◽  
Human Peripheral Blood ◽  
Control Sample ◽  
Blood Products ◽  
Peripheral Blood Mononuclear ◽  
Pathogen Reduction ◽  
Additive Solution

Abstract Abstract 2116 Poster Board II-93 During the transfusion of blood or blood products, a recipient can receive a large number of allogeneic leukocytes. This can lead to leukocyte-mediated adverse reactions in the recipient and include donor anti-recipient responses such as the life-threatening transfusion-associated graft versus host disease (TA-GVHD) and cytokine production; or recipient anti-donor responses that are induced by direct presentation of foreign antigen by donor leukocytes or indirectly after processing of the donor cells by recipient antigen-presenting cells. To avoid or minimize leukocyte mediated reactions, the leukocytes present in blood products are inactivated or depleted prior to administration. Nucleic acid targeted pathogen reduction processes (PRT) are well suited for leukocyte inactivation. The Mirasol® PRT System uses riboflavin (Vitamin B2) and ultraviolet (UV) light to reduce the active pathogen load and inactivate residual leukocytes in blood products used for transfusion. To make the PRT System more widely applicable, the effect of treating leukocytes in the presence of platelet additive solution (PAS) was tested. Human peripheral blood mononuclear cells (PBMNC) were purified by Ficoll-Hypaque discontinuous centrifugation and placed in 350 ml of storage solution consisting of 65% PAS (SSP+) and 35% plasma. An untreated control sample was removed before addition of 35 ml of riboflavin (500 μM) and exposure to UV light (9.1 J/ml). PBMNC were recovered after treatment and tested for their ability to proliferate in response to polyclonal stimulators such as phytohemagglutinin, and anti-CD3/CD28 or to allogeneic stimulator cells in a mixed lymphocyte culture (MLC). Treatment was found to inhibit proliferation as well as T cell activation as measured by the upregulation of CD69 expression when incubated with phorbol 12-myristate 13-acetate. Treated PBMNC were unable to produce inflammatory or TH1/TH2 cytokines when stimulated with lipopolysaccharide for 24 hours or anti-CD3/CD28 for 72 hours. Levels of cytokines that are released in the absence of activation, such as IL-6, IL-8 and IL1β, were reduced below levels of detection of the assay after PRT-treatment. Quantitation of the degree of inactivation using limiting dilution assays showed that 5.2 log inactivation could be achieved at the specified energy doses. These treatment conditions resulted in acceptable platelet cell quality over 8 days in storage. In summary, PRT treatment was able to functionally inactivate leukocytes in the presence of PAS to the levels seen with gamma-irradiation without adversely affecting the quality of the platelets. Disclosures: Fast: CaridianBCT Biotechnologies: Research Funding. Marschner:CaridianBCT Biotechnologies: Employment. Goodrich:CaridianBCT Biotechnologies: Employment.

scholarly journals A252 FUNCTIONAL ANALYSIS OF GENETIC AETIOLOGIES IN A DOWNSTREAM OF TYROSINE KINASE (DOK) PROTEIN IN THE PATHOGENESIS OF PEDIATRIC INFLAMMATORY BOWEL DISEASE (IBD)

2020 ◽  
Vol 3 (Supplement_1) ◽  
pp. 129-130
Author(s):  
V Batura ◽  
C Guo ◽  
N Warner ◽  
G Leung ◽  
A Ricciuto ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Cell Function ◽  
Immune Cell ◽  
Imaging Techniques ◽  
Inflammatory Disorder ◽  
Zebrafish Model ◽  
Peripheral Blood Mononuclear

Abstract Background IBD is a form of chronic inflammatory disorder of the gastrointestinal tract that arises due to genetic, environmental, immunological and microbial factors. The precise pathological mechanisms remain elusive. It is thought that the onset of pediatric IBD can largely be attributed to genetics. Muise lab, at SickKids, regularly screens children at the SickKids IBD clinic and through an international consortium to find possible genetic links to the disease. We report a patient at SickKids with biallelic mutations in DOK4 who has severe Crohn’s Disease along with other inflammatory conditions. Downstream of kinase (DOK) proteins are a family of adaptor molecules that serve as scaffolding proteins important in regulating cell signaling, especially in T cells. DOK4 has been shown to have negative regulatory effects on T cell activation but is also expressed across various other tissues where its function is yet to be determined. We predict that these mutations are causing immune cell dysregulation, which may be contributing to the patients IBD. Aims Through this study, we aim to enhance our understanding of the pathobiological mechanism of novel mutations in DOK4. Methods We have established T cell lines, expressing wild type and mutated DOK4, which will be used to perform functional tests, such as localization analysis through immunofluorescence and cytokine profiling, to check for T cell function. We have patient derived organoids, which will be used to assess changes in gut morphology using imaging techniques. We will also generate mutant zebrafish model that will be used to determine the susceptibility to colitis related to this mutation, disease progression and gut peristalsis using live imaging technology. Results Preliminary data shows variation in expression of the protein within patient derived peripheral blood mononuclear cells (PBMCs) compared to a healthy donor. Conclusions With this study, we hope to identify new therapeutic targets for patients with DOK4 mutations. Funding Agencies CIHRThe Leona M. and Harry B. Helmsley Charitable Trust

scholarly journals Antibiotics Differentially Modulate Lipoteichoic Acid-Mediated Host Immune Response

Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 573
Author(s):  
Marquerita Algorri ◽  
Annie Wong-Beringer
Keyword(s):  
Immune Response ◽  
Cell Surface ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
Ex Vivo ◽  
Human Peripheral Blood ◽  
Lipoteichoic Acid ◽  
Cytokine Response ◽  
Hla Dr

In Staphylococcus aureus bacteremia, our group has shown that a dysregulated balance of pro- and anti-inflammatory cytokine response biased towards an immunoparalysis phenotype is predictive of persistence and mortality, despite receipt of antibiotics. Certain antibiotics, as well as lipoteichoic acid (LTA) released from S. aureus, can modulate immune response ex vivo. Here, we evaluated the effects of three anti-staphylococcal antibiotics (vancomycin, tedizolid, and daptomycin) on the expression of cytokines and cell surface markers of immune activation (TNFα, HLA-DR) and immunoparalysis (IL-10, PD-L1) in human peripheral blood mononuclear cells (PBMC) exposed to high (10 μg) and low (1 μg) doses of LTA. Results suggested a dose-dependent relationship between LTA and induction of anti- and pro-inflammatory immune responses. Differential antibiotic effects were prominently observed at high but not low LTA condition. Vancomycin significantly induced IL-10 and TNFα expression, whereas daptomycin had no effects on cytokine response or expression of cell surface receptors. Tedizolid increased TNFα and modestly increased HLA-DR expression, suggesting a stimulatory effect. These findings suggest that anti-staphylococcal agents differentially alter LTA-mediated immune cell activation status and cytokine response, providing support for future clinical studies to better elucidate the complexities of host–microbial–antibiotic interaction that can help direct precision therapy for S. aureus bacteremia.

scholarly journals The Scribble Complex PDZ Proteins in Immune Cell Polarities

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Dante Barreda ◽  
Luis H. Gutiérrez-González ◽  
Erasmo Martínez-Cordero ◽  
Carlos Cabello-Gutiérrez ◽  
Rommel Chacón-Salinas ◽  
...  
Keyword(s):  
Immune System ◽  
T Cell Activation ◽  
Cell Biology ◽  
Cell Activation ◽  
Immune Cell ◽  
Immunological Synapse ◽  
Cell Polarization ◽  
Cell Functions ◽  
Wide Range

hScrib and hDlg belong to the PDZ family of proteins. Since the identification of these highly phylogenetically conserved scaffolds, an increasing amount of experiments has elucidated the roles of hScrib and hDlg in a variety of cell functions. Remarkably, their participation during the establishment of polarity in epithelial cells is well documented. Although the role of both proteins in the immune system is scantly known, it has become a growing field of investigation. Here, we summarize the interactions and functions of hScrib and hDlg1, which participate in diverse functions involving cell polarization in immune cells, and discuss their relevance in the immune cell biology. The fundamental role of hScrib and hDlg1 during the establishment of the immunological synapse, hence T cell activation, and the recently described role of hScrib in reactive oxygen species production in macrophages and of hDlg1 in cytokine production by dendritic cells highlight the importance of both proteins in immune cell biology. The expression of these proteins in other leukocytes can be anticipated and needs to be confirmed. Due to their multiple interaction domains, there is a wide range of possible interactions of hScrib and hDlg1 that remains to be explored in the immune system.

Inactivation of Human White Blood Cells in Red Blood Cell Products Using the MIRASOL® System for Whole Blood.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2897-2897
Author(s):  
Loren D. Fast ◽  
Susanne Marschner ◽  
Gilbert DiLeone ◽  
Suzann Doane ◽  
Christy Fitzpatrick ◽  
...  
Keyword(s):  
Immune Responses ◽  
T Cell Activation ◽  
Whole Blood ◽  
Blood Cells ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Protein Quality ◽  
Human Peripheral Blood ◽  
White Blood Cells ◽  
Blood Products

Abstract Transfusion of blood products containing white blood cells (WBC) can result in the induction of immune responses that can negatively impact the recipient. An approach that would mitigate these consequences would be beneficial. Previous studies had shown that exposure of platelet concentrates to light in the presence of riboflavin was able to inhibit immune responses mediated by WBC. To make this protocol more widely applicable the effect of treating whole blood units with riboflavin and varying amounts of light was tested. Human peripheral blood mononuclear cells were purified by Ficoll-Hypaque discontinuous centrifugation from aliquots of nonleukoreduced whole blood units that were untreated or exposed to Mirasol treatment using varying light dosages. Viability and phenotype of treated cells was unchanged compared to untreated controls. The results showed that exposure of whole blood units to 33J/mL red blood cells (RBC) UV light in the presence of riboflavin completely inhibited proliferation of WBC in response to polyclonal stimulators such as phytohemagglutinin, and anti-CD3/CD28 or to allogeneic stimulator cells in a mixed lymphocyte culture (MLC). Additional assays showed that treated WBC were unable to induce proliferation of normal responder cells in an MLC. Treated cells did not produce inflammatory or TH1/TH2 cytokines when stimulated with lipopolysaccharide for 24 hours or anti-CD3/CD28 for 72 hours. In addition, treatment was found to inhibit T cell activation as evidenced by the lack of CD69 expression in treated compared to untreated control cells when incubated with phorbol 12-myristate 13-acetate. These treatment conditions did not induce crossmatch incompatibility. Methemoglobin levels and hemolysis in RBC units stayed below 1% during storage for 42 days in AS-3. Platelet and plasma units separated from whole blood after treatment showed acceptable cell and protein quality over 5 days in storage or as fresh frozen plasma, respectively. In summary, Mirasol treatment was able to functionally inactivate WBC in whole blood products without adversely affecting the quality of the RBC, platelets and plasma. This technique offers potential means to achieve inactivation of WBC in whole blood units that can subsequently be separated into RBC, platelet and plasma components.

scholarly journals Functional comaparison of PBMCs isolated by Cell Preparation Tubes (CPT) vs Lymphoprep Tubes

2020 ◽  
Author(s):  
Han Chen ◽  
Christian M Schürch ◽  
Kevin Noble ◽  
Kenneth Kim ◽  
Peter Krutzik ◽  
...  
Keyword(s):  
T Cell ◽  
Density Gradient ◽  
T Cell Activation ◽  
Mononuclear Cells ◽  
Immune Cell ◽  
Human Peripheral Blood ◽  
Sample Type ◽  
Cell Preparation ◽  
Density Gradient Medium ◽  
Gradient Medium

Abstract Background : Cryopreserved human peripheral blood mononuclear cells (PBMCs) are a commonly used sample type for a variety of immunological assays. Many factors can affect the quality of PBMCs, and careful consideration and validation of an appropriate PBMC isolation and cryopreservation method is important for well-designed clinical studies. A major point of divergence in PBMC isolation protocols is the collection of blood, either directly into vacutainers pre-filled with density gradient medium or the use of conical tubes containing a porous barrier to separate the density gradient medium from blood. Results : To address potential differences in sample outcome, we isolated, cryopreserved, and compared frequency and functionality of PBMCs using parallel protocols differing only in the use of one of two common tube types for isolation. Whole blood was processed in parallel using both Cell Preparation Tubesä (CPT, BD Biosciences) and Lymphoprepä Tubes (Axis-Shield) and assessed for yield and viability prior to cryopreservation. After thawing, samples were further examined by flow cytometry for cell yield, cell viability, frequency of ten cell subsets, and capacity for stimulation-dependent CD4+ and CD8+ T cell intracellular cytokine production. Cell recovery, viability, frequency of immune cell subsets, and T cell functionality between PBMC samples isolated using CPT or Lymphoprep tubes were comparable. Conclusion : CPT and Lymphoprep tubes are both effective for PBMC isolation and may be used interchangeably for immunological studies involving T cell activation.

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