scholarly journals Respiratory Syncytial Virus Fusion Protein Mediates Inhibition of Mitogen-Induced T-Cell Proliferation by Contact

2002 ◽  
Vol 76 (3) ◽  
pp. 1163-1170 ◽  
Author(s):  
Jörg Schlender ◽  
Gunther Walliser ◽  
Jens Fricke ◽  
Karl-Klaus Conzelmann
Keyword(s):  
Respiratory Syncytial Virus ◽  
T Cell ◽  
Fusion Protein ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ex Vivo ◽  
Cell Contact ◽  
Activation Markers ◽  
Syncytial Virus

ABSTRACT Human respiratory syncytial virus (HRSV) and bovine respiratory syncytial virus (BRSV) are major pathogens in infants and calves, respectively. Experimental BRSV infection of calves and lambs is associated with lymphopenia and a reduction in responsiveness of peripheral blood lymphocytes (PBLs) to mitogens ex vivo. In this report, we show that in vitro mitogen-induced proliferation of PBLs is inhibited after contact with RSV-infected and UV-inactivated cells or with cells expressing RSV envelope proteins on the cell surface. The protein responsible was identified as the RSV fusion protein (F), as cells infected with a recombinant RSV expressing F as the single envelope protein or cells transfected with a plasmid encoding F were able to induce this effect. Thus, direct contact with RSV F is necessary and sufficient to inhibit proliferation of PBLs. Interestingly, F derived from HRSV was more efficient in inhibiting human PBL proliferation, while F from BRSV was more efficient in inhibiting bovine PBLs. Since various T-cell activation markers were upregulated after presenter cell contact, T lymphocytes are viable and may still be activated by mitogen. However, a significant fraction of PBLs were delayed or defective in G0/G1 to S-phase transit.

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 CCL21 mediates CD4+ T-cell costimulation via a DOCK2/Rac-dependent pathway

Blood ◽  
2009 ◽  
Vol 114 (3) ◽  
pp. 580-588 ◽  
Author(s):  
Kathrin Gollmer ◽  
François Asperti-Boursin ◽  
Yoshihiko Tanaka ◽  
Klaus Okkenhaug ◽  
Bart Vanhaesebroeck ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Early Time ◽  
Cell Receptor ◽  
Tcr Signaling ◽  
Activation Markers

Abstract CD4+ T cells use the chemokine receptor CCR7 to home to and migrate within lymphoid tissue, where T-cell activation takes place. Using primary T-cell receptor (TCR)–transgenic (tg) CD4+ T cells, we explored the effect of CCR7 ligands, in particular CCL21, on T-cell activation. We found that the presence of CCL21 during early time points strongly increased in vitro T-cell proliferation after TCR stimulation, correlating with increased expression of early activation markers. CCL21 costimulation resulted in increased Ras- and Rac-GTP formation and enhanced phosphorylation of Akt, MEK, and ERK but not p38 or JNK. Kinase-dead PI3KδD910A/D910A or PI3Kγ-deficient TCR-tg CD4+ T cells showed similar responsiveness to CCL21 costimulation as control CD4+ T cells. Conversely, deficiency in the Rac guanine exchange factor DOCK2 significantly impaired CCL21-mediated costimulation in TCR-tg CD4+ T cells, concomitant with impaired Rac- but not Ras-GTP formation. Using lymph node slices for live monitoring of T-cell behavior and activation, we found that G protein-coupled receptor signaling was required for early CD69 expression but not for Ca2+ signaling. Our data suggest that the presence of CCL21 during early TCR signaling lowers the activation threshold through Ras- and Rac-dependent pathways leading to increased ERK phosphorylation.

scholarly journals TRPM2 Is Not Required for T-Cell Activation and Differentiation

2022 ◽  
Vol 12 ◽  
Author(s):  
Niels C. Lory ◽  
Mikolaj Nawrocki ◽  
Martina Corazza ◽  
Joanna Schmid ◽  
Valéa Schumacher ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Transient Receptor Potential ◽  
Cell Function ◽  
Intestinal Inflammation ◽  
Activation Markers

Antigen recognition by the T-cell receptor induces a cytosolic Ca2+ signal that is crucial for T-cell function. The Ca2+ channel TRPM2 (transient receptor potential cation channel subfamily M member 2) has been shown to facilitate influx of extracellular Ca2+ through the plasma membrane of T cells. Therefore, it was suggested that TRPM2 is involved in T-cell activation and differentiation. However, these results are largely derived from in vitro studies using T-cell lines and non-physiologic means of TRPM2 activation. Thus, the relevance of TRPM2-mediated Ca2+ signaling in T cells remains unclear. Here, we use TRPM2-deficient mice to investigate the function of TRPM2 in T-cell activation and differentiation. In response to TCR stimulation in vitro, Trpm2-/- and WT CD4+ and CD8+ T cells similarly upregulated the early activation markers NUR77, IRF4, and CD69. We also observed regular proliferation of Trpm2-/- CD8+ T cells and unimpaired differentiation of CD4+ T cells into Th1, Th17, and Treg cells under specific polarizing conditions. In vivo, Trpm2-/- and WT CD8+ T cells showed equal specific responses to Listeria monocytogenes after infection of WT and Trpm2-/- mice and after transfer of WT and Trpm2-/- CD8+ T cells into infected recipients. CD4+ T-cell responses were investigated in the model of anti-CD3 mAb-induced intestinal inflammation, which allows analysis of Th1, Th17, Treg, and Tr1-cell differentiation. Here again, we detected similar responses of WT and Trpm2-/- CD4+ T cells. In conclusion, our results argue against a major function of TRPM2 in T-cell activation and differentiation.

scholarly journals GABAA receptor α4-subunit knockout enhances lung inflammation and airway reactivity in a murine asthma model

2017 ◽  
Vol 313 (2) ◽  
pp. L406-L415 ◽  
Author(s):  
Gene T. Yocum ◽  
Damian L. Turner ◽  
Jennifer Danielsson ◽  
Matthew B. Barajas ◽  
Yi Zhang ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Immune Cells ◽  
Cell Activation ◽  
Cell Function ◽  
Immune Cell ◽  
Therapeutic Potential ◽  
Ex Vivo ◽  
Asthma Model

Emerging evidence indicates that hypnotic anesthetics affect immune function. Many anesthetics potentiate γ-aminobutyric acid A receptor (GABAAR) activation, and these receptors are expressed on multiple subtypes of immune cells, providing a potential mechanistic link. Like immune cells, airway smooth muscle (ASM) cells also express GABAARs, particularly isoforms containing α4-subunits, and activation of these receptors leads to ASM relaxation. We sought to determine if GABAAR signaling modulates the ASM contractile and inflammatory phenotype of a murine allergic asthma model utilizing GABAAR α4-subunit global knockout (KO; Gabra40/0) mice. Wild-type (WT) and Gabra4 KO mice were sensitized with house dust mite (HDM) antigen or exposed to PBS intranasally 5 days/wk for 3 wk. Ex vivo tracheal rings from HDM-sensitized WT and Gabra4 KO mice exhibited similar magnitudes of acetylcholine-induced contractile force and isoproterenol-induced relaxation ( P = not significant; n = 4). In contrast, in vivo airway resistance (flexiVent) was significantly increased in Gabra4 KO mice ( P < 0.05, n = 8). Moreover, the Gabra4 KO mice demonstrated increased eosinophilic lung infiltration ( P < 0.05; n = 4) and increased markers of lung T-cell activation/memory (CD62L low, CD44 high; P < 0.01, n = 4). In vitro, Gabra4 KO CD4+ cells produced increased cytokines and exhibited increased proliferation after stimulation of the T-cell receptor as compared with WT CD4+ cells. These data suggest that the GABAAR α4-subunit plays a role in immune cell function during allergic lung sensitization. Thus GABAAR α4-subunit-specific agonists have the therapeutic potential to treat asthma via two mechanisms: direct ASM relaxation and inhibition of airway inflammation.

scholarly journals Contribution of Fcγreceptors to human respiratory syncytial virus pathogenesis and the impairment of T-cell activation by dendritic cells

Immunology ◽  
2015 ◽  
Vol 147 (1) ◽  
pp. 55-72 ◽  
Author(s):  
Roberto S. Gómez ◽  
Bruno A. Ramirez ◽  
Pablo F. Céspedes ◽  
Kelly M. Cautivo ◽  
Sebastián A. Riquelme ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Respiratory Syncytial Virus ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Human Respiratory Syncytial Virus ◽  
Syncytial Virus

scholarly journals Flow Cytometric Evaluation of T Cell Activation Markers after Cardiopulmonary Bypass

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Maja-Theresa Dieterlen ◽  
Hartmuth B. Bittner ◽  
Attila Tarnok ◽  
Jens Garbade ◽  
Stefan Dhein ◽  
...  
Keyword(s):  
Cardiopulmonary Bypass ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ex Vivo ◽  
Activation Markers ◽  
Increased Risk ◽  
Patients At Risk ◽  
Inflammatory Processes ◽  
Activation Pathways

Background. Cardiopulmonary bypass surgery (CPBS) is associated with an increased risk for infections or with subsequent organ dysfunction. As T cell activation is a central mechanism during inflammatory processes, we developed an assay to evaluate T cell activation pathways in patients undergoing CPBS.Methods. Blood was obtained from eleven patients undergoing CPBS preoperatively, on postoperative day (POD)-3, and on POD-7 and was stimulated with different concentrations of Concanavalin A (ConA). Cyclosporine and sirolimus, inhibiting different pathways of the T cell cycle, were added to blood ex vivo. Expression of T cell activation markers CD25 and CD95 was analyzed by flow cytometry.Results. In untreated blood, expression of CD25 and CD95 significantly increased with higher ConA concentrations(P<0.05)and decreased for all ConA concentrations for both antigens over the study time(P<0.05). Independently from the ConA concentration, inhibition of CD25 and CD95 expression was highest preoperatively for sirolimus and on POD-3 for cyclosporine. At all time points, inhibition of CD25 and CD95 expression was significantly higher after cyclosporine compared to sirolimus treatment(P<0.001).Conclusion. Our results showed that different pathways of T cell activation are impaired after CPBS. Such knowledge may offer the opportunity to identify patients at risk for postoperative complications.

T-cell redirected killing and cure of pancreatic and gastric cancer xenografts by targeting Trop-2.

2015 ◽  
Vol 33 (3_suppl) ◽  
pp. 262-262
Author(s):  
David M. Goldenberg ◽  
Edmund A. Rossi ◽  
Diane L Rossi ◽  
Thomas M. Cardillo ◽  
Chien-Hsing Chang
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ex Vivo ◽  
Control Group ◽  
Calcium Signal ◽  
Target Cells ◽  
Normal Tissues

262 Background: Trop-2 [also called tumor-associated calcium signal transducer 2 (TACSTD2), EGP-1 (epithelial glycoprotein-1), GA733-1, or M1S1]is a 35 kDa transmembrane glycoprotein that is overexpressed relative to normal tissues in a variety of human cancers, including pancreatic and gastric carcinomas, where increased expression correlates with poor prognosis. Trop-2 appears to be more tumor-specific than the related molecule, EpCAM (Trop-1). MT110, the EpCAM antibody x CD3 bispecific T-cell engager (BiTE), is currently undergoing a Phase I study in various solid tumors, including lung, gastric, colorectal, breast, prostate, and ovarian cancers. We produced a similar T-cell redirecting bispecific tandem scFv, E1-3, using the variable domains of hRS7 (humanized anti-Trop-2 mAb) and Okt-3 (anti-CD3 mAb). Methods: T-cell activation, cytokine induction and cytotoxicity were evaluated ex vivo using PBMCs or purified T cells with human pancreatic (Capan-1 and BxPC3) and gastric (NCI-N87) cancer cell lines as target cells. In vivo activity was assayed with NCI-N87 xenografts that were inoculated s.c. in a mixture with twice the number of human PBMCs and matrigel. Results: In the presence of target cells and PBMCs, E1-3 potently induced T-cell activation, proliferation, and dose-dependent cytokine production of IL-2 (>2 ng/mL), IL-6 (>1 ng/mL), IL-10 (>7 ng/mL), TNF-α (>1 ng/mL) and IFN-γ (>50 ng/mL). In vitro, E1-3 mediated a highly potent T-cell lysis of BxPC3 [IC50=0.09(±0.04) pM], Capan-1 [IC50=1.2(±1.1) pM] and NCI-N87 [IC50=1.2(±1.2) pM] target cells. In vivo, two 50-µg doses of E1-3 given three days apart cured all of the mice (N=8) bearing NCI-N87 xenografts (P=0.0005; Log-Rank). Tumors in the control group (PBMCs only) reached the endpoint (TV>1 cm3) with a median of 39.5 days. All mice remained tumor-free in the E1-3 group at 78 days. Conclusions: Trop-2 is an attractive target for T-cell-mediated killing of pancreatic, gastric and other epithelial cancers.

scholarly journals In vitro T-cell activation of monocyte-derived macrophages by soluble messengers or cell-to-cell contact in bovine tuberculosis

Immunology ◽  
2000 ◽  
Vol 100 (2) ◽  
pp. 194-202 ◽  
Author(s):  
E. Liebana ◽  
A. Aranaz ◽  
M. Welsh ◽  
S. D. Neill ◽  
J. M. Pollock
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Bovine Tuberculosis ◽  
Cell Activation ◽  
Cell Contact

scholarly journals The c-SMAC

2005 ◽  
Vol 170 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Joseph Lin ◽  
Mark J. Miller ◽  
Andrey S. Shaw
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Contact Area ◽  
Cell Activation ◽  
Immunological Synapse ◽  
Central Area ◽  
Scaffolding Protein ◽  
Cell Contact

T cells integrate and transduce the key signals necessary to mount an appropriate immune response. To do this, they rely on both secreted factors as well as physical cell–cell contact. Much attention has focused on the organization of proteins at the contact area between a T cell and an antigen-presenting cell, known as the immunological synapse. It has been shown in vitro that proteins segregate into two distinct regions within this contact area, a central area referred to as the c-SMAC, where the T cell receptor and associated signaling molecules are enriched, and a peripheral region called the p-SMAC containing LFA-1 and the scaffolding protein talin. Whether or not these structures form in vivo and how they function in T cell activation remain issues of great interest. Here, we review recently published work and propose several possible functions for the role of the c-SMAC in T cell activation.

scholarly journals IL-6 regulates CCR5 expression and immunosuppressive capacity of MDSC in murine melanoma

2020 ◽  
Vol 8 (2) ◽  
pp. e000949 ◽  
Author(s):  
Rebekka Weber ◽  
Zeno Riester ◽  
Laura Hüser ◽  
Carsten Sticht ◽  
Alina Siebenmorgen ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Ccr5 Expression ◽  
Myeloid Suppressor Cell ◽  
Cell Functions ◽  
Arginase 1

BackgroundMyeloid-derived suppressor cells (MDSC) play a major role in the immunosuppressive melanoma microenvironment. They are generated under chronic inflammatory conditions characterized by the constant production of inflammatory cytokines, chemokines and growth factors, including IL-6. Recruitment of MDSC to the tumor is mediated by the interaction between chemokines and chemokine receptors, in particular C–C chemokine receptor (CCR)5. Here, we studied the mechanisms of CCR5 upregulation and increased immunosuppressive function of CCR5+ MDSC.MethodsThe immortalized myeloid suppressor cell line MSC-2, primary immature myeloid cells and in vitro differentiated MDSC were used to determine factors and molecular mechanisms regulating CCR5 expression and immunosuppressive markers at the mRNA and protein levels. The relevance of the identified pathways was validated on the RET transgenic mouse melanoma model, which was also used to target the identified pathways in vivo.ResultsIL-6 upregulated the expression of CCR5 and arginase 1 in MDSC by a STAT3-dependent mechanism. MDSC differentiated in the presence of IL-6 strongly inhibited CD8+ T cell functions compared with MDSC differentiated without IL-6. A correlation between IL-6 levels, phosphorylated STAT3 and CCR5 expression in tumor-infiltrating MDSC was demonstrated in the RET transgenic melanoma mouse model. Surprisingly, IL-6 overexpressing tumors grew significantly slower in mice accompanied by CD8+ T cell activation. Moreover, transgenic melanoma-bearing mice treated with IL-6 blocking antibodies showed significantly accelerated tumor development.ConclusionOur in vitro and ex vivo findings demonstrated that IL-6 induced CCR5 expression and a strong immunosuppressive activity of MDSC, highlighting this cytokine as a promising target for melanoma immunotherapy. However, IL-6 blocking therapy did not prove to be effective in RET transgenic melanoma-bearing mice but rather aggravated tumor progression. Further studies are needed to identify particular combination therapies, cancer entities or patient subsets to benefit from the anti-IL-6 treatment.

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