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 ◽  
...  

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.

2021 ◽  
Vol 22 (13) ◽  
pp. 7187
Author(s):  
Kaschin Jamal Jameel ◽  
Willem-Jakob Gallert ◽  
Sarah D. Yanik ◽  
Susanne Panek ◽  
Juliane Kronsbein ◽  
...  

In smoking-induced chronic obstructive pulmonary disease (COPD), various comorbidities are linked to systemic inflammation and infection-induced exacerbations. The underlying mechanisms are unclear but might provide therapeutic targets. T-cell activity is central in systemic inflammation and for infection-defense mechanisms and might be influenced by comorbidities. Hypothesis: Circulating biomarkers of comorbidities modulate the activity of T-cells of the T-helper type 1 (Th1) and/or T-cytotoxic type 1 (Tc1). T-cells in peripheral blood mononuclear cells (PBMCs) from non-smokers (NS), current smokers without COPD (S), and COPD subjects (total n = 34) were ex vivo activated towards Th1/Tc1 and were then stimulated with biomarkers for metabolic and/or cardiovascular comorbidities (Brain Natriuretic Peptide, BNP; chemokine (C-C motif) ligand 18, CCL18; C-X3-C motif chemokine ligand 1, CX3CL1; interleukin-18, IL-18) or for asthma- and/or cancer-related comorbidities (CCL22; epidermal growth factor, EGF; IL-17; periostin) each at 10 or 50 ng/mL. The Th1/Tc1 activation markers interferon-γ (IFNγ), tumor necrosis factor-α (TNFα), and granulocyte-macrophage colony-stimulating factor (GM-CSF) were analyzed in culture supernatants by Enzyme-Linked Immunosorbent Assay (ELISA). Ex-vivo activation induced IFNγ and TNFα without differences between the groups but GM-CSF more in S vs. NS. At 10 ng/mL, the different biomarkers increased or reduced the T-cell activation markers without a clear trend for one direction in the different categories of comorbidities or for the different T-cell activation markers. At 50 ng/mL, there was a clear shift towards suppressive effects, particularly for the asthma— and cancer-related biomarkers and in cells of S and COPD. Comorbidities might suppress T-cell immunity in COPD. This could explain the association of comorbidities with frequent exacerbations.


2002 ◽  
Vol 76 (3) ◽  
pp. 1163-1170 ◽  
Author(s):  
Jörg Schlender ◽  
Gunther Walliser ◽  
Jens Fricke ◽  
Karl-Klaus Conzelmann

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.


Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3818
Author(s):  
Maud Plantinga ◽  
Denise A. M. H. van den Beemt ◽  
Ester Dünnebach ◽  
Stefan Nierkens

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.


Blood ◽  
2009 ◽  
Vol 114 (3) ◽  
pp. 580-588 ◽  
Author(s):  
Kathrin Gollmer ◽  
François Asperti-Boursin ◽  
Yoshihiko Tanaka ◽  
Klaus Okkenhaug ◽  
Bart Vanhaesebroeck ◽  
...  

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.


Blood ◽  
2021 ◽  
Author(s):  
Muzaffar H Qazilbash ◽  
Neeraj Y Saini ◽  
Cha Soung-chul ◽  
Zhe Wang ◽  
Edward Stadtmauer ◽  
...  

We hypothesized that combining adoptively transferred autologous T cells with a cancer vaccine strategy would enhance therapeutic efficacy by adding anti-myeloma idiotype-keyhole limpet hemocyanin (Id-KLH) vaccine to vaccine-specific co-stimulated T cells. In this randomized, phase II trial, eligible patients received either the control (KLH only) or Id-KLH vaccine, an auto-transplant, vaccine-specific co-stimulated T-cells expanded ex-vivo, and two booster doses of the assigned vaccine. In 36 patients (20 in KLH, 16 in Id-KLH) enrolled, no dose-limiting toxicity was seen in either arm. At last evaluation, 6 (30%) and 8 (50%) had achieved complete remission in KLH-only and Id-KLH, respectively (p=0.22) and no difference in 3-year progression-free survival was observed (59% and 56%, respectively; p=0.32). In a 594 Nanostring nCounter gene panel analyzed for immune reconstitution (IR), compared with KLH-only patients, there was a greater change in IR genes in T-cells in Id-KLH patients relative to baseline. Specifically, upregulation of genes associated with activation, induction of effector function, and generation of memory CD8+ T cells after Id-KLH, but not after KLH control vaccination, was observed. Similarly, responding patients across both arms were associated with upregulation of genes associated with T-cell activation. At baseline, all patients had greater expression of CD8+ T-cell exhaustion markers. These changes were associated with functional Id-specific immune responses in a subset of Id-KLH patients analyzed. In conclusion, in this combination immunotherapy approach, we observed a significantly more robust IR in CD4+ and CD8+ T cells in the Id-KLH arm, supporting further investigation of vaccine and adoptive immunotherapy strategies.


2022 ◽  
Vol 12 ◽  
Author(s):  
Niels C. Lory ◽  
Mikolaj Nawrocki ◽  
Martina Corazza ◽  
Joanna Schmid ◽  
Valéa Schumacher ◽  
...  

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.


2020 ◽  
Author(s):  
Thomas Vollbrecht ◽  
Aaron O. Angerstein ◽  
Bryson Menke ◽  
Nikesh M. Kumar ◽  
Michelli Faria Oliveira ◽  
...  

Abstract BackgroundA reservoir of replication-competent but latent virus is the main obstacle to a cure for HIV-infection. Much of this reservoir resides in memory CD4 T cells. We hypothesized that these cells can be reactivated with antigens from HIV and other common pathogens to reverse latency. ResultsWe obtained mononuclear cells from the peripheral blood of antiretroviral-treated patients with suppressed viremia. We tested pools of peptides and proteins derived from HIV and from other pathogens including CMV for their ability to reverse latency ex vivo by activation of memory responses. We assessed activation of the CD4 T cells by measuring the up-regulation of cell-surface CD69. We assessed HIV-expression using two assays: a real-time PCR assay for virion-associated viral RNA and a droplet digital PCR assay for cell-associated, multiply spliced viral mRNA. Reversal of latency occurred in a minority of cells from some participants, but no single antigen induced HIV-expression ex vivo consistently. When reversal of latency was induced by a specific peptide pool or protein, the extent was proportionally greater than that of T cell activation. ConclusionsIn this group of patients in whom antiretroviral therapy was started during chronic infection, the latent reservoir does not appear to consistently reside in CD4 T cells of a predominant antigen-specificity. Peptide-antigens reversed HIV-latency ex vivo with modest and variable activity. When latency was reversed by specific peptides or proteins, it was proportionally greater than the extent of T cell activation, suggesting partial enrichment of the latent reservoir in cells of specific antigen-reactivity.


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