Versinia pestis YopJ, YopT, and YopK coordinate programmed cell death and cytokine responses to promote pneumonic plague

2017 ◽  
Author(s):  
◽  
Rachel M. Olson
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Bacterial Growth ◽  
Cell Function ◽  
Immune Cell ◽  
Effector Proteins ◽  
University Of Missouri ◽  
Cellular Machinery ◽  
The University ◽  
Inflammatory Macrophages

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Yersinia pestis has been responsible for three major pandemics of plague, including the infamous Black Death that killed 250 million people in Europe. The disease progresses rapidly due to a combination of bacterial growth and host immunopathology. During infection, Y. pestis utilizes a type III secretion system (T3SS), which is essential for virulence, to inject effector proteins that disrupt immune cell function. The majority of the Yops are dedicated to the control of programmed cell death of immune cells, namely macrophages and neutrophils, and through this, it has been proposed that initially there is immune suppression followed by an acute inflammatory response that accelerates bacterial growth and disease. Recent work has focused on the inflammasome, cellular machinery that is activated upon insertion of the translocation pore that results in host cell lysis and the release of inflammatory cytokines. In this work, we defined a novel pathogenesis mechanism involving the activation of rapid lysis of inflammatory macrophages via necroptosis by injected bacterial effectors YopT and YopJ, each with cysteine protease activity. We show that YopT is a virulence factor for plague, while deletion of YopJ had no detectable impact on virulence. Further, we found that injection of catalytically inactive YopJ induces strong activation of the inflammasome and stimulates host defense against plague. YopK modulates the effects of YopT and YopJ. Overall, it appears that induction of necroptosis by YopT and YopJ subverts the activation of the inflammasome and contributes to pathogenesis of plague.

scholarly journals Serum-derived exosomes promote CD8+ T cells to overexpress PD-1, affecting the prognosis of hypopharyngeal carcinoma

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Qian Gao ◽  
Hui-Ting Liu ◽  
Yu-Qin Xu ◽  
Lin Zhang ◽  
Yuan-Ru Liu ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
T Cell ◽  
Programmed Cell Death ◽  
Cd8 T Cells ◽  
Poor Prognosis ◽  
Cell Function ◽  
Immune Escape ◽  
Cd8 T Cell ◽  
Serum Exosomes

Abstract Background Hypopharyngeal cancer (HPC) is associated with a poor prognosis and a high recurrence rate. Immune escape is one of the reasons for the poor prognosis of malignant tumors. Programmed cell death ligand 1 (PD-L1) and programmed cell death-1 (PD-1) have been shown to play important roles in immune escape. However, the role of PD-1/PD-L1 in HPC remains unclear. In this experiment, we investigated the effect of exosomes from HPC patient serum on CD8+ T cell function and PD-1/PD-L1 expression and, thus, on prognosis. We hope to provide guidance for the identification of new targets for HPC immunotherapy. Methods PD-1 and CD8 expression in 71 HPC tissues and 16 paracarcinoma tissues was detected by immunohistochemistry. Concurrently, the clinicopathological data of the patients were obtained to conduct correlation analysis. Exosomes were isolated from serum and then identified by Western blotting (WB), transmission electron microscopy (TEM), and nanoparticle tracking analysis (NTA). Flow cytometry was used to assess the activity of CD8+ T cells after exosome stimulation. The effects of exosomes on the ability of CD8+ T cells to kill FaDu cells were assessed by CCK-8 assay. The expression of IL-10 and TGF-β1 was measured by enzyme-linked immunosorbent assay (ELISA). PD-L1 expression in HPC tissue samples was evaluated by immunohistochemistry, and the relationship between PD-1/PD-L1 expression and prognosis was investigated with patient specimens. Results PD-1 expression was significantly upregulated on CD8+ T cells in tumor tissues compared with those in normal tissues. The overall survival (OS) and disease-free survival (DFS) of PD-1-overexpressing patients were decreased. Serum exosomes from patients can elevate PD-1 expression on CD8+ T cells and suppress their killing capacity and secretory function. The rate of positive PD-L1 expression was increased in HPC tissues compared with paracancerous tissues. The DFS and OS of the PD-1(+)-PD-L1(+) group were significantly lower than those of the PD-1(−)-PD-L1(−) group. Conclusion Our findings indicate that serum exosomes from HPC patients can inhibit CD8+ T cell function and that the PD-1-PD-L1 pathway plays an important role in the immune escape of HPC. Exosomes combined with immunotherapy may guide the treatment of patients with advanced disease in the future.

scholarly journals The ubiquitin-editing enzyme A20 controls NK cell homeostasis through regulation of mTOR activity and TNF

2019 ◽  
Vol 216 (9) ◽  
pp. 2010-2023 ◽  
Author(s):  
Jessica Vetters ◽  
Mary J. van Helden ◽  
Sigrid Wahlen ◽  
Simon J. Tavernier ◽  
Arne Martens ◽  
...  
Keyword(s):  
Cell Death ◽  
Nk Cells ◽  
Cell Function ◽  
Immune Cell ◽  
Nk Cell ◽  
Cell Homeostasis ◽  
Life And Death ◽  
Cytotoxic Molecules ◽  
Editing Enzyme ◽  
Mtor Activity

The ubiquitin-editing enzyme A20 is a well-known regulator of immune cell function and homeostasis. In addition, A20 protects cells from death in an ill-defined manner. While most studies focus on its role in the TNF-receptor complex, we here identify a novel component in the A20-mediated decision between life and death. Loss of A20 in NK cells led to spontaneous NK cell death and severe NK cell lymphopenia. The few remaining NK cells showed an immature, hyperactivated phenotype, hallmarked by the basal release of cytokines and cytotoxic molecules. NK-A20−/− cells were hypersensitive to TNF-induced cell death and could be rescued, at least partially, by a combined deficiency with TNF. Unexpectedly, rapamycin, a well-established inhibitor of mTOR, also strongly protected NK-A20−/− cells from death, and further studies revealed that A20 restricts mTOR activation in NK cells. This study therefore maps A20 as a crucial regulator of mTOR signaling and underscores the need for a tightly balanced mTOR pathway in NK cell homeostasis.

scholarly journals Blockade of Lactate Dehydrogenase-A (LDH-A) Improves Efficacy of Anti-Programmed Cell Death-1 (PD-1) Therapy in Melanoma

Cancers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 450 ◽  
Author(s):  
Saeed Daneshmandi ◽  
Barbara Wegiel ◽  
Pankaj Seth
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Lactate Dehydrogenase ◽  
Programmed Cell Death ◽  
Immune Cell ◽  
Cytotoxic T Cells ◽  
Treg Cells ◽  
Interferon Γ ◽  
Mitochondrial Activity ◽  
Small Subset

Immunotherapy is a curable treatment for certain cancers, but it is still only effective in a small subset of patients. We have recently reported that programmed cell death protein-1 (PD-1) ligand (PD-L1) expression is regulated by lactate present at high levels in the tumor microenvironment (TME). We hypothesized that the efficacy of anti-PD-1 treatment can be improved by blocking the lactate-generating enzyme, lactate dehydrogenase-A (LDH-A). Anti-PD-1 treatment of mice harboring LDH-A deficient B16-F10 melanoma tumors led to an increase in anti-tumor immune responses compared to mice implanted with tumors expressing LDH-A. Specifically, we observed heightened infiltration of natural killer (NK) cells and CD8+ cytotoxic T cells in the LDH-A deficient tumors. These infiltrated cytotoxic cells had an elevated production of interferon-γ (IFN-γ) and granzyme B. Mechanistically, CD8+ T cells isolated from the TME of LDH-A deficient B16-F10 melanoma tumors and treated with anti-PD-1 showed enhanced mitochondrial activity and increased reactive oxygen species (ROS) levels. Moreover, infiltration of T regulatory (Treg) cells was diminished in LDH-A deficient tumors treated with anti-PD-1. These altered immune cell profiles were clinically relevant as they were accompanied by significantly reduced tumor growth. Our study suggests that blocking LDH-A in the tumor might improve the efficacy of anti-PD-1 therapy.

scholarly journals Unveiling the immune infiltrate modulation in cancer and response to immunotherapy by MIXTURE—an enhanced deconvolution method

2020 ◽  
Author(s):  
Elmer A Fernández ◽  
Yamil D Mahmoud ◽  
Florencia Veigas ◽  
Darío Rocha ◽  
Matías Miranda ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Immune Cells ◽  
Immune Cell ◽  
Immune Escape ◽  
Intratumor Heterogeneity ◽  
Support Vector ◽  
Tumor Immune Escape ◽  
Immune Infiltrate ◽  
Tumor Biopsies

Abstract The accurate quantification of tumor-infiltrating immune cells turns crucial to uncover their role in tumor immune escape, to determine patient prognosis and to predict response to immune checkpoint blockade. Current state-of-the-art methods that quantify immune cells from tumor biopsies using gene expression data apply computational deconvolution methods that present multicollinearity and estimation errors resulting in the overestimation or underestimation of the diversity of infiltrating immune cells and their quantity. To overcome such limitations, we developed MIXTURE, a new ν-support vector regression-based noise constrained recursive feature selection algorithm based on validated immune cell molecular signatures. MIXTURE provides increased robustness to cell type identification and proportion estimation, outperforms the current methods, and is available to the wider scientific community. We applied MIXTURE to transcriptomic data from tumor biopsies and found relevant novel associations between the components of the immune infiltrate and molecular subtypes, tumor driver biomarkers, tumor mutational burden, microsatellite instability, intratumor heterogeneity, cytolytic score, programmed cell death ligand 1 expression, patients’ survival and response to anti-cytotoxic T-lymphocyte-associated antigen 4 and anti-programmed cell death protein 1 immunotherapy.

Programmed Cell Death 1 (PD-1) Ligand (PD-L1) Expression in Solid Tumors As a Predictive Biomarker of Benefit From PD-1/PD-L1 Axis Inhibitors: A Systematic Review and Meta-Analysis

2017 ◽  
pp. 1-15 ◽  
Author(s):  
Monica Khunger ◽  
Adrian V. Hernandez ◽  
Vinay Pasupuleti ◽  
Sagar Rakshit ◽  
Nathan A. Pennell ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Solid Tumors ◽  
Immune Cell ◽  
Meta Analysis ◽  
Objective Response ◽  
Small Cell Lung ◽  
Programmed Cell Death 1 ◽  
Tumor Types

Purpose Drugs targeting the programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway show significant clinical activity across several tumor types. However, a majority of patients do not respond to these agents. Use of biomarker assays to predict response to these agents is an active area of research; however, the predictive value of PD-L1 immunohistochemistry (IHC) assays is largely inconsistent across clinical trials. In this meta-analysis of clinical trials of PD-1/PD-L1–targeted agents, we evaluate the predictive value of a tumor and tumor-infiltrating immune cell PD-L1 IHC assay as a biomarker for objective response to PD-1/PD-L1 inhibitors. Methods We searched databases (PubMed, Medline, ASCO abstracts, European Society for Medical Oncology abstracts, and Scopus) up until December 2016 for clinical trials using PD-1/PD-L1 inhibitors with reported PD-L1 biomarker data. Objective response rates (primary end point) from all phase I to III trials investigating nivolumab, pembrolizumab, atezolizumab, durvalumab, and avelumab in advanced solid tumors were collected. Odds ratios (ORs) for response in PD-L1–positive patients compared with PD-L1–negative patients were calculated using the DerSimonian-Laird random effects model to combine trials. We performed meta-analysis as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results Forty-one distinct trials with 6,664 patients were identified. PD-L1 expression was predictive of favorable response across all tumor types (OR, 2.26; 95% CI, 1.85 to 2.75; P < .001), with the significantly largest effect observed in non–small-cell lung cancer (OR, 2.51; 95% CI, 1.99 to 3.17; P < .001). A subgroup analysis across all non–small-cell lung cancer trials using nivolumab and Dako clone 28-8 (Dako, Carpinteria, CA) IHC antibody assay yielded a significantly higher objective response rate in patients with tumor PD-L1 expression even at the minimum cutoff value of 1% (OR, 2.17; 95% CI, 1.03 to 4.57). Conclusion Our meta-analysis shows that tumor and tumor-infiltrating immune cell PD-L1 overexpression based on IHC is associated with significantly higher response rates to PD-1/PD-L1 axis inhibitors across a range of malignant solid tumors.

scholarly journals Immune-Checkpoint Blockade Therapy in Lymphoma

2020 ◽  
Vol 21 (15) ◽  
pp. 5456 ◽  
Author(s):  
Ayumi Kuzume ◽  
SungGi Chi ◽  
Nobuhiko Yamauchi ◽  
Yosuke Minami
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Malignant Lymphoma ◽  
Hodgkin Lymphoma ◽  
Immune Checkpoint ◽  
Immune Cell ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade ◽  
Host Immune System ◽  
Cell Death Protein

Tumor cells use immune-checkpoint pathways to evade the host immune system and suppress immune cell function. These cells express programmed cell-death protein 1 ligand 1 (PD-L1)/PD-L2, which bind to the programmed cell-death protein 1 (PD-1) present on cytotoxic T cells, trigger inhibitory signaling, and reduce cytotoxicity and T-cell exhaustion. Immune-checkpoint blockade can inhibit this signal and may serve as an effective therapeutic strategy in patients with solid tumors. Several trials have been conducted on immune-checkpoint inhibitor therapy in patients with malignant lymphoma and their efficacy has been reported. For example, in Hodgkin lymphoma, immune-checkpoint blockade has resulted in response rates of 65% to 75%. However, in non-Hodgkin lymphoma, the response rate to immune-checkpoint blockade was lower. In this review, we evaluate the biology of immune-checkpoint inhibition and the current data on its efficacy in malignant lymphoma, and identify the cases in which the treatment was more effective.

scholarly journals Stress Management in Cyst-Forming Free-Living Protists: Programmed Cell Death and/or Encystment

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Naveed Ahmed Khan ◽  
Junaid Iqbal ◽  
Ruqaiyyah Siddiqui
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Stress Management ◽  
Environmental Conditions ◽  
Free Living ◽  
Cyst Form ◽  
The Face ◽  
A Cell ◽  
Cellular Machinery ◽  
Harsh Conditions

In the face of harsh conditions and given a choice, a cell may (i) undergo programmed cell death, (ii) transform into a cancer cell, or (iii) enclose itself into a cyst form. In metazoans, the available evidence suggests that cellular machinery exists only to execute or avoid programmed cell death, while the ability to form a cyst was either lost or never developed. For cyst-forming free-living protists, here we pose the question whether the ability to encyst was gained at the expense of the programmed cell death or both functions coexist to counter unfavorable environmental conditions with mutually exclusive phenotypes.

scholarly journals Pseudomonas Type III Effector AvrPto Suppresses the Programmed Cell Death Induced by Two Nonhost Pathogens in Nicotiana benthamiana and Tomato

2004 ◽  
Vol 17 (12) ◽  
pp. 1328-1336 ◽  
Author(s):  
Li Kang ◽  
Xiaoyan Tang ◽  
Kirankumar S. Mysore
Keyword(s):  
Cell Death ◽  
Disease Resistance ◽  
Programmed Cell Death ◽  
Pseudomonas Syringae ◽  
Type Iii Secretion ◽  
Nicotiana Benthamiana ◽  
Effector Proteins ◽  
Type Iii ◽  
Bacterial Pathogenicity ◽  
Suppression Effects

Many gram-negative bacterial pathogens rely on a type III secretion system to deliver a number of effector proteins into the host cell. Though a number of these effectors have been shown to contribute to bacterial pathogenicity, their functions remain elusive. Here we report that AvrPto, an effector known for its ability to interact with Pto and induce Pto-mediated disease resistance, inhibited the hypersensitive response (HR) induced by nonhost pathogen interactions. Pseudomonas syringae pv. tomato T1 causes an HR-like cell death on Nicotiana benthamiana. This rapid cell death was delayed significantly in plants inoculated with P. syringae pv. tomato expressing avrPto. In addition, P. syringae pv. tabaci expressing avrPto suppressed nonhost HR on tomato prf3 and ptoS lines. Transient expression of avrPto in both N. benthamiana and tomato prf3 plants also was able to suppress nonhost HR. Interestingly, AvrPto failed to suppress cell death caused by other elicitors and nonhost pathogens. AvrPto also failed to suppress cell death caused by certain gene-for-gene disease resistance interactions. Experiments with avrPto mutants revealed several residues important for the suppression effects. AvrPto mutants G2A, G99V, P146L, and a 12-amino-acid C-terminal deletion mutant partially lost the suppression ability, whereas S94P and I96T enhanced suppression of cell death in N. benthamiana. These results, together with other discoveries, demonstrated that suppression of host-programmed cell death may serve as one of the strategies bacterial pathoens use for successful invasion.

scholarly journals Validated programmed cell death ligand 1 immunohistochemistry assays (E1L3N and SP142) reveal similar immune cell staining patterns in melanoma when using the same sensitive detection system

2016 ◽  
Vol 70 (2) ◽  
pp. 253-263 ◽  
Author(s):  
Kelly A Schats ◽  
Emily A Van Vré ◽  
Stefanie De Schepper ◽  
Carolien Boeckx ◽  
Dorien M Schrijvers ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Immune Cell ◽  
Detection System ◽  
Sensitive Detection ◽  
Cell Staining
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