bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exploring the role of YAP signaling in CD4+ T cell biology
Authors: Meng Kevin , Butte Manish J 
Published: January 2023

Abstract
The adaptive immune system’s ability to defend against infections and destroy cancerous cells is highly dependent on T cell proliferation. A long-standing observation through in vitro and in vivo studies is that T cells cluster together during activation and subsequent proliferation. In contrast, the vast majority of other cell types turn off division machinery upon cell-cell contact. The highly conserved Hippo signaling pathway controls for cell size and number through proliferation and apoptosis, thereby making it essential for regulating organ size. At the core of the Hippo cascade is the transcription factor YAP. Upon activation, YAP translocates into the nucleus and binds with transcription enhancer factors (TEADs) to drive transcription of proliferation-related genes. While YAP signaling has been extensively studied in epithelial cells, its role in CD4+ T cell effector function and proliferation remains unexplored. Our data indicates that overall YAP protein levels rises during T cell activation. Interestingly, although YAP activation increases proliferation of epithelial cells, our data suggests that YAP is a negative regulator of cellular proliferation in CD4+ T cells. Upon YAP depletion and then restimulating T cells in vitro, we discovered that the T cells knocked down by YAP exhibited greater proliferation and produced more IL-2 than T cells transduced with control shRNA. In support of this surprising finding, expressing a constitutively active YAP with all five phosphorylation sites mutated (YAP 5SA) in T cells led to decreased proliferation of CD4+ T cells. These results hint at potentially novel functions of YAP and warrants further analysis into how YAP signaling affects T cell proliferation.
Bystander-activated memory T lymphocytes cluster around infected cells early after infection
Authors: Maurice Nicholas Joseph , Roepke Sarah , Prlic Martin 
Published: January 2023

Abstract
Innate and adaptive immune responses are typically considered to occur sequentially following an infection. The innate immune system responds initially to an infection and the antigen-specific T and B cell response develops subsequently. Although the peak of the antigen-specific T cell response lags days behind the innate response, inflammatory signals lead to rapid expression of Granzyme B and Interferon-γ in memory CD8+ T cells. This occurs in a T cell receptor (TCR) independent manner and is referred to as “bystander activation.” We and others have demonstrated that these bystander-activated cytotoxic T lymphocytes (BA-CTL) can kill target cells in an NKG2D-dependent, TCR-independent fashion early after infection. This suggests that T cells use innate-like mechanisms for rapid TCR-independent responses to infection. Here we report that during WT Listeria monocytogenes (LM) infection, antigen non-specific BA-CTL rapidly migrate to cluster around infected cells, surrounding foci of LM in splenic white pulp at 24h post infection. These clusters at early time-points closely resemble antigen-specific effector T cell clustering on day 7 post-infection. We describe the mechanisms driving this early activation and define distinct stages of this innate-like effector program. We propose that the purpose of driving bystander-activated T cells to sites of infection and eliciting these innate-like functional capacities is to limit early pathogen replication.
T cell activation requires force generation and is mediated by
Authors: Hu Kenneth H , Butte Manish J 
Published: January 2023

Abstract
Triggering of the T-cell receptor (TCR) has been shown to involve both binding kinetics and mechanical forces. The source of these mechanical forces is likely cytoskeletal activity by the T cell. To understand the contribution of the T-cell cytoskeleton to these forces, we developed an atomic force microscopy (AFM) based method for presenting a stimulatory signal to the T cell and monitoring the force exerted on the cantilever while simultaneously imaging with optical microscopy. T cells respond forcefully, exhibiting pushing and pulling forces that seem temporally correlated with calcium flux. If we perturbed F-actin polymerization through Latrunculin A treatment, we observed abrogation of both force generation and calcium flux. We were then able to rescue calcium flux by applying an oscillatory force through the stimulatory cantilever. Spacing out these forces resulted in a weaker response, suggesting a characteristic timescale for signal integration. We also investigated what components of the cytoskeleton could contribute to the observed force profile through pharmacological inhibition. The pull phase appears to be mediated by myosin contractility. These studies suggest a mechanical-chemical feedback loop whereby initial TCR triggering results in generation of forceful contacts with APCs to amplify signaling.
Macroautophagy regulates T helper cell activation and tolerance
Authors: Dowling Samuel Dae , Mocholi Enric , Gruber Ross , Shafit-Zagardo Bridget , Macian Fernando 
Published: January 2023

Abstract
Macroautophagy is a catabolic process whereby cell components, which range from soluble proteins to whole organelles, are sequestered in de novo formed double-membrane autophagosomes that fuse with lysosomes to degrade their cargo. Effector T helper cells induce macroautophagy during activation to maintain cell proliferation and cytokine production. T cells that are unable to upregulate macroautophagy activity show a reduction in ATP generation, suggesting that macroautophagy is necessary to maintain the energy metabolism required to meet the demands of T cell activation. It is presently unknown whether macroautophagy regulates the activation state and functional capacity of CD4+T cells. We explored the instructive role of macroautophagy in effector T helper cell activation and tolerance. Inhibition of macroautophagy during activation of CD4+T helper type 1 (TH1) cells induces a long-lasting state of hyporesponsiveness, with a molecular signature that resembles that of anergic T cells. Moreover, inhibition of macroautophagy prevented activated TH1 cells from upregulating glycolysis and mitochondrial respiration, supporting that macroautophagy may regulate metabolic homeostasis during activation of effector T helper cells. Consequently, inhibition of macroautophagy in vivo prevents CD4+ T cell activation in response to immunization and results in decreased severity of experimental autoimmune encephalomyelitis. Our data support that macroautophagy, likely by regulating metabolism, is necessary for the activation of effector T helper cells and that its absence induces a tolerant state.
3D biodistribution of pre-treated MSC in mouse model of liver disease using CryoViz™
Authors: Gargesha Madhu , de Witte Samantha , Newsome Philip , Hirschfield Gideon , Clissmann Ciaran , Macarthur Victoria , Elliman Stephen , Watt Suzanne , Hollyman Daniel , Baan Carla , Hoogduijn Martin , Viola Antonella , Roy Debashish 
Published: January 2023

Abstract
‘MERLIN’ (Mesenchymal stem cells to reduce liver inflammation) is an EU FP7-funded project in which BioInVision, Inc. (Cleveland, OH, USA) is partnering with EU establishments that are developing MSC cellular therapy for primary sclerosing cholangitis (PSC), a type of liver disease. MSC have low immunogenicity and possess promising immune modulatory and regulatory capabilities, making them suitable candidates for treating PSC. In MERLIN project, BioInVision’s CryoViz™ cryo-imaging system is being used to study MSC survival under various pre-treatments in a CCL4 liver injury whole mouse model. CryoViz™ consists of a fully automated system for sectioning and tiled microscopic imaging of tissues, providing anatomical brightfield and molecular fluorescence with single cell sensitivity. Umbilical cord-derived MSC (UCMSC) were pre-treated for three days in the presence of pro-/anti-inflammatory cytokines, vitamins and serum-deprivation after which assays were performed to examine their immunogenicity, phenotype, and susceptibility to NK lysis. Subsequently, whole mice intravenously injected with the different pre-treated MSC [no treatment, IFNγ, IFNβ, TGFβ, Starvation, VitB6, (Starvation+VitB6), RA] were frozen and cryo-imaged. Global biodistribution results from CryoViz™ indicate that pretreatment had an effect on cell survival. Localized biodistribution showed preferential distribution in some organs such as the lung and the liver. The cryo-imaging study has revealed that MSC could be optimized to become less immunogenic and more immunomodulatory, which is an important step towards further development of MSC for cellular therapy.
PI3K-AKT-mTOR pathway mediates trafficking of diabetogenic T cells by modulating CXCR3 via T-bet
Authors: Chen Weirong , Ukah Tobechukwu Kenneth , Miller Mindy M , Zaghouani Habib , Wan Xiaoxiao 
Published: January 2023

Abstract
Type 1 diabetes (T1D) is an autoimmune disease in which insulin-producing beta-cells are selectively destroyed by self-reactive T cells. In prior studies, we incorporated mimotope p79 into an Ig molecule and the resulting Ig-p79 chimera was able to prevent adoptive transfer of T1D by diabetogenic BDC2.5 T cells. Further analysis has shown that these T cells are retained in the spleen and cannot migrate to the pancreas due to diminished expression of the transcription factor T-bet and downregulation of the chemokine receptor CXCR3. Investigation of the molecular mechanisms underlying this form of T cell tolerance indicates that expression of mammalian target of rapamycin (mTOR), a conserved serine/threonine kinase, is inhibited and its function is impaired. In contrast, overexpression of mTOR or its positive regulator, AKT, in BDC2.5 T cells restores the expression of T-bet and CXCR3, reestablishes the pancreatic infiltration of those T cells and consequently, nullifies antigen-induced tolerance. These findings suggest that PI3K-AKT-mTOR pathway, via modulating CXCR3, determines the trafficking ability of self-reactive T cells. Thus, this study not only delineates the molecular mechanisms underlying migration of diabetogenic T cell, but also provides a useful target for modulation of pathogenic T cells and treatment of type 1 diabetes.
Class-biased regulation of humoral immunity and mTORC1 inhibition by physiological hypoxia
Authors: Cho Sung Hoon , Ariel Raybuck , Wei Mei , Haase Volker , Boothby Mark 
Published: January 2023

Abstract
B lymphocytes activated by cognate antigen (Ag) proliferate, are selected for affinity maturation, undergo antibody (Ab) class switching dependent on the cytosine deaminase AID, and yield major forms of memory via germinal center (GC) reactions. Although metabolic programming has emerged as a means of mediating or initiating changes in immunity, nothing is known as to the metabolic landscape in lymphoid organs. Here we show that B lymphocytes in GC are hypoxic, and that low oxygen alters B cell Ab response as well as metabolic programming. In addition to increased B cell death, restricted oxygen concentrations impaired Ab class switching by reducing expression of AID and suppressing the pro-inflammatory IgG2c Ab isotype. Prolyl hydroxyl dioxygenases (PHD) and von Hippel-Lindau (VHL) are central to regulation of hypoxia-induced factors (HIF) in hypoxic responses. B cell-intrinsic deficiency of VHL attenuated Ag-specific IgG2c, and decreased levels of Ag-specific GC, early memory B cells, and Ab responses. Hypoxia and VHL deficiency each also inhibited activity of mTORC1 in a manner dependent on HIF proteins. Genetic limitation of mTORC1 in B cells reduced their clonal expansion, AID expression, and IgG2c Ab responses. Collectively, these results provide evidence that GC reactions are sites of physiologic hypoxia that in turn regulates vital functions of B cells through interruption of program that maintains mTORC1 activity. We propose that this restriction of oxygen regulates the balance of fate choices made by GC B cells, and that pathophysiological states that alter oxygen homeostasis may moderate the pro-inflammatory component of humoral immunity.
Glycerol Monolaurate (GML) inhibits human T cell signaling, metabolism, and function by disrupting lipid dynamics
Authors: Zhang Michael S. , Sandouk Aline , Houtman Jon C.D 
Published: January 2023

Abstract
Glycerol Monolaurate (GML) is a naturally occurring fatty acid widely utilized in food, cosmetics, and homeopathic supplements. GML is a potent antimicrobial agent that targets a range of bacteria, fungi, and enveloped viruses. Interestingly, GML suppresses mitogen induced lymphocyte proliferation and inositol triphosphate production, suggesting that GML has immunomodulatory functions. In this study, we have mechanistically examined if GML affects the signaling, metabolism, and functional output of human primary T cells. We found that GML potently altered lipid order and disorder dynamics in the plasma membrane that resulted in reduced membrane localized clustering of the proteins LAT, PLC-γ, and AKT, events integral for proper T cell receptor (TCR) signal propagation. Altered membrane signaling events induced selective inhibition of TCR-induced phosphorylation of SLP-76, regulatory P85 subunit of PI3K, and AKT as well as abrogated calcium influx. In addition to signaling defects, GML treated cells have profoundly altered metabolism profiles characterized by suppressed oxidative phosphorylation and increased glycolysis. Functionally, GML treatment potently reduced TCR-induced production of the cytokines IL-2, IFN-γ, TNF-α, and IL-10. Our data reveal that the widely used anti-microbial agent GML alters the lipid dynamics of human T cells, leading to their defective signaling, metabolism, and function.
PIK3IP1- A novel negative regulator of PI3K
Authors: Uche Uzodinma N , Kane Lawrence P 
Published: January 2023

Abstract
Phosphatidylinositide-3-Kinases (PI3Ks) are a family of lipid kinases that play important intracellular signaling roles in cellular functions such as cell proliferation, motility, growth, intracellular trafficking, differentiation and survival. PI3K produces PIP3 which further facilitates the activation of downstream effectors such as Akt and PDK1. These effectors facilitate the cellular processes associated with PI3K activity. Conversely, because of the nature of PI3Ks roles, dysregulation of PI3K is implicated in many cancers. PTEN, SHIP and INPP4B are negative regulators of PI3K activity that function downstream of PI3K and have been shown to act as tumor suppressors. Recently, PI3K Interacting Protein 1 (PIK3IP1), a novel negative regulator that functions upstream and proximal to PI3K, has been identified. PIK3IP1 is a transmembrane protein that down-regulates PI3K activity, leading to reduced Akt phosphorylation. Our lab recently showed that PIK3IP1 can inhibit TCR signaling and TCR activation. To better understand the role of PIK3IP1 in immune cells, we have begun to carefully define the roles of the various domains that comprise PIK3IP1. In addition, we have produced a PIK3IP1 ecto-domain Fc fusion protein, which we have used to develop monoclonal antibodies against PIK3IP1. This ecto-domain Fc fusion protein is also being used to define possible ligands for PIK3IP1. Finally, we have obtained knockout mice lacking expression of PIK3IP1 in T cell and mast cell compartments, to better define the requirements for PIK3IP1 in primary T and mast cells.
SerpinB1 Deficiency Ameliorates Experimental Autoimmune Encephalomyelitis
Authors: Hou Lifei , Winau Florian , Remold-O’Donnell Eileen 
Published: January 2023

Abstract
Increasing evidence shows that, in autoimmune settings, Th17 cells are converted to pathogenic Th17 cells (patho-Th17), which produce GM-CSF and IFNγ and are pivotal for pathogenesis. We recently discovered that serpinB1, a protease inhibitor, is the signature gene of Th17 cells and forms a regulatory module with cathepsin L that controls Th17 cell generation: Th17 differentiation is restricted by serpinB1 and counter-regulated by cathepsin L.
In the current study, we investigated serpinB1 regulation of Th17 cell pathogenicity in experimental autoimmune encephalomyelitis (EAE). As anticipated, expression of serpinB1 and other Th17 genes were significantly increased in effector CD4 cells in the EAE mouse. Surprisingly, serpinB1 deficient (sb1−/−) mice immunized with MOG35–55 are resistant to EAE, manifested by dramatically decreased disease incidence and severity. Adoptive transfer experiments showed that the protective effect of serpinB1 deficiency is CD4 cell specific. Cytokine profiling showed that, despite producing more Th17 cells, serpinB1 deficiency selectively diminished patho-Th17 cells. Furthermore, Ki-67 and Annexin V staining together with BrdU pulse/chase strategy confirmed that proliferation is not defective in sb1−/− Th17 and patho-Th17 cells. In contrast, sb1−/− patho-Th17 cells showed significantly shortened life span and were eliminated upon antigen-recall. Finally, in vivo administration of E64D, a broad-acting cysteine protease inhibitor, partially reversed the effects of serpinB1 deficiency. Thus, our study identified a protease-protease inhibitor regulatory module acting on Th17 cell differentiation and separately on pathogenicity with potential for targeting in autoimmune diseases.
Autocrine NLPR3 inflammasome activity is critical to normal adaptive immunity via regulation of IFN-γ in CD4+ T cells
Authors: West Erin E , Arbore Giuseppina , Robertson Avril A.B. , Klos Andreas , Woodruff Trent M , O’Neill Luke A. , Coll Rebecca C. , Sher Alan , Leonard Warren J , Köhl Jörg , Monk Pete , Cooper Matthew A. , Afzali Behdad , Lachmann Helen J. , Cope Andrew P. , Mayer-Barber Katrin , Kemper Claudia 
Published: January 2023

Abstract
The NLRP3 inflammasome controls IL-1β maturation in antigen presenting cells but a direct role in human adaptive immune cells has not been described. Here we show that the NLRP3 inflammasome assembles in human CD4+ T cells and initiates caspase-1-dependent IL-1b secretion, thereby promoting IFN-γ production and Th1 differentiation in an autocrine fashion. Importantly, NLRP3 assembly requires intracellular C5 activation and stimulation of C5a receptor 1 (C5aR1), which drive reactive oxygen species (ROS) production. The alternative cell surface expressed C5a receptor 2 (C5aR2) negatively regulates this process. Dysregulation of NLRP3 activity in T cells affects inflammatory responses in autoimmune disease or infection. Firstly, CD4+ T cells from patients with cryopyrin-associated periodic syndromes (CAPS), who have constitutively-active NLRP3, exhibit overactive Th1 responses that are normalized by NLRP3 inhibitor treatment. Secondly, IFN-γ production is impaired in T cells from Nlpr3−/− or Il1a/Il1b−/− mice upon viral infection. Our results demonstrate that NLRP3 inflammasome activity is not confined to ‘innate immune cells’ but is an integral component of normal adaptive Th1 responses.
yidC is required for virulent Francisella tularensis to modulate IRF1 and resist killing by host cells
Authors: Drumheller L Brock , Wehrly Tara , Di Russo Case Elizabeth , Celli Jean , Bosio Catharine M 
Published: January 2023

Abstract
Francisella tularensis is a gram negative, intracellular pathogen that causes the lethal disease known as tularemia. One virulence mechanism used by F. tularensis is the inhibition of the activation of Interferon Regulatory Transcription Factor 1 (IRF1). IRF1 is an important transcription factor for Type I and II Interferons and other proteins involved in host defense. The genes encoded by Francisella responsible for modulation of IRF1 activation have not been defined. To identify which genes are involved in the process of IRF1 inhibition, we developed a high throughput assay of IRF1 activation and screened a HIMAR transposon library of Francisella mutants. We identified yidC, which encodes a membrane protein insertase, as a required bacterial gene for inhibition of IRF1. Consistent with its inability to negatively modulate IRF1, yidC mutants were more susceptible to IFN-gamma mediated killing compared to wild type controls. Together, our data points toward a novel role for yidC, and by extension membrane proteins, in the modulation of IRF1 and resistance to host cell antimicrobial responses.
Increased Susceptibility of S1PR3-Deficient Mice to Escherichia coli Sepsis Is Associated with an Impaired Bactericidal Activity in Macrophage
Authors: Fang XiangMing , Hou Jinchao , Shu Qiang 
Published: January 2023

Abstract

Background
Sepsis, a leading cause of death in critically ill patients worldwide, is characterized with imbalanced proinflammatory responses and compromised bacterial clearance in host immunity. Monocytes/macrophages play a crucial role in elimination of bacteria through innate immunity receptors.

Methods
We explored the effect of Sphingosine-1-phosphate receptor 3 (S1PR3) gene deficiency on mortality, organ injury, and bacterial clearance in cecal ligation and puncture (CLP) or Escherichia coli (E. coli)-induced sepsis. Signaling molecules responsible for S1PR3-mediated bactericidal function were dissected in peritoneal macrophages. Furthermore, S1PR3 specific agonist (GPS-725.017) was evaluated for treatment of sepsis.

Results
After sepsis onset, S1pr3−/− mice showed increased mortality and organ injury, which attributed to markedly decreased E. coli killing. Mechanically, S1PR3 regulated activity of the NADPH oxidase NOX2 complex and phagolysosomal maturation through recruiting the intracellular class III phosphatidylinositol kinase Vps34 to the phagosome. S1PR3 specific agonist (GPS-725.017) enhanced NOX2 activity in E. coli-containing phagosomes and bactericidal function in wild-type macrophages. Additionally, the survival of mice treated with GPS-725.017 was improved when compared with those treated with vehicle.

Conclusion
S1PR3 is an important receptor to connect bacterial phagosome to ubiquitous cellular machinery responsible for control of bacterial killing in macrophage. Interventions targeting S1PR3 signaling may serve as promising therapeutic approaches for sepsis.
Nicotine-containing e-cigarette exposure influences the inflammatory response in an animal model of heart failure.
Authors: Molina Megan Stanley , Gamboa Antonio , Lima Vanessa Souza , Cameron D. Joshua , O’Barr Stephen A 
Published: January 2023

Abstract
Heart failure is a leading cause of hospitalization and death worldwide, and it is known that the initiation and progression of the inflammatory response is highly indicative of long-term patient outcomes. Interestingly, while smoking is a well-known risk factor for cardiovascular disease, recent findings reveal that smokers have improved clinical outcomes, a shorter length of stay in the hospital, and lower in-hospital mortality and mortality risk compared to non-smokers. While the precise mechanisms behind this finding, deemed the “smoker’s paradox”, are currently unknown, the phenomenon raises questions regarding the possible therapeutic benefit of nicotine. Additionally, the health effects of electronic cigarettes (e-cigs) in the setting of heart failure also come into question. In order to investigate the possible therapeutic benefit of nicotine and the health effects of e-cigs we have emulated the smoker’s paradox by creating a chronic smoking regime in which animals are pre-treated with nicotine-containing e-cigarette vapor for 20 minutes per day for four consecutive days. On day four following a short washout period, heart failure is chemically induced and survival is recorded. Here we show that pre-treatment with nicotine-containing e-cigarette vapor significantly improves survivability in a concentration dependent manner. Furthermore, analysis of blood and heart tissue shows that pre-treatment with e-cigarette vapor induces changes in circulating levels of key cytokines and in gene expression within the myocardium. These data indicate that nicotine indeed influences the inflammatory response to heart failure and therefore influences the pathogenesis of cardiovascular disease.