bluuebunny/crossref_metadata_2025_split huggingface dataset:
CD8 T cell exhaustion is dynamically controlled by the chromatin regulator factor BRD4
Authors: Mullins Genevieve N , Green Jarred Michael , Green William David , Milner J Justin 
Published: January 2023

Abstract
In the context of chronic viral infections and cancer, the protective potential of CD8 T lymphocytes is often dramatically blunted and characterized by a functionally exhausted cell state. T cell exhaustion contributes to pathogen persistence and can limit responsiveness to promising immunotherapy strategies. Therefore, defining the signals controlling the development and maintenance of an exhausted T cell state has critical implications for global public health. While it has become apparent that T cell exhaustion is a transcriptionally and epigenetically driven process, critical epigenetic mechanisms mediating T cell exhaustion remain unresolved. To this end, we sought to define how the ‘chromatin reader’ BRD4 controls an exhausted state in a CD8 T cell-intrinsic manner during chronic viral infection. Utilizing inducible deletion mouse models and RNAi, we found that BRD4 is a critical regulator of T cell differentiation and function. BRD4 was essential for driving a terminally exhausted CD8 T cell state. Mechanistically, BRD4 was found to bind near and modulate expression of key genes that influence T cell differentiation and exhaustion. These findings provide insights into the epigenetic underpinnings of T cell exhaustion and have important implications for enhancing immunotherapy efficacy.
Supported by grants
Differential localization and kinetics of antiviral CD8 T cell responses to chronic and acute murine norovirus infections from initiation onwards
Authors: Hardman Blair K , Osborne Lisa C 
Published: January 2023

Abstract
Recent global events have highlighted the need to better understand mucosal antiviral immunity. Murine Norovirus (MNV) is small non-enveloped positive sense RNA virus that can be used as a model of intestinal viral infection. In this work we use two highly related MNV strains with distinct biological behaviors; CR6 establishes chronic colonic infection, while CW3 establishes systemic infection initiated in the small intestine and is cleared by day 8, correlating with the peak of cell-mediated adaptive immunity. Using flow cytometry and quantitative immunofluorescent microscopy (QIM) of transgenic P14 CD8 T cells specific to recombinant CR6gp33 and CW3gp33, we characterized CD8 T cell responses to CR6 and CW3 from initiation to clearance of CW3. Our data indicate that initiation of CD8 T cell division in response to CR6 infection is delayed, less robust, and largely limited to the mesenteric lymph nodes (MLNs) with less splenic division compared to CW3 infection. Further, the biogeography of P14 T cell priming differs, as early T cell expansion was restricted to distinct nodes of the MLN complex. These early differences propagate out to the time of CW3 clearance. By day 8, there is differential localization of P14 cells in the GI tract to the site of highest viral load and a larger systemic population of P14 cells following CW3 infection. Infection of MLN-deficient mice revealed a critical role for MLN surveillance in targeting P14 T cells to the GI tract following CR6 infection while the spleen plays a compensatory role in response to CW3. These results show how distinct infectious locations of a continuous mucosal surface influence the responses of antiviral CD8 T cells without confounding effects of antigenicity.
This work is supported by the Canadian Institutes for Health Research (CIHR) and a UBC 4 Year Fellowship awarded to Blair K Hardman
Early heterogeneity of IL2R□ expression influences the programming of exhausted CD8T cells during chronic infection
Authors: Toumi Ryma , Xiao Hanxi , Deo Rucha , Reed Steven James , Sarkar Surojit , Kalia Vandana 
Published: January 2023

Abstract
IL-2 signaling at the time of CD8 T cell activation is a critical factor dictating effector and memory CD8 T cell differentiation. However, how IL-2 signaling impacts exhausted CD8 T cell fate outcomes remains poorly defined. Here, we address the role of IL-2 signaling in regulating the differentiation of the stem-like and terminally exhausted CD8 T cells. Prolonged expression of the high affinity IL-2 receptor (IL-2Ra, CD25), and resultant increase in IL-2 signaling drives terminal differentiation of effector cells during acute infection. We hypothesized that curtailing this signal would prevent terminal differentiation and promote the formation of less exhausted stem-cell like TCF-1+CD8T cells in chronic antigenic setting. Our studies show that blocking IL-2 signals at the early phase of chronic infection significantly increased the proportions of TCF-1+CD8T cells. Similarly, knocking down Il2ra augmented the development of TCF-1+CD8T cells. The therapeutic success of PD-1/PD-L1 checkpoint blockade immunotherapy (CBI) relies primarily on stem-cell like cells for vigorous expansion and effector responses. Thus, we next investigated how FACS-purified CD25Hi and CD25Lo cells adoptively transferred into infection-matched chronically infected recipients respond to PD-1 CBI. In contrast to CD25Hi cells, CD25Lo cells underwent vigorous proliferation after PD-1 CBI and produced high amount of effector molecules (GzmB, TNF-α and IFN-γ). Collectively, these data highlight the role of IL-2 signaling in the regulation of CD8 T cell exhaustion, which may be therapeutically exploited to optimize treatments of chronic infections and cancers with immune checkpoint inhibitors.
Supported by NIH R21AI154363 NIH R01AI32819
Localization of terminal memory CD8 T cells in the lungs during respiratory infection
Authors: Suarez-Ramirez Jenny E , Chandiran Karthik , Cauley Linda S 
Published: January 2023

Abstract
Cytotoxic CD8 T cells (CTLs) play an important role in recovery from respiratory virus infection and provide protective immunity by targeting epitopes in well-conserved viral proteins that are shared by different strains of the virus. To provide immunity, CTLs migrate to different anatomical compartments in the lungs and destroy infected cells by injecting lytic molecules into the cytoplasm. Several adhesion molecules aid migration to the infected tissues and cytolysis. These molecules include killer lectin like receptor G1 (KLRG1), which is a membrane bound adhesion molecule that is expressed on terminally differentiated CD8 T effector (Teff) cells. Recently, several studies identified some long lived “terminal memory CD8 T cells (TTM)” that express KLRG1. The goal of our study is to determine the location of these TTM cells within the different compartments of the lungs during a respiratory infection. Our previous work showed that SMAD4 regulates several homing receptors on activated CTLs including KLRG1. We used transfer experiments to examine the distribution of WT cells that express SMAD4 and mutant CTLs that lack SMAD4 in the lungs. At 30 days after intranasal infection with Listeria monocytogenes, there were larger numbers of mutant CTLs in the airways (BAL fluid), while WT CTLs were primarily located in the lung tissue. Interestingly, the localization of the WT cells correlated with the expression of KLRG1. We are using in situ imaging to visualize these transferred CTLs during respiratory infection to better understand their role in protective immunity. Intravascular staining will be used to determine whether these CTLs remain in the blood vessels or enter the tissues of the infected recipient mice.
This work was supported by NIH Grant AI123864.
The Protective Role of IL-36/IL-36R Signal in Con A-Induced Acute Hepatitis
Authors: Sun Jiaren , Wang Xiaofang , Soong Lynn , Liang Yuejin 
Published: January 2023

Abstract
The IL-36 family, including IL-36α, IL-36β, IL-36γ, and IL-36 receptor antagonist (IL-36Ra), belongs to the IL-1 super-family. Although IL-36 is known to play a role in autoimmune diseases, it remains unclear as how IL-36 regulates inflammation in the liver. To determine the role of IL-36/IL-36R signaling pathways, we established an acute hepatitis mouse model by intravenous injection of the plant lectin concanavalin A (Con A), and found that the levels of IL-36 were increased in the liver following Con A injection. We also demonstrated that intrahepatic leukocytes, but not hepatocytes, were the main source of IL-36. Moreover, further research verified that infiltrated neutrophils were the main source of IL-36γ in the liver. Using the IL-36R knockout mouse model (H-2b), surprisingly, we found that the absence of IL-36 signals led to aggravated liver injuries, as evidenced by increased mortality, accompanied by elevated serum ALT and AST levels and severe pathological changes in the liver. Further investigations demonstrated that a lack of IL-36 signaling induced intrahepatic activation of CD4+ and CD8+ T lymphocytes and increased the production of inflammatory cytokines. In addition, IL-36R knockout mice had reduced Treg cell functions and chemotaxis in the liver. Together, our results suggest a vital role of IL-36 in regulating T cell function and homeostasis during liver injury and inflammation.
Supported by grants from NIH (R01 EY028773, AI132674, R21 AI153586)
Interferon-gamma controls pathogenic T-helper 17 and B cells in a new Aquaporin-4 induced experimental autoimmune encephalomyelitis
Authors: Arellano Gabriel , Loda Eileah , Chen Yanan , Popko Brian , Balabanov Roumen , Miller Stephen D 
Published: January 2023

Abstract

Background
Neuromyelitis Optica (NMO) is an autoimmune disease of the Central Nervous System (CNS) mediated by Th17 cells and antibody response to the water channel protein Aquaporin 4 (AQP4), leading to chronic damage of the optic nerves and spinal cord. NMO animal models are substandard inducing disease inconsistently and weakly.

Objectives
Characterize a new NMO mouse model, which best represents the human disease in terms of incidence and chronicity of the disease, severity of symptoms and underlying molecular mechanisms.

Methods
C57BL/6 (WT) and IFN-γ receptor knockout (R-KO) mice were immunized subcutaneously with the AQP4201–220 peptide in Complete Freund Adjuvant and treated with pertussis toxin at day 0 and +2. WT were treated weakly with neutralizing anti-IFN-γ antibodies. mRNA expression and flow cytometry analysis of infiltrating CNS cells were performed. CNS histopathology was determined by immunofluorescence. In vivo B-cell depletion was made using anti-CD20 antibodies.

Results
WT mice treated with anti-IFN-γ and RKO mice showed ascendant paralysis starting from the tail to complete hind limb paralysis. Mice showed increased disease incidence and symptoms were more severe and chronic. CNS IL-17 expressing T cells and Th17 associated genes were upregulated in the absence of IFN-γ. CSN histological analysis showed an increased presence of T and B cells in lesion sites, associated with astrocytes and myelin loss. B-cell depletion in AQP4 primed RKO mice, diminished the incidence and severity of the disease confirming B cell pathogenicity.

Conclusions
AQP4 mouse model is strictly regulated by IFN-γ and its signaling, which control the disease progression and severity, by restraining pathogenic Th17 and B cells.
Supported by grant from NIH (R21 Grant 12878760)
Role of type l IFN in lacrimal gland-protective Treg dysfunction in nonobese diabetic mouse model of Sjögren’s disease
Authors: Allred Merri-Grace , Lieberman Scott M 
Published: January 2023

Abstract
Sjogren’s disease is a chronic autoimmune disease of the lacrimal and salivary glands characterized by foci of inflammation in the tissue composed of aggregations of lymphocytes. Male non-obese diabetic (NOD) mice spontaneously develop autoimmunity of the lacrimal glands. Tregs from these mice are dysfunctional. Disruption of the type I interferon (IFN) signaling pathway protects NOD mice from developing lacrimal gland disease. Whether type l IFN signaling drives lacrimal gland protective Treg dysfunction is not known.
Here we investigated the role of type l IFN in modulating Treg phenotype and function. Through adoptive transfer studies comparing cells from wild-type or IFNAR1-deficient donor mice, we found that recipients of IFNAR1-deficient cells had fewer foci of inflammation. IFNAR1 expression was correlated with a population of CD44loCD62Lhi Tregs. Co-adoptive transfer of both WT and IFNAR1-deficient cells determined that this altered Treg phenotype was due to intrinsic type l IFN signaling. In vitro studies suggest that Treg phenotype can be shaped by IFNα in a dose dependent manner. Ongoing in vivo studies will interrogate the impact of IFNAR1 expression on Treg function.
Type l IFN signaling plays a role in shaping Treg phenotype and may antagonize Treg function. These studies will help define the role of type l IFN signaling in early pathogenesis of Sjögren’s disease and may provide insight into other systemic autoimmune diseases.
Supported by grants from NIH (R01EY027731-01A1)
C57BL/6 Mouse Transgenic for Human MeCP2 as a Murine Model of Neuropsychiatric Lupus
Authors: Wu Tianfu , Li Yaxi , Zhang Shu 
Published: January 2023

Abstract

Introduction
Systemic Lupus Erythematosus (SLE) impacts the central nervous system (CNS), leading to severe neurological and psychiatric manifestations known as neuropsychiatric lupus (NPSLE). To dissect the underlying disease mechanism and to discover novel drug targets of NPSLE, a robust animal model of NPSLE is highly desirable.

Methods
C57BL/6 mice transgenic for human MeCP2 (B6.MECP2Tg1) were phenotyped, including autoantibody profiling, analysis of cellularity and activation of splenic immune cells, proteinuria, as well as neuropsychiatric functions.

Results
The protein expression and phosphorylation of MeCP2 were significantly elevated in the brain of a spontaneous lupus mouse model MRL/lpr, compared to normal B6 mice. The B6.MECP2Tg1 transgenic mice exhibited elevated proteinuria, increased proinflammatory cytokines, altered autoantibody profiles, augmented IgG deposition and macrophage infiltration in the kidney, compared to B6 mice. Effector memory T cells, germinal center B cells and plasma B cells were markedly increased in the female B6.MeCP2Tg1 mice. In addition, B6.MECP2Tg1 mice exhibited anxiety and depression-like behavior, as well as cognitive disorders as early as 9 weeks of age. The abnormal behaviors of the B6.MECP2Tg1 mice are associated with the aberrant neurogenesis and inflammation in the hippocampus, immune cell infiltration in the choroid plexus, as well as the disrupted blood-brain barrier (BBB) and activated microglia, as demonstrated by immunofluorescence microscopy.

Conclusion
Collectively, this work demonstrates that B6.MECP2Tg1 mice exhibit lupus-like phenotypes as well as robust CNS dysfunctions, suggesting it may represent a new animal model for NPSLE.
Murine Epidermis Harbors Functionally Distinct Langerhans Cell Subsets
Authors: Dimitrion Peter Michael , Adrianto Indra , Pawlitz Michael , Yao Yi , Yin Congcong , Peng Hongmei , Zhou Li , Mi Qing-Sheng 
Published: January 2023

Abstract
Epidermal Langerhans cells (LCs) derive from embryonic myeloid progenitors at the steady-state and monocyte progenitors under inflammatory conditions. LCs have the capacity to induce both immunity and tolerance in the skin, but how a single population of LCs mediates both these functions has perplexed researchers for decades. We hypothesized that LCs in murine epidermis have functionally heterogenous subpopulations. We employed single-cell RNA sequencing (scRNAseq) and scATACseq to identify transcriptional and epigenetic heterogeneity in LCs during late embryonic development, adult steady-state and inflamed-state. We found three transcriptionally distinct clusters in adult at steady-state: ATF3hi CD207lo (LC1), ATF3lo CD207hi(LC2), and CD207+ cells expressing keratinocyte (KC) genes (kLCs). Ingenuity pathway analysis showed LC1 had downregulated immunostimulatory pathways and LC2 had upregulated immunostimulatory pathways. LCs from ATF3 knockout mice promoted Th1/2/17 immunity in co-culture experiments, confirming the immunotolerant function of LC1s. LC1 and LC2 clusters had corresponding scATACseq clusters but kLCs did not, suggesting that kLCs may acquire cellular material (i.e. mRNA) through interactions with KCs. scRNAseq analyses of E18.5 pre-LCs and 3 weeks post UVC-treatment also identified ATF3hi and ATF3lo clusters, but kLCs were neither present at E18.5 nor after UVC treatment. Overall, our single cell analyses uncover murine epidermal LC subsets with distinct functions during late embryonic development, steady-state and inflamed-state.
Supported by NIH/NIAMS, R01AR078688-01A1
IL-7 Receptor marks entire embryo-derived Mast Cell
Authors: Kobayashi Michihiro , Cornelius Samuel , Valiente Noemi , Cheng Haizi , Yoshimoto Momoko 
Published: January 2023

Abstract
Mast cell (MC) is an unique immune cell displaying wide variety of functions. Recent break through concluded MC generation is mostly provided by embryonic Yolk Sac (YS) and AGM, and post-natal BM HSC does not supply MC (HSC-independent) as our last presentation. Because YS erythro-myeloid progenitor (EMP) provide earliest tissue resident macrophage (brain microglia) and MC together as a common progenitor, and one report shows part of tissue resident macrophages are marked by IL-7 receptor (IL-7R) as an exception of lymphoid essential lineage marking, we hypothesized that MC could be also marked by IL-7R. We tested by utilizing IL-7Rcre/flox-dTom model and found that newborn to young peritoneal cavity (PerC) and skin MCs, surprisingly, exhibited more than 90% dTom positivity (90.8 ± 3.1%). IL-7R protein was not expressed on the mouse PerC, skin MCs and E12.5 Fetal Liver MC progenitors. To confirm functional IL-7R involvement for the MC development, we measured MCs in IL-7Rcre/+(Het) and IL-7Rcre/cre (KO) mice. Despite marked reductions of T/B cell counts, PerC MC count was comparable (WT: 2.4 ± 1.6 vs KO: 4.1 ± 2.3 × 10e4), suggesting IL-7R is temporarily expressed in early EMP stage in an only short period.
We also tested MC differentiation from the adult BM dTom-negative Lin− Sca+ Kit+ (LSK) cells. MC production was comparable between Het and KO and interestingly enough, both WT/KO LSK derived MCs showed least dTom positivity (3.4± 2.5 vs 4.7 ± 3.1 %) whereas more than 70% of macrophages turned dTom positive, suggesting embryonic and adult MC differentiation used different program respectively. Consistently, %dTom in PerC MC was reduced (79.2 ± 8.1 %) in old mice (&gt; 1year), indicating that post-natal de novo MC production is minimum without IL-7R use.
Supported by R01AI121197-01A1 NIAID R01AI147685-01 NIAID
Cell autonomous metabolic remodeling governs regeneration of the thymus
Authors: Kinsella Sinéad , Evandy Cindy Anggelica , Cooper Kirsten , Hopwo Kayla , Iovino Lorenzo , deRoos Paul , Smith Colton , Granadier David , Dudakov Jarrod A 
Published: January 2023

Abstract
Competent T cell development relies on efficient functioning of the thymus, which is extremely sensitive to acute and chronic insults, but has a remarkable ability to regenerate. We identified that cell-specific metabolic remodeling triggers key molecular mechanisms driving this endogenous regeneration process, namely the transcription of Foxn1 by thymic epithelial cells (TECs). Firstly, following acute damage (sub-lethal total body irradiation) murine CD4+CD8+ (DP) thymocytes, which undergo high levels of death, have a disrupted glycolytic flux triggering a switch to OXPHOS, with reduced mitophagy and increased mitochondrial ROS, an effect not observed in TECs, which are relatively damage-resistant, suggesting metabolic stability confers protection. Furthermore, DPs preferentially undergo pyroptotic cell death after damage facilitated by increased pyruvate-induced TCA cycling, evidenced by an acute surge in caspase 1 cleavage compared to caspase 3. Importantly, pyroptotic thymocytes induce Foxn1 transcription in cortical TECs (cTECs) and in vitro screening revealed the purinergic receptors P2Y2 as a critical molecular target. Moreover, we translated this therapeutic strategy in vivo and demonstrated enhanced thymic regeneration after damage in mice treated with a P2Y2 agonist. Together these data describe an innovative mechanism of immunometabolic regulation of T cell development and tissue regeneration and provides a novel therapeutic strategy to enhance immune function.
VEDOLIZUMAB REDUCES DENDRITIC CELLS AND NAÏVE LYMPHOCYTES IN THE COLON MUCOSA
Authors: Lord James D , Kongala Ramya , Juarez Julius 
Published: January 2023

Abstract
Vedolizumab blocks integrin alpha4/beta7 interaction with MAdCAM-1 on intestinal vascular endothelial cells. It is believed to treat inflammatory bowel disease (IBD) by preventing alpha4/beta7+ cells in blood from entering the intestinal mucosa. By CyTOF and flow cytometry, we found high expression of alph4/beta7 on nearly all myeloid dendritic cells in the blood. Flow cytometry was also performed on colon biopsies from 71 IBD patients on vedolizumab matched 1:1 with similar biopsies from 71 matched IBD patients not on vedolizumab. In the colon, vedolizumab use was associated with significantly fewer intramucosal myeloid dendritic cells (CD1c+, CD14−, CD11c+, HLA-DR+, Wilcoxon p=0.000001) in patients responsive to vedolizumab, but not in non-responders, relative to their respective controls. Fewer intramucosal naïve B (IgD+, Wilcoxon p=0.0001) and CD4 T cells (CD45RA+, Wilcoxon p=0.001) were also observed, regardless of treatment efficacy. No differences were observed in the frequency of other T or B cell subsets, including CD8 T cells, effector T cells, plasma cells and memory B cells expressing different immunoglobin isotypes, suggesting that they have an alternative means of recruitment not present among naïve lymphocytes, such as integrin alpha4/beta1, which binds VCAM-1. Thus we find no evidence that that vedolizumab functions by preventing effector lymphocytes from entering the intestinal mucosa. We instead associated vedolizumab use with fewer colonic naïve lymphocyte and myeloid dendritic cells. The latter is of particular interest, as it alone correlates with clinical response to this therapy.
Supported by a collaborative research agreement with Takeda Pharmaceuticals
Peripheral IgE+ plasmablasts as a biomarker of clinical allergy onset and severity
Authors: Larson Elisabeth M , Babasyan Susanna M , Wagner Bettina 
Published: January 2023

Abstract
IgE-mediated allergies depend on the continuous production of allergen-specific IgE to maintain allergic sensitization. While IgE+ plasma cells are the primary source of this IgE, IgE+ plasmablasts can provide a snapshot in peripheral blood of the current response to allergen. We developed a novel approach to characterize IgE+ plasmablasts in peripheral blood and determined the relationship between allergen exposure, IgE+ plasmablasts and clinical disease. We used a unique large animal model of naturally occurring allergy, equine Culicoides hypersensitivity, which allowed all individuals to have similar timing and frequency of allergen exposure and allowed longitudinal collection of samples from the same allergic and healthy individuals over time. We found that peripheral IgE+ plasmablasts spontaneously secrete IgE, express high levels of the IgE receptor CD23 on their surface, and positively correlate with clinical disease severity. In conclusion, IgE+ plasmablasts are critical in the mechanism of allergy through IgE secretion and serve as a quantitative biomarker of allergic disease development and severity.
This work was supported by the Harry M. Zweig Memorial Fund for Equine Research at Cornell University; the USDA/NIFA [#2005-01812, #2015-67015-23072, and #2019-67015-29833]; and National Institutes of Health [#1S10RR025502 through Cornell University’s Biotechnology Resource Center].