bluuebunny/crossref_metadata_2025_split huggingface dataset:
Primary bovine CD4+ T cells rapidly reprogram metabolism to meet energetic demands during activation
Authors: Eder Jordan , Sacco Randy E 
Published: January 2023

Abstract
T lymphocytes undergo a metabolic reprogramming from predominantly oxidative phosphorylation in the resting state to aerobic glycolysis in an activated state. Efforts aimed at understanding T cell metabolism have concentrated primarily on humans and mice, however T cell metabolism in large animals, such as cattle and pigs, has yet to be examined in detail. Food production animals have been selected for maximal growth at minimal cost. Understanding the link between immunity and metabolism would be beneficial to producers in improving health status and longevity of their herd. As large animals can serve as alternative models in translational research, understanding species-specific immunometabolism is critical. Here, we characterized the metabolic processes in bovine CD4+ cells by interrogating mitochondrial respiration and glycolysis using the Seahorse Extracellular Flux Analyzer. We show that bovine CD4+ cells tend to have lower basal oxygen consumption rates (OCR) as well as lower extracellular acidification rates (ECAR) compared to mouse CD4+ T cells. Despite this, bovine CD4+ cells have an increased metabolic potential, % spare respiratory capacity, and % glycolytic reserve in comparison to mouse CD4+ T cells. Bovine CD4+ cells do not have as pronounced a mitochondrial or glycolytic response in comparison to the mouse CD4+ cells, but would be capable of rapidly modifying their cellular metabolism in the event of environmental stressors.
Relievable effect of dietary Allium hookeri on LPS induced intestinal inflammation response in young broiler chickens
Authors: Lee Youngsub , Lee Sunghyen , Gadde Ujvala Deepthi , Oh Sungtaek , Lillehoj Hyun S. 
Published: January 2023

Abstract
A study using 150 one-day-old broilers was conducted to assess the effects of Allium hookeri (AH) root and fermented root on inflammatory responses and intestinal barrier integrity of LPS challenged broiler chickens. Birds were randomly assigned to six groups (n = 25 birds/treatment) and fed standard diets supplemented with AH root or fermented root at two different levels (1% or 5%). Control birds were provided with non-supplemented basal diets. At 7 days of age, 5 groups (n = 125) in each dietary treatment were injected with LPS (1 mg/kg body weight), and the remaining 25 birds were injected with sterile PBS for negative control. LPS challenge significantly reduced average body weight gain at 24hr post-injection compared to PBS control, and increased by 1% with fermented root supplementation compared to LPS-challenged control. Serum α-1-AGP levels and transcript levels of IL-1b, IL-8, TNFSF15 and LITAF in jejunum were significantly higher in LPS-injected chickens, α-1-AGP levels in serum were reduced by AH root or fermented root (1, 5%) supplementation. Cytokine levels (IL-1b, IL-8 and LITAF) were also down-regulated by AH root and fermented root (1 and 5%) supplementation. However, TNFSF15 reduction was only significant by fermented root (1 and 5%) supplementation. The reduced expression of tight junction proteins (JAM2 and occludin) and MUC2 by LPS challenge was induced by root or fermented root (1% and 5%) supplementation, but there was no significant effect in ZO1. These findings demonstrated that dietary AH root or fermented root influences anti-inflammatory activity and tight junction protein expression in LPS-induced chickens.
Role of lipid inositol phosphatase SHIP-1 in Germinal Center B cell selection and function
Authors: Trivedi Nikita H , Luo Wei , Hawse William F , Shlomchik Mark J 
Published: January 2023

Abstract
Germinal Centers (GC) are sites within secondary lymphoid organs in which B cells undergo proliferation and differentiation. The PI3K signaling pathway is a central modulator of GC B cells (GCBC) selection and function. The PI3K pathway can be regulated by several enzymes including Src homology 2-containing inositol 5’-phosphatase (SHIP-1). SHIP-1 is known to be hyper-phosphorylated in GCBCs. Upon activation, SHIP-1 hydrolyzes phosphatidyl inositol triphosphate (PIP3) to generate phosphatidyl inositol 3,4 biphosphate (PIP2). PIP2 can bind to signaling proteins that are crucial to BCR signaling such as TAPP1/2 and Akt/PKB. To ascertain the role of SHIP-1 in survival and selection of GCBC we used a tamoxifen inducible Cre system to delete SHIP-1 from B cells during an ongoing GC response to NP-CGG. SHIP-1 deletion led to bi-modal expression of SHIP-1 in GCBC expressing intermediate (SHIP-1 int) and low levels of SHIP-1 (SHIP-1 lo) compared to WT controls (SHIP-1 hi). SHIP-1 int GCBC showed reduced phosphorylation of signaling proteins S6 and increased phosphorylation of Btk upon BCR crosslinking with anti-u antibody. SHIP-1 lo cells were un-responsive to BCR crosslinking and had the highest frequency of dead cells and Caspase 3 positive cells among all 3 groups. This data suggests that SHIP-1 expression and activity is crucial to GCBC signaling and survival. The role of PIP2 in regulating BCR signaling in GCBC remains to be elucidated.
Small size of membrane-tethered ligands regulates phosphatase segregation in γδ TCR triggering
Authors: Li Fenglei , Choudhuri Kaushik 
Published: January 2023

Abstract
Ligand recognition by the T cell antigen receptor (TCR) is central to effective immunity. Unlike αβ T cells, γδ T cells do not recognize pMHC antigens or use coreceptors CD4/8. Instead they recognize invariant membrane-tethered ligands, which are upregulated at sites of inflammation and infection. The substantial structural similarities between αβ and γδ TCRs prompted us to investigate whether they share triggering mechanisms. However, recent studies show that binding-induced γδ TCR conformational changes are not induced by physiological ligands, leaving open the possibility that other mechanisms are involved. We investigated the stress-inducible murine surface protein T22, that is recognized by the G8 γδ TCR - since detailed biophysical and structural information is available for this system. Here we tested whether ‘size-based’ kinase-phosphatase segregation (also known as the kinetic-segregation model) mediates G8 TCR signal initiation. Elongation of the T22 ectodomain leads to failure of TCR phosphorylation and IL-2 release. Electron microscopy showed that elongated T22/G8 leads to increased intermembrane spacing at the immunological synapse. Conversely, truncation of the large CD45 ectodomain attenuated triggering, pointing to a critical dependence on ‘close contact’ for phosphatase exclusion. To establish the physiological relevance of our findings, we confirmed that T22 elongation abrogates triggering in primary G8 γδ T cells, and using a second γδ TCR (KN6). We are currently completing investigations on the role of kinetic-segregation in hapten-specific and human γδ TCR triggering. Taken together, our findings establish that γδ TCR triggering occurs primarily through the kinetic-segregation mechanism.
Role of the butyrophilin juxtamembrane region in ligand binding and T cell activation
Authors: Wiemer Andrew J. , Nguyen Khiem , Li Jin , Puthenveetil Robbins , Lin Xiaochen , Hsiao Chia-Hung Christine , Vinogradova Olga 
Published: January 2023

Abstract
The B7 protein butyrophilin 3A1 (BTN3A1) is an immune receptor for pathogen-derived small isoprenoid diphosphates such as (E)-4-hydroxy-3-methyl-but-2-enyl diphosphate (HMBPP). Binding to these ligands promotes a multifaceted immune response including activation of Vγ2Vδ2 T cells. Here, we use small-angle x-ray scattering (SAXS) to visualize the internal domain of BTN3A1 as it undergoes a conformational change following ligand binding. To better understand the cause of the conformational change, we used nuclear magnetic resonance (NMR) spectroscopy to determine that the juxtamembrane region is important to BTN3A1 activation by HMBPP. The spectral location of the affected amide peaks, partial NMR assignments, and juxtamembrane mutants (ST297AA or T304A) investigated confirm that the backbone amide of at least one threonine residue (T304), adjacent to conserved serine, comes close to HMBPP, while double mutation of non-conserved residues (ST297) perturbs the local fold of the protein. Threonine residue mutation reduces the ability of BTN3A1 in K562 cells to trigger activation of primary human Vγ2Vδ2 T cells in response to HMBPP. Our results show that ligand binding to BTN3A1 induces a conformational change within the intracellular domain that is mediated by the juxtamembrane region and required for activation. These results provide insight into the unique activation mechanism of butyrophilin-type immune receptors.
Notch ligands DLL4 and Jagged1 exert differential effects in allergic airway inflammation
Authors: Huang Miao-Tzu , Chen Yi-Lien , Lien Chia-I , Hsu Li-Chung , Chiang Bor-Luen 
Published: January 2023

Abstract
Notch is a pleiotropic signaling family that has been implicated in pathogenesis of allergic airway diseases; however, the distinct function of individual Notch ligands remains elusive. By using an OVA-induced murine asthma model, we investigated whether Notch ligands, Jagged1 and DLL4, exert differential effects during allergic airway inflammation. We found that whilst Jagged1 inhibition mitigated Th2-dominated airway inflammation, blockage of DLL4 aggravated the Th2-mediated asthma phenotypes. Additionally, blockage of Jagged1 signaling enhanced IL-17 production and neutrophilic airway infiltration. In vitro, exogenous Jagged1 induced Th2-skewed responses, whereas augmented DLL4 signaling displayed a dual role by promoting expansion of both Tregs and Th17. In vivo, DLL4 blockage impaired Treg differentiation which plausibly resulted in exaggerated asthma phenotypes. On the contrary, administration of DLL4-expressing antigen-presenting cells promoted endogenous Treg expansion and ameliorated the allergic responses. Therefore, whilst Jagged1 induces Th2-skewed inflammation, DLL4 elicits an essential self-regulatory mechanism via Treg-mediated pathway that overcomes Jagged1-induced Th2 responses and facilitates resolution of the airway inflammation. These findings uncover a disparate function of Jagged1 and DLL4 in allergic airway diseases, suggesting the feasibility of Notch ligand-specific targeting in therapy of allergic airway diseases.
IL-7 plays as a critical factor for the maintenance of allergen-specific memory CD4 T cells in the lung and airways
Authors: Yeon Seung-min , Jung Yong Woo 
Published: January 2023

Abstract
Memory T cells can respond rapidly against repeated antigen exposure, and maintain their population with extended period of time. While these characteristics of memory T cells have mainly been studied during viral infections, their roles in allergic diseases remain to be determined. Since allergic patients suffer relapses and exacerbations of the diseases by intermittent exposure to allergens, we hypothesized that allergen-specific memory CD4 T cells are present in the lung and airways and the crucial survival factors for these cells are provided in their microenvironments. In order to test this hypothesis, we transferred ovalbumin (OVA)-specific T cells into naïve Balb/c mice intravenously and induced allergic inflammation by treating these mice with a mixture of house dust mite and OVA intranasally. We found that allergen-specific memory CD4 T cells were present and survived more than 70 days in the lung and airways. In order to understand how these cells maintain their homeostasis, we blocked IL-7 signaling by treating these mice with an anti-IL-7Rα antibody. The numbers of allergen-specific memory CD4 T cells decreased in the mediastinal lymph node, lung and airways after IL-7Rα blockade. Furthermore, we found that allergen-specific memory CD4 T cells in the lung and airways induced airway inflammation regardless of T cell recruitment from circulation. In conclusion, the allergen-specific memory CD4 T cells are present in the allergic lung and airways, and the IL-7 signaling plays a critical role in the maintenance of these cells.
Estrogen contributes to sex differences in M2-polarization during asthma
Authors: Keselman Aleksander M , Fang Jessie , White Preston B. , Heller Nicola M 
Published: January 2023

Abstract
Asthma is a chronic inflammation of the airways that affects over 300 million people worldwide. Asthma exhibits sex differences, affecting mostly boys in childhood and women in adulthood. Alveolar macrophages have emerged as major mediators of allergic lung inflammation. Macrophages express receptors that recognize and respond to estrogen. We hypothesized that estrogen enhances M2 polarization of alveolar macrophages and thereby contributes to asthma. We found increased expression of the canonical mouse M2 marker YM1 by alveolar macrophages from allergic female mice compared to male mice. Consistently, bone marrow derived macrophages (BMMs) from female mice exhibited higher levels of YM1 and ARG1 than did BMMs from male mice following stimulation with IL-4. This sex difference is reflected on the epigenetic level as M2 promoters in BMMs from female mice exhibited enhanced acetylated H3 compared to BMMs from male mice following stimulation with IL-4. Pretreatment of BMMs from female mice with estrogen receptor ligands enhanced IL-4-induced M2-gene expression. Using ovariectomized (OVx) and LysMCREERaflox/floxmice, we show that an absence of either estrogen or the estrogen receptor-a (ERa) impairs M2 polarization following challenge with OVA. Thus, macrophages exhibit sex differences in their ability to polarize to an M2-phenotype in vitro and in vivo. Estrogen and ERa engagement augment IL-4-induced M2-gene expression. Together these data suggest that sex and hormonal factors contribute to sex differences in macrophage responses during asthma. Understanding the role of estrogen signaling in M2-polarization is paramount for identifying novel therapeutic targets to better treat women with asthma.
Pathogenic epigenetic programming of expanded B cell subsets in systemic lupus erythematosus
Authors: Scharer Christopher , Blalock Emily , Barwick Benjamin G , Gandham Bhanu , Neary Bridget , Sanz Ignacio , Boss Jeremy M 
Published: January 2023

Abstract
Systemic lupus erythematosus (SLE) is characterized by multiple B cell abnormalities that contribute to disease pathogenesis through the production of autoantibodies. The recent characterizations of immune cells from SLE patients suggest that distinct B cell subsets are expanded and that defects in epigenetic programming may be a contributing factor to disease etiology. Using high-dimensional flow cytometry, five B cell subsets were isolated from cohorts of SLE and HC subjects. To create a molecular map of each cell type, the transcriptome was defined by RNA-seq and the epigenome by dual DNA methylation (RRBS) and chromatin accessibility (ATAC-seq) profiling. These data reveal cell-type relationships that suggest pathogenic B cell subsets are programmed to differentiate down a different trajectory than normal B cells. Across all SLE B cell subsets a distinct disease signature was observed in each of the three data sets. Resting naïve B cells displayed a similar SLE signature to expanded B cell subsets indicating that a disease programming exists early in the differentiation pathway. Distinct epigenetic footprints were identified for transcriptional networks active in SLE B cells, revealing the unique environmental signals these cells receive. These results provide insights into the molecular programming of human B cell subsets, identify loci that may contribute to the expansion of distinct pathogenic B cell subsets, and suggest that early alterations in programming predispose B cells towards a disease fate.
Role and Regulation of CD11chi T-bet+ B cells in SLE
Authors: Wang Shu , Wang Jingya , Kumar Varsha , Naiman Brian , Karnell Jodi L. , Gross Phillip S. , Rahman Saifur , Manna Zerai , Hasni Sarfaraz , Siegel Richard , Sanjuan Miguel A , Cancro Michael , Kolbeck Roland , Ettinger Rachel 
Published: January 2023

Abstract
We examined a large cohort of systemic lupus erythematosus (SLE) patients and found an unusual B cell subset highly expanded. These B cells displayed a unique phenotype and expressed antigens not present on other B cell populations, including high densities of CD11c, FcRL5, and the T-box transcription factor, T-bet, but unexpectedly, were CD40lo and CD24−. Although these CD11chi cells were largely negative for the memory B cell antigen CD27, their telomere length was consistent with memory, rather than naïve B cells. Notably, the increase of CD11chi B cells in SLE significantly correlated with disease severity scores as well as with other markers of disease activity including serum IL-21. While memory B cells characteristically express low densities of IL-21R, these memory CD11chi B cells were IL-21R bright. In culture, IL-21 was a potent driver of CD11c expression when B cells were co-stimulated through the B cell receptor and CD40. Lastly, CD11chi B cells in SLE significantly correlated with blood plasma cells as well as a distinct set of autoantibodies, and importantly, were efficiently driven to differentiate into plasma cells in response to activated T cells. These data indicate that among the many roles of IL-21 in regard to B cell activation and differentiation, this pleiotropic cytokine also regulates CD11chi B cells, and presumably contributes to autoimmunity through the differentiation of autoreactive CD11chi B cells in SLE.
B cell αv integrins regulate development of autoimmunity in murine lupus models
Authors: Lacy-Hulbert Adam , Raso Fiona , Acharya Mridu 
Published: January 2023

Abstract
B cell activation by self-antigen and signaling through Toll-like receptors (TLR) such as TLR7 and TLR9 has been implicated in the development of autoimmunity. We have recently identified a mechanism by which αvβ3 integrin limit excessive B cell responses to antigens containing TLR ligands, including self-antigens. We have previously reported that mice in which αv integrins are selectively deleted from B cells develop increased levels of autoantibodies to RNA and double stranded DNA.
Based on these findings, we hypothesized that deletion of αv integrins would accelerate TLR dependent autoimmunity. To study this further, we crossed mice lacking αv integrins on B cells (αv-CD19 mice) with mice expressing increased levels of TLR7 (TLR7.1tg mice) that develop Lupus-like autoimmunity. We find that the resulting αv-CD19 TLR7tg mice had increased spleen weight in comparison with age-matched TLR7tg littermates. αv-CD19 TLR7tg mice also had increased number of IgG2c+ plasma cells and increased autoantibodies to RNA, all indicative of enhanced B Cell activation and development of autoimmunity. In addition, deletion of αv integrin on B Cells in this model leads to enhanced activation of T Cells. Currently, we are investigating the role of αv integrins on B Cell subpopulations in driving T Cell activation and antigen presentation in this model of autoimmunity.
B Cells contribute to autoimmunity by activating T Cells in addition to producing autoantibodies and cytokines. These studies allow us to understand how altered B Cell TLR signaling can lead to enhanced immune activation in autoimmunity and highlight the importance of αv integrins in regulating this process.
FDCs regulate self-reactive memory B cells through CD21
Authors: Das Abhishek , Heesters Balthasar , Bialas Allison , O’Flynn Joseph , Carroll Michael C 
Published: January 2023

Abstract
B cells are the key mediators in many autoimmune diseases like systemic lupus erythematosus (SLE). Yet little is known about the cells and factors that are vital for maturation and sustenance of autoreactive B cells. One of the hallmarks of autoimmunity is the formation of germinal centers (GCs), which are the site where self-reactive B cells expand and differentiate. Follicular dendritic cells (FDC), which are central to GCs, serve as an important source of antigen and chemokines and are essential for maintenance of GCs and B cell memory in response against foreign antigens. Whether FDCs play a similar role with self-antigens is not known. Using the 564Igi lupus strain in which autoimmunity is Type I interferon alpha (IFNa)-dependent, we found out FDCs are crucial for self-reactive GCs and secretion of autoantibody. Unexpectedly, we found that FDC uptake of nucleolar antigens via the CD21 receptor triggered endosomal TLR7 signaling and induction of IFNa, which is essential for escape of tolerance by self-reactive B cells. We postulated that self-antigen complexes were internalized via CD21. To test this idea, mice were treated with a neutralizing antibody specific for CD21 (clone 7G6). The treatment effectively “purged” FDC of self-antigen complexes leading to a reduction in interferon secretion, restoration of B cell tolerance and reduction in GC. Furthermore, using the Aid-cre-YFPflox-reporter strain, which permanently marks GC+ B cells, crossed with 564Igi, we found that blockade of CD21 resulted in a significant loss of self-reactive GC and memory B cells. These combined findings identify FDC as a novel therapeutic target for lupus.
Engagement of TLR4 with MAM superantigen promotes HMGB1-mediated induction of IRF7 and IFNα in synoviocytes of a mouse model of human RA
Authors: Mu Hong-Hua , Xia Neil 
Published: January 2023

Abstract
Mycoplasma arthritidis mitogen (MAM), a potent superantigen (SAg) secreted by M. arthritidis, is known to contribute to arthritis in mouse models of human rheumatoid arthritis (RA). Type I interferons (IFNs) are known to play an important role in RA. IFN gene transcription is activated by IFN-regulatory factors (IRFs) in response to innate immune recognition. We previously demonstrated that mouse strains with differing expression of the innate immune receptor TLR4 or/and TLR2 differ in their response to MAM. In this study, we investigated if MAM, or MAM with an autoantigen collagen II, can stimulate synovial fibroblasts (SF) to mount inflammatory responses in a mouse arthritis model. We found that in vitro stimulation of naïve SF with MAM in an arthritis susceptible mouse strain greatly increased level of IRF7 and IFNα. HMGB1, a heat-shock stress protein was also detected to produce in the cell culture of MAM-stimulated SF. In vivo studies showed mice injected with CII and MAM developed severe arthritis and exhibited a high HMGB1 level. An increased HMGB1 level was linked to the upregulation of the intracellular IRF7 and IFNα, and IRF7 was effectively inhibited by an anti-HMGB1 treatment, suggesting HMGB1 dependence. This led to the reduction of inflammatory mediators IL-6 and MMPs in inflamed joints of arthritis mice. Thus, our results suggest that MAM is capable of selecting the SF for local joint inflammation by promoting HMGB1 and IRF7 following interaction with TLR4. Our findings clearly demonstrates microbial agents, such as MAM SAg, can modify host tissue components, such as CII and stimulate synoviocytes, thus promoting local joint inflammation in autoimmune arthritis.