bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating the role of Quaking in antigen presentation by Dendritic Cells
Authors: Li Yating , Hu Jian , Yee Cassian 
Published: January 2023

Abstract
Dendritic Cells (DCs) are considered the most potent antigen-presenting cells due to their superior capacity to cross-present exogenous antigens to CD8 T cells for effective adaptive immunity. They internalize foreign antigens by phagocytosis, receptor-mediated endocytosis or macropinocytosis, which are then processed in endo/lysosomal compartments and loaded on MHC class I. However, the molecular mechanisms regulating exogenous antigen uptake and cross-presentation by DCs remain unclear. We revealed a potential regulatory role of an RNA-binding protein, Quaking (QKI), in antigen presentation. Our previous studies in neural stem cells and microglia identified QKI as a novel regulator of phagosome maturation and endosome signaling via interaction with the transcription factor PPARβ/δ. Therefore, we hypothesize that QKI, together with PPARβ/δ enhances DC antigen uptake and cross-presentation via promoting phagosome and endolysosome signaling. We found QKI and PPARβ/δ to be significantly unregulated in human monocyte-derived DCs, and demonstrated that activating the QKI-PPARβ/δ complex in DCs upregulates QKI targets and significantly promotes DC phagocytosis activity, suggesting QKI cooperates with PPARβ/δ to enhance antigen uptake. The biological role of QKI in antigen cross-presentation and the effect of QKI enhancement on induction of CD8 T cell response by DC are currently under investigation. Understanding the role of QKI in DC may reveal how antigen presentation is regulated and provide new strategies to improve DC-based immunotherapy.
Inhibition of autoimmune enteritis in IFABP-Ova mice by LCMV infection
Authors: Bhela Siddheshvar , Stolley J. Michael , Weyu Eyob , Quarnstrom Clare , Nelson Christine , Vezys Vaiva 
Published: January 2023

Abstract
Epidemiological data indicate that infections play a role in preventing autoimmunity. Thus, the decline in the incidences of infectious diseases and the increase in the frequency of autoimmune diseases also known as the hygiene hypothesis suggest that there might be a link between the two phenomena. In this study using the iFABP-Ova transgenic mouse model, that expresses ovalbumin in the small intestine, we showed that prior LCMV infection dampened self-reactive effector CD8 T cell responses and protected mice from enteric autoimmunity. LCMV specific memory CD8 T cells, generated after infection, were not required for this protection as elimination of these cells using a depleting antibody still protected the mice from enteric autoimmunity. Moreover, we found that infection induced suppression is specific to self antigen reactive CD8 T cells without affecting foreign antigen specific CD8 T cell responses. Lastly, we found that a similar suppression of self-reactive CD8 T cells occurs in iFABP-Ova mice when tolerant CD8 T cells are previously present. Thus there might be some similarities in the mechanism of suppression of self-reactive CD8 T cells by viral infections and tolerance generation. Taken together these data demonstrate that prior viral infections or tolerant CD8 T cells have the ability to suppress self-reactive autoimmune responses and provide protective effects without compromising immunity to foreign pathogens.
The novel role of signal transducer and activator of transcription 5B (STAT5B) in mediating T cell differentiation and regulatory functions
Authors: HSIEH HAO , Shieh Chi-Chang 
Published: January 2023

Abstract
Autosomal-recessive mutations in signal transducer and activator of transcription 5B (STAT5B) have been reported to cause abnormality in growth and immune development in patients. We recently encountered a male patient (designated patient C) who suffered from post-natal growth retardation, severe skin inflammation and lymphoproliferative syndrome. A novel heterozygous STAT5B missense mutation was identified in this patient. The point mutation is alanine to threonine variant (exon9, p.Ala371Thr) which locates on the DNA binding domain of STAT5B. We investigated the role of heterozygous STAT5BA371T variant in the pathogenesis of his immune dysregulation in this study. We confirmed that the mutation did not interfere the STAT5B protein expression and tyrosine phosphorylation response to IL-2 stimulation. Remarkably, significant reduction of p-STAT5 levels in the PBMC from the patient after TCR activation were noted. We found that normal proportion of CD4+CD25+ T cells in the PBMC of the patient before TCR stimulation. Furthermore, significant decrease in CD4+CD25high T cells was found in the patient’s PBMC after T cell activation. Given that CD25 is one of the STAT5B target genes in T cells, lower CD25 expression implicates that novel STAT5BA371T variant is a loss-of-function mutation. Lower CD25 expression in turn leads to lower sensitivity to IL-2 hence ineffective induction of induced regulatory T (iTreg) cells. Our data showed that a dominate-negative heterozygous STAT5BA371T variant may cause the immune dysregulation syndrome by deterring iTreg differentiation, suggesting a critical role of STAT5B in iTreg differentiation.
Prosthetic joint wear particle analogs induce osteoblast apoptosis
Authors: Fisher Cody , Patel Robin 
Published: January 2023

Abstract
Loosening of prosthetic joint implants is a leading cause of arthroplasty failure and the need for surgical revision. Though the mechanisms that induce loosening are complex and not fully understood, implant-derived wear debris has been suggested to be an important player in the interaction between the prosthesis and surrounding cells needed for post-operative immune response, bone remodeling and implant retention. In this study, MC-3T3 pre-osteoblasts were grown in media supplemented with wear particle analogs [titanium (II) oxide (TiO), chromium (III) oxide (Cr2O3), or cobalt (II, III) oxide (Co3O4) particles] for up to seven days and analyzed for apoptotic marker regulation and cell viability. An increase in apoptotic marker staining and a decrease in viability was found in osteoblasts cultured with TiO and Cr2O3 at concentrations &gt;10 μg/ml after just one day and lasting through seven days of exposure. Similar apoptotic and viability response was observed in Co3O4 treated osteoblasts, but only after seven days of particle exposure. Osteoblasts exposed to 100 μg/ml of TiO, Cr2O3, or Co3O4 for seven days had AnnexinV+ frequencies of 60.2%, 74.7%, and 13.4%, respectively. No difference was detected in osteoblasts exposed to particle concentrations ≤10 μg/ml at any time point. Additionally, particles were found localized to cell membranes and the cytoplasm within a single day of treatment; internalization, specific intracellular location, and downstream processing of the particles are under active investigation. This work provides insight into interactions between prosthetic joint arthroplasty wear particles and the osteoblasts necessary for proper bone homeostasis and joint retention.
The actin-bundling protein L-plastin regulates NLRP3 inflammasome activation in macrophages
Authors: Joshi Hemant , Anaya Edgar , Almgren-Bell Alison , Szasz Talyor P. , Todd Elizabeth M. , Morley Sharon Celeste 
Published: January 2023

Abstract
In macrophages, inflammasome pathways induce IL-1β release and pyroptotic cell death to clear infections. For example, NLRP3 inflammasome activation in lung resident alveolar macrophages (AMs) is crucial in controlling pneumonia. We have found that mice lacking the actin-bundling protein L-plastin (LPL−/−) mice are highly susceptible to Streptococcus pnuemoniae lung infection and produce less IL-1β. LPL is also required for podosome formation. Podosomes are integrin-based sites of adhesion that anchor the actin cytoskeleton of AMs to the extracellular environment. As such, AMs can sense their mechanical environment via podosomes. We have found that AMs lacking LPL exhibit defective NLRP3 inflammasome activation in ex-vivo stimulation. Specifically, LPL is required for ASC oligomerization and downstream IL-1β processing after NLRP3 assembly. Since LPL also supports mechanosensitive integrin signaling, we hypothesized that LPL might link contact-based mechanosensation to inflammasome activation in macrophages. To test this hypothesis, we challenged LPL−/− mice with bleomycin, as bleomycin-induced lung injury and fibrosis is thought to be dependent upon NLRP3 activation. LPL−/− mice were resistant to bleomycin-induced lung injury, suggesting a previously unrecognized mechanosensitive mechanism regulating inflammasome activation in macrophages. We propose that the increased lung stiffness in fibrotic lung exerts mechanical stress on AMs and thus may contribute in inflammasome signaling. Increased understanding how mechanical signaling regulates may thus aid in developing therapies to treat lung pathologies i.e. acute respiratory distress syndrome (ARDS), COPD and lung fibrosis.
Endocannabinoid hydrolysis inhibition unmasks that unsaturated fatty acids induce a robust synthesis of 2-arachidonoyl-glycerol and its congeners in human myeloid leukocytes
Authors: Archambault Anne-Sophie , Turcotte Caroline , Dumais Elizabeth , Martin Cyril , Blanchet Marie-Renée , Bissonnette Elyse , Ohashi Nami , Yamamoto Keiko , Itoh Toshimasa , Laviolette Michel , Veilleux Alain , Boulet Louis-Philippe , Di Marzo Vincenzo , Flamand Nicolas 
Published: January 2023

Abstract
The endocannabinoid 2-arachidonoyl-gycerol (2-AG) modulates immune responses by activating cannabinoid receptors or through its multiple metabolites, notably eicosanoids. Thus, 2-AG hydrolysis inhibition might represent an interesting anti-inflammatory strategy that would simultaneously increase the levels of 2-AG and decrease those of eicosanoids. Accordingly, 2-AG hydrolysis inhibition increased 2-AG half-life in neutrophils. Under such setting, neutrophils, eosinophils and monocytes synthesized large amounts of 2-AG and other monoacylglycerols (MAGs) in response to arachidonic acid and other unsaturated fatty acids (UFAs). Arachidonic acid and UFAs were ~1000-fold more potent than GPCR agonists at stimulating MAG biosynthesis. Triascin C and thimerosal, which respectively inhibit fatty acyl-CoA synthases and acyl-CoA transferases, prevented the UFA-induced MAG synthesis, implying glycerolipid remodeling is essential in this process. 2-AG and other MAG biosynthesis was preceded by that of the corresponding lysophosphatidic acid (LPA). However, we could not directly implicate LPA dephosphorylation in MAG biosynthesis. While the GPCR agonists PAF, fMLP and LTB4 poorly or did not induced 2-AG biosynthesis, they inhibited that induced by AA by 25–50%, suggesting that 2-AG biosynthesis is decreased when leukocytes are surrounded by a pro-inflammatory entourage. Our data conclusively indicate that human leukocytes use AA and UFAs to biosynthesize biologically significant concentrations of 2-AG and other MAGs and that hijacking the immune system with 2-AG hydrolysis inhibitors might diminish inflammation in humans.
Characterization of the local and systemic temporal changes to the lipid mediator and cytokine cascades following osteotomy and polytrauma
Authors: Muire Preeti Judith , Mangum Lauren H , Mangum Lee C , Garcia Gerardo R , Romano Desiree R , Wenke Joseph C 
Published: January 2023

Abstract
Polytrauma (PT) inducesglobal changes to inflammatory signaling, contributing to delayed fracturehealing. In a rat model of PT encompassing burn, blunt trauma, and osteotomy, we characterized the local and systemic temporal changes to the lipid mediator(LM) cascade, circulating white blood cells (WBCs), and local levels of growthfactors (GF)s and cytokines. Male rats received either a non-critical 3mmfemoral osteotomy (OST) or PT trauma procedures and were survived for 6, 24,48, 72, 96, 168, or 240hrs and blood, plasma, and fractured femurs werecollected. Whole femurs were homogenized to extract LMs, protein, and RNA, while blood and plasma were used for WBC and LM analysis, respectively. At the fracture site, prostaglandin (PG) E2 was significantly higher in OST at 24 and 72hrs, levels of PGF2α were higher in OST at 24hrs, while resolvin (Rv) D1 was higher in PTat 6hrs post injury. There were no differences in the expression ofcyclooxygenase-2 (COX-2), or lipoxygenase-5 (LOX-5) and LOX-15. In plasma, there were no significant differences in PG levels at any time. Plasma RvE1 was elevated in PT immediately following injury while maresin 1 (MaR1) was significantly lower in PT at 168hrs. Total WBCs and lymphocytes (103cells/uL) were lower in PT overall and significantly so at 72 and 96hrs, respectively. Additionally, the percent of neutrophils in PT was significantlyelevated and percent lymphocytes was decreased at 48 and 168hrs compared toOST. Protein analysis of the fracture site found early elevation of cytokines(IL-1β, IL-13, IL-6) and GFs in PT at 48 and 72hrs. These results indicate thatchanges to circulating LM and WBCs may provide predictive measures of non-unionand therapeutic targets to improve fracture healing.
Characterization of immune cells found in keloid versus normal skin tissue
Authors: Anderson Jaclyn B , Harrant Alexander B , Navarro-Alvarez Nalu , Wang Zhaohui , van Bokhoven Adrie , High Whitney , Chong Tae W , Huang Christene A 
Published: January 2023

Abstract
Keloids are abnormal scar formation that extends beyond the confines of the original injury. Immune cell infiltration is associated with keloid pathogenesis, but the exact mechanisms remain unknown. We aim to characterize the immune profile of keloid skin compared to normal skin in order to further understand the role of specific immune subsets in keloid formation. One abdominal normal skin sample and five keloid samples (four ear and one shoulder) were obtained from the Plastic Surgery clinics and the University of Colorado Biorepository Core Facility. Paraffin-embedded samples were stained with CD19+, CD20+, CD3+, CD8+ and FoxP3+ by the Human Immunology and Immunotherapy Initiative. The multiplex immunohistochemistry slides were scanned using Vectra 3 (PerkinElmer, MA, US) and captured images were analyzed with InForm Tissue Finder, phenotpr, and phenoptrReports (Akoya Biosciences, CA, US). CD20+ and CD19+ B cells were significantly increased in keloid tissue compared to normal skin (14.50% and 14.20% vs 6.47% and 7.56%), respectively. In contrast, no significant difference was observed in the percentage of CD3+ and CD8+ cell subsets in keloids compared to normal skin (12.92% and 4.98% vs 8.19% and 4.04%), respectively. Moreover, there was a significant increase in FoxP3+ positive cells found in keloid scars (9.68%) compared to normal skin (2.89%). Further studies examining the role of B cells and FoxP3+ cells in keloid pathogenesis are warranted.
PD-L1 expression at the single cell level in Myeloid Derived Suppressor Cells using a stimulatory functional assay to evaluate immunotherapy strategies in multiple myeloma
Authors: Bradford Jolene A , Rico Laura G. , Junca Jordi , Bardina Jorge , Bistue-Rovira Angel , Ward Michael D. , Petriz Jordi 
Published: January 2023

Abstract

Background
Multiple myeloma (MM) is characterized by malignant plasma cells in the bone marrow with an associated immunosuppressive microenvironment. PD-L1 suppresses immune response and is overexpressed in MM plasma cells and MDSCs. PD-L1 plays an important role in tumor immune evasion and drug resistance. PD-L1 is considered a therapeutic target, yet some MM individuals do not respond to treatments with PD-L1 or PD-1 inhibitors. The aim of this study was to design a screening assay to identify PD-L1+ MDSCs using flow cytometry.

Methods
Using no-lyse no-wash methods, samples were labeled with Vybrant DyeCycle Violet Stain to identify nucleated cells and with antibodies to identify MDSCs. PD-L1 surface expression was studied ± PMA stimulation. Kinetics of surface expression of PD-L1 were studied over time. PD-L1 cell surface and cytoplasmic expression were compared. Competitive experiments with Durvalumab were studied. Samples were analyzed using Attune NxT Flow Cytometer.

Results
PD-L1 surface expression increased after stimulation, but showed variation among subjects. PD-L1 surface expression was highest after 1-5 minute stimulation. Cytoplasmic levels of PD-L1 were undetectable. Co-incubation with Durvalumab resulted in variable inhibitory PD-L1 profiles.

Conclusions
Since cytoplasmic PD-L1 is not found, PD-L1 may reveal steric changes in response to stimulation, which may be associated with a PD-L1 immunoregulatory mechanism affecting therapies. Assessment of PD-L1 folding may help to develop better treatment strategies or to predict therapy resistance. No-lyse no-wash methodologies show promise as an emerging strategy to model conformational changes in the target site. For research use only.
Disease-associated dominant negative CARD11 mutations interfere with the CARD11 Opening Step during antigen receptor signaling to NF-κB and JNK2
Authors: Bedsaul Jacquelyn Renee , Pomerantz Joel 
Published: January 2023

Abstract
CARD11 mediates lymphocyte activation by functioning as a scaffold in antigen receptor signaling to NF-κB, JNK, and mTOR. Antigen-induced CARD11 signaling proceeds through an ordered series of steps, including Opening, Cofactor Recruitment, Enzyme Activation, and Complex Disassembly. Recently, several forms of Primary Immunodeficiency have been described that are due to germline CARD11 mutations. One of these syndromes, Combined Immunodeficiency (CID) with atopy, is inherited in an autosomal dominant manner and caused by loss-of-function (LOF) CARD11 alleles, which display dominant negative activity that poisons signaling from co-expressed wild-type CARD11. To investigate the mechanistic basis for disease-associated dominant negative activity we reconstituted CARD11-deficient T cells with a panel of LOF CARD11 variants in the absence and presence of co-expressed wild-type CARD11. In the absence of wild-type CARD11, the LOF variants were indistinguishable, such that each variant failed to promote the signal-induced 1) recruitment of the cofactors Bcl10, HOIP, and MALT1 to CARD11, 2) Bcl10 polyubiquitinylation, 3) MALT1 protease activation, 4) NF-κB activation, and 5) JNK2 activation. In the presence of co-expressed wild-type CARD11, the LOF variants surprisingly displayed a range of dominant negative activity from strong to intermediate to weak, indicating a specific potency of some mutations to disrupt signaling when heterozygous. Our results suggest that disease-associated dominant negative CARD11 mutations interfere with the Opening Step in the CARD11 signaling cycle and provide a mechanistic basis to explain why some LOF CARD11 mutations can cause disease when heterozygous while others do so when homozygous.
T-cells dysregulate hematopoiesis in Myeloproliferative Neoplasm through increased interferon-gamma production
Authors: Lai Hew Yeng , Ramanathan Gajalakshmi , Brooks Stefan , Craver Brianna , Fleischman Angela 
Published: January 2023

Abstract
Chronic inflammation is a key feature of myeloproliferative neoplasm (MPN), a hematological malignancy. MPN is characterized acquisition of a somatic mutation in hematopoietic stem cells, most commonly the JAK2V617F mutation, which leads to unrestrained expansion of myeloid cells. Although lymphoid compartments do not have the JAK2V617F mutation, these cells are key mediators of inflammation. The precise role of lymphoid cells in disease pathogenesis is unclear. We found that CD4+ T cells from MPN patients produce significantly more interferon gamma (IFNg) than normal CD4+ T cells. IFNg has been reported to suppress the growth of myeloid colonies. We found that removal of T cells from peripheral blood mononuclear cells of MPN patients enhance myeloid colony formation. Removal of T cell also increase fraction of wild-type myeloid colonies, demonstrating that wild-type cells are more sensitive to suppression by T cells.
In addition, MPN mouse model using transduction-transplantation of JAK2V617F in RAG2−/− mice, lacking in T and B cells, display an attenuated MPN phenotype. Moreover, transplantation of JAK2V617F RAG2−/− bone marrow with wild-type bone marrow into lethally irradiated wild-type recipient restored the MPN pathology, such as erythrocytosis and expansion of megakaryocytes. This implicates that lymphocytes play an important role in driving MPN pathogenesis. More importantly, inhibition of T cells in JAK2V617F transplanted mouse using cyclosporine attenuates spleen size and marrow fibrosis, demonstrating that suppression of T cells after disease has already been established is therapeutic. In sum, these data shows that T mediates pathogenesis in MPN, and that suppressing T cells in MPN may have therapeutic benefit.
Over-expression of Chitotriosidase Modulates ECM Distribution in Atherosclerotic Plaques of Mice
Authors: Yap Jonathan , Mccurdy Sara , Garo Jan , Irei Jason , Alcala Martin , Kitamoto Shiro , Boisvert William A 
Published: January 2023

Abstract
Macrophage is the predominant cell type in all phases of atherosclerosis and it plays a major role in disease progression. Although mammals have no endogenous chitin, macrophages produce chitotriosidase-1 (CHIT1) as part of the innate immune response in various inflammatory conditions including atherosclerosis. We aimed to investigate mechanisms by which CHIT1 may modulate the progression of atherosclerosis using CHIT1-overexpressing, Ldlr−/− mice, and also to determine whether overexpression of CHIT1 by macrophages affects the morphology of atherosclerotic plaques. We developed an atherosclerosis-prone, conditional CHIT1 over-expressing (CHIT1-OE) mouse model which allowed us to study the effects of macrophage CHIT1 over-expression on morphological characteristics as well as extracellular matrix (ECM) formation in vivo. Further, bone marrow-derived macrophages (BMDM) from CHIT1-OE mice and littermate controls were used to determine the cellular mechanisms of non-enzymatic CHIT1 signaling in vitro. Over-expression of CHIT1 in Ldlr−/− mice after 12 weeks of high-fat diet modulated the ECM by altering the accumulation and localization of hyaluronic acid (HA) and collagen in atherosclerotic plaques observed within the aortic sinus. We also found, in vitro, that macrophage invasiveness was significantly enhanced in BMDM from CHIT1-OE mice upon addition of IL-13 as an immunoregulator. Our findings indicate that CHIT1 over-expression modulates ECM properties in the atherosclerotic plaques of Ldlr−/− mice and macrophage behavior in vitro, which may be atheroprotective and promote plaque stability.