bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tregs expressing high Tl1a are proinflammatory and do not protect from T cell induced colitis. (CCR5P.204)
Authors: Sidhu Maninder , Shih David , Targan Stephan 
Published: January 2023

Abstract
Patients with Crohn’s disease have increased mucosal expression of TL1A. TL1A co-stimulates T cells and can promote expansion of activated and regulatory T cells. Mice generated with sustained and elevated T cell expression of Tl1a (L-Tg) have increased Foxp3+ Treg cells yet develop worsened ileitis, proximal migration of colitis and intestinal fibrosis. The aim of this study was to investigate the role of Tl1a in the differentiation and function of Tregs.In the L-Tg mice, the CD4+ T cell population was comprised of GFPhigh and GFPlowcells that correlated with the level of Tl1a expression.Foxp3 expression and suppression function was significantly lower in the Tregs expressing high Tl1a. Indeed, addition of high levels of exogenous rTl1a under iTreg differentiation conditions advances the expansion of IL-13 producing effector T cells. The percentage of GFPhigh Foxp3+ Tregs co-expressing GATA3 were significantly higher explaining the possible Th2 polarization of Tregs expressing high Tl1a. Additionally, in the T cell transfer model of colitis, RAG mice cotransferred with GFPlowFoxp3+ Tregs were better protected from inflammation and weight loss compared to mice cotransferred with GFPhighFoxp3+ T cells.These data reveal a novel role for TL1A in regulating T cell mediated immune responses such that the level of Tl1a (high v. low) can differentially influence the expansion of effector and Treg cells leading to either a pro-inflammatory or protective mucosal environment.
Dimeric IL-2 induces necrosis of Interleukin-2 receptor positive cells (CCR6P.217)
Authors: Ganesan Ramya , Arumugam Prakash , Clabaugh Suzanne , Kozak Ashot , Wrenshall Lucile 
Published: January 2023

Abstract
Mice deficient in T regulatory cells (T regs) die from systemic inflammation. Breeding these mice with IL-2KO mice clears inflammation in lungs and skin, suggesting that IL-2 has pro-inflammatory functions beyond promoting survival of T regs. We recently identified a dimeric form of IL2 mammalian tissues that is cytotoxic to cells expressing IL-2 receptor (IL-2R), which provides an explanation for the above. Exposure of IL-2R+ cells to dimeric IL-2 results in rapid release of LDH. We hypothesized that dimer-mediated cell death is consistent with the characteristics of necrosis. To test this hypothesis, we exposed Jurkat cells to dimeric IL-2 and processed them for electron microscopy at 5 minutes. EM revealed swollen nuclear membranes and mitochondria consistent with early necrosis. Exposure of vascular smooth muscle cells (VSMC) to dimeric IL-2 induced 50% loss of cellular ATP at 5 minutes and nearly complete loss at 20 minutes. Using the mitochondrial membrane potential indicator JC-1 in VSMC, nearly all mitochondria lost their MMP by 10 minutes. These data indicate that dimeric IL-2 kills cells by necrosis. Our finding that dimeric IL-2 is cytotoxic to cells expressing IL-2R, lymphoid or non-lymphoid, has implications beyond the immune system. These studies combined with prior studies showing presence of matrix-bound IL-2 in arteries, suggests dimeric IL-2 may contribute to vascular inflammation in processes such as atherosclerosis.
Real time visualization of the differential contribution of medullary thymic epithelial cells versus dendritic cells to central tolerance in the thymus (HEM7P.233)
Authors: Lancaster Jessica , Ehrlich Lauren 
Published: January 2023

Abstract
Tolerance for tissue-restricted antigens (TRAs) is established through interactions of thymocytes with medullary thymic epithelial cells (mTECs) and dendritic cells (DCs) in the thymic medulla, though their relative contributions remain unclear. Previous studies using genetic models to impair antigen presentation by mTECs or DCs showed that either subset could contribute to negative selection; however, because interactions between thymocytes and stromal cells are necessary for maintenance of a differentiated stromal compartment, results from these models may not reflect physiologic contributions of mTECs or DCs. Thus, we adopted a two-photon fluorescence microscopy approach to directly quantify interactions between thymocytes and mTECs or DCs at the outset of negative selection in an intact thymic environment. We find that both mTECs and DCs activate TCR signaling in CD8+ and CD4+ thymocytes in the context of secreted and membrane-bound forms of a negatively selecting TRA. mTECs account for more selection than DCs, regardless of the TRA form, and their contribution is greatest with a membrane-bound TRA. Strikingly, while interactions with mTECs and DCs account for all antigen-driven signaling of CD8+ thymocytes, our data suggest other cells also present TRAs to CD4+ thymocytes. Altogether, we find that mTECs make the most significant contribution to negative selection against Aire-driven TRAs, though DCs also contribute in the context of a physiologic thymic microenvironment.
An ultra-conserved element in Hoxa2 is required for the normal expression of Hoxa3 and normal thymus development (HEM7P.223)
Authors: Condie Brian , Buac Kristina , Mallo Moises 
Published: January 2023

Abstract
We analyzed thymus development in a Hoxa2 mutant mouse (Hoxa21) that carries a deletion of an ultraconserved element in the protein coding sequence of Hoxa2. Our phenotypic analysis revealed that the Hoxa21 mutants exhibit hypoplastic and ectopic thymii. Further analysis demonstrated delayed Foxn1 expression within the developing thymus of the mutants. These phenotypes resemble the alterations in thymus development found in Hoxa3 mutant embryos. Intriguingly, analysis of thymus development in mutants carrying a different Hoxa2 null allele that contains an intact ultraconserved element (Hoxa22) revealed no alteration in thymus development. This findings suggested that the abnormal thymus development seen in the Hoxa21 mutants may be due to alterations in Hoxa3 expression. Consistent with this hypothesis Hoxa21 mutants exhibited greatly reduced Hoxa3 expression in neural crest-derived mesenchyme and pharyngeal endoderm, embryonic cell types required for normal thymus development. In addition analysis of Hoxa21+/- Hoxa3 null/+ compound heterozygotes revealed thymus phenotypes that were very similar to Hoxa3-deficient mutants. These data suggest that Hoxa2, although expressed in thymic primordium, does not play a direct role in thymic organogenesis. Our results suggest that the ultraconserved enhancer element located the first exon of Hoxa2 is necessary for normal Hoxa3 expression in cell types necessary for normal thymus development.
Endothelial cells promote endogenous thymic regeneration via BMP4 signaling and activation of Foxn1 (HEM7P.224)
Authors: Dudakov Jarrod , Wertheimer Tobias , Velardi Enrico , Brede Christian , Young Lauren , Ginsberg Michael , Nolan Daniel , Beilhack Andreas , Rafii Shahin , Butler Jason , Van Den Brink Marcel 
Published: January 2023

Abstract
Although the thymus has a remarkable capacity for repair following damage, the mechanisms underlying this endogenous regeneration remain poorly understood. Here we reveal a critical role for endothelial cells (ECs) in aiding thymic recovery following acute injury. We found that ECs represent a highly damage-resistant niche in the thymus and, moreover, rather than just being passive conduits that deliver oxygen and nutrients, ECs are active participants in organ function producing distinct paracrine factors that orchestrate tissue repair. In particular, we demonstrated that after damage ECs induce upregulation by cortical thymic epithelial cells (TECs) of Foxn1, a key transcription factor implicated in TEC development and thymic regeneration. Further investigation revealed that the mechanism by which ECs induced upregulation of Foxn1 was via a soluble factor that could be inhibited by Noggin, strongly suggesting the involvement of BMP signaling. Consistent with this, ECs were found to be potent producers of BMP4 after thymic damage and inhibition of BMP4 signals by ECs, achieved either pharmacologically or genetically, led to significantly worse thymic recovery after acute injury caused by TBI. These findings not only provide the first evidence of the role of ECs in endogenous thymic regeneration but, given the significant clinical need for strategies to promote immunity, also offer an innovative therapy to boost thymic function.
Transcriptional landscape of immune responses to naturally acquired influenza (HUM6P.248)
Authors: Allen E. , Ohlson Maikke , Finkelstein David , Rosenberger Carrie , Thomas Paul 
Published: January 2023

Abstract
Several human population studies have sought to determine what components of the immune system confer protection to influenza infection. The aim of our study was to detect transcriptional changes contributing to the illness outcome in patients with naturally acquired influenza infection. Patients with naturally acquired influenza infection were recruited into a five year prospective, longitudinal cohort. Whole blood was sampled at day of enrollment (Day 0) and Days 3, 7, 10, and 28. Additionally, clinical data was collected during the course of infection including symptoms (upper respiratory, lower respiratory, systemic, and gastrointestinal symptoms). RNA was extracted from PBMCs collected at Day 0 in a subset of influenza infected patients (N=45) and was analyzed by RNA-Seq. Genes were ranked using Median Absolute Deviation (MAD) and then hierarchical clustering analysis was conducted using Spotfire and WGCNA. We detected two distinct clusters of individuals with large differences in their transcriptional landscapes falling into four clusters of genes. Principal components analysis was unable to define the clusters using any clinical traits including age, race, gender, and illness severity. One of the four clusters was characterized as an interferon response, where the other clusters have more complex annotations. Ongoing analyses are exploring upstream mechanisms that might lead to the observed divergent transcriptional outcomes.
Acute Epstein Barr virus-induced infectious mononucleosis leads to expansion of highly diverse CD8 T cell repertoires crossreactive with influenza A (HUM6P.249)
Authors: Gil Anna , Aslan Nuray , Mishra Rabi , Selin Liisa 
Published: January 2023

Abstract
The competence of T cell responses predominantly depends on how efficient T cell receptors (TCRs) are at recognizing antigenic epitopes. We show here that during acute infectious mononucleosis (IM) there was an expansion of IAV-M1-specific memory cells that are crossreactive with both EBV-BMLF1 and EBV-BRLF1 double-tetramer+ cells directly ex-vivo in HLA-A2+ patients. These crossreactive populations expanded dramatically in culture. For instance, there were multiple crossreactive populations in the IAV-M1 stimulated line. We systematically examined the characteristics of these crossreactive populations and compared them to the cognate IAV-M1, EBV-BMLF and -BRLF1 populations using TCR deep sequencing and gene array analysis of tetramer sorted cells. Surprisingly, both crossreactive and non-crossreactive populations were highly polyclonal with 1500-3500 different VA and VB clonotypes. The dominant clonotypes differed between the different populations. However, there were overlaps in either VB or VA usage consistent with their ability to bind both ligands. In one patient the M1-specific response used was an unusual dominant VB and was identical with the BMLF1-specific VB (VB2J2.7) but they differed in VA with M1 using VA13J50.1 and BMLF1 VA 12.1J12.1. Immune response signatures from gene array differed between the crossreactive and non-crossreactive populations consistent with the concept that crossreactive TCR selection may play a role in disease outcome. (NIHAI49320).
MicroRNA-21 drives severe, steroid-insensitive experimental asthma by amplifying PI3K-mediated suppression of HDAC2 (HYP7P.262)
Authors: Hansbro Philip , Kim Richard , Pinkerton James , Starkey Malcolm , Essilfie Ama-Tawiah , Mayall Jemma , Jones Bernadette , Haw Tatt , Keely Simon , Mattes Joerg , Adcock Ian , Foster Paul , Horvat Jay 
Published: January 2023

Abstract
BACKGROUND: Severe, steroid-insensitive (SSI) asthma is a substantial clinical problem. Effective treatments are urgently required, however, their development is hampered by a lack of understanding of the mechanisms that promote disease. SSI asthma is associated with respiratory infections and non-eosinophilic endotypes of disease, including neutrophilic asthma. OBJECTIVES: To develop and use mouse models of SSI neutrophilic asthma to investigate pathogenic mechanisms involving microRNA (miR)-21, phosphoinositide-3-kinase (PI3K) and histone deacetylase (HDAC)2 in order to identify new therapeutic approaches. METHODS: Novel mouse models of respiratory infection and ovalbumin-induced, SSI neutrophilic allergic airway disease (SSIAAD) in BALB/c mice were developed. The roles of infection-induced miR-21 expression and PI3K-dependent signalling in the lung were examined using a specific miR-21 inhibitor (antagomir-21) and the pan-PI3K inhibitor LY294002. RESULTS: Infection induced a miR-21-dependent, PI3K-mediated signalling pathway that decreased nuclear HDAC2 levels and promoted steroid-insensitive neutrophilic inflammation and airway hyper-responsiveness (AHR) in AAD. Inhibition of miR-21 or PI3K suppressed nuclear pAkt levels and restored HDAC2 levels and steroid sensitivity. CONCLUSIONS: We have identified a novel role for a miR-21/PI3K/HDAC2 signalling axis in SSIAAD. Our data highlights miR-21 as a novel target for treating this form of asthma.
Characterization of peanut-reactive monoclonal antibodies (HYP7P.265)
Authors: Little Christopher 
Published: January 2023

Abstract
Peanut allergies are a rising concern in Western society. Incidence and prevalence of affected children has tripled from 1997 to 2010. The exact cause for this increase is unknown, but lack of exposure to pathogens and increasing hygienic conditions has been implicated. Exposure to peanuts causes the immune system to become sensitized to peanut proteins. Subsequent exposure to peanuts causes hypersensitivity reactions which may escalate to anaphylaxis and death. The only course of prevention is complete avoidance. Limiting peanut exposure is difficult as even trace amounts of peanut (100µg-50mg; 1 peanut ≈ 1g) consumed can cause a reaction. Immunotherapies aim to increase the tolerance of these severely allergic individuals. Current approaches are limited to certain populations and are potentially dangerous. Better therapeutics require thorough characterization of peanut proteins responsible for peanut allergies. In this study, C3H/HeJ mice were sensitized to crude peanut extract (CPE). The mice were then exposed to CPE to induce a hypersensitive reaction. Hybridomas were generated , characterized for antibody production, subtype, and screened for peanut-specific immunoreactivity, as well as specific peanut proteins believed to be involved with peanut allergies. Characterization of peanut-specific monoclonal antibodies (MAb) may aid in the identification of immunodominant epitopes and lead to/aid in the development of immunotherapeutic interventions.
The transcriptional co-factor PARP14 limits severity of allergic skin inflammation (HYP7P.274)
Authors: Krishnamurthy Purna , Serezani Ana , Kaplan Mark 
Published: January 2023

Abstract
Atopic dermatitis (AD) is a chronic relapsing inflammatory condition of the skin that is characterized by pruritic skin lesions, erythema, and swelling, resulting in an impaired skin barrier. Patients with AD and mice subjected to models of AD develop an inflammatory T helper 2 (Th2) immune response and reduced expression of epidermal differentiation complex (EDC) genes, which encode proteins needed for keratinocyte maturation and barrier integrity. To identify potential therapeutic targets, we are exploring the molecular controls regulating Th2 cells and keratinocytes in a mouse model of AD. Poly-ADP ribose polymerse-14 (PARP14) is a transcription co-factor that enhances Th2 differentiation. Correspondingly, PARP14-deficient mice have reduced lung inflammation in a model of allergic airway disease; however, its potential role in AD has not been explored. Surprisingly, PARP14 deficiency resulted in an increase in the severity and number of skin lesions in an experimental mouse model of AD. Disease severity corresponded with increases in Th2 cytokine secretion and antibody production (IgE, IgG1). PARP14 deficiency resulted in altered EDC gene expression in the skin. Thus, PARP14 serves conflicting roles in allergic disease: promoting pathogenic Th2 immune responses while potentially limiting inflammatory responses during skin inflammation.
Oncostatin M promotes epithelial barrier dysfunction and is elevated in eosinophilic mucosal disease (HYP7P.255)
Authors: Pothoven Kathryn , Norton James , Suh Lydia , Carter Roderick , Hulse Kathryn , Liu Mark , Gonsalves Nirmala , Peters Anju , Harris Kathleen , Shintani Smith Stephanie , Conley David , Grammer Leslie , Kato Atsushi , Kern Robert , Bryce Paul , Tan Bruce , Schleimer Robert 
Published: January 2023

Abstract
Epithelial barrier dysfunction is thought to play a role in many mucosal diseases including asthma, chronic rhinosinusitis (CRS), and eosinophilic esophagitis (EoE). Oncostatin M (OSM), was elevated in both mRNA (28.3 fold, p&lt;.01, n=12) and protein (4.4 fold, p&lt;.05, n=12-19) in the nasal polyps of CRS patients compared to control tissue. OSM protein was also elevated in bronchoalveolar lavage (BAL) of allergic asthma (AA) patients following segmental allergen challenge (SAC) vs. saline challenge (14 fold, p&lt;.0001). Additionally, OSM mRNA was elevated in esophageal biopsies of EoE patients vs. controls, (3 fold, p&lt;.01). OSM stimulation of differentiated airway epithelium induced barrier dysfunction, as measured by decreased transepithelial electrical resistance (63% reduction, p&lt;.0001, n=11) and increased permeability to 10kD dextran (2.45 fold, p&lt;.05, n=5). Staining for the tight junction protein, occludin showed that OSM stimulation of differentiated airway epithelium impaired the organization of the tight junctions compared to unstimulated controls (n=5). Levels of OSM protein in tissue lysates from CRS and controls correlated with levels of α2-macroglobulin, a marker of epithelial leak, in matched nasal secretions (r=.5055, p&lt;.01). Additionally, OSM in the BAL following SAC in AA patients correlated with serum albumin, another marker of epithelial leak (r=.8062, p&lt;.001). These results suggest that OSM may play a role in epithelial barrier dysfunction in mucosal disease.
Repeated challenge with the hapten oxazolone provokes persistent vulvar mechanical sensitivity and labiar T cell changes in previously sensitized ND4 mice (HYP7P.258)
Authors: Chatterjea Devavani , Benck Charles , Mengistu Hanna 
Published: January 2023

Abstract
Epidemiological evidence suggests a link between environmental allergies and the risk of developing vulvodynia—a chronic provoked vulvar pain condition affecting up to 8-16% of 18-60 year old women. We have previously shown that acute labiar exposure to the hapten allergen oxazolone provokes increased vulvar mechanical sensitivity in ND4 Swiss mice. Here, we show that repeated oxazolone challenge produces persistent vulvar mechanical sensitivity in sensitized mice for at least12 days after final allergen exposure. T cell amplification in the draining iliac lymph nodes resolves within 5 days after final challenge. Persistent sensitivity in the skin is accompanied by sustained changes in skin T cells; CD44+ CD8 and CD4 subsets remain elevated, T cell transcription factors T-bet and FoxP3 continue to be upregulated for up to 17 days after 10 allergen challenges. This is the first characterization of immune infiltrate accompanying sustained allergen-provoked mechanical sensitivity that persists after the resolution of overt inflammatory events following repeated allergen exposures. Our findings can be used to used to elucidate the underlying etiology of allergy-driven subsets of chronic pain conditions.
Novel insights into Th17 mediated airway inflammation (HYP7P.259)
Authors: Koralov Sergei , Fogli Laura , Fanok Melania , Durbin Joan , Cadwell Ken , Bajwa Sofia , Rajewsky Klaus , goel swati , Sundrud Mark , Segal Leopoldo 
Published: January 2023

Abstract
Th17 cells are a proinflammatory subset of effector T cells that have been implicated in the pathogenesis of asthma. Yet the direct impact of IL-17 and IL-22 on the lung epithelium remains to be fully elucidated. We took advantage of conditional gene targeting to generate a novel animal model of spontaneous Th17-driven lung inflammation that exhibits many similarities to neutrophilic asthma in humans. We have found that STAT3 hyperactivity in T lymphocytes causes an expansion of Th17 cells, which home preferentially to the lungs. We demonstrate that IL-17 secretion then leads to neutrophil infiltration and lung epithelial changes, in turn leading to a chronic inflammatory state with increased mucus production and decreased lung function. We used this model to investigate the effects of IL-17 and IL-22 activity on airway epithelium transcriptional program and identified several important changes that contribute to neutrophil recruitment. The neutralization of IL-17 and IL-22 greatly ameliorates airway inflammation and improves lung function, underscoring a key role of these two cytokines in promoting chronic airway inflammation. We believe this novel mouse model will be highly valuable for the development of novel therapies targeting Th17 cells in steroid resistant asthma and COPD. We are now taking advantage of this animal model to explore the role of T cell receptor specificity and antigen (microbial and enviromental) to Th17 mediated airway inflammation.
Tpl2 is required for neutrophil antimicrobial functions (INC6P.311)
Authors: Elmore Jessica , Acuff Nicole , Kuriakose Teneema , Rada Balazs , Watford Wendy 
Published: January 2023

Abstract
Tumor progression locus 2 (Tpl2) is a serine/threonine kinase that promotes inflammatory cytokine production by activating the MEK/ERK pathway. Tpl2 has been shown to be important for the antimicrobial properties of macrophages. However, there is relatively little known about Tpl2’s contribution to neutrophil effector functions. This is an important consideration, since neutrophils provide the first line of defense against infection in the innate immune system. Gene expression analysis revealed that Tpl2 is highly expressed in both human and murine neutrophils, suggesting a potential function role for Tpl2 within this lineage. Despite a significantly higher proportion of bone marrow neutrophils in Tpl2-/- mice compared to wild type mice, Tpl2-/- mice had a significantly lower proportion of circulating neutrophils. In response to infection, neutrophils secrete inflammatory cytokines and produce reactive oxygen species (ROS). Tpl2 ablation impaired neutrophil TNF production in response to LPS stimulation and superoxide generation in response to fMLP, a chemotactic peptide. These results implicate Tpl2 in the regulation of multiple neutrophil antimicrobial pathways, including inflammatory cytokine secretion and oxidative burst. These studies suggest that Tpl2 functions very early during infection to bolster neutrophil-mediated innate immunity against extracellular bacteria, and current studies are evaluating the regulation of neutrophil-mediated bacterial killing by Tpl2.