bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pulmonary anti-α-1,3-glucan IgA-secreting B cells are protective against cockroach-induced allergic disease
Authors: Patel Preeyam S , Kearney John F 
Published: January 2023

Abstract
Currently, an estimated 20% of the population worldwide suffers from an allergic disorder. Children born in industrialized countries have a higher risk of acquiring allergies and asthma than those in developing countries. This difference has been attributed to lower exposure to microbial antigens during early life and the consequent lack of stimulation for the developing immune system. We have previously demonstrated that bacteria and allergens can bear similar epitopes. German cockroach allergen and an enteric Enterobacter species isolated from mice bear similarly-recognized α-1,3-glucan epitopes. Neonatal mice have a large frequency of anti-α-1,3-glucan-IgA secreting cells that significantly decrease by 5 weeks of age. Following challenge with cockroach allergen, neonatal, but not adult, mice immunized with α-1,3-glucan-bearing Enterobacter had a significantly decreased frequency of eosinophils and T cells in the pulmonary parenchyma, antigen-specific memory T cells in the mediastinal lymph node, and IgE in the blood compared to mice immunized with α-1,3-glucan-deficient Enterobacter. A unique population of anti-α-1,3-glucan IgA-secreting cells were identified in the lungs of mice immunized with α-1,3-glucan-bearing Enterobacter as neonates, but not in those immunized as adults. IgA-deficient mice immunized with α-1,3-glucan-bearing Enterobacter as neonates were no longer protected against allergic disease development. We suggest that early immunization with α-1,3-glucan selects neonatal anti-α-1,3-glucan-IgA secreting clones for incorporation in to the adult repertoire such that these B cells have the ability to suppress the development of cockroach-induced allergic disease during adult life.
Small size of membrane-tethered ligands regulates kinase-phosphatase segregation in γδ TCR triggering.
Authors: 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 undergo canonical thymic selection, and consequently are not restricted by pMHC antigens or the co-receptors CD4/8. Some of these unconventional T cells recognize invariant membrane-tethered ligands, and their rapid activation and recruitment to sites of inflammation serves as a ‘first line of defense’ against incipient infection. The substantial structural and stoichiometric similarities between αβ and γδ TCRs prompted us to investigate whether γδ TCR ligand-recognition and triggering shared basic physicochemical constraints with conventional αβ TCRs. We chose as a model system the stress-inducible murine surface protein T22 that is recognized by the G8 γδ TCR - for which detailed biophysical and structural information is available. Since T22 is similar in size to pMHC molecules, we tested whether ‘size-based’ kinase-phosphatase segregation, following G8 engagement by T22, controls initiation of TCR signaling. In our ongoing studies, we have established that the small axial size of T22 is critical for G8 triggering. Elongation of the T22 ectodomain leads to failure of TCR phosphorylation and IL-2 responses. Using optical and electron microscopy we show that elongated T22/G8 complexes increases access of inhibitory phosphatases to sites of TCR engagement at cell-cell contacts. We are testing whether truncation of the ectodomain of the large cell surface phosphatases CD45/CD148, which are normally sterically segregated from engaged TCR, affects triggering. Finally, we are adapting these strategies, to investigate mechanisms of triggering by γδ T cells that recognize small-molecule organic compounds.
C-type lectin-like NKC-encoded immunoreceptors NKp80 and NKp65 are selectively expressed by human innate lymphocyte subsets, uniquely signal via hemITAMs and facilitate tissue-specific immunosurveillance via their genetically linked ligands AICL and KACL
Authors: Steinle Alexander Luis , Bauer Björn , Vogler Isabel , Leibelt Stefan 
Published: January 2023

Abstract
NKp80 is an activating C-type lectin-like immunoreceptor (CTLR) on human NK cells. Upon ligation by its cognate ligand ‘activation-induced C-type lectin’ (AICL) up-regulated on PAMP-stimulated myeloid cells and interleukin-experienced NK cells, NKp80 stimulates NK cytotoxicity and cytokine secretion. Unlike other NK receptors, NKp80 uses an atypical cytoplasmic hemITAM for cellular activation. In contrast to “classical” hemITAMs of related myeloid CTLR, we showed that the NKp80 hemITAM does not recruit Syk upon phosphorylation. However, we now provide evidence for specific recruitment of other signaling molecules by NKp80.
Alike its close relative NKp80, NKp65 is a homodimeric CTLR with a cytoplasmic hemITAM and encoded in the Natural Killer Gene Complex (NKC). NKp65 binds with high affinity to its cognate genetically linked ligand KACL almost exclusively expressed by human keratinocytes. We previously showed that NKp65/KACL interaction activates cytotoxicity by NK-92 cells. However, while NKp80 is expressed by virtually all human NK cells, physiological expression of NKp65 remained elusive. Generation of NKp65-specific mAb enabled us to trace NKp65 expression to a minor subset of human innate lymphocytes. Transcriptomics revealed strict correlation between NKp65 expression ILC hallmark genes. Hence, NKp65 expression defines that ILC subset and enables a tissue-specific cross-talk with human keratinocytes. Moreover, we show that NKp80 and NKp65 are mutually exclusive expressed by NK cells and that ILC subset, qualifying NKp80 and NKp65 as markers of these 2 distinct innate lymphocyte lineages and raising questions for their respective subset-associated function.
Hypoxia inducible factor-2α in resting macrophages tempers mitochondrial reactive oxygen species to selectively repress MARCO-dependent phagocytosis.
Authors: Dehn Shirley , Thorp Edward B 
Published: January 2023

Abstract
Hypoxia Inducible Factor α (HIF-α) isoforms promote many key components during wound healing including angiogenesis and glycolytic energy metabolism. In particular, HIF2α is required during proinflammatory cytokine induction within macrophages. However, requirements for HIF2α during inflammation resolution pathways, including signaling during nonphlogistic phagocytosis of apoptotic cells, i.e. efferocytosis, is unclear. While HIF2α was not required for hypoxic efferocytosis, basal HIF2α levels under normoxic conditions in resting bone marrow macrophages were both necessary and sufficient to inhibit the clearance of apoptotic targets, indicating that HIF2α functions as a native suppressor of efferocytosis. A screen of candidate phagocytosis receptors revealed that absence of HIF2α led to selective transcriptional induction of the scavenger receptor MARCO. Antibody blocking or MARCO-deficiency prevented the enhanced engulfment phenotype in HIF2α−/− macrophages. Gene silencing identified the antioxidant NRF2 as the transcription factor responsible for driving elevated MARCO levels. Concordantly, Hif2α−/− phagocytes expressed reduced antioxidants and increased levels of mitochondrial ROS. Inhibition of mROS suppressed NRF2 nuclear translocation, MARCO expression, and efferocytosis. Ex vivo findings were recapitulated in vivo, wherein the enhanced engulfment phenotype was extended to bacterial clearance. Uniquely, HIF2α can act as a phagocytic repressor in resting macrophages in a novel mechanism that maintains cellular quiescence through blockade of a MARCO bacterial response pathway. This implicates HIF2α as a master regulator of cellular oxidative state during macrophage homeostasis.
Characterization of the regulatory functions of lncRNA in Inflammation
Authors: Carpenter Susan 
Published: January 2023

Abstract
The rapid development of deep sequencing technologies has provided us with an unprecedented view of the human genome. One of the most fascinating findings is that less than 3% of the genome codes for protein coding exons, yet more than 85% of the genome is transcribed. Consortium wide efforts such as the ENCODE project and FANTOM are dedicated to the identification of all functional elements present in our genomes. The largest group of RNA produced from the genome is Long noncoding RNA (lncRNA). LncRNA are described as transcripts greater than 200 nucleotides in length that do not code for protein. GENCODE represents the gene set of the ENCODE project and its most recent release GENCODE 24 indicates that there are 15,941 lncRNA present in the human genome. To date there is experimental data available on approximately 1% of known lncRNA. We have developed strategies to enable low to high throughput studies of lncRNA both in vitro and in vivo. In order to study the functions of lncRNA in the inducible inflammatory response we have developed both human and murine NFkB reporter macrophage cell lines. These lines serve as excellent tools for high throughput manipulation of lncRNA, which we are currently testing using whole genome shRNA libraries in addition to CRISPR/Cas9 editing approaches. We know lincRNA-Cox2 is highly inducible following inflammatory stimulation and we have developed a lincRNA-Cox2 transgenic mouse using site-specific TARGATT system and knockout mice using CRISPR/Cas9 technology to study the importance of this lncRNA in host defense against infection. Such approaches provide an efficient workflow for the characterization of any lncRNA in our model system of inflammation.
Human natural killer cell education is dynamically controlled by environmental and cell-intrinsic HLA
Authors: Boudreau Jeanette , Liu Xiao-Rong , Zhao Zeguo , Zhang Aaron , Shultz Leonard D , Greiner Dale L , Dupont Bo , Hsu Katharine C 
Published: January 2023

Abstract
NK cell education is determined by inhibitory KIR and HLA, but how their interactions potentiate reactivity is unknown. Human NK cells derived from CD34+ stem cells transplanted into a novel HLA-B*27:05 transgenic mouse are educated by HLA on both donor human hematopoietic cells and recipient mouse stromal cells. Similarly, NK reactivity in hematopoietic cell transplant patients reflects education by both donor and recipient HLA. Upon transfer to HLA-B*27:05+ mice, mature, uneducated KIR3DL1+ NK cells gain reactive potential, demonstrating that NK cell education can respond to alterations in the HLA available in the local environment. Bone marrow chimera studies reveal that HLA from either hematopoietic or stromal cells is sufficient for this re-education. Strikingly, educated NK cells do not lose reactivity after transfer to HLA-negative mice, implicating a cell-intrinsic contribution of HLA to the maintenance of NK education. We find that HLA knockdown diminishes NK reactivity, and FRET studies reveal that HLA and KIR complex in cis. HLA can be acquired from neighboring cells by trogocytosis, illuminating a mechanism by which ligands can be acquired from trans sources for cis education of NK cells. Altogether, these findings define how KIR and HLA shape NK function and may be applicable in cell therapies to potentiate donor NK reactivity.
The cGAS-STING pathway is present and active in human plasmacytoid dendritic cells
Authors: Deb Pratik , Dai Jihong , Singh Sukhwinder , Fitzgerald-Bocarsly Patricia 
Published: January 2023

Abstract
Plasmacytoid dendritic cells(pDCs) function as sentinels against viral infection in humans by producingabundant amounts of Type-I and Type-III interferons as well as other cytokines. Detection of viral nucleic acids remains the major initiating factor forinterferon and cytokine production in pDCs. Although the Toll-likereceptor-mediated endosomal pathway of nucleic acid detection has been studiedand documented in great detail, detection of cytoplasmic DNA in human pDCsremains, for the most part, unexplored. Recently, a cytoplasmic pathway of DNArecognition and interferon expression has been discovered in the murine systemand certain human cell lines. This pathway is mediated by the cytoplasmicprotein cGAMP synthetase (cGAS), which initiates Type-I interferon productionvia a cyclic dinucleotide called 2′3′ cyclic GMP-AMP (cGAMP), which in turn,activates the endoplasmic reticulum resident protein Stimulator of InterferonGenes (STING) and leads to cytokine expression. Here, for the first time, wedemonstrate the existence of components of the cGAS/STING pathway present inhuman pDCs. Our data indicate that both cGAS and STING are transcribed and translatedin primary human pDCs. We have also confirmed the functionality of the pathwayby inducing cytokine (IFN-α, IFN-λ, TNF-α, IL-6) production through stimulatingpDCs by exogenous cGAMP. Our study suggests that this cGAS-STING-mediatedcytokine response exists in parallel to the TLR9-mediated DNA recognition andimmune activation in human pDCs.
Identifying the interactome of the RIG-I-like Receptor LGP2
Authors: Thompson Ahna B , Stone Amy EL , Gale Michael J 
Published: January 2023

Abstract
RIG-I-like receptors (RLRs) are DEAD box helicases and cytoplasmic pathogen recognition receptors that recognize and bind to nonself/viral RNA and trigger innate antiviral immunity. RLRs are essential for detection of RNA virus infection, and include RIG-I, MDA5, and LGP2. LGP2 has been implicated as RIG-I or MDA5 cofactor to regulate their activity. We conducted a yeast 2 hybrid (Y2H) screen (using LGP2 as bait) of a human hepatic cDNA library to identify protein binding partners of LGP2. Identified proteins were validated as LGP2 interactors through overexpression and co-immunoprecipitation assays of LGP2 binding. The validated proteins were then submitted to a cell-based interferon beta-promoter-luciferase assay model of Sendai virus (SenV) infection as well as a cell based NFkB-luciferase assay of the same system. Endogenous expression of the validated proteins was then assayed through the Huh7 human hepatoma cell line system with various stimuli including viral infection with SenV and Interferon-beta treatment. Through these studies we will define the LGP2 interactome and identify proteins that act as co-factors in RLR signaling.
SLAP negatively regulates FcɛRI receptor-mediated mast cell response in mice
Authors: Sharma Namit , Ernoult Emilie , McGlade Catherine Jane 
Published: January 2023

Abstract
Mast cells (MCs) are key mediators of innate immune response to pathogens and allergens, etiological factors for drugs, dust and peanut-induced anaphylaxis. Degranulation of MCs in response to binding of high affinity FcɛRI receptor (IgE receptor) to allergen-induced IgE results in the release of preformed mediators including histamine, and de novo synthesis of cytokines causing hypersensitivity symptoms including anaphylaxis. Src-like adapter protein (SLAP), has been shown to regulate signaling downstream of T cell receptor (TCR), B cell receptor (BCR) and receptor tyrosine kinases (RTK) including c-Kit, FLT3 and CSF-1 via recruitment of the Cbl ubiquitin ligase. Here, we show that bone marrow-derived mast cells (BMMCs) from SLAP knockout (SLAP KO) mice displayed significantly enhanced degranulation and de novo synthesis of IL-6 but not TNFα compared to wild type (WT) BMMCs. SLAP KO BMMCs also displayed significantly reduced F-actin polymerization upon stimulation of IgE receptor in comparison to WT BMMCs. In addition, SLAP KO BMMCs maintained enhanced cell surface expression of FcɛRI receptor post stimulation suggesting reduced endocytosis/degradation. While WT and SLAP KO mice have equal numbers of MCs in ear skin, SLAP KO mice showed enhanced passive cutaneous anaphylaxis response. Thus, these results suggest that SLAP negatively regulates MC-induced anaphylaxis reaction via IgE-DNP pathway.
ICOS-dependent PI3K signaling in regulatory T cell development and function
Authors: Mittelsteadt Kristen L , Sullivan Jenna M , Campbell Daniel J. 
Published: January 2023

Abstract
Foxp3+ regulatory T cells (TR) are critical for maintaining immune tolerance and preventing inflammatory disease. Given their immunosuppressive capabilities, manipulation of TR function and/or abundance is a promising therapeutic strategy to either augment or inhibit immune responses in the context of disease. A detailed understanding of the key factors that control TR development, homeostasis, and function is essential for the successful application of TR-based therapies. Recent work suggests that inducible T cell costimulator (ICOS) signaling is required for maintenance of effector TR (eTR) cells, which migrate to peripheral sites of inflammation. ICOS ligation is most notably a potent activator of phosphatidylinositol 3-kinase (PI3K), however the key signaling pathways downstream of ICOS that support eTR have not been investigated. In order to study the role of ICOS-dependent PI3K signaling, we obtained mice that carry a knock-in mutation in the Icos gene that alters the cytoplasmic tail motif of the ICOS protein, thereby specifically abolishing ICOS-mediated PI3K activation (IcosY181F mice). The frequency of TR is reduced in these mice, as is the proliferation of ICOShi TR in secondary lymphoid organs. CD4+ IcosY181F cells have impaired regulation of downstream PI3K targets, including p-AKT, p-S6, and CD62L. IcosY181F mice develop more severe disease earlier than WT controls using a model of experimental autoimmune encephalomyelitis and have lower eTR frequencies at effector sites. Taken together, data from our lab suggest an important role for ICOS-mediated PI3K activation in the development, maintenance, and function of TR.
The microtubule-associated protein Lis1 regulates T lymphocyte homeostasis and differentiation
Authors: Ngoi Soo M , Lopez Justine , Chang John T 
Published: January 2023

Abstract
The microtubule-associated protein Lissencephaly 1 (Lis1) is a key regulator of cell division during stem cell renewal and differentiation. We examined the role of Lis1 in T lymphocyte homeostasis and fate diversification in response to microbial infection. T cell-specific deletion of Lis1 resulted in depletion of the peripheral CD4+ and CD8+ T lymphocyte pool, owing to a selective loss of homeostatic, cytokine-induced proliferation. By contrast, cognate antigen-triggered proliferation was relatively unaffected in CD8+ T cells, enabling Lis1-deficient T cells to differentiate into terminal effector cells in response to microbial infection. Strikingly, however, Lis1-deficient CD8+ T cells failed to develop into long-lived memory lymphocytes. Taken together, these findings suggest that Lis1 plays an important role in T cell homeostasis and the generation of memory T lymphocytes.
The impact of hypoxia on metabolic subsets of bone marrow plasma cells.
Authors: Minges Wols Heather A , Aguilera Alexya N. , Witte Pamela L 
Published: January 2023

Abstract
The metabolic stress of being an antibody-secreting cell is likely great. Indeed, existing literature suggests short-lived plasma cells (SLPC) die due to high metabolic stress. How long-lived (LL) PC maintain longevity and escape the same fate as SLPC is unknown. We hypothesized that LLPC in the marrow may adapt to metabolic stress by employing a different strategy such as glycolysis, which may be triggered by the hypoxic nature of the marrow environment. LLPC reside in hypoxic niches, as evidenced by Hypoxyprobe™-1 (PIM)-positivity. Here, we show that PC are divided into two distinct subsets based on fluorescence following MitoTracker Red CM H2Xros staining: a predominant MitoHI subset, suggestive of aerobic respiration, and a rarer MitoLO subset, suggestive of glycolysis. MitoLO PC have higher lactate levels and less NADH than MitoHI PC. Following immunization and boost with TNP-KLH, Ag-specific PC are detected in both subsets at similar frequencies, indicating newly-made PC are filling both compartments equally. Further, comparable amounts of Ig are detected from 24h supernatants of MitoHI and MitoLO PC. As PC are in hypoxic niches, and at least a subset of PC appears to use glycolysis, we also tested the ability of MitoHI and LO PC to survive in hypoxic versus normoxic conditions. Notably, MitoHI and LO PC are comparable in function following 24h culture at 3 or 20% O2, as detected by ELISPOT and ELISA. However, 24h survival may be slightly enhanced in the MitoLO PC. In all, these PC subsets appear to function similarly despite metabolic differences. It is interesting that most LLPC use aerobic respiration while residing in a hypoxic environment; this is in contrast to HSC, which reside in similar hypoxic marrow niches but use glycolysis.
The role of AP-1 family transcription factor networks in regulating Th17 cell identity
Authors: Ciofani Maria , Carr Tiffany 
Published: January 2023

Abstract
CD4 T cells can adopt one of two opposing fates: a helper T cell (Th) specialized in supporting pathogen clearance, or a regulatory T cell (Treg) that attenuates immune responses. IL-17A-producing inflammatory Th17 cells stand out among Th cells, possessing a high level of inherent plasticity in response to altered environments. The underlying mechanisms controlling such flexibility are largely unknown. In this regard, we have identified the AP-1 family of transcription factors (TFs) as key regulators of Th17 cell identity. Our previous work revealed the pioneering role of BATF in supporting global enhancer accessibility and flexibility in CD4 T cells, and here, we describe an antagonistic AP-1 TF, JunB, that limits Th17 plasticity. Indeed, we find that CD4 T cells deficient in JunB exhibit dysregulated effector cytokine and TF expression signatures, and lack disease potential in a mouse model of autoimmunity. In particular, JunB serves to restrain inappropriate Treg and Th1 differentiation. Here, we (i) use fate-mapping reporter mice to dissect the requirement for JunB in maintaining Th17 cell stability, (ii) define the JunB targets that facilitate subset conversion events; (iii) define novel genomic lineage-restriction elements regulated by AP-1 complexes; and (iv) define activating and repressing roles of JunB that support Th17 lineage stability. Such mechanistic insight is key to guiding future work aimed at exploiting the AP-1 balance in Th17 cells to divert damaging inflammatory responses into favorable regulatory responses.
Mutation of the SH3 binding site within the chB6 alloantigen
Authors: Funk Phillip E , Bhattacharya Rohini 
Published: January 2023

Abstract
It is well established that central tolerance of B cells involves the deletion of large numbers of B cell clones. However, the mechanism of this deletion remains unclear. Chickens are one of the classic models of vertebrate immunity and bursa of Fabricius presents model system to study this process. Our lab has been interested in the role of the chB6 alloantigen (formerly called Bu1) in the developing of B cells within the bursa. We have shown that chB6 can trigger apoptosis when stimulated by anti-chB6 antibody and this apoptosis uses intermediates commonly found in death receptor signaling pathways. Recently, chB6 has been found in close proximity to the BCR on DT40 cells. Others have noted that BCR signals in DT40 lead to apoptosis. Homology analysis places chB6 within the larger CD2/SLAM family of proteins based on the presence of two extracellular Ig domains. CD2/SLAM family members serve to modulate signals in immune cells. How chB6 initiates signals, and how those signals might be coordinated with other components of the BCR complex, remains unclear. Previous work indicated a 15 amino acid stretch in the cytoplasmic domain and critical in initiating apoptosis. Within this region is the PXXP motif indicating a binding site for SH3 domain containing proteins. We have mutated the proline codons within this region and transfected these mutated chB6 cDNAs into BK3a cells to test the hypothesis that this SH3 binding site is important in death signaling via chB6. Preliminary evidence suggests that this region is in fact critical in transducing a death signal. This project furthers our efforts to understand the biology of chB6. This work supported by a grant from the DePaul University Research Council.