bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural analysis of epitopes recognized by two anti-CϵmX mAbs reveals intrinsic disorder of the CϵmX domain (P6002)
Authors: Chu Hsing-Mao , Wright Jon , Chan Yueh-Hsuan , Wu Pheidias C. , Lim Carmay , Chang Tse Wen 
Published: January 2023

Abstract
In human membrane-bound IgE (mIgE), a CϵmX domain containing 52 aa residues is located between the CH4 domain and the C-terminal membrane-anchoring segment. Antibodies specific for CϵmX, which can cause lysis of mIgE+ B cells, are being developed to treat allergic diseases and an anti-CϵmX mAb h47H4 is in phase IIb clinical trials. Hence, structural characterization of CϵmX free and complexed with anti-CϵmX mAb is of wide interest and importance. We have solved the crystal structures of (i) free CϵmX fused to IgG1-Fc and (ii) part of CϵmX complexed with an anti-CϵmX mAb, h4B12-Fab, at 1.94 Å resolution. The crystal structure of the IgG1-Fc•CϵmX fusion protein of homodimer exhibits a lack of well-defined electron density for residues 10 to 52 of A subunit and in absence of B subunit in dimeric CϵmX domain. The first 33 residues are also predicted to be intrinsically disordered. The 3D complex structure and epitope mapping by ELISA showed that the anti-CϵmX mAb, h4B12, binds to GLAGGSAQSQRAPDR, which has been reported to bind another anti-CϵmX mAb, h47H4, except for the first 6 residues (in italics). Comparison of the 3-D complex structure of h4B12 and h47H4 revealed different conformations of AQSQRAPDR, a feature characteristic of the intrinsically disordered regions in the CϵmX domain. This is the first report showing that the drug target, CϵmX, contains an intrinsically disordered region that can switch to different conformations upon binding to different anti-CϵmX mAbs.
T cell dependent induction of novel mast cell-lineage cells in spleen (P6006)
Authors: Toyoshima Shota , Abe Ryo 
Published: January 2023

Abstract
Mast cells and basophil are known to exert a variety of functions in normal as well as pathological immune responses. Although mutual dependencies between mast cell lineage cells (MCs) and T cells have been recently well documented, how antigen-specific T cell responses leads to differentiate MCs and to MCs-dependent immune responses is not fully understood. When we attempted to generate antigen-specific T cell lines from OVA and KLH immunized mice by repeatedly stimulating their spleen cells or lymph node (LN) cells in vitro, we observed dominant expansion of FcϵR1 and c-kit positive cells in spleen cell culture, not in LN cell culture. Although this surface phenotype has been classified as that of MC, toluidine blue staining and electron microscopic analysis demonstrated that granules found in these cells appeared more like those seen in classic basophils rather than MCs. The functions of these cells were equivalent to those of classical MCs or basophils such as β-hexomidase release in vitro and PCA reaction in vivo. Consistently, expression pattern of MCPs revealed mixed phenotypes of MCs and basophils. These cells produced IFN-γ when they were co-cultured with antigen specific T cells in the presence of relevant antigen, which occurred in mast cell-T cell contact manner. These results suggested the existence of unique mast cell lineage in spleen contributing T cell dependent immune responses. Roles of these cells in vivo are currently under investigation.
Cardif regulates mouse natural killer cell development and maturation. (P1454)
Authors: Haynes LaTeira , Hedrick Catherine 
Published: January 2023

Abstract
Cardif, also known as IPS-1, VISA and, MAVS, is an intracellular adaptor protein that functions downstream of the RIG-I family of pattern recognition receptors. Cardif is required for the production of type I-IFNs and other inflammatory cytokines after RIG-I like receptors recognize intracellular antigenic RNA. Studies have recently shown that Cardif may have other roles in the immune system in addition to its role in viral immunity. In our study, we find that the absence of Cardif hinders normal natural killer cell development and maturation. Cardif-/- mice have a 35% loss of stage 5 mature NK cells in the periphery. There are also fewer pre-NK cells in the bone marrow of Cardif-/- mice. However, Cardif-/- NK cells produce more IFNg upon stimulation. Mixed chimeric mice revealed that the retarded progression from early NK cell progenitors to pre-NK cells is a cell-intrinsic mechanism. In addition, Cardif-/- NK cells are at a competitive disadvantage in the periphery of chimeric mice. Our results reveal a novel role for Cardif signaling in the development and maturation of NK cells.
The impact of short CYLD in medullary thymic epithelial cell development (P1425)
Authors: Reissig Sonja , Hövelmeyer Nadine , Riemann Marc , Weih Debra , Weih Falk , Waisman Ari 
Published: January 2023

Abstract
CYLD is a deubiquitinating enzyme and acts as a negative regulator of NF-κB signaling. To analyse the function of CYLD in vivo we used CYLDex7/8 mice, which are characterized by loss of the full-length transcript and overexpression of a short splice variant of cyld (sCYLD). In these mice thymic and peripheral CD4 and CD8 T cells were reduced compared to controls. Hence, we were interested to investigate the contribution of CYLD in positive and negative selection in the thymus in vivo. For this purpose we crossed the HY-TCR transgene (HYtg) to CYLDex7/8 mice. The analysis of CYLDex7/8 HYtg males revealed an increase in CD4+CD8+ DP as well as in CD8 SP thymocytes, suggesting a less pronounced negative selection in CYLD mutant mice compared to HYtg control mice. Since medullary thymic epithelial cells (mTECs) play an essential role in the negative selection process of thymocytes, the levels of mTECs in the medullary compartment were examined by histology and FACS analysis. We observed reduced numbers of mTECs, combined with decreased expression levels of the mTEC markers UEA-1, keratin-5, claudin-3 and claudin-4. Interestingly, specifically immature mTECs were significantly reduced compared to controls, suggesting a developmental block in the transition of immature to mature mTECs. Taken together, these results display a crucial role of sCYLD in the development and maturation of mTECs.
The role of commensal microbiota in the formation and maintenance of antigen-specific memory CD4 T cells (P3174)
Authors: Spasova Darina , Surh Charles 
Published: January 2023

Abstract
The mammalian intestinal mucosa harbors over one trillion microbes, predominantly comprised of bacterial species, which easily surpass the number of host cells. Given this large number and the possible threat of opportunistic infections, the host immune system constantly monitors the epithelial mucosal barriers and regulates microbial interactions at these surfaces. This crosstalk and mutualism established between host and microbe has been heavily researched in recent years. The main efforts have focused on identifying the gut’s role in the formation of a functional immune system, whereas little light has been shed on the specific role of gut bacteria on T cell responses and memory to systemic and local pathogens. Here, we interrogate the role of gut flora on CD4 T cell responses to pathogens by comparing germ-free and specific-pathogen-free mice during systemic (acute LCMV) or localized (oral Listeria monocytogenes) infection as models pathogens. Our results indicate a marked difference between T cell responses in germ-free and specific pathogen free mice, suggesting a role for commensal bacteria not just in shaping the immune system but also in preparing it to respond with effector cells and later sustaining memory cells.
High fat diet-induced obesity affects CD4+ T cell differentiation in the small intestine (P3176)
Authors: Hong Chun Pyo , Yang Bo Gie , Kim Jung-Hwan , Jang Min Seong , Lee Eun-Jung , Jeun Eun Ji , Kim Chan , Seoh Ju-Young , Jang Myoung Ho 
Published: January 2023

Abstract
Obesity-induced metabolic diseases are caused by the excess infiltration of pro-inflammatory cells to metabolic tissues including adipose and liver. However, systematic understanding of correlation between obesity and alterations of gut immunity is unclear. We hypothesized that immune cells in small intestine may be affected substantially upon high-fat feeding since dietary lipids are absorbed at luminal surface of small intestine. Here we found that small intestinal CD4+ and CD8+ T cells but not B cells were decreased in obese state. In CD4+ T cell subsets, the proportion of TH1 cells was increased in obese state, whereas the proportion of TH17 cells was decreased. The regulation of Intestinal T cells is dependent on antigen presenting cells such as macrophages and dendritic cells. We found intestinal macrophage subsets but not dendritic cells were changed in obese state. We next investigated that which antigen presenting cells from small intestine control CD4+ T cell differentiation during obese state ex vivo. We found that two macrophage subsets control balance of TH1 and TH17 cells inversely. These results show that small intestinal macrophages can have a key role in modulating small intestinal CD4+ T cell differentiation during obesity.
Initiation of food allergy by a CD4+ T cell-intrinsic IL-4 program, controlled by OX40L (P6204)
Authors: Chu Derek , Mohammed-Ali Zahraa , Walker Tina , Goncharova Susanna , Llop-Guevara Alba , Barra Nicole , Gillgrass Amy , Ashkar Ali , Bramson Jonathan , Humbles Alison , Kolbeck Roland , Waserman Susan , Jordana Manel 
Published: January 2023

Abstract
Intestinal Th2 immunity in food allergy results in the production of IgG1 and IgE, and upon antigen challenge, anaphylaxis and eosinophilic inflammation. Although allergic sensitization critically requires IL-4 to develop, the source and control of IL-4 during the initiation of Th2 immunity remains unclear. Non-intestinal and non-food allergy systems have suggested a role for innate lymphocytes such as NKT or γδ T cells as a rapid source of IL-4 required to induce Th2 polarization. In contrast, we show here that NKT-deficient IL-15 KO, β2m KO and anti-NK1.1 treated mice have completely intact Th2 food allergic responses comparable to NKT-sufficient mice, including antigen-specific IgG1 and IgE, anaphylaxis, eosinophilic inflammation and cytokine production. Likewise, γδ T cell-deficient TCRδ KO mice mount comparable Th2 immune responses to oral antigen as their WT counterparts. By restricting IL-4 expression to only CD4+ Th cells, we find that IL-4 from CD4+ Th cells themselves induce food allergy. Further, IL-4 reporter mice show that CD4+ Th cell production of IL-4 in vivo is dependent on OX40L, a costimulatory molecule that we have shown to be highly expressed on allergen-exposed dendritic cells (DCs). Although NKT and γδ T cells express IL-4, this is not upregulated after allergen priming. Together, these data show that intestinal Th2 immunity in food allergy is initiated by a CD4+ Th cell-intrinsic IL-4 program that is controlled by DC-OX40L and not NKT or γδ T cells.
T cell activation is attenuated in transgenic mice rich in omega-3 fatty acids (P6227)
Authors: Jang Hyun-Young , Song Mi-Young , Lee Sang-Myeong , Park Byung-Hyun 
Published: January 2023

Abstract
Cytokines such as interleukin (IL)-4, IL-5 and IL-13 mainly produced by CD4+ type 2 helper T lymphocytes (Th2 cells) have an important role in pathophysiology of allergic airway inflammation. Therefore, modulation of Th2 cells may offer a novel therapeutic approach to control allergic asthma. It has been suggested that n-3 PUFA can be used as preventive or therapeutic strategy to control allergic asthma. However, mechanisms by which n-3 PUFA modulates this disease are not fully understood. Here, the effects of elevated n-3 PUFA on OVA-induced airway inflammation were investigated using Fat-1 transgenic mice which can convert n-6 PUFA to n-3 PUFA endogenously. First, this study tested whether Fat-1 expression modulates CD4+ T cell activation, proliferation, and differentiation in vitro and found that Fat-1 expression attenuated all of these CD4+ T cell responses. When Fat-1 mice were sensitized and challenged with OVA, these mice showed significantly reduced inflammatory cell recruitment into airway, lower levels of Th2 cytokines, mucin production and eotaxin in brochoalveolar lavage (BAL) and lung tissues. OVA-specific IgE were also significantly lower in Fat-1 mice. Furthermore, suppressed CD4+ T cell activation and differentiation were also observed in Fat-1 mice. Taken together, these results demonstrate that elevated n-3 PUFA play a protective role in airway inflammation by modulating CD4+ T cell activation and differentiation in Fat-1 mice.
Is the α2M/LRP-1 axis integral to the allergenicity of proteases? (P6220)
Authors: Downey Jordan , McAlees Jaclyn , Flick Leah , Herz Joachim , Wills-Karp Marsha , Karp Christopher 
Published: January 2023

Abstract
Allergic diseases are increasingly prevalent in Westernized environments. Recent data indicate that the molecular substrates of allergenicity are a function of direct interactions with pathways of innate immune activation that evolved to sense microbial infection. After lipid-binding proteins exemplified by Der p 2, proteases represent the next most common class of allergens. The relevant mechanisms by which proteases lead to innate immune activation remain under-defined. α2-macroglobulin (α2M) is a plasma protein that inhibits extracellular proteases, targeting them for internalization by LDL receptor-related protein 1 (LRP1). In antigen presenting cells (APC), LRP1 directs α2M-associated proteins for antigen presentation. We hypothesized that protease adjuvanticity and allergenicity result from interactions with α2M and LRP1. Thus, we intratracheally challenged mice with papain, an occupational allergen and cysteine protease. In C57Bl/6 mice, this induced eosinophil and lymphocyte recruitment to the lung and increases in total and papain-specific IgE. While α2M-deficient mice exhibited no defects in the generation of allergic responses to papain, deletion of LRP-1 on APCs resulted in increased allergic inflammatory responses after challenge. These data suggest a role for α2M/LRP-1 in the clearance of protease allergens and suppression of excessive immune activation.
Pulmonary surfactant protein A increases IL-4-induced rat alveolar macrophages’ alternative activation (P1314)
Authors: M. Minutti Carlos , García-Fojeda Belén , Casals Cristina 
Published: January 2023

Abstract
It is well established that IL-4 induces alternative activation of macrophages involving intracellular activation of STAT6. Furthermore, it has been suggested that this cytokine has a proliferative effect on macrophages. On the other hand, there is evidence that pulmonary surfactant protein A (SP-A) plays an important role in modulating inflammatory response of alveolar macrophages (aMϕ). However, little is known about the effect of SP-A on the alternative activation of aMϕ. The aim of this study was to determine the effect of SP-A on aMϕ stimulated with IL-4. To accomplish this, purified rat aMϕ were stimulated with IL-4, different doses of SP-A, and combinations thereof. We measured arginase activity, cell viability, and STAT6 phosphorylation. We found that SP-A increased both IL-4-induced arginase activity and STAT6 phosphorylation. Finally, we observed more viable aMϕ in the presence of IL-4 and SP-A. We conclude that SP-A has a synergistic effect with IL-4 to lead aMϕ to an alternative activation. Furthermore, SP-A together with IL-4 may have either the protective effect of preventing aMϕ death or may cause cellular proliferation. Ongoing studies will allow us to discover the mechanism by which SP-A modulates the effect of IL-4 in aMϕ and determine if SP-A together with IL-4 causes either aMϕ survival or proliferation.
Regulatory T cell dysfunction in lipocalin 2 knockout mice exacerbates serum-induced arthritis (P1326)
Authors: Shashidharamurthy Rangaiah , Bozeman Erica , Aitken Jesse , Selvaraj Periasamy , Vijay-Kumar Matam 
Published: January 2023

Abstract
Lipocalin 2 (Lcn2), a 25KDa innate immune protein, known to be dramatically up regulated in various inflammatory disorders including antibody-mediated arthritis, yet its biological role remains unclear. More recently our studies have suggested that the regulation might be necessary for the initiation and further resolution of inflammatory process. However, the exact mechanism involved in this process is still unknown. In this study, we report that Lcn2 is up regulated up to 5 fold during the course of serum-induced arthritis (SIA) in wild type (WT) mice. Likewise, Lcn2KO mice suffered a severe arthritic disease with elevated systemic proinflammatory cytokines as compared to their WT littermates. Immunological analysis revealed a considerable increase in granulocytic population (Gr1+, CD11b+, CD11c+), and a significant decrease (4.2 fold) in regulatory T cell (CD4+, CD25+ and FoxP3+) population in Lcn2KO arthritic mice as compared to their WT littermates. Accordingly, Lcn2KO mice exhibited a defect in T cell proliferation as compared to their WT counterparts, suggesting a novel role for Lcn2 in splenocyte proliferation and T-reg expansion. Collectively, our data suggests a crucial role of Lcn2 in resolution of arthritic inflammation via T-reg expansion, making it a promising target in designing better therapeutic strategies for the treatment of rheumatoid arthritis.
CS1 (CRACC, CD319, SLAMF7) inhibits production of proinflammatory cytokines by activated monocytes (P1335)
Authors: Mathew Stephen , Kim Jongrok , Mathew Porunelloor 
Published: January 2023

Abstract
CS1 (CRACC, CD319, SLAMF7) is a member of the Signaling Lymphocyte Activation Molecule family expressed on immune cells mediating host defense. CS1 is a self-ligand and has both activating and inhibitory functions in Natural Killer (NK) cells. However, induction and function of CS1 in human monocytes are currently unknown. The purpose of this study was to evaluate the control of CS1 surface expression in activated monocytes and to assess the effect of CS1 triggering on proinflammatory cytokine production to better understand the role of CS1 in the control of monocyte function. Our study revealed that adherent or LPS-activated monocytes express CS1, and CS1 induction is via NF-κB and PI3K signaling pathways. Importantly, CS1 engagement resulted in reduced production of proinflammatory cytokines TNF-α and IL12p70. Our study implicates that CS1 plays an inhibitory role in human monocytes to control proinflammatory immune responses.
Hepcidin is cytotoxic to myeloma cells (P1337)
Authors: Conrad David , Power Coombs Melanie , Hilchie Ashley , Zemlak Tyler , Doucette Carolyn , Hoskin David , Liwski Robert 
Published: January 2023

Abstract
Recent studies suggest that some cationic antimicrobial peptides (CAPs) contribute to innate anticancer immunity. Hepcidin is a CAP and acute phase reactant well known for its antibacterial properties and its role in iron homeostasis. No anticancer function has yet been assigned to hepcidin, although elevated hepcidin levels are found in patients with hematologic malignancies, including plasma cell myeloma. We therefore investigated the anticancer properties of hepcidin against myeloma cells in vitro. A hepcidin isoform lacking the iron-regulatory domain was used. Hepcidin toxicity was assessed by MTT survival assays and DNA fragmentation tests. Propidium iodide (PI) staining was used to measure plasma membrane damage, and scanning electron microscopy (SEM) was performed to visualize cellular membrane changes. Hepcidin impaired the survival of mouse and human myeloma cells and induced DNA fragmentation, suggesting that cytotoxicity may be due to apoptosis. Hepcidin caused substantial PI uptake in the myeloma cells, and SEM confirmed that hepcidin treatment resulted in cellular membrane pore formation. Interestingly, hepcidin was more toxic to melphalan-resistant myeloma cells than to melphalan-sensitive controls. Our data implicate a role for hepcidin in innate immunity against plasma cell myeloma. Further studies on the anticancer properties of hepcidin are warranted in order to fully understand its physiological role in the context of neoplastic disease.
The functional role of PAI-2 in IL-1β production (P1345)
Authors: Hsu Li-Chung , Chuang Shih-Yi 
Published: January 2023

Abstract
Sepsis caused by uncontrolled inflammation is the leading cause of death in intensive care units today, but no effective therapeutic medication is available currently. During microbial infections, pathogen-associated molecular patterns (PAMPs) are recognized by the host innate immune system, which then mounts a defensive response. Myeloid cells play central roles in PAMP recognition. Recent studies indicate that a novel system termed the inflammasome carries out processing of cytoplasmic stored pro-IL-1β, and pro-IL-18. Both IL-1β and IL-18 are highly potent proinflammatory cytokines. Dyregulation of the inflammasome activity contributes to the pathogenesis of many diseases, but its regulation remains poorly defined. Plasminogen activator inhibitor 2 (PAI-2), a member of a large group of proteins that inhibit serine proteases, is regulated by IKKβ-dependent activation of the transcription factor NF-κB. We previous demonstrated that mice with Ikkβ deletion in myeloid cells are hypersusceptible to endotoxin (LPS)-induced septic shock, and increased LPS susceptibility is associated with elevated plasma IL-1β. Reconstitution of Ikkβ-deficient macrophages with PAI-2 blocks apoptosis and IL-1β release. We also found that depletion of PAI-2 in macrophages resulted in IL-1β secretion after LPS stimulation. Our study unraveled a novel function of IKKβ/NF-κB in the negative regulation of IL-1β production via induction of PAI-2.
Properdin is increased after allergen challenge of asthmatic patients and contributes to OVA-induced airway inflammation and AHR at the effector phase by enhancing C3a generation in mice (P1355)
Authors: Wang Yuan , Ducka-Kokalari Blerina , Redai Imre , Miwa Takashi , Sato Sayaka , Gullipalli Damodar , Haczku Angela , Song Wen-Chao 
Published: January 2023

Abstract
The complement alternative pathway (AP) and anaphylatoxins have been implicated in allergic asthma, but the significance and mechanisms remain to be fully characterized. We hypothesized that factor properdin (fP), the only known positive regulator of AP contributes to allergen-induced airway inflammation. In human asthmatic patients, BALF collected after allergen challenge contained higher fP levels than before challenge. Mice were sensitized and challenged with OVA and examined for fP levels and airway inflammation. High levels of fP were detected in the BALF of OVA-sensitized and challenged but not naïve mice. Compared with WT mice, fP-deficient (fP-/-) mice had significantly reduced cell counts in BALF. fP-/- mice also had significantly attenuated AHR to methacholine stimulation. Antibody blocking of fP at both sensitization and challenge or at challenge phase alone, but not at sensitization phase alone, reduced airway inflammation. Conversely, intranasal reconstitution of fP to fP-/- mice at the challenge phase restored airway inflammation to WT levels. Notably, we found C3a levels in the BALF of OVA-challenged fP-/- mice to be significantly lower than in challenged WT mice, and intranasal co-administration of anti-C3a mAb with fP to fP-/- mice prevented restoration of airway inflammation. Collectively, our data suggest a detrimental role of fP in allergen-induced airway inflammation via C3a production and therapeutic targeting of fP may be beneficial in human asthma.