bluuebunny/crossref_metadata_2025_split huggingface dataset:
Humanized mouse model of mast cell-mediated passive cutaneous anaphylaxis and passive systemic anaphylaxis (HYP4P.302)
Authors: Kenney Laurie , Bryce Paul , Falahati Rustom , Bebbington Chris , Tomasevic Nenad , Shultz Leonard , Greiner Dale , Brehm Michael 
Published: January 2023

Abstract
Mast cells are critical components of allergic responses in humans, and animal models that allow the in vivo investigation of human allergic responses and the evaluation of new human-specific therapeutics are urgently needed. Here we have developed a new humanized mouse model for human mast cell engraftment and human IgE-dependent allergic responses. This model is based on the NOD-scid IL2rgnull IL3/GM-CSF/SCF (NSG-SGM3) strain of mouse engrafted with human fetal thymus, liver and hematopoietic stem cells (termed the BLT model). Large numbers of human mast cells develop in NSG-SGM3 BLT mice and populate peripheral lymphoid tissues, mucosal tissues and the peritoneal cavity. The human mast cells in NSG-SGM3 BLT mice express CD117, tryptase, and IgE-receptor, undergo a calcium flux and degranulate in an IgE-dependent antigen-specific manner, and can readily be cultured and expanded in vitro. The NSG-SGM3-BLT mice develop a human mast cell dependent, antigen-specific IgE-mediated passive cutaneous anaphylaxis (PCA) response upon intradermal challenge. Moreover, we describe the first report of a human mast cell antigen-dependent passive systemic anaphylaxis (PSA) response in humanized mice following intravenous challenge with antigen. The NSG-SGM3 BLT mouse provides a readily available source of human mast cells and is a promising pre-clinical model to investigate the pathogenesis of human allergic responses and to testing new therapeutics.
Involvement of RIP2 in mast cell activation downstream of the high-affinity IgE receptor FcεRI (HYP4P.304)
Authors: Tigno-Aranjuez Justine 
Published: January 2023

Abstract
RIP2 is a dual-specificity kinase which is activated following the engagement of the peptidoglycan sensors NOD1 and NOD2. Despite abundant expression of RIP2 in various tissues and cell types, as well as having numerous reported binding partners, its role has primarily been demonstrated as important solely downstream of NOD1/2 signaling. We report that RIP2 potentially has a role downstream of signaling through the high affinity IgE receptor, FcεRI. We demonstrate that members of the Src family kinases as well as Syk, which are involved in FcεRI signaling, bind to and promote tyrosine phosphorylation of RIP2. Importantly, we show that loss of RIP2 affects mast cell activation downstream of FcεRI but not activation mediated through other pathways such as through purinergic receptor engagement. Lastly, use of Gefitnib, a potent RIP2 inhibitor, shows downregulation of FcεRI-mediated responses. Altogether, these data provide evidence for the involvement of RIP2 in a novel, non-NOD-mediated signaling pathway and suggest that Gefitinib or specific RIP2 inhibitors may be useful for the treatment of disorders in which mast cell FcεRI signaling play an important role such as in allergy or asthma.
Inhibition of CD23-mediated IgE transcytosis suppresses the initiation and development of airway allergic inflammation (HYP4P.308)
Authors: Palaniyandi Senthilkumar , Liu Xiaoyang , Periasamy Sivakumar , Ma Aiying , Tang Jin , Jenkins Mark , Tuo Wenbin , Song Wenxia , Keegan Achsah , Conrad Daniel , Zhu Xiaoping 
Published: January 2023

Abstract
The human low affinity IgE receptor, CD23 (FceRII), is capable of transporting IgE or IgE-allergen complexes across the polarized human airway epithelial cell (AEC) monolayer in vitro. However, it remains completely unknown whether CD23-dependent IgE transfer pathway in AECs initiates and facilitates allergic inflammation in vivo. To prove this, we first showed that epithelial CD23 in wild-type (WT) mice transcytosed either IgE or ovalbumin (OVA)-IgE complexes across the airway epithelial barrier. Neither type of transcytosis was observed in CD23-knockout (KO) mice. The OVA sensitization and aerosol challenge of the irradiated WT/WT or CD23KO/WT chimeric mice that CD23 expressed on radioresistant airway structural cells, mainly in epithelial cells, resulted in airway eosinophilia, lung damages including collagen deposition and significantly increased goblet cells, and increased airways hyperreactivity. In contrast, the absence of CD23 expression on airway structural or epithelial cells, but not on hematopoietic cells, of the bone-marrow chimeric mice (WT/CD23KO) significantly reduced OVA-driven allergic airway inflammation. Finally inhalation of a CD23-blocking B3B4 antibody to target exposed CD23 in AECs of the sensitized WT mice before airway challenge suppressed the salient features of asthma, including bronchial hyperreactivity. Our study further suggests that the functional inhibition of CD23 on AECs is a potential therapeutic means to intervene the asthma development.
Mast cells produce factor XIIIA and mast cell chymase reduces factor XIIIa activity during sepsis through proteolytic degradation (HYP5P.318)
Authors: Shubin Nicholas , Glukhova Veronika , Clauson Morgan , Truong Phuong , Vaisar Tomas , Abrink Magnus , Pejler Gunnar , White Nathan , James Richard , Piliponsky Adrian 
Published: January 2023

Abstract
Previously, we reported that mast cell (MC) chymase, and its mouse homologue, mast cell protease 4 (MCPT4), protect from septic morbidity and mortality by limiting inflammation via TNF degradation. Here, we identified another potential MCPT4 substrate; factor XIIIa (FXIIIa; the essential fibrin-crosslinking/clot stabilizing FXIII catalytic subunit). We found that extracellular FXIIIA (the pro-form of FXIIIa) protein levels were significantly increased in IgE-stimulated MCPT4-/- peritoneal MC (PMC) supernatants compared with WT PMCs (FXIIIA mRNA levels were unchanged). These data suggest that MCs both secrete FXIIIA and are capable of degrading it via MCPT4. Based on these results, and on published data demonstrating that FXIIIa activity correlated with sepsis severity, we hypothesize that chymase/MCPT4 mediated cleavage of FXIIIa participates in the previously-noted protective effect of chymase during sepsis. First, we verified that chymase is capable of degrading FXIIIA and reducing FXIIIa activity in-vitro and in-vivo. Additionally, we identified 6 chymase-driven primary cleavage sites in human FXIIIA. Finally, we observed that following experimentally-induced sepsis, plasma and peritoneal FXIIIA levels as well as plasma FXIIIa activity were significantly diminished in WT compared with MCPT4-/- mice. In conclusion, these data demonstrate that MCs produce FXIIIA and that MCPT4 reduces FXIIIa activity during experimental sepsis.
Splenic monocytes traffic to the thyroid and produce a novel TSHβ splice variant during acute Listeria infection in mice (INC4P.334)
Authors: Klein John , Montufar-Solis Dina 
Published: January 2023

Abstract
It has been known for over three decades that thyroid stimulating hormone (TSH) is produced by cells of the immune system; however, the functional role of that TSH has remained obscure. We recently identified a novel splice variant of the thyroid stimulating hormone β-subunit (TSHβv) that is primarily produced by cells of the immune system, in particular by myeloid cells in the bone marrow (BM) and spleen. During acute infection with virulent L. monocytogenes, TSHβv synthesis increased in CD14+, F4/80+ BM cells and spleen cells. In vitro culture of the mouse AM macrophage cell line with LPS or zymosan, or following stimulation with anti-CD14 or anti-TLR2 antibodies, resulted in increased synthesis of TSHβv. Three days post-infection with Listeria, there was an infiltration of CD14+, F4/80+ cells into the thyroid that was followed by an increase in intrathyroidal TSHβv gene expression on days 4 and 5 compared to non-infected mice. Following in vivo transfer of CFSE-labeled spleen cells from infected mice into normal non-infected mice, CFSE+ cells were present throughout the thyroid, demonstrating an active process of trafficking of TSHβv-producing spleen cell into the thyroid during an acute infection. These findings point to a novel mechanism of host metabolic regulation by the immune system during systemic bacterial infection, and they define a functional role for TSHβv in that process.
A novel population of IFN-γ-producing B cells promote innate defense against Listeria monocytogenes infection (INC4P.337)
Authors: Bao Yan , Cao Xuetao 
Published: January 2023

Abstract
Although B cells play important roles in the humoral immune response and the regulation of adaptive immunity, B cell subpopulations with unique phenotypes, particularly those with non-classical immune functions, should be investigated further. By challenging mice with Listeria monocytogenes, Escherichia coli, vesicular stomatitis virus, and TLR ligands, we identified an inducible CD11ahiFcγRIIIhi B cell subpopulation that is significantly expanded and produces high levels of IFN-γ during the early stage of pathogen infection. This subpopulation of B cells can promote macrophage activation via IFN-γ, thereby facilitating the innate immune response against intracellular bacterial infection. As this new subpopulation is of B-cell origin and exhibits the phenotypic characteristics of B cells, we designated these cells as IFN-γ-producing innate B cells. Dendritic cells were essential for the inducible generation of innate B cells from follicular B cells via CD40L-CD40 ligation, and increased Btk activation was found to be responsible for the increased activation of noncanonical NF-κB in innate B cells after CD40 ligation, with the consequent induction of additional IFN-γ production. The identification of this new population of innate B cells may contribute to a better understanding of B cell functions in anti-infection immune responses and immune regulation.
The role of ATG5-dependent autophagy during Rickettsia australis infection. (INC4P.339)
Authors: Bechelli Jeremy , Zhao Xuemei , Smalley Claire , Hwang Seungmin , Popov Vsevolod , Leoncio Leoncio , Walker David , Fang Rong 
Published: January 2023

Abstract
Rickettsiae are obligate intracellular bacteria that replicate in the cytoplasm of eukaryotic cells. We found that degradative autophagy is induced upon the infection of murine bone marrow macrophages (BMMs) with R. australis and the bacteria are specifically targeted by autophagosomes for degradation. Inhibition of autophagy using 3-methylamine (3-MA) significantly increased bacterial burden in BMMs. Consistently, rickettsial loads in livers of infected Atg5flox/flox Lyz-Cre mice were significantly greater than those of Atg5flox/flox littermates. As a consequence, host survival was significantly reduced in autophagy-deficient Atg5flox/flox Lyz-Cre animals, suggesting that macrophage autophagy mediates host cellular immunity against rickettsiae in vivo. In contrast, limited level of autophagy was induced in human endothelial cells, which are the major targets of rickettsiae. Taken together, our results suggest that R. australis induces autophagy in murine macrophages and plays a role in bacterial clearance both in vitro and in vivo. However, levels of autophagy in human endothelial cells early during infections appear to be lower compared to those in murine macrophages.
Improved antibacterial resistance of alcohol fed mice 7 days after alcohol abstinence (INC4P.323)
Authors: Ohama Hideko , Asai Akira , Ito Ichiaki , Yokohama Keisuke , Nakamura Ken , Tsuchimoto Yusuke , Fukunishi Shinya , Tsuda Yasuhiro , Higuchi Kazuhide , Kobayashi Makiko , Suzuki Fujio 
Published: January 2023

Abstract
MRSA enteritis is one of the most serious complications which develop into sepsis in alcoholics. In this study, we examined the effect of alcohol abstinence on the host antibacterial resistance of the alcohol fed mice (AF-mice) orally infected with MRSA. AF-mice were BALB/C mice fed 5% ethanol-containing Lieber-DeCarli liquid diet ad libitum for 1 to 3 weeks. These mice were subjected to alcohol abstinence for 7days. Three to 6 days after alcohol abstinence, all of the mice were decontaminated with an antibiotic mixture and treated with a proton pump inhibitor. On day 8, these mice were orally infected with 107 CFU/mouse of MRSA. The effects of alcohol abstinence on the host antibacterial resistance of AF-mice were evaluated by bacterial growth in mesenteric lymph nodes (MLNs) and mortality rates. In the results, sever growth of MRSA was demonstrated in MLNs of AF-mice without alcohol abstinence, while the pathogen was not isolated from MLNs of alcohol abstinent AF-mice 4 days after the infection. All of AF-mice died within 10 days of MRSA infection, while 100% of alcohol abstinent AF-mice survived. CCL1+IL-10+F4/80+ cells (M2bMϕ) were isolated from MLNs of AF-mice, while alcohol abstinent AF-mice were shown to be a non carrier of M2bMϕ in their MLNs. These results indicate that impaired host antibacterial resistance of AF-mice against MRSA enteritis was effectively improved by alcohol abstinence for 7 days
Alarmin function of galectin-9 in murine respiratory tularemia (INC4P.341)
Authors: Sharma Jyotika , Steichen Anthony , Simonson Tanner , Salmon Sharon , Metzger Dennis , Mishra Bibhuti 
Published: January 2023

Abstract
Sepsis is a complex immune disorder that is characterized by systemic hyperinflammation. Alarmins, which are multifunctional endogenous factors, have been implicated in exacerbation of inflammation in many immune disorders including sepsis. Here we show that that Galectin-9, a host endogenous β-galactoside binding lectin, functions as an alarmin capable of mediating inflammatory response during sepsis resulting from pulmonary infection with Francisella novicida, a Gram negative bacterial pathogen. Our results show that this galectin is upregulated and released during tissue damage in the lungs of F. novicida infected septic mice. In-vitro, purified recombinant Galectin-9 exacerbated F. novicida-induced production of inflammatory mediators by macrophages and neutrophils. Concomitantly, Galectin-9 deficient (Gal-9-/-) mice exhibited improved lung pathology, reduced cell death and reduced leukocyte infiltration, particularly neutrophils, in their lungs. This positively correlated with overall improved survival of F. novicida infected Gal-9-/- mice as compared to their wild-type counterparts. Collectively, these findings suggest that exatracellular galectin-9 functions as a novel alarmin by augmenting the inflammatory response in sepsis development during pulmonary F. novicida infection.
Differential caspase regulation of actin dynamics during Legionella pneumophila infection (INC4P.324)
Authors: Caution Kyle , Akhter Anwari , Hassan Hoda , Tazi Mia , Ahmed Amro , Hoque Sheshadri , Ghonime Mohammed , Gavrilin Mikhail , Amer Amal 
Published: January 2023

Abstract
Legionella pneumophila (Legionella) is the causative agent of Legionnaires’ disease. Clearance of Legionella requires efficient phagolysosomal fusion. Regulation of the host actin cytoskeleton is crucial for proper vesicle trafficking. It has been determined that activation of caspases-1/11 are required for trafficking and fusion during infection. The molecular mechanisms of caspase-mediated clearance are unknown. It is this study’s objective to decipher the effects of caspase-1/11 on actin dynamics to promote phagolysosomal fusion and restriction. During Legionella infection, caspase-1 and -11-/- macrophages exhibited diminished F/G-actin ratios compared to WT counterparts. In addition, the absence of caspase-1 or -11 prevented the colocalization of the bacterium with F-actin, inhibiting fusion. In elucidating the molecular mechanism, it was found that caspase-1 and -11 differentially distinct molecules upstream of the actin regulator cofilin. We found that the activation of cofilin was affected by both caspases distinctly to promote phagolysosomal fusion, during Legionella infection. These data establish that inflammasome caspases differentially regulate actin polymerization during Legionella infection by modulating F-actin assembly via the activation of cofilin. Understanding the novel molecular mechanisms of caspase-mediated regulation of the host cytoskeletal network will provide novel targets to develop therapeutic interventions for numerous infectious diseases.
Shaping the lung IL-22 response during invasive aspergillosis (INC4P.325)
Authors: Reeder Kristen , Godwin Matthew , Zindl Carlene , Dunaway Chad , Weaver Casey , Steele Chad 
Published: January 2023

Abstract
Exposure to the opportunistic mold Aspergillus fumigatus may result in a wide range of infectious diseases. Among these infections, invasive aspergillosis is the most common and the most lethal. Our lab has previously shown a protective role for Dectin-dependent IL-22 production. In our current studies we sought to identify potential cell source(s) of IL-22 as well as factors critical for its production during invasive aspergillosis. Employing human CD4 IL-22 reporter mice, we show that iNKT cells and γδ T cells are sources of IL-22 48 h post-A. fumigatus exposure. In subsequent studies, we observed an early impairment in IL-22 production by lung cells from CD1d deficient (iNKT deficient) mice that returned to wild type levels by 48 h. In contrast, mice deficient in γδ T cells had relatively intact IL-22 production early after A. fumigatus exposure that became significantly attenuated by 48 h post-challenge. In order to identify factors critical for IL-22 production we interrogated the role of several pertinent transcription factors including: related orphan receptor-γ (RORγ), the aryl hydrocarbon receptor (Ahr), MyD88, and TRIF. Collectively, our data shows that iNKT cells and γδ T cells support early vs. late IL-22 production, which is fully dependent on RORγ and MyD88, partially dependent on Ahr, and independent of TRIF.
STING senses Brucella abortus DNA and triggers pro-inflammatory cytokine production and resistance against bacterial infection (INC4P.330)
Authors: Oliveira Sergio , Marim Fernanda , Barber Glen 
Published: January 2023

Abstract
Immunity against Brucella abortus depends on the recognition of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs). Signaling pathways triggered by Brucella DNA involves TLR9, AIM2 and possibly STING. Previous studies reported by our research group showed that B. abortus-induced IFN-b is dependent on STING. Herein, we demonstrated that STING is required for Brucella abortus control in vivo. STING KO mice showed enhanced susceptibility at three- and six-weeks post-infection compared to wild-type animals. Furthermore, we observed reduced levels of IFN-g production in spleen cells of STING KO compared to wild-type that corroborates with enhanced susceptibility. Moreover, additional results showed that STING plays an important role in the response to infection in vitro. Macrophages derived from STING KO mice showed reduction in IL-12 and IL-1b cytokine production, when infected with the bacteria or stimulated with bacterial DNA. Diminished production of IL-1b in KO macrophages implicates STING as possible regulator of inflammasome activation. Additionally, murine embryonic fibroblasts (MEFs) from STING KO mice produced much less IL-6 when stimulated with Brucella DNA compared to wild-type MEFs. In summary, we demonstrated the importance of STING as a cytosolic sensor during Brucella abortus infection and its contribution to bacterial control in vivo.
Effects of lipid signaling on innate immune networks during influenza infection. (INM3P.360)
Authors: Oguin Thomas , Lindsley Craig , Thomas Paul , Brown H. 
Published: January 2023

Abstract
If critical steps in the influenza infection process are identified, druggable targets could be discovered. We have uncovered the role of lipid signaling through phospholipase D (PLD) during influenza infection. Our findings suggest that influenza virus takes advantage of PLD activity to quickly and quietly enter the host cell. By inhibiting PLD with small molecules, we found that endocytosis kinetics were subdued. Slowing influenza entry allowed innate immune proteins to sense the pathogen and mount an effective defense. The molecules required for defense included Rig-I, MxA, and IRF3. When these proteins were knocked down in cells treated with PLD2 inhibitor, protection was lost. Inhibition of PLD2 protected cells from several influenza subtypes, including H5N1 and the newly emerged H7N9. Additionally, viral growth in mice treated with the PLD2 inhibitor was reduced, and mice were more likely to survive when treated with PLD2 inhibitor. Our data suggest that signaling through PLD during influenza infection plays a critical role in innate immune detection and defense mechanisms, and that drugging PLD2, allows a better chance to defend against pathogens using innate molecules. Currently, second generation small molecule inhibitors of PLD2 are proving to be more efficacious and potent. Additionally, further insights are being gained regarding the temporal-spatial regulation of innate immune molecules during the first hours of infection.
Inflammation directs waning vaccine immunity during the aging proces (IRM12P.653)
Authors: Norton Elizabeth 
Published: January 2023

Abstract
Aging is a risk factor for disease characterized by complex changes to the immune system and increased disease susceptibility. Vaccination remains the key strategy to prevent infections (e.g., Influenza) in adults. We hypothesized that the age-dependent increase in inflammation directs vaccination outcomes. We tested our hypothesis using commercial Fluzone or TDaP vaccines and BALB/c mice of three ages: young adult (14 weeks), middle-aged (50 weeks), and old (100 weeks). Naive mice exhibited a progressive increase in inflammation (inflammatory cytokines, cellular proliferation) with age. Vaccinated mice exhibited a progressive decrease in development of vaccine antigen-specific immunity with age. Adoptive transfer of splenocytes from young mice did not rescue vaccine responsiveness in older mice. Curiously, we found progressively higher expression of IκBζ with age and vaccination. Lastly, we confirmed our findings using human blood samples and ex vivo PBMC cultures. Overall, our results supported our hypothesis. Altered IκBζ activity (a non-classical NFκB inhibitor) was unexpected as age is linked to higher NFκB expression. However, IκBζ has been linked to cellular senescence and inflammatory cytokine secretion. This suggests that waning vaccine efficacy with age is not a “failure to respond” but a nonproductive immune response post-antigen challenge within a setting of chronic inflammation, much like the theory of Inflammaging.