bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clinical isolates of Mycobacterium tuberculosis associated with different transmission phenotypes induce differential activation of the host immune response (HEM4P.251)
Authors: Verma Sheetal , Rodrigues Rodrigo , Jones-Lopez Edward , Palaci Moises , Alland David , Dietze Reynaldo , Ellner Jerrold , Salgame Padmini 
Published: January 2023

Abstract
In a Household contact (HHC) study conducted in Brazil, we have categorized “index” cases into High (HT) and Low (LT) transmission groups based on the number of their household contacts testing positive for the tuberculin skin test. A balanced induction of lipid mediators (Leukotriene B4, Prostaglandin E2 and Lipoxin A4) and Tumor necrosis factor (TNF) is essential for host defenses. Virulent Mycobacterium tuberculosis (Mtb) strains induce an imbalance in host lipid mediators to result in increased TNF production and activation of pro-necrotic pathway in macrophages. As necrosis is associated with increased growth of extracellular bacilli, we hypothesize that Mtb isolates derived from HT index cases exploit the TNF/necrotic axis in macrophages to increase the infectiousness in the index case, while LT isolates reduced necrosis but enhanced intracellular replication. Consistent with this, preliminary analysis of eight isolates confirms significantly higher TNF expression in human monocyte-derived macrophages infected with HT isolates in comparison to LT isolates. All isolates induced similar expression of IL-1β, IL-8 and IL-10. Ongoing experiments are evaluating the lipid mediator response, induction of pro-necrotic pathway, and bacterial growth in cells infected with HT and LT Mtb isolates. Together, the findings will provide insight into the role of Mtb strain variation and the resultant differing host immune response that contributes to their transmission phenotype.
TSLP signaling in CD4 T cells is required for T helper 2 memory (HYP6P.259)
Authors: Zhou Baohua , Wang Qun , Du Jianguang , Zhu Jingjing 
Published: January 2023

Abstract
Thymic stromal lymphopoietin (TSLP) plays important roles in the differentiation of T helper 2 (Th2) cells and thus the pathogenesis of allergic diseases. Whether TSLP is required for the generation and maintenance of Th2 memory cells has not been clearly defined. In this study, we show that TSLP signaling in CD4 T cells is required for the generation of memory cells following OVA+Alum priming. TSLPR-deficient CD4 T cells have no defects in proliferation but fail to survive one week after sensitization, while elevated TSLP expression during sensitization significantly increased the frequency of memory cells. Although in vitro differentiated TSLPR-deficient Th2 cells develop into memory cells with equal efficiency to wild type cells, the recall response to airway antigen challenge is impaired. Moreover, after antigen challenge of mice receiving in vitro primed Th2 cells, TSLP signaling in CD4 T cells significantly affects memory cell generation from the secondary effector cells. Therefore, TSLP plays a critical role not only in Th2 memory generation in vivo, but also in recall response of the memory cells to local antigen challenge.
Visualization of allergic immunity reveals non-coordinate expression of IL-4 and IL-13 in the innate immune system (HYP6P.260)
Authors: O'Brien Thomas , Bao Katherine , Ang Wei Xin Gladys , Abraham Soman , Reinhardt Richard 
Published: January 2023

Abstract
Allergic disease affects more than 3 billion people globally. In developed countries, allergic disease manifests itself as allergy and asthma, while in developing countries it takes the form of parasitic infections. The pathogenesis that develops as a consequence of allergic inflammation is mediated by the cytokines interleukin-4 (IL-4) and IL-13. Re-stimulation studies have demonstrated that a variety of cells in the lung are competent to produce IL-4 and IL-13 in vitro. At the present time, however, we have no clear understanding of which cells are responsible for producing these cytokines in vivo. In order to examine the cellular sources of IL-4 and IL-13 during allergic inflammation, we used IL-4 and IL-13 cytokine reporter mice to directly visualize cytokine production in vivo. These studies revealed that CD4+ T cells were the primary source of both IL-4 and IL-13 in allergic inflammation. Additionally, these studies revealed that CD4+ T cells produce IL-4 and IL-13 equivalently on a per cell basis. This is in stark contrast to innate cells, which preferentially produce either IL-4 or IL-13. NKT cells, eosinophils, and basophils produce IL-4, while ILC2 cells produce IL-13. Interestingly, IL-13 production was restricted to cells expressing high GATA-3. No such relationship was observed in IL-4 producing innate cells. In summary, these findings challenge the current dogma of coordinate regulation of IL-4 and IL-13 during allergic inflammation.
Proinflammatory role of natural killer cells in allergic airway disease (HYP6P.264)
Authors: Mathias Clinton , Guernsey Linda , Zammit David , Brammer Clair , Thrall Roger , Aguila Hector 
Published: January 2023

Abstract
Natural Killer (NK) cells have been implicated in the development of allergic airway inflammation. However the in vivo role of NK cells has not been firmly established due to the lack of animal models with selective NK cell deficiencies. We studied the role of NK cells in a model of ovalbumin-induced allergic airway disease (OVA-AAD) using NK-deficient (NKD) mice, perforin-/- mice, and mice depleted of Ly49A/D/G+ NK cell subsets. Induction of OVA-AAD in wild-type (WT) mice resulted in the expansion of airway NK cells and the development of pronounced airway eosinophilia. In the absence of NK cells or specific NK cell subsets, either in NKD mice, or after depletion of Ly49A/D/G+ NK cells, the development of OVA-AAD was significantly impaired as seen by decreased airway inflammation, decreased secretion of IL-4, IL-5 and IL-13 and diminished OVA-specific antibody production. Furthermore, while OVA-exposure induced a dramatic expansion of dendritic cells in WT mice, their induction was significantly attenuated in NKD mice. Development of OVA-AAD in perforin-/- mice suggested that the proinflammatory role of NK cells is not dependent on perforin-mediated cytotoxicity. Lastly, induction of allergic disease by OVA-specific CD4 T cells from WT but not NK-depleted or NKD mice in RAG-/- recipients, demonstrates that NK cells are essential for T cell priming. In summary, our data demonstrate that NK cells play an important and distinct role in the development of AAD.
Crosstalk between lungs and bone marrow during allergic inflammation (HYP7P.278)
Authors: Anderson Erik , Kobayashi Takao , Iijima Koji , Kephart Gail , Bartemes Kathleen , Chen Chien-Chang , Kita Hirohito 
Published: January 2023

Abstract
We used an established model of asthma that involves intranasal administration of the fungal extract of Alternaria. Upon lung exposure to Alternaria, IL-33 was released by epithelial cells within one hour, followed by increased production of IL-5 in the lungs. We also found elevated serum levels of IL-5 in response to Alternaria exposure, which reached a peak at 6 hours post Alternaria administration. After prolonged exposure to Alternaria over 6 days, a significant increase in mature eosinophils was observed in bone marrow. In addition, the serum from mice challenged with Alternaria was able to stimulate bone marrow cells to undergo eosinophil maturation in vitro. Intraperitoneal administration of IL-5-blocking antibody in vivo decreased eosinophil maturation in bone marrow in response to intranasal Alternaria below intranasal PBS baseline levels. We have shown the source of IL-5 is by type 2 innate lymphoid cells directly through IL-5 reporter mice, and indirectly through IL-5 serum levels in CD127 knockout mice. Taken together, this study illustrates that the type 2 innate immune responses in the lungs leads to enhanced production of eosinophils in the bone marrow through the increase in lung and blood levels of IL-5. Thus, distant organs communicate during allergic inflammation by using cytokines as mediators. This concept will aid in the identification of novel therapeutic strategies to alleviate symptoms of asthma and allergic diseases.
A role for beta-2 adrenergic receptors in the moderate aerobic exercise-modulated T regulatory cell function within a murine OVA-driven allergic asthmatic lung (HYP7P.287)
Authors: Dugger Kari , Watson Kacie , Sayner Sarah , Chastain Parker 
Published: January 2023

Abstract
We have shown moderate aerobic exercise can increase both the number and function of T regulatory (TREG) cells that suppress Th2 responses of an ovalbumin (OVA)-driven murine asthma model by an unknown mechanism. Exercise can communicate with TREG cells with the systemic release of catecholamines that bind to Beta-2-adrenergic receptors (β2-AR) and generate cAMP signals that can affect cell function. In these studies, we investigated a role for β2-AR in the exercise-mediated modulation of TREG cell function. For these studies, TREG cells (CD4+CD25+) were depleted from female BALB/cJ mice by i.v. injection of anti-CD25. Either 500,000 wt or β2-AR-/- TREG cells were adoptively transferred into the TREG-depleted BALB/cJ mice. Mice were sensitized/challenged with OVA to mimic allergic asthma pathogenesis. Mice were moderately exercised 45 min post-OVA challenge on a treadmill for 1hr 3x/wk for 4wks. Upon protocol completion, mice were examined for changes in TREG cell suppressive function and their resulting TREG cAMP levels. Our results show that exercise increases TREG function in vitro as compared with sedentary controls. However, the increase in TREG function of exercised TREG cells was abrogated in the absence of β2-ARs. We conclude that moderate aerobic exercise attenuates asthma-related airway inflammation via a mechanism that involves increased TREG cell function modulated by their expression of β2-ARs and subsequent production of cAMP.
Induction of regulatory alveolar macrophages in a biphasic model of house dust mite-induced asthma (HYP7P.279)
Authors: Bracken Sonali , Adami Alexander , Szczepanek Steven , Natarajan Prabitha , Guernsey Linda , Thrall Roger 
Published: January 2023

Abstract
Alveolar macrophages (AMs) are among the first cells to encounter inhaled allergens. While pro-inflammatory AMs are known to enhance the severity of asthma, the role of regulatory (IL-10+TGF-β+) AMs in suppression of allergic inflammation is not well defined. To determine whether suppression of asthma is associated with an increase in regulatory AMs, Vert-X IL-10-eGFP mice (n=5-6 per group) were challenged daily with 2 or 11 wks intranasal (i.n.) house dust mite (HDM). We have established that acute (2 wk) HDM exposure induces hallmarks of allergic inflammation whereas chronic (11 wk) exposure promotes tolerance to HDM. Tolerant (11 wk) mice exhibited a 2-fold increase in frequency and number of AMs when compared to diseased (2 wk) mice (p&lt;0.001). AMs isolated from 11 wk mice produced higher amounts of IL-10 than 2 wk AMs, as demonstrated by a significant increase in frequency of GFP+ AMs and in mean fluorescence intensity of GFP (p&lt;0.001). AMs from 11 wk mice also exhibited a 3-fold increase in TGF-β production (p&lt;0.06) and a 2-fold decrease in MHC-II expression (p&lt;0.05) when compared to AMs from 2 wk mice, indicating conversion to a regulatory phenotype. Moreover, the appearance of regulatory AMs in 11 wk mice was associated with a decrease in pro-inflammatory AM populations (p&lt;0.01). These findings suggest that skewing of AMs towards a regulatory phenotype may be of critical importance to the generation of immunological tolerance against chronically inhaled allergens.
Increased severity of murine anaphylaxis in the absence of signaling through the C3a and C5a receptors (HYP7P.307)
Authors: Strait Richard , Koehl Joerg , Finkelman Fred 
Published: January 2023

Abstract
Because the complement activation products C3a and C5a can induce anaphylaxis by activating mast cells, basophils, macrophages, neutrophils and other cell types, we hypothesized that murine anaphylaxis mediated by a complement-activating antibody isotype would be less severe in mice deficient in the receptors for these anaphylatoxins or in the central complement component, C3, than in wild-type mice. Surprisingly, anaphylaxis mediated by the complement-activating isotype, IgG2a, was considerably more severe in mice deficient in C3 or in both C3aR and C5aR; with approximately twice the drop in body temperature in the mutant as in the wild-type mice on the same genetic background and ~75% mortality in the mutant mice vs. no deaths in the wild-type mice. Anaphylaxis mediated by the non-complement-activating isotypes, IgG1 and IgE, was also considerably more severe in C3aR/C5aR double-deficient mice than in wild-type mice. Furthermore, injecting histamine or platelet activating factor induced more severe shock in the receptor double-deficient than in wild-type mice. In contrast, mice solely deficient in C3aR or C5aR resembled wild-type mice, rather than the double-deficient or C3-deficient mice. These observations suggest that signaling through either the C3aR or C5aR protects against anaphylaxis by decreasing sensitivity to vasoactive mediators and raises the concern that chronic suppression of signaling through both receptors might increase the severity of allergic disorders.
Curcumin inhibits the development of food allergy by suppressing mast cell function in an NF-κB-dependent manner (HYP7P.308)
Authors: Mathias Clinton , Xing Wei , Kinney Shannon , Mazzamurro Jeffrey , Carlson Logan , Schneider Sallie 
Published: January 2023

Abstract
Mast cells play critical roles in the establishment of allergic responses to food antigens. We have previously shown that frequent ingestion of the curry spice curcumin, inhibits mast cell expansion and suppresses intestinal anaphylaxis in a murine model of ovalbumin (OVA)-induced food allergy. Here, we demonstrate that the protective effects of curcumin are conferred during the mast cell-dependent, OVA-challenge phase of the model and are mediated by inhibition of NF-κB activation. Exposure to curcumin during OVA-challenge, but not OVA-sensitization, results in inhibition of allergic diarrhea, intestinal mastocytosis and Th2 cytokine production. This suggests that while curcumin has limited inhibitory effects on Th2 sensitization, it has direct suppressive effects on mast cell homeostasis and function. Suppression of mast cell activation was also associated with inhibition of NF-κB in OVA-gavaged, curcumin-treated animals suggesting that the inhibitory effects of curcumin may be mediated in an NF-κB-dependent manner. In summary, our data demonstrate that curcumin inhibits allergic responses to food antigens by blocking NF-κB activation and suppression of mast cell-dependent responses.
Kinetics of inflammation and leukocyte recruitment in a murine model of asthma: eosinophils versus neutrophils (HYP7P.284)
Authors: Berdnikovs Sergejs , Abdala-Valencia Hiam 
Published: January 2023

Abstract
Murine model of ovalbumin-induced allergic inflammation remains to be a popular choice for approximating human acute asthma condition. Despite its widespread usage, exact timing and sequence of inflammatory events in this model remain obscure. We used a BALB/cJ mouse model with two intraperitoneal sensitizations and six intranasal challenges, and monitored inflammatory parameters at 6 and 24 hours after each ovalbumin challenge. Multicolor flow cytometry was used to assess recruitment dynamics of leukocytes in the digested lung tissue and bronchoalveolar lavage (BAL). Although neutrophil recruitment dominated the initial response to allergen, eosinophils started to appear almost simultaneously, gradually increasing their presence with each challenge. Interestingly, while still present in the lung tissue, neutrophils ceased mucosal surveillance (measured as BAL infiltrate) after three challenges, at which time point eosinophilia increased dramatically. This increase in BAL eosinophilia correlated with upregulation of integrin CD11c by CD11b+Siglec-F+Ly6Glow eosinophils in the tissue. Mediators such as IL-4, IL-6, IL-9 and IL-33 exhibited peak expression during the first three challenges. Other mediators, such as CCL11, IL-5, IL-13 and Slit2-roundabout signals were more prevalent later in the model. Collectively, our results demonstrate progression of events that govern presence of eosinophils versus neutrophils in the lung tissue and airways during allergic inflammation.
Kainate receptors are critical for Th2 immune responses in allergic disease (HYP7P.286)
Authors: Sturgill Jamie , Martin Rebecca , Elkovich Andrea , Conrad Daniel 
Published: January 2023

Abstract
Asthma is a complex disease in which many cell types play a pathogenic role. The asthmatic response requires T cells to make appropriate cytokines, B cells to make antigen specific IgE, mast cells to bind IgE and react upon subsequent antigen encounter, and lung cells to respond to MC derived mediators. To date there have been no pharmacologic interventions that can address all of these aspects of the disease, thus polytherapy is the norm. A serendipitous discovery made in our laboratory led to the pivotal finding that kainate receptors (KARs) are present in the immune system. In our hands, an antagonist of this receptor was shown to strongly inhibit polyclonal IgE production in in vitro human cultures. We have extended these studies to demonstrate that in the murine in vitro system, the KAR is also critical for the in vitro production of IgE and that signaling through this receptor also leads to increased ADAM10 activity, production of soluble CD23 release, and subsequent IgE production. Furthermore, we determined in vivo relevance for this receptor. Mice deficient in the KAR post antigen challenge produce significantly less antigen specific IgE and mucus production in a house dust mite (HDM) model of allergic asthma. Interestingly, these mice have normal Th1 immune response upon challenge with Ova/CFA. Thus, KARs may serve as an innovative specific pharmacological target for the treatment of asthma and other IgE mediated disease.
Complement mediated phagocytosis induces the activation of the NALP3 Inflammasome (INC5P.331)
Authors: Suresh Rahul , Sutterwala Fayyaz , Mosser David 
Published: January 2023

Abstract
The Complement System is an important component of innate immunity, whose activation has been associated with acute inflammation. Activation of complement leads to the generation of a Membrane Attack Complex (MAC) composed of C5b-C9. The function of the MAC has been primarily associated with target cell death though the polymerization and insertion of C9 on the surface of the activating particle. In this study we provide evidence that MAC assembled on the surface of complement activating particles, can be transferred to host macrophages during the process of phagocytosis. This “bystander activation” onto macrophages causes potassium efflux and ROS production, which can induce the activation of the NALP3 inflammasome. The activation of caspase-1 then induces the secretion of IL-1β and IL-18 to regulate both innate and adaptive immunity. We show that macrophages activated by MAC, can induce T cell differentiation into Th17 cells when used as APCs. This study demonstrates that the phagocytosis of complement-opsonized particles can induce inflammasome activation by a novel mechanism involving MAC mediated “bystander” activation of host macrophages. This work provides another mechanism whereby complement activation can lead to acute inflammation and it emphasizes the importance of a previously undescribed function of the MAC to activate inflammasomes on phagocytic macrophages.
Microglial CX3CR1 required for M2 polarization and recovery after intracerebral hemorrhage (INC5P.322)
Authors: Taylor Roslyn , Hammond Matthew , Ai Youxi , Sansing Lauren 
Published: January 2023

Abstract
Intracerebral hemorrhage (ICH) occurs when a blood vessel in the brain ruptures, resulting in the activation of microglia. Upon activation, microglia polarize into a pro-inflammatory, M1 phenotype or an M2 phenotype associated with repair. Microglia and monocyte subsets express the chemokine receptor CX3CR1. CX3CR1-null microglia have been shown to have dysregulated inflammation. We hypothesize that microglial CX3CR1-deficiency promotes dysregulated, M1 microglia that do not aid in repair. C57BL/6 (WT) and CX3CR1GFP/GFP (CX3CR1-null) mice were irradiated and reconstituted with bone marrow from WT mice (CD45.1) to generate bone marrow chimeras (CD45.1→WT or CD45.1→CX3CR1-null). ICH was modeled by injecting 20μl of blood into the right striatum. Behavioral outcomes were measured using gait analysis, cylinder test, and beam walking. Mice were sacrificed 14 days after ICH; perihematomal regions were harvested for intracellular staining. The CD45.1→CX3CR1-null mice display greater neurological deficit 14 days after ICH by cylinder test (p=0.002), beam walking (p=&lt;0.001) and gait analysis (p=0.02). By intracellular staining, WT microglia have produce more for IL-10 (p=0.002) and IL-4 (p=0.0003) than CX3CR1-null microglia. CX3CR1-null microglia have less SIRPα (p=0.02) and higher CD36 expression (p=0.0004) compared to WT microglia. Our results suggest CX3CR1 signaling is necessary for microglia to transition from M1 to M2 and contributes to recovery after ICH.
Oxidative stress-induced pulmonary neutrophil recruitment is independent of conventional dendritic cells (INC5P.325)
Authors: Brand Jeffrey , Mathews Joel , Kasahara David , Neto Felippe , Shore Stephanie 
Published: January 2023

Abstract
Oxidative stress and airway neutrophilia are key features of some asthma phenotypes. Ozone (O3), a potent oxidant, induces pulmonary neutrophil recruitment which requires IL-17A+ γδ T cells. IL-23 is required for IL-17A production by T cells and conventional dendritic cells (cDC) are a potent source of IL-23. We therefore hypothesized that oxidative stress-induced IL-17A+ γδ T cells require IL-23 production from cDC. Wild type (WT), Tcrd-/- (lacking γδ T cells), and flt3l-/- (deficient in cDC) mice were exposed to air or 0.3 ppm O3 for 72 h. Bronchoalveolar lavage (BAL) was collected for cell differentials and lungs were processed for qPCR analysis. Lungs from mice which were not lavaged were used for flow cytometric analysis. In WT mice, O3 caused a 4 fold increase in the percentage of lung CD11c+/MHCII+/Siglec-F+ dendritic cells. IL-23 mRNA was also increased after O3 exposure. Flt3l-/- and WT mice had similar amounts of IL-23 and IL-17A mRNA and BAL neutrophils, thus indicating that cDC are not the source of IL-23 after such oxidative stress. However, IL-23 mRNA was reduced in Tcrd-/- mice which had fewer CD11c-/ CD11b+/F4/80+ myeloid cells. These cells are thus the potential source of IL-23. Altogether these data suggest oxidative stress induces IL-23 production by non-dendritic myeloid cells leading to IL-17A+ γδ T cell driven neutrophil recruitment.