bluuebunny/crossref_metadata_2025_split huggingface dataset:
Defects in pro-apoptotic genes, Bim or Bax/Bak, cause accumulation of TCRβhi DN4 cells in thymus (HEM4P.241)
Authors: Li Kun-Po , Roy Eron , Hildeman David 
Published: January 2023

Abstract
Regulated induction of apoptosis during thymocyte development is critical to prevent the generation of self-reactive T cells whilst maintaining a repertoire of T cells that can promote protective immunity. Although the pro-apoptotic Bcl-2 family member Bim has been shown to promote apoptotic negative selection of self-reactive thymocytes, the role of Bim in this process is controversial. Here, we have investigated the role of Bim and downstream mediators Bax and Bak on thymocyte selection. Surprisingly, the absence of Bim results in a striking accumulation of DN4 cells with surface TCRβhi feature in the thymus. Similar results were observed in mice with a T cell specific loss of Bax in a Bak knock out background. DN4 cells from Bim-/- or LckCreBaxfl/flBak-/- mice cultured with OP9-DL1 cells largely failed to generate DP cells relative to WT DN4 cells. Further, using a dLckCre system, in which Cre is expressed late in the DP stage, revealed that conditional knock out of Bim or Bax did not result in an accumulation of DN4-TCRβhi cells. Combined, these data suggest that accumulation of DN4-TCRβhi cells in either Bim-/- or LckCreBaxfl/flBak-/- are the result of cells having failed negative selection that downregulate CD4 and CD8 coreceptors. Such a strategy would inherently limit their TCR avidity and reduce their potential for autoreactivity. Our current studies are examining the persistence and location of DN-TCRβhi cells in the periphery of Bim-/- or LckCreBaxfl/flBak-/- mice.
Metabolic inhibition by inositol-tetrakisphosphate delays thymocyte β-selection and renders it notch-dependent (HEM4P.227)
Authors: Sauer Karsten , Huang Yina , Rigaud Stephanie , Conche Claire , Nosaka Lyn'Al , Siegemund Sabine , Sternberg Luise 
Published: January 2023

Abstract
In β-selection, surface-expression of a pre-T cell receptor (pre-TCR) induces thymocyte metabolic activation, proliferation, survival and differentiation. This pivotal αβ T cell fate-determining event requires co-stimulatory Notch signals. Here, we show that this Notch dependence is enforced through antagonistic signaling by inositol-trisphosphate 3-kinase B (Itpkb) and phosphoinositide 3-kinase (PI3K). Itpkb produces soluble inositol-tetrakisphosphate which competes with the PI3K lipid-product PIP3 for binding to the effector-kinase Akt. Itpkb-/- thymocytes are pre-TCR hyperresponsive, hyperactivate Akt, downstream mTOR and metabolism, undergo an accelerated β-selection and can develop to CD4+CD8+ cells without Notch. This is reversed by inhibition of Akt, mTOR or glucose-metabolism. Thus, Itpkb restricts pre-TCR induced metabolic activation to enforce coincidence-detection of pre-TCR expression and Notch-engagement, and to prevent premature thymocyte maturation.
Convergence of NF-κB-mediated inflammatory and HNF4α-mediated metabolic signaling networks in age-related thymic involution (HEM4P.229)
Authors: Weinberg Kenneth , Min Dullei , Venkatasubrahmanyam Shivkumar , Chung Brile , Yang Yujun , Goetz Christine , Winston Brent , Krampf Mark , Karamchandani Jason , Blazar Bruce , Butte Atul 
Published: January 2023

Abstract
Thymic epithelial cell loss results in age-related thymic involution and immune deficiency. We investigated mechanisms of TEC loss during chronological aging (6 weeks, 7 months, 15 months) of normal C57BL6/J mice. Aged TEC showed replicative senescence with increased apoptosis, decreased proliferation, decreased telomerase activity and shortened telomere length. A subpopulation of aged TEC expressed Fas in response to pro-inflammatory cytokines (TNFα,IL-1β) made by aged thymocytes. Fas signaling and caspase-8 activation were induced by FasL selectively expressed by aged intrathymic memory T cells. Combined pharmacological inhibition of Caspase-8 and TEC growth stimulation by KGF restored thymopoiesis to neonatal levels. Aged TEC differentially expressed a 175-gene set predicted to be dually regulated by two transcription factors, NF-κB and HNF4α, which are activated by inflammatory cytokines and fatty acids, respectively. NF-κB and HNF4α signaling in aged TEC was confirmed by ChIP assays demonstrating binding to promoters of age-related genes, gene reporter assays, and synergistic induction of TEC apoptosis by inflammatory cytokines and fatty acids. TEC aging is mediated by the convergence of different TFs responsive to inflammatory and metabolic signals on shared promoters. Thymic regeneration in aging will require mitigation of the effects of non-autonomous inflammatory and metabolic signals, e.g., from infection and obesity, which drive TEC death and thymic involution.
Protein tyrosine kinase 7 promotes PI3K/AKT signaling and survival in primary and neoplastic CD4+ T-lineage cells. (HEM4P.231)
Authors: Acharya Swati , Dionis-Petersen Kira , Jackson Peter , Admas Christopher , Lewis David 
Published: January 2023

Abstract
Protein tyrosine kinase 7 (PTK7), a catalytically inactive receptor tyrosine kinase (RTK) that is highly expressed in intrathymic development, is a novel marker for human CD4+ recent thymic emigrants (RTEs), and is also highly expressed on some T-lineage thymomas, e.g., Jurkat cells. The function of PTK7 in normal human T-cell development and tumors remains unclear. Here, using RNAi-mediated gene silencing in T-lineage tumor cells, primary human peripheral T-cells and thymocytes, we found that targeting PTK7 consistently decreased cell survival by augmenting caspase-3 activation of apoptosis. The PTK7 knockdown also decreased AKT phosphorylation and PI3 kinase activity, suggesting an essential role for PTK7 in survival of RTEs and developing thymocytes involving the PI3K/AKT pathway. Using mass spectrometry of we identified insulin-like growth factor-1 (IGF-1) receptor as an active kinase partner of PTK7. Knockdown of PTK7 reduced IGF-1 receptor function in primary T-lineage cells, confirming the biologic importance of this physical association. This role for PTK7 in promoting cell survival via its effects on cell survival via the PI3K/AKT pathway may not only be relevant to normal T-cell development, including the RTE compartment, but also to the oncogenesis of T-lineage and epithelial cell tumors.
B cells support a dominant Th17 cytokine signature in type 2 diabetes (HEM4P.255)
Authors: Belkina Anna , DeFuria Jason , Jagannathan-Bogdan Madhumita , Hasson Brooke , Kuchibhatla Ramya , McDonnell Marie , Apovian Caroline , Istfan Nawfal , Xiao Qiang , Nikolajczyk Barbara 
Published: January 2023

Abstract
T cell inflammation plays critical roles in the development of obesity-associated type 2 diabetes (T2D). B cells support T cell-mediated inflammation in T2D, but the mechanisms underlying lymphocyte cross-talk and the relative importance of T cell inflammation in human T2D remain untested. Using peripheral blood mononuclear cells (PBMC) and/or purified cells from T2D and non-diabetic (ND) subjects, we show that B cell contact upregulates a pro-inflammatory CD4+ Th17 T cell program in T2D. Neutralization of either B cell CD80/86 or the downstream production of T cell IL-17A/F significantly decreased production of classical diabetogenic cytokines (TNFα, IL-6) in samples from T2D subjects. Although monocytes, B cells and T cells produced TNFα in response to treatment of PBMCs with αCD3/CD28, monocyte TNFα production was independent of IL-17A/F, while IL-17F was critical for maximal TNFα production by both T and B cells. IL-17A/F neutralization also reduced IL-17A and IL-17F production by CD4+ T cells, indicating Th17 function is auto-regulated. We conclude that human B cell co-stimulation broadly supports Th17 cells, which in turn stimulate lymphocytes (but not monocytes) to produce the classical diabetogenic cytokine TNFα.
The rare IL-13R105Q variant, strongly enhances IL-13 protein activity (HYP6P.268)
Authors: Rosenbaum David , Hawkins Gregory , Zhu Lingxiang , Chen Yin , Bleecker Eugene , Meyers Deborah , Vercelli Donata 
Published: January 2023

Abstract
Because common genetic variants account for only a modest proportion of human complex disease risk, rare variants are currently under investigation as potential sources of phenotypic variance. Focusing on IL13, one of the most replicated asthma/allergy susceptibility genes, we sought to assess the contribution of rare coding variants to disease risk by coupling sequencing-based variant discovery with in vitro studies of protein activity. Sequencing of IL13 exons in DNA from 96 non-Hispanic White and 96 African American asthmatics identified a rare non-synonymous variant (rs140828306, minor allele frequency 1.6% in African Americans) in exon 4 that results in a non-conservative arginine (R) /glutamine (Q) substitution at amino acid position 105, immediately upstream of a conserved IL-13 receptor binding domain. For functional studies, recombinant WT IL-13 and IL-13R105Q were expressed in eukaryotic cells and quantified by ELISA adjusting for differential antibody recognition of the variant. IL-13R105Q was significantly more potent than WT IL-13 in inducing STAT6 phosphorylation (16-fold) and CD23 expression (5-fold) in human monocytes, and transcription of allergy-associated genes in primary human epithelial cells grown at an air-liquid interface (3-43-fold). Neither protein acted on human T cells. These results show that IL-13R105Q is a gain-of-function variant that is likely to significantly enhance IL-13-dependent events in vivo.
Differences in macrophage polarization in allergic inflammation (HYP6P.271)
Authors: Spears Nicole , Fang Jessie , Heller Nicola 
Published: January 2023

Abstract
Lung macrophages (alternatively activated or “M2” macrophages) are critical modulators of the severity of pulmonary inflammation. M2 macrophages differentiate from mature macrophages upon exposure to Th2 cytokines, IL-4 and IL-13, abundant during allergic lung inflammation. Greater numbers of M2 macrophages were found in the lungs of female mice than male mice and in patients with asthma compared to healthy controls. SOCS1 and SOCS3 are negative regulators that control M1/M2 polarization of macrophages and they may be regulated by estrogen. We hypothesize that monocytes from asthmatic females are more responsive to IL-4/IL-13 than those from asthmatic men and that estrogen increases and androgen diminishes monocyte responses to IL-4 and IL-13. To compare sex differences in IL-4/IL-13 responses in monocytes, we purified and stimulated monocytes from male and female allergic and healthy donors with IL-4 and IL-13. We found high levels of SOCS3 in monocytes from allergic donors compared to healthy controls after IL-4 stimulation. Interestingly, expression of ERα mRNA was higher in allergic compared to healthy human macrophages, whereas ERβ and AR expression was lower. Differences in SOCS induction will provide clues to understanding sensitivity of monocyte-macrophages from allergic individuals to IL-4 and IL-13. The role of ERα, β and AR to IL-4-induced M2 macrophage polarization will help us understand why the prevalence of asthma in adult women is higher than in men.
ILC2 + DC = Th2, group 2 innate lymphoid cell derived IL-13 is essential for efficient T helper 2 cell differentiation in allergic lung inflammation. (HYP6P.258)
Authors: Halim Timotheus , Steer Catherine , Matha Laura , Gold Matthew , Martinez-Gonzalez Itziar , McNagny Kelly , McKenzie Andrew , Takei Fumio 
Published: January 2023

Abstract
Naïve CD4+ T cell differentiation into distinct subsets of T helper (Th) cells is a pivotal process in the initiation of the adaptive immune response. Allergens predominantly stimulate Th2 cells, causing allergic inflammation. However, why allergens induce Th2 cell differentiation is not understood. Here we show that Group 2 Innate Lymphoid Cells (ILC2) are required to mount a robust Th2 cell response to the protease-allergen papain. Intranasal administration of papain stimulates ILC2 and Th2 cells, causing allergic lung inflammation and elevated IgE titre. This process is severely impaired in ILC2-deficient mice. More careful analysis reveals that ILC2 derived IL-13 is important for Th2 cell differentiation. Adoptive transplant of WT but not IL-13KO ILC2s restores the Th2 response. Recombinant IL-13 administration also rescues the Th2 defect in ILC2-deficient mice. Notably, intranasal IL-13 + OVA injection efficiently drives Th2 skewing of OTII transgenic T cells. Mechanistically, we show that IL-13 has a profound effect on homing of dendritic cells to the draining lymph-node, where they prime naïve CD4+ T cells. Lung explant from IL-13KO mice cultured in a transwell system show severely impaired DC migration to lymph-node homing chemokine gradients. Moreover, these processes require IL-33-dependent ILC2 activation, which suggests a common pathway in the initiation of the Th2 response to allergens.
T helper 9 (Th9) cellular proliferation and cytokine production is regulated by cAMP responsive element modulator (Crem) (HYP7P.289)
Authors: Hufford Matthew , Jabeen Rukhsana , Kaplan Mark 
Published: January 2023

Abstract
Th9 cells, a CD4+ T cell subset characterized by their robust production of interleukin (IL)-9, can promote allergic inflammation in mice and are associated with atopic disease in humans. Because it might provide targets for therapeutic intervention, it is important to understand the molecular controls governing overall Th9 development and their subsequent effector function. To understand the Th9 transcriptional profile, we recently performed microarray analysis to highlight gene expression enriched in Th9 cells compared to other Th subsets. Crem, which expresses a basic leucine zip domain protein with roles in activating and repressing genes, was among a number of genes with increased expression in Th9 cells. Analysis of mRNA and protein expression among in vitro differentiated Th subsets confirmed Crem was enriched in Th9 cells compared to other subsets. Interestingly, ectopic expression of Crem in Th9 cells repressed their capacity to produce IL-9 upon CD3 re-stimulation while promoting overall cellular proliferation. Crem ectopic expression also promoted cellular expansion in other cultured Th subsets. Conversely, acute siRNA knockdown of Crem mRNA in Th9 differentiated cells resulted in reduced cellular proliferation and enhanced IL-9 production upon CD3 restimulation. Therefore, Crem potentially serves a role in modifying Th9 effector activities upon T cell receptor signaling during allergic disease.
BATF dependency of Th9-associated genes (HYP7P.290)
Authors: Jabeen Rukhsana , Awe Olufolakemi , Kaplan Mark 
Published: January 2023

Abstract
Th9 cells are a recently described T helper subset that develops in the presence of TGF-β and IL-4. Th9 cells promote allergic inflammation, anti-tumor immunity, and may contribute to the regulation of auto inflammatory disease. Th9 cells are specialized for IL-9 production and this requires transcription factors including STAT6, PU.1 and IRF4. We have recently described that BATF promotes Th9 development in both mouse and human cells and BATF is required for T cells to promote the development of allergic inflammation. BATF-transduced Th9 cells demonstrated a potent ability to promote allergic inflammation in vivo compared to control transduced Th9 cells. To begin to define the transcriptional network controlling genes in Th9 cells, we characterized the dependence of Th9-enriched genes on each transcription factor, including BATF. Multiple genes including transcription factors, cytokines, and cytokine receptors were BATF-dependent. Unique functional properties of Th9 cells are suggested by the Th9-enriched expression of IL-33R, IL-25R, granzyme A, ephrin A5, and the salt-sensitive serum glucocorticoid kinase. BATF is required for 14/19 genes studied in detail thus far, suggesting that it is a major controller of the Th9 genetic program. Further defining of the module of BATF-dependent genes will aid in integrating the circuitry of Th9 development and function.
Maternal and postnatal dietary probiotic supplementation enhances splenic regulatory T helper cell population and reduces ovalbumin allergen-induced hypersensitivity responses in mice (HYP7P.305)
Authors: Toomer Ondulla , Ferguson Martine , Pereira Marion , Do Andrew , Bigley Elmer , Gaines Dennis , Williams Kristina 
Published: January 2023

Abstract
Neonatal to early childhood is the critical period for establishing a balance of T helper 1 (Th1) versus T helper 2 (Th2) mucosal immunity, which is strongly influenced by the source and establishment of gut microflora. Probiotic administration has been shown to attenuate Th2-biased cellular immunity and predisposition to food allergies. To test this hypothesis we fed a probiotic-supplemented or control diet to lactating dams with suckling pups and weaned pups until 10 weeks of age. Weaned mice were sensitized with egg allergen ovalbumin, saline or adjuvant at 6, 8 and 10 weeks of age. At 3, 6, 8 and 10 weeks, fecal samples were collected for microbial analysis, while blood samples were analyzed for ovalbumin and total plasma IgE levels. At termination, splenic T helper population subtypes were determined by FACS analysis and gene expression by PCR array. At 21 days of age, pups suckled by lactating dams fed the probiotic supplemented diet had significantly enhanced Lactobacillus acidophilus fecal counts compared to controls. Moreover, mice fed the probiotic supplemented diet had enhanced splenic naturally occurring and induced regulatory T cell populations, enhanced TGFβ gene expression and reduced expression of allergic mediator IL13 compared to controls. These results provide evidence that early probiotic supplementation may provide host protection from hypersensitivity reactions to food allergens by attenuating food allergen inflammatory responses.
Transplacental passage of IgG anti-IgE/IgE immune complexes (HYP7P.306)
Authors: Matson Adam , Bundhoo Arvin , Paveglio Sara , Blumberg Richard , Rafti Ektor 
Published: January 2023

Abstract
Maternal IgG mediates the transplacental passage of several antigens; however, it is unclear if maternal IgE may be transferred across the placenta as IgG anti-IgE/IgE immune complexes. In this study, we determined maternal and cord blood serum concentrations of IgG anti-IgE/IgE immune complexes in a cohort of allergic and non-allergic mother/infant dyads. We found a strong correlation (r = 0.88) between maternal and cord serum concentrations, which is strongly suggestive of placental transmission. Subclass analysis demonstrated the majority of IgG anti-IgE/IgE immune complexes in maternal sera were of the IgG1 and IgG4 subclasses, while those in cord blood were of the IgG1 subclass. Levels of IgG1 anti-IgE/IgE immune complexes were significantly higher in allergic vs. non-allergic pregnant women. To investigate the role of FcRn in the transplacental passage of IgG anti-IgE/IgE immune complexes, we used MDCK cells stably transfected with hFcRn. IgG, IgG anti-IgE, and IgG anti-IgE/IgE immune complexes bound to hFcRn-expressing MDCK cells in a pH-dependent manner whereas IgE alone did not. The addition of an FcRn blocking antibody effectively inhibited the binding of IgG anti-IgE/IgE immune complexes. Ongoing experiments are being conducted using the MDCK cells to demonstrate FcRn-mediated transcytosis. The ability of maternal IgG anti-IgE/IgE immune complexes to bind fetal myeloid dendritic cells and regulate FcεRI-dependent pro-inflammatory responses is being investigated.
Specialized proresolving lipid mediators (SPMs) decrease human B cell IgE production: implications for allergy and asthma (HYP7P.309)
Authors: Phipps Richard , Kim Nina , Ramon Sesquile , Sime Patricia , Zehr Lindsey 
Published: January 2023

Abstract
Resolution of inflammation is a biologically active process regulated by newly identified specialized proresolving lipid mediators (SPMs). These endogenous lipid-derived mediators promote the resolution of inflammation and maintain homeostasis by regulating the immune system. Little is known about the functions of SPMs on adaptive immune cells, such as B cells. Our laboratory has discovered that certain omega-3 fatty acid derived SPMs promote human B cell IgM and IgG antibody production in vitro. Human B cells also produce IgE antibodies, which play an essential role in the onset of inflammatory diseases, such as seasonal allergies and asthma. Here, we show that certain SPMs decrease human B cell IgE production in vitro. Omega-3-derived SPMs, 17-HDHA (17-hydoxydocosahexaenoic acid) and RvD1 (resolvin D1), strongly decreased the IgE production in B cells, as well as the number of IgE-secreting cells in peripheral blood of healthy and asthmatic human donors. In addition, 17-HDHA and RvD1 also reduced IgE production by the spontaneously IgE secreting multiple myeloma B cell line, U266. These results show that SPMs are non-immunosuppressive endogenous mediators that could specifically dampen IgE production and have potential as therapeutics for asthma. Moreover, SPMs might also be effective on other IgE-mediated inflammatory diseases such as atopic dermatitis.
The inhibitory cytokine IL-35 in Treg-mediated control of allergic diseases (HYP7P.285)
Authors: Sawant Deepali , Corry David , Vignali Dario 
Published: January 2023

Abstract
Regulatory T cells (Tregs) represent a critical suppressive T cell population that maintains immune homeostasis and tolerance. Increasing evidence suggests reduced Treg numbers or compromised Treg function in atopic and asthmatic individuals. Treg derived suppressive cytokines, IL-10 and TGFβ, alleviate Th2 inflammation through allergen-specific immunotherapy. Studies on experimental asthma highlight an undisputed role for Tregs in allergic diseases; however, they fail to pinpoint a single/predominant mechanism employed by Tregs to control asthmatic inflammation. Our lab has identified a novel Treg-derived suppressive cytokine IL-35 (a heterodimer of Ebi3 and Il12a/p35) that is essential for their maximal suppressive activity. IL-35 also induces the conversion of naïve T cells into an IL-35-dependent suppressive population termed iTr35 cells. We hypothesize that IL-35-secreting Tregs and iTr35 cells are potent suppressors of Th2 allergic responses. We demonstrate that allergic inflammation induces the IL-35-mediated regulatory milieu (IL-35-expressing Tregs and iTr35 cells) in two distinct models of asthma (OVA/Alum and fungal protease). Further, IL-35 neutralization exacerbates asthmatic inflammation. Current studies using IL-35 reporter and gene-deficient mouse strains are directed at evaluating the expression, function and mechanisms of IL-35-mediated Treg control of allergic inflammation and have the potential to lead to novel IL-35-based therapeutic regimens.