bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pyruvate Dehydrogenase Operates as an Intramolecular Nitroxyl Generator During Macrophage Metabolic Reprogramming
Authors: Palmieri Erika M , Holewinski Ronald , McGinity Christopher , Pierri Ciro , Maio Nunziata , Wink David , McVicar Daniel W 
Published: August 2023

Abstract
M1 macrophages “commit” to a glycolytic state when endogenous nitric oxide (NO) reprograms mitochondrial metabolism by limiting aconitase (Aco)-2 and pyruvate dehydrogenase (PDH). Here we provide evidence that NOdirectly targets the PDH complex using lipoate to generate nitroxyl (HNO). PDH E2-associated lipoate is modified in NO-rich macrophages while the PDH E3 subunit is irreversibly inhibited. Mechanistically, we show that lipoate facilitates NO-mediated HNO production that interacts with thiols forming modifications resistant to reduction. Consequently, we reveal a macrophage signature of proteins with reduction resistant modifications, including E3, and identify a subset of potential HNO targets. Consistently, recombinant E3 is modified in HNO-dependent manner at Cys477 and Cys484, and molecular modeling shows these cause impairment of functional E3 homodimer formation. Our work demonstrates that HNO is produced physiologically, and its presence is peculiar to the lipoate rich PDH complex facilitating irreversible modifications critical in NO-dependent metabolic rewiring.
Androgen Receptor regulates Ptpn22
Authors: Lee Jean A , Yurkovetskiy Leonid A , Frommer Laura , Strong Zoe , Chang Anthony , Khan Aly A , Kahaly George J , Chervonsky Alexander V 
Published: August 2023

Abstract
The need to rear the offspring necessitated the evolution of female’s immune system to mount stronger responses than males. One consequence of it is that major autoimmune diseases manifest in a sex biased manner with a predominance in females. However, mechanisms underlying the bias have not been clearly defined. We investigated the molecular mechanisms by which male sex hormones (androgens) regulate αβ T cell function in sex biased autoimmunity. We identified Ptpn22, a gene encoding a lymphoid-specific phosphatase that negatively regulates proximal TCR signaling events, as a direct target of a transcription factor Androgen Receptor (AR) in T cells. In T cells isolated from sham-operated or castrated mice, transcription of Ptpn22 correlated with the presence of androgens. Furthermore, stimulation of Jurkat T cells with AR agonist resulted in induction of Ptpn22 transcription only in the presence of AR. Deletion of Ptpn22 in the B6.NZM mouse model of Systemic Lupus Erythematosus (SLE) led to exacerbation of autoimmunity accompanied by the loss of sexual dimorphism. We identified an androgen response element (ARE) in the 5′ UTR of Ptpn22 and found that its CRISPR/Cas9-mediated mutation enhanced both in vitro and in vivo the autoreactivity of T cells in NOD/ShiLtJ mouse model of Type I Diabetes (T1D). In humans, PTPN22 R620W mutation associated with several autoimmune disorders inversely correlated with the sexual dimorphism of autoimmunity. Thus, the ‘wild-type’ common allele of PTPN22 is likely to be involved in sex bias in autoimmune conditions.
NIH grant R01 AI 127411
Early peripheral B cells in inactive SLE are transcriptionally and epigenetically primed for T-dependent activation
Authors: Rose James R , Ishii Yusho , Hicks Sakeenah , Scharer Christopher D , Sanz Ignacio , Boss Jeremy 
Published: August 2023

Abstract
Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease characterized by repeated episodes of increased disease activity followed by periods of inactivity and remission. Increased titer of anti-dsDNA autoantibodies is often associated with active disease and the proliferation of autoreactive B cells are thought to play a major role in the progression of disease. In this study we investigated the transcriptional and epigenetic profile of early peripheral B cells—transitional (T1T2) and resting naïve (rN)—in inactive and active disease from a large cohort (n=46) of African American SLE patients. Our results show that the transcriptome of these B cells show a dysregulated signature as previously reported, but this signature is distinct between inactive and active SLE. Active disease is characterized by a greater number of differentially expressed genes (DEG) compared to healthy controls (HC), however, rN B cells in inactive disease patients express high levels of genes associated with T-dependent activation, IL4 signaling, and germinal center reactions. Chromatin accessibility across the genome of inactive disease B cells show that they share a subset of differentially accessible regions (DAR) from HC that are similarly dysregulated in both inactive and active flaring individuals, but inactive SLE B cells also have acquired several hundred unique DAR regions—some of which correspond with motifs or loci encoding important B cell development transcription factors. These findings suggest a distinct profile in early B cells from inactive disease patients that remains present during disease remission and may predispose these cells towards T-dependent activation as a response to long-term disease.
Supported by grants from NIH (T32 GM0008490, 3U19 AI110483-08S2 8744)
IL2 signaling and Foxp1 expression maintain Treg identity in the absence of Foxp3
Authors: Hill Charlotte Nicole , Zhong Yuelin , Zemmour David , Charbonnier Louis-Marie 
Published: August 2023

Abstract
Regulatory T cells (Treg) have a pivotal role in tolerance and immune homeostasis. In autoimmunity, Treg are destabilized and degenerate, loosing Foxp3 expression and compromising their regulatory function, while gaining a T effector cell (Teff)-like phenotype. Upon Foxp3 loss-of-function, Treg development gives rise to a heterogeneous population of Treg cells (ΔTreg). ΔTreg retain the core Treg transcriptome and epigenetic imprint and can be classified based on the expression of the high-affinity IL-2 receptor-alpha, CD25, and Foxp3 locus activity. We herein propose a stepwise degeneration driven by a decrease in IL2/CD25 signaling and subsequent loss of Foxp1 expression.
CD25+ ΔTreg expression profile, as compared to the one of CD25− ΔTreg cells, presented increased levels of genes typically expressed in Treg, such as Il2ra and Il10. Consistently, CD25− ΔTreg were biased toward Th1, presented impaired suppressive capacity, and downregulated Foxp1. Treatment with IL2/aIL2 and STAT5b gain of function upregulated CD25, decreased Th1 bias and inflammation, supporting the role of IL2 signaling halting the passage from CD25+ to CD25− ΔTreg. ΔTreg-specific depletion of Foxp1 led to a steep decrease in the frequency of ΔTreg, increased T-bet expression, and a reduction in the Foxp3 locus activity, suggesting that Foxp1 loss drives ΔCD25− ΔTregs into a terminally degenerated state. Our results indicate that IL2 signaling is sufficient to maintain ΔTreg regulatory capacity, while Foxp1 expression is necessary to stabilize their identity and prevent terminal degeneration. We are currently doing scRNAseq and ChIPseq to elucidate the molecular mechanisms by which IL2 signaling and Foxp1 maintain Treg identity in the absence of Foxp3.
National Institutes of Health grant R01AI153174
PDGFRα promotes organ resistance to immune-mediated damage
Authors: Rosetti Florencia , Meléndez-Pérez Diana Laura , de la Cruz Abigail , Larios-Orozco Emiliano , González-Yáñez Marysol , Furuzawa-Carballeda Janette , Villanueva Raul , Cevallos Cristina , Madera-Salcedo Iris Karina , Crispin Jose C 
Published: August 2023

Abstract
Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that exhibits great clinical heterogeneity. Development and clinical expression of autoimmune diseases is strongly influenced by genetic variants. The single nucleotide polymorphism (SNP) rs1364989, located close to PDGFRA, has been associated with the development of lupus nephritis through an unknown mechanism. Because PDGF, through its α and β receptors, regulates tissue response to inflammation, we hypothesized that rs1364989 could modulate the behavior of renal cells in the context of immune-mediated glomerulonephritis.
To determine whether rs1364989 affects the expression of PDGFRα, we analyzed umbilical cord mesenchymal cells from carriers of risk and protective alleles. We observed that the presence of the risk allele was associated with reduced PDGFRα expression. Next, we analyzed whether inflammatory mediators could modulate PDGFRα expression in in vitro and in vivo settings. We documented that its levels increase during acute inflammation in a murine model of glomerulonephritis. In vitro, this effect could be reproduced by IL-17. Absence of PDGFRα increased kidney damage during immune complex-induced glomerulonephritis. An analogous effect was observed in joints of mice with collagen-induced arthritis.
Our results demonstrate that the SLE-associated allele of rs1364989 reduces the expression of PDGFRα and that this receptor may activate a pathway that protects tissues in response to local inflammation. These findings highlight the importance of tissue resilience as a factor that can protect an organ from inflammatory damage in the setting of autoimmunity.
This work was supported by the Consejo Nacional de Ciencia y Tecnología (CONACYT), Mexico
Lymphoid Follicle Transcriptome Reveals Maladaptive Immune Responses In Severe Chronic Obstructive Pulmonary Disease (COPD)
Authors: Rojas-Quintero Joselyn J , McKenna Neil J , Ochsner Scott A , Cala-Garcua Juan D , Kheradmand Farrah , Rosas Ivan O , Polverino Francesca 
Published: August 2023

Abstract

Rationale
Increases in the number and size of lymphoid follicles (LFs) are present in severe stages of COPD and have not been fully characterized. HLA complex is crucial in enabling the immune system to recognize “self” versus “non-self” antigens and plays a major role in immune responses to cigarette smoke exposure.

Methods
Lung follicles from COPD patients with milder (GOLD I–II) and more severe (GOLD III–IV) COPD were sampled using GeoMX® Digital Spatial Transcriptional Profiling. Data were analyzed and normalized using GeoMx® DSP Analysis Suite.

Results
Pathway analysis showed that B cell activation pathways had the highest fold enrichment. GOLD I–II compared to GOLD III–IV COPD patients had the highest expression of HLA-C and its ligands (KIR2DS2, KIR2DS1, KIR3DL1; p&lt;0.0001) which facilitate CD8-mediated cytotoxicity, and HLA-G and its receptor LILRB4 (p=0.01) which are key modulators of immune tolerance. GOLD III–IV COPD patients had the highest HLA enrichment in LFs, with upregulation of transcription factors (HIF1A, IRF1, NFYBand NFYC) and assembly components (CALR, TAPBP, ERP27, MARCHF1, B2M, and CIITA) of HLA (p&lt;0.01). Compared to GOLD I–II, LFs from GOLD III–IV COPD patients had much higher expression of HLAs involved in autoimmune responses to self-antigens and adaptive immune evasion, such HLA-DRA, HLA-DRB1, HLA-DPA1, HLA-DPB1, HLA-DQA1, HLA-DQB1, HLA-E and HLA-B (p&lt;0.0001).

Conclusions
We show for the first time that LFs from patients with severe COPD are characterized by expression of HLAs associated with immune evasion and autoimmune responses, whereas LFs in milder stages of COPD are characterized by induction of immune responses controlled by tolerance mechanisms

R01 HL 149744-04/06
Microbiota dampen type 2 immunity by epigenetically restricting tuft cell differentiation
Authors: Eshleman Emily M , Rice Taylor , Potter Crystal , Woo Vivienne , Field Sydney , Hashimoto-Hill Seika , Waddell Amanda , Engelman Laura , Finkelman Fred D , Alenghat Theresa 
Published: August 2023

Abstract
Type 2 immune responses at mucosal surfaces are both required to expel helminthic parasites and central to allergic disease pathogenesis. Tuft cells are central regulators of type 2 immunity that instruct downstream type 2 innate lymphoid cells (ILC2s). Although the microbiota are known to shape immune responses, the impact of commensal microbes on regulation of tuft cell-dependent immunity remains poorly understood. Here, we find that butyrate-producing commensal bacteria suppress tuft cell-dependent type 2 immunity in the intestine. Butyrate suppression of tuft cells required the microbiota-sensitive epigenetic modifying enzyme histone deacetylase 3 (HDAC3), suggesting that HDAC3 may promote tuft cell-dependent immune defense. Consistent with this, epithelial-intrinsic HDAC3 actively stimulated tuft cell responses, was required to initiate the tuft cell-ILC2 feed-forward response to Nippostrongylus brasiliensis infection, and promoted expulsion of this helminthic parasite. Furthermore, butyrate epigenetically restricted stem cell differentiation into tuft cells, and inhibition of HDAC3 in adult mice and human intestinal organoids was sufficient to block tuft cell differentiation. Collectively, these data reveal a microbiota-sensitive epigenetic pathway in stem cells that dampens tuft cell mediated type 2 immunity, and highlight a new level of regulation through which commensal bacteria can calibrate mucosal inflammation.
This research is supported by the National Institutes of Health (DK114123, DK116868 to T.A., and F32AI147591 to E.M.E.), and a Kenneth Rainin Foundation award to T.A. T.A. holds an Investigator in the Pathogenesis of Infectious Disease Award from the Burroughs Wellcome Fund. This project is supported in part by PHS grant P30 DK078392 and the CCHMC Trustee Award and Procter Scholar’s Program.
MHCII Expression by Intestinal Goblet Cells in Immune Homeostasis
Authors: Barrios Bibiana E , John Vini , Floyd Alexandria , Davis Jazmyne , Udayan Sreeram , Schill Ellen , McDonald Keely , Newberry Rodney D 
Published: August 2023

Abstract
As the primary barrier in the gut, intestinal epithelial cells (IECs) are positioned to promote tolerance and immunity against pathogens. MHCII is highly expressed on IECs, however MHCII expression on epithelial cell subsets is largely unexplored. Goblet cells (GCs) are specialized epithelial cells that have critical role in barrier maintenance and immunity. GC can form Goblet cells associated passage (GAPs) and deliver luminal antigens to lamina propria (LP) antigen presenting cells (APC) to induce adaptive immune responses. Here, we report that MHCII is highly expressed on small intestinal GCs as compared with other IECs and colon IECs, which do not form GAPs in the steady state. Moreover, expression of coinhibitory and costimulatory molecules by GCs was higher when compared with other IECs. Interestingly, flow analysis and quantification of MHCII on CD45.2+ MHC-II−/− donor-derived leukocytes showed MHCII acquisition by donor-derived small intestinal lamina propria (siLP) APCs 7 weeks after BM-transplant into CD45.1+ recipients. Indeed, carbachol, which induces GAPs formation resulted in increased MHCII acquisition by CD45.2+MHC-II−/− donor-derived siLP MNPs. Furthermore, selective deletion of MHCII on GCs, resulted in a significant reduction of transferred dietary antigen specific OT-II+CD45.1+CD4+ T cells in mLN in a model of oral tolerance. Bulk RNAseq analysis on the small intestine of mice with GC deletion of MHCII revealed an expansion of B cell responses and significant increase in IgA+ cells in Peyer’s patches. This data suggests that GC expression of MHCII has a role in antigen-specific responses to luminal antigens and in regulating intestinal homeostasis.
Supported by grants from NIH
T cell receptor signaling mediates enhanced IFNγ production by γδ intraepithelial lymphocytes in response to type I interferon
Authors: Fischer Matthew , Jia Luo , Edelblum Karen 
Published: August 2023

Abstract
Intraepithelial lymphocytes (IEL) expressing the γδ T cell receptor (TCR) provide a rapid response to limit enteric pathogen invasion. Despite constant γδTCR triggering in vivo, these IELs remain immunologically quiescent until their activation threshold is surpassed. Activated γδ IELs limit viral replication by producing type I interferons (IFN), such as IFNα, yet the extent to which IFNα activates γδ IELs remains unknown. To this end, murine small intestinal γδ IELs were stimulated ex vivo with 1 ug/mL αCD3, 10 ng/mL IFNα or both for 5 h. We observed a 26%±10 increase in IFNγ+ γδ IELs treated with αCD3 and IFNα compared to αCD3 treatment alone (p&lt;0.0001) and a 2-fold increase in IFNγ MFI (p&lt;0.0001). Using Nur77-GFP mice, we found that only Nur77+ γδ IELs produced IFNγ (p&lt;0.0001), indicating that TCR signaling is necessary for IFNα-induced effector function. Suboptimal αCD3 stimulation (0.1 ug/mL) was sufficient to increase the frequency of IFNγ+ γδ IELs following IFNα exposure relative to αCD3 alone (p&lt;0.001). To interrogate the molecular mechanism involved in IFNα co-stimulation, γδ IELs were treated with PMA and/or ionomycin in the presence or absence of IFNα. Ionomycin and IFNα increased the frequency of IFNγ+ γδ IELs by 16%±7 compared to ionomycin alone (p&lt;0.0001), whereas PMA had no effect. Pharmacological inhibition of NFAT signaling (10 uM INCA6) abrogated both TCR- or IFNα-induced γδ IEL IFNγ production (p&lt;0.01 or p&lt;0.0001, respectively). Lastly, we observed that the co-stimulatory effect of IFNα was lost in STAT4-deficient γδ IELs compared to WT (p&lt;0.0001). Together, these data indicate that low level TCR signaling through NFAT is required for IFNα to rapidly enhance γδ IEL IFNγ production in a STAT4-dependent manner.
This work was supported by the National Institutes of Health R01 DK119349, the New Jersey Commission on Cancer Research, Busch Biomedical Research grant and the RBHS Chancellor Scholar Award (KLE).
CaV3.2 links mast cells, tryptase and pain
Authors: Fairlie Samantha E , Chovanec Jack , Liu Yihui , Walitt Brian , Saligan Leorey , Lyons Jonathan J 
Published: August 2023

Abstract
Hereditary a-tryptasemia (HaT) is a genetic trait defined by elevated serum tryptase caused by increased TPSAB1 copy number and associated with multiple phenotypes including pain. CACNA1H encoding the voltage-gated calcium channel CaV3.2 overlaps the tryptase locus where a partial gain-of-function (GOF) haplotype containing 3 linked variants has been shown to be co-inherited with HaT in ~2/3 of individuals. While CaV3.2 is expressed in neurons where it contributes to pain perception, expression has also been observed in other cells. Mast cells are the principal source of tryptase, exist in proximity with nerves, and have been implicated in pain sensation. We set out to investigate links between these variants, mast cells, and pain. Performing tryptase and CACNA1H genotyping via ddPCR in a cohort of fibromyalgia patients we found that HaT was enriched compared to the general population (p=0.029). However, the CACNA1H haplotype was universally present, suggesting these variants were driving the association. In support of this observation, enrichment of the GOF variants was also observed among those without HaT. Using flow cytometry, immunoblotting, ddPCR, and immunofluorescence, we found LAD2 cells express CaV3.2 where it co-localizes at the cell surface with calnexin and confirmed expression in primary cultured human mast cells. To our knowledge, this is the first report of a voltage-gated calcium channel on mast cells. While calcium flux is critical for mast cell activation, mechanisms driving voltage-gated channel activation remain to be elucidated. Future studies will help unravel the mechanisms linking mast cell activation and pain pathways enabling the development of therapies for these commonly linked clinical phenotypes.
Supported by grant from DIR NIAID NIH, grant: ZIA AI001192
BLOC1S1: An Unexpected Regulator of Th2 Cell-driven Inflammatory Responses
Authors: Sharma Rahul , Wu Kaiyuan , Han Kim K , Singh Komudi , Sack Michael N 
Published: August 2023

Abstract
BLOC1S1 is an adaptor protein that modulates endosome-lysosome function as a component of numerous multiprotein complexes. We postulated that its modulation in CD4+ T cells may help us uncover the role of endosome-lysosome biology in adaptive immunity. In primary CD4+ T cells BLOC1S1 cre-recombinase knockout resulted in the preferential induction of Th2 compared to Th1 and Th17 cytokine production following T cell receptor activation. As atopic dermatitis is an allergic inflammatory skin disease characterized by the production of the type 2 cytokines in the skin we evaluated the effect of CD4+ T cell BLOC1S1 KO vs controls in calcipotriol-induced atopic dermatitis in mice. The absence of BLOC1S1 exhibited exacerbated atopic dermatitis accompanied with significantly elevated plasma IgE, skin eosinophilia, elevated type 2 responses, and inflammatory pathology relative to wild-type mice. The transcription factor Gata-3 is expressed in Th2 but not Th1 cells and plays a critical role in Th2 differentiation and atopic dermatitis. BLOC1S1 deficient CD4+ T cells showed enhanced nuclear factor kB (NF-kB), Gata3 and LC3 positive autophagosomes. Inhibition of NF-kB activity prevented Gata-3 expression, LC3 positive autophagosomes and Th2 cytokine production in BLOC1S1 −/− CD4+ T cells. This mouse model will now give us a platform to explore the role of endo-lysosomal biology in Th2 polarization and activation.
NHLBI Division of Intramural Research (MNS-ZIA-HL005102)
Therapeutic efficacy and mechanism of a solubilized Sturgeon oil in a mouse model of house dust mite-induced atopic dermatitis
Authors: Lee Hee-Sung , Park Ji-Hyun , Park Chan-Su , Lee Chong-Kil 
Published: August 2023

Abstract
The therapeutic effect and action mechanism of solubilized Sturgeon oil (SSO) against atopic dermatitis (AD) were examined in NC/Nga mice. SSO was prepared from the fish oil obtained from Sturgeons using physical solubilization processes. AD was induced by topical application of house dust mite (HDM) extract on the dorsal skin of NC/Nga mice, and then treated with SSO. SSO exerted potent therapeutic activity on AD symptoms. Histological analysis revealed that SSO reduced epidermal hyperplasia and suppressed infiltration of mast cells and eosinophils in the dorsal skin. In addition, SSO significantly reduced the serum total IgE and HDM-specific IgE levels in AD-induced NC/Nga mice. Analysis of the dorsal skin tissues showed that SSO significantly downregulated the expression levels of IL-4, 5, 13, 17A and COX-2, while upregulated the expression levels of IL-10 and filaggrin. In vitro studies also showed that SSO suppressed the production of Th2 cytokines including IL-4, 5 and 13, while increasing the production of IL-10, from anti-CD3/CD28-stimulated Th2 cells. These results show that SSO exerts therapeutic effect on AD in NC/Nga mice through Th2-related immunomodulatory activities.