bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neuropeptides stimulate pro-inflammatory mediator secretion from human microglia through mammalian target of rapamycin signaling, which is inhibited by the flavonoids luteolin and tetramethoxyluteolin (IRM9P.457)
Authors: Patel Arti , Tsilioni Irene , Theoharides Theoharis 
Published: January 2023

Abstract
Despite the rise in diagnosis of Autism Spectrum Disorders (ASD, 1:68 children), the pathogenesis and treatment remain unknown. Mounting evidence supports the involvement of brain inflammation and immune dysfunction. Microglia, the brain-resident immune cells are critical gatekeepers of neuronal function show aberrant growth and activation in ASD brains. Some ASD patients also have elevated serum levels of neurotensin (NT) and corticotropin-releasing hormone (CRH), which are stress-related neuropeptides. Moreover, 1-5% of ASD cases have mutations in proteins that inhibit signaling through the mammalian target of rapamycin complex 1 (mTORC1), which regulates immune cell proliferation and mediator production. We hypothesized that NT and CRH act synergistically to stimulate human microglia through activation of mTORC1 leading to pro-inflammatory mediator release. We show that unstimulated human microglia express the NT receptor-3, but not the CRH receptor-1 (CRHR-1). Stimulation with NT and CRH significantly increases the gene expression of CRHR-1, as well as expression and secretion of the pro-inflammatory interleukin IL-1beta, CXCL8, CCL2, and GM-CSF. Pretreatment with mTORC1 inhibitors and the natural flavonoids luteolin and tetramethoxyluteolin, significantly decreases mediator secretion. Our results implicate the involvement of mTORC1 signaling for microglia activation, which is inhibited by novel flavonoids that could be developed into effective ASD treatments.
B cell TLR1/2, TLR4, TLR7 and TLR9 interact in induction of class switch DNA recombination: modulation by BCR and CD40, and relevance to T-independent antibody responses (IRM10P.608)
Authors: Lam Tonika , Pone Egest , Lou Zheng , Wang Rui , Greenberg Milton , Xu Zhenming , Casali Paolo 
Published: January 2023

Abstract
CSR in B cells is crucial to the maturation of antibody responses. It is induced by engagement of CD40 or dual engagement of a TLR and BCR. Here, we have addressed cross-regulation between two different TLRs or between a TLR and CD40 in CSR induction by using a B cell stimulation system involving LPS. LPS mediated long-term primary class-switched antibody responses and induced generation of class-switched B cells and plasma cells. Consistent with the requirement for dual TLR and BCR engagement in CSR induction, LPS, which engages TLR4 through its lipid A moiety, triggered cytosolic Ca2+ flux in B cells through its BCR-engaging polysaccharidic moiety. In the presence of BCR crosslinking, LPS synergized with a TLR1/2 ligand (Pam3CSK4) in CSR induction, but much less efficiently with a TLR7 (R-848) or TLR9 (CpG) ligand. In the absence of BCR crosslinking, R-848 and CpG, virtually abrogated CSR, as induced by LPS or CD154, and reduced secretion of class-switched Igs, without affecting B cell proliferation or IgM expression. The CSR inhibition by TLR9 was associated with reduced AID expression and/or IgH germline IH-S-CH transcription, and required co-stimulation of B cells by CpG with LPS or CD154. Unexpectedly, B cells also failed to undergo CSR when co-stimulated by LPS and CD154. Our study suggests the complexity of how different stimuli cross-regulate an important B cell differentiation process and an important role of TLRs in inducing T-independent antibody responses.
5-methoxytryptophan is a circulating anti-inflammatory molecule that controls lipopolysaccharide-induced systemic inflammation and sepsis (IRM11P.622)
Authors: Wang YiFu , Wu Hsu-Feng , Hsu Yu-Juei , Lee Guan-Lin , Wu Jing-Yiing , Huang Shih-Ming , Yet Shaw-Fang , Wu Kenneth , Kuo Cheng-Chin 
Published: January 2023

Abstract
We identified in the conditioned medium of human fibroblasts a tryptophan metabolite, 5-methoxytryptophan (5-MTP) which controls cyclooxgenase-2 expression and inhibits NF-κB binding and p300 activity. We postulated that as with fibroblasts, human endothelial cells produce 5-MTP which plays an important role in controlling systemic inflammatory responses. Human endothelial cells produced and released 5-MTP into the conditioned medium. Lipopolysaccharide (LPS) suppressed 5-MTP production in endothelial cells and induced 5-MTP deficiency in the murine sepsis model. Intraperitoneal infusion of 5-MTP restored serum 5-MTP accompanied by inhibition of systemic pro-inflammatory cytokines, chemokines, and pro-inflammatory mediators. 5-MTP administration rescued organ failure and prevented mortality. The beneficial effect of 5-MTP was correlated with inhibition of cytokine production and COX-2 expression in macrophages. 5-MTP inhibited LPS-induced p38 MAPK, p300 HAT and NF-κB activation in macrophages and endotoxemic lung tissues in vivo. Importantly, a considerable amount of 5-MTP was detected in 30 healthy subjects (1.05 ± 0.39 μM) which was significantly reduced in 50 sepsis patients (0.37 ± 0.15 μM, p&lt;0.0001). 5-MTP is a novel circulating anti-inflammatory molecule which protects against excessive systemic inflammatory responses. It ameliorates LPS-induced sepsis and is a valuable lead compound for developing new drugs to treat sepsis and systemic inflammatory disorders.
Arginine methylation modulation of T cell responses (IRM11P.636)
Authors: Guerau-De-Arellano Mireia , Savardekar Himanshu , Jablonski Kyle , Amici Stephanie , Panfil Amanda , Webb Lindsay , Thornton Kelsey , Li Linsen , Green Patrick , Baiocchi Robert , Li Chenlong 
Published: January 2023

Abstract
Inhibition of methylation reactions suppresses T cell proliferation and inflammatory responses but the specific methylation enzyme target responsible for these effects is unknown. Protein Arginine Methyltranferases (PRMT), enzymes that catalyze dimethylation of arginine in histones and other proteins, have been proposed to mediate these effects. Among PRMTs, PRMT5 symmetrically dimethylates protein arginine and is associated with embryonic development and cancer but has no known role in T cells. Here, we used myelin-specific memory Th cells that model autoimmune responses in Multiple Sclerosis to investigate the role of PRMT5 in memory Th1 cell responses. PRMT5 was up-regulated as Th1 cells undergoing activation, with kinetics that closely matched the cycle of T cell proliferation. PRMT5 protein up-regulation correlated with loss of miR-96, an inhibitor of PRMT5 translation. Further, a highly selective, small molecule PRMT5 inhibitor blunted memory T cell proliferation, an effect that could be partially rescued by IL-2. These data implicate PRMT5 in regulation of adaptive memory T helper cell responses and open novel therapeutic opportunities for T cell-mediated autoimmune disease.
DNA damage repair enzyme APE1 is a non-classical secretory protein and acts as a mediator of IL6 dependent inflammatory responses (IRM11P.626)
Authors: Nath Somsubhra , Shukla Ashima , Joshi Shantaram , Bhakat Kishor 
Published: January 2023

Abstract
Apurinic/apyrimidinic endonuclease 1 (APE1) is a pleiotropic nuclear protein with roles in DNA base excision repair (BER) pathway as well as in transcriptional regulation. APE1 has been found to be systematically released in blood plasma during endotoxemia in rats. However, the physiological importance of this secretion remains elusive. Here, we show that both normal human monocytes and monocytic cell line THP-1 secrete APE1 upon inflammatory challenges. This secretion follows a non-classical route of transportation and requires ATP-binding cassette transporters. Challenging the THP-1 cells with purified recombinant APE1 (recAPE1) in culture media shows increased expression and secretion of pro-inflammatory cytokine IL6. Phosphorylation of transcription factor NFҡB-p65 upon recAPE1 treatment precedes increased occupancy to IL6 promoter resulting in induced expression of the cytokine. Extracellular IL6 further promotes the secretion of APE1 thus working in a positive feedback loop. Moreover, release of APE1 by necrotic cells indicates stress responsive behavior of this secretion. Together, our study demonstrates a novel role of extracellular APE1 and identifies secretory APE1 as a mediator of IL6 dependent inflammatory responses.
Adenovirus Serotype 5 Vectors Trigger IL-27-Dependent Inhibitory CD4+ T Cell Responses
Authors: Larocca Rafael Assumpção , Provine Nicholas M , Iampietro Mark Justin , Borducchi Erica N , Penaloza-MacMaster Pablo A , Badamchi-Zadeh Alexander , Bricault Christine A , Blass Eryn , Parenteau Lily R , Blackmore Stephen , Stephenson Kathryn E , Barouch Dan H 
Published: January 2023

Abstract
Viral vectors are attractive vaccine platforms that elicit robust innate and adaptive immune responses, but they vary greatly in their ability to induce protective immunity. Adenovirus serotype 5 (Ad5) vectors elicit robust CD8+ T cell responses but are typically characterized by an exhausted phenotype. The mechanisms by which Ad5 vectors induce dysfunctional CD8+ T cells have not been fully elucidated. Here we demonstrate that Ad5 vectors, but not Ad26 vectors, elicit exhausted antigen-specific IL-10+PD1+ CD4+ T cells with a dysfunctional transcriptional profile, and these cells effectively suppress CD8+ T cell responses in vivo. The blockade of IL-10 increased the frequency of antigen-specific CD8+ T cells with enhanced cytokine polyfunctionality and protective capacity against a Listeria monocytogenes challenge. Induction of inhibitory CD4+ T cells by Ad5 vectors is associated with increased IL-27 expression, and IL-27 blockade improves CD4+ T cell cytokine polyfunctionality. Together our data highlight a novel role for IL-27 induced inhibitory CD4+ T cells in regulating responses to viral vector vaccines.
Exhaustion of Human Dendritic Cells Results in a Switch from the IL-15R/IL-15- to IL-2R/IL-2-driven Expansion of Antigen-specific CD8+ T Cells
Authors: Kalinski Pawel , Obermajer Natasa , Edwards Robert , Svane Inge-Marie , Hansen Morten 
Published: January 2023

Abstract
Maturation of dendritic cell (DC) is considered to be crucial for their ability to promote clonal expansion of antigen-specific T cells. Here, we show that the ability to expand human antigen-specific CD8+ T cells is a feature of specialized “effector” DCs at early stages of maturation, and it is suppressed in “exhausted” DCs at late stages of maturation and in DCs matured in the conditions of chronic inflammation.
Effector DCs, at early stages of maturation induced by TLR ligands and interferons, express membrane IL-15Rα/IL-15 complex, which promotes highly efficient and IL-2/IL-2Rα-independent expansion of MART-1-specific IL-15Rαhigh CD8+ T cells and cooperates with DC-produced IL-12p70 in inducing poly-functional CTL phenotype. In sharp contrast, exhausted DCs which lack membrane IL-15Rα/IL-15 complex, utilize a significantly less efficient IL-2Rα/IL-2 trans-presentation pathway to co-stimulate CD8+ T cells.
The currently-reported switch from the IL-15Rα/IL-15- to IL-2Rα/IL-2 costimulatory pathway in exhausted DCs helps to understand the role of inflammation in clonal expansion and contraction of CD8+ T cells at different stages of immune responses and helps to design improved modes of immunotherapy of cancer and chronic infections.
Myeloid cytokines distinctly and reversibly control LAIR-1 (CD305) expression on monocytes-mΦs/monocyte-DCs.
Authors: Santiago-Schwarz Frances , Son Myoungsun , Diamond Betty 
Published: January 2023

Abstract
Cross-linking of the inhibitory immunoreceptor LAIR-1 (CD305) on the cell surface phosphorylates LAIR-1 inhibitory motifs (ITIM) and restricts the growth of monocyte-derived dendritic cells (mono-DCs). Despite the suggestion that LAIR-1’s ability to prevent unwarranted immunity is compromised in autoimmunity, much remains to be learned about the control of LAIR-1 expression.
Here, we compared the ability of various myeloid cytokines to control LAIR-1 expression on the surface of monocytes/macrophages (mϕs) and mono-DCs. Treatment of freshly isolated blood monocytes from healthy donors with mono-DC growth factors (GM-CSF+IL-4/GM-CSF+IL-13) led to reduced levels of LAIR-1 at the critical monocyte-to-mono-DC juncture. In contrast, M-CSF (a steady state/M2 cytokine) sustained LAIR-1+CD14+CD33m/M+CD16+ mono-mϕs. M-CSF effects on LAIR-1 occurred under serum-supplemented and serum-free conditions.
Addition of M-CSF to mono-DCs previously cultured in GM-CSF+IL-4 promptly reversed the down-regulatory effects of GM-CSF+IL-4 producing increases in LAIR-1+CD14+ cells. Conversely, addition of GM-CSF+IL-4 to M-CSF exposed cultures lowered levels of LAIR-1 and CD14. M-CSF treatment of SLE blood myeloid cells (featuring activated monocytes/mono-DCs lacking LAIR-1, CD14) produced high levels of LAIR-1 and CD14 vs GM-CSF/IL-4. Thus: 1. The expression of LAIR-1 on monocytes/mϕs and mono-DCs is distinctly and reversibly controlled by myeloid cytokines. 2. LAIR-1 expression on circulating myeloid cells in SLE may be regulated by M-CSF.
Ly6C expression on T cells is modulated by IL-27, interferon-gamma and TCR stimulation
Authors: DeLong Jonathan Howard , Hall Aisling O’Hara , Muallem Gaia , Hunter Christopher A 
Published: January 2023

Abstract
Ly6C is a GPI-anchored glycoprotein expressed on a range of hematopoietic cell lineages. On T cells, its expression distinguishes short-lived effector CD4+ T cells from memory precursor effector cells. The function of Ly6C is unclear but this surface molecule is associated with homing to lymph nodes and crosslinking Ly6C with antibodies reduces T cell production of IL-2. We are investigating the factors that regulate the expression of Ly6C and their possible roles in infection. Using sorted Ly6C-negative naive T cells we found that TCR stimulation is not sufficient to induce Ly6C expression, whereas the cytokines IL-27 and interferon-gamma (IFNg) alone can induce Ly6C expression. However, this cytokine-mediated induction is enhanced by TCR stimulation. The in vivo significance of this pathway is seen during toxoplasmosis, when both naïve and activated parasite specific effector CD4+ and CD8+ T cells upregulated Ly6C expression. This upregulation was reduced in mice that lack IL-27. While these results suggest that cytokines have a major role in the regulation of Ly6C expression, it remains unclear how this affects T cell function and what role cytokine-mediated expression plays in the specific expression of Ly6C on effector but not memory populations.
CD103 expression on DCs regulates the onset and severity of TH17 airway inflammation
Authors: Bernatchez Emilie , Langlois Anick , Brassard Julyanne , Marsolais David , Blanchet Marie-Renée 
Published: January 2023

Abstract
Pulmonary dendritic cells (DCs) drive TH17 immunopathological responses to foreign antigens, including Saccharopolyspora rectivirgula (SR), a causative agent of hypersensitivity pneumonitis (HP). More specifically, CD103+ DCs, a DC cell subset found in the lung, are associated with the induction of TH17 responses; however, this remains controversial, as they are also associated with regulatory activity. Furthermore, the importance and modulation of CD103 expression on DCs and T cells in homeostasis maintenance and the regulation of TH17 hypersensitivity responses is elusive. We aimed to verify whether modulation of CD103 expression is important in the onset and regulation of the TH17 hypersensitivity lung response in HP. Exposure to SR in Cd103−/− mice led to an exacerbation of the inflammatory response as early as 18h after the first exposure to SR. Using DC and T cell transfers experiments, we demonstrate that CD103 expression on DCs specifically (and not T cells) is crucial in regulating this TH17 response. Interestingly, we observed that SR exposure (in vivo and in vitro) reduces rapidly CD103 protein and mRNA expression by DCs. In conclusion, we demonstrate that CD103 expression by DCs at the onset of the TH17 inflammatory response is crucial for homeostasis maintenance and regulation of the TH17 hypersensitivity response, and that loss of CD103 expression following antigen exposure may be a new mechanism leading to homeostasis breakdown in the lung.
Identifying exosome binding and internalization in blood cell subsets by imaging flow cytometry.
Authors: Pugsley Haley Renee , Friend Sherree , Probst Christine , Morrissey Phil 
Published: January 2023

Abstract
Only recently has the importance of extracellular vesicles as key mediators of intercellular communication been appreciated. Extracellular vesicles are membrane derived structures that include exosomes, microvesicles and apoptotic bodies. Exosomes have been shown to transfer molecules between cells and have the potential to transfer signals between cells. Exosomes are released under normal physiological conditions; however, they are also believed to serve as mediators in the pathogenesis of neurological, vascular, hematological and autoimmune diseases as well as cancer. Quantifying and characterizing exosomes in a reproducible and reliable manner has been difficult due to their small size (50 – 100 nm in diameter). Exosomes analysis can be done using high-magnification microscopy however this technique has a very low throughput. Attempts to analyze exosomes using traditional flow cytometers has been hampered by the limit of detection of such small particles and low refractive index. To overcome these limitations we have employed multispectral imaging flow cytometry that has the advantage of combining high throughput flow cytometry with higher sensitivity to small particles and the added benefit of imaging that can provide visual confirmation of particle integrity and characterization. In this study we use multispectral imaging flow cytometry to investigate the interaction of exosomes with white blood cells. Exosomes derived from different cell types will be investigated for their preferential interactions with blood cell subsets by combining immunophenotyping with morphological parameters to measure their binding and internalization.
Hepatocyte-dependent cross-presentation of soluble antigens induces antigen-specific CD8+ T cell tolerance
Authors: Damo Martina , Wilson D. Scott , Hubbell Jeffrey A. 
Published: January 2023

Abstract
The ability of hepatocytes to cross-present soluble extracellular antigens and the related immunological outcomes remain poorly investigated.
Our work shows that murine primary hepatocytes actively uptake and process extracellular antigens in EEA1+ and TAP1+ phagosomes, which are functionally related to cross-presentation. In fact EEA1+TAP1+ organelles, which are one of the signatures of professional cross-presenting cells, are also found in the cytoplasm of hepatocytes. Moreover, in vitro hepatocyte-dependent cross-presentation of OVA to OT-I cells is sensitive to specific drug inhibitors of endosomal and proteasomal activity, providing direct evidence that endocytosed antigens enter the cross-presentation pathway.
In vivo, cross-presenting hepatocytes induce tolerance of adoptively transferred OT-I cells by clonal deletion, as pro-apoptotic markers are upregulated on hepatocyte-educated OT-I cells. Non-deleted OT-I cells show instead significantly reduced response to vaccination, indicative of anergy. Active engulfment or emperipolesis of antigen cross-presenting hepatocytes by OT-I cells is also detected in vitro, as an additional means of T cell deletion.
PD-1/PD-L1 interactions participate in the induction of hepatocyte-dependent cross-tolerance, as specific blockage of PD-L1 on hepatocytes significantly reduces the development of hepatocyte-dependent cross-tolerance.
Due to their physiologic metabolic functions and their capacity to cross-present extracellular antigens here described, we propose hepatocytes as one of the major players in the establishment of antigen-specific CD8+ T cell peripheral tolerance.
Transcriptional control of RORγt across innate and adaptive immunity.
Authors: Pokrovskii Maria , Kim Sang Yong , Ciofani Maria , Littman Dan R 
Published: January 2023

Abstract
RORγt is the transcription factor responsible for the development and function of T helper 17 (Th17), γδT17, and innate lymphoid cells (ILC3s), which are key drivers of both immunity in tissues proximal to barrier surfaces and of autoimmune pathogenesis. An understanding of how regulation of the RORγt locus contributes to the programming of these separate lineages is crucial to dissecting the confounding ability of RORγt to drive such divergent responses. Examination of mice deficient in individual transcription factors that we found to constitute a key regulatory module driving Th17 cell development revealed divergent control of RORγt in innate and adaptive immune cells. This evidence suggests that distinct genomic cis-acting regulatory elements drive RORγt expression in a context dependent manner. Indeed, we found that cell-specific combinatorial usage of enhancers regulates the development and function of RORγt+ lineages in-vivo. Specifically, Th17 and ILC3 have largely unique enhancer usage while innate-like gdT17 cells share both innate and adaptive elements. We show that in vivo deletion of individual enhancer elements can modulate RORγt expression in a cell-type specific manner, the tuning of which affects cell frequency and function. Our findings provide new opportunities to study the contributions of individual RORγt+ lineages to immunity and inflammation. Moreover, these enhancers, which are highly conserved in humans, can be used to locate novel polymorphisms involved in the stratification of RORγt-dependent disease.
Structure-functional dissection of VTCN1 protein: Impact of individual extracellular domains and N-linked glycosylation modifications on its co-inhibitory function.
Authors: Amatya Christina , Radichev Ilian , Savinov Alexei 
Published: January 2023

Abstract
V-set Domain-Containing T Cell Activation Inhibitor 1 (VTCN1), also known as B7-H4, is a negative co-stimulatory ligand that inhibits T cell activation/proliferation. We have previously shown that VTCN1 signaling is impaired in context of type I diabetes in both mouse models and human patients. Moreover, aberrant VTCN1 expression has been associated with certain ovarian and renal carcinomas. These findings highlight the importance of VTCN1 as a potential therapeutic target.
At present, neither the receptor, nor the mechanism of VTCN1 action is known. Structurally, VCTN1 is a 283 a. a.-long heavily glycosylated protein with a very short intracellular tail followed by a type 1 hydrophobic transmembrane domain and a long extracellular part consisting of Ig-like V-set (IgV) and Ig-like C-set (IgC) domains. Here, we used reductionist approach to study discrete contributions of VTCN1 Ig-like domains, as well as impact of separate/combined N-linked glycosylation modifications in VTCN1 co-inhibitory function. Accordingly, we generated a set of mouse VTCN1 protein mutants, engineered to contain each of its two domains alone and/or in combination, and carrying either deletion(s) or point mutation(s) of the potential proteins’ glycosylation sites. We then evaluated the ability of these mutant proteins to bind pre-activated T cells in culture and influence T cell proliferation and cytokine production.
We show that both IgV and IgC VTCN1 domains retain inhibitory activities, even though IgV domain mostly constrains T cell proliferation, while IgC domain predominantly inhibits cytokine production. Additionally, we reveal that glycosylation of VTCN1 is crucial for its membrane trafficking, folding and negative co-stimulatory functions.