bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fasting-induced FOXO4 blunts human CD4+ T helper cell responsiveness
Authors: Han Kim K , Singh Komudi , Rodman Matthew J , Hassanzadeh Shahin , Wu Kaiyuan , Huffstutler Rebecca D , Dagur Pradeep K , Saxena Ankit , McCoy J. Philip , Teague Heather J , Mehta Nehal N , Pirooznia Mehdi , Sack Michael N 
Published: February 2023

Abstract
Intermittent fasting blunts inflammation in asthma and rheumatoid arthritis, suggesting that fasting may be exploited as an immune-modulatory intervention. However, mechanisms underpinning anti-inflammatory effects of fasting remain poorly characterized. Here, we show that fasting in humans is sufficient to blunt CD4+ T helper cell responsiveness. RNA-seq and flow cytometric immunophenotyping of peripheral blood mononuclear cells (PBMCs) from volunteers subjected to overnight or 24-hour fasting, and 3-hours of refeeding implicate that fasting blunts CD4+ T helper cell activation and differentiation. Transcriptomic analysis reveal that the longer fast-duration has a more robust effect on CD4+ T cell biology. Through bioinformatic analyses, we identify the transcription factor FOXO4 and its canonical target FKBP5 as a potential fasting-responsive regulatory axis. Genetic gain- or loss-of-function of FOXO4 and FKBP5 is sufficient to modulate Th1 and Th17 cytokine production. Moreover, we find that fasting-induced or genetic overexpression of FOXO4 and FKBP5 is sufficient to downregulate mTORC1 signaling and suppress STAT1/3 activation. Our results identify FOXO4-FKBP5 as a novel fasting-induced, STAT-mediated, regulatory pathway to blunt human CD4+ T helper cell responsiveness.
Synergistic induction of TNF-α by palmitate and oxidative stress in human monocytic cells involves the NF-κB/p38 MAPK signaling
Authors: Sindhu Sardar T.A.K. , Akhter Nadeem , Wilson Ajit , Al-Rashed Fatema , Al-Madhoun Ashraf , Arefanian Hossein , AL-Mulla Fahd , Ahmad Rasheed 
Published: February 2023

Abstract
Tumor necrosis factor (TNF)-α is a key proinflammatory cytokine expressed in obesity/ type-2 diabetes. In metabolic disease conditions, TNF-α is co-expressed with increased circulatory levels of free fatty acids, such as long-chain unsaturated fatty acid palmitate. The hypoxic milieu in the adipose tissue is known to exert oxidative stress. Although it is known that palmitate may induce TNF-α in different cell types, it still remains unclear whether the oxidative stress could augment TNF-α expression in human monocytic cells, and thus exacerbate metabolic inflammation. To test the hypothesis, THP-1 monocytic cells were stimulated with palmitate, in presence or absence of hydrogen peroxide (H2O2) or 1% hypoxia. TNF-α, CHOP, ERN1, and HIF-1α mRNA expression was assessed by qRT-PCR; TNF-α protein expression was detected by flow cytometry/ immunohistochemistry; reactive oxygen species (ROS) expression was measured by DCFH-DA assay; and NF-κB/p38 MAPK phosphorylation was detected by western blotting. We found that TNF-α mRNA and protein expression were significantly upregulated in THP-1 cells co-stimulated with palmitate and H2O2/hypoxia. TNF-α expression associated positively with intracellular ROS, transcripts of CHOP, ERN1, HIF-1α, and phosphorylation of NF-κB/p38 MAPK. Synergistic TNF-α expression co-induced by palmitate and H2O2/hypoxia was diminished by cell treatments with curcumin, apocynin, or N-acetyl cysteine (P&lt;0.01). In conclusion, palmitate and oxidative stress promote the TNF-α expression in human monocytic cells via the mechanisms involving ER stress, HIF-1α stabilization, and NF-κB/p38 MAPK signaling. These findings may have pathophysiological significance in metabolic inflammatory conditions.
The Wnt antagonist Dickkopf1(DKK1) promotes pulmonary fibrosis via M2-like macrophage polarization
Authors: Chae Wook-Jin , Sung Eun-Ah , Hur Brian , Park Min Hee 
Published: February 2023

Abstract
Tissue fibrosis is a progressive pathological process induced by repeated tissue injury and inflammation resulting in excessive collagen deposition. The Wnt signaling pathway regulates cell proliferation and differentiation for tissue repair processes. Dickkopf1 (DKK1) is a quintessential inhibitory ligand of the Wnt pathway. M2-like macrophages, induced by type 2 cytokines such as IL-13, play a central role in tissue fibrosis. We found that DKK1 protein expression markedly increased in both lung tissues of human idiopathic pulmonary fibrosis (IPF) and lungs from the murine bleomycin (BLM)-induced fibrosis model. To investigate the role of DKK1 in lung fibrosis, we used the DKK1 hypomorphic doubleridge (Dkk1d/d) mouse model. Collagen mRNA and protein expressions were markedly decreased in the lungs of Dkk1d/d mice compared to those of WT mice upon BLM challenge. The infiltration of macrophages was significantly decreased in the lungs of Dkk1d/d mice upon lung injury. We tested whether DKK1 modulates the polarization of M2-like macrophages in vitro using mouse bone marrow-derived macrophages (BMDMs). Interestingly, DKK1 induced M2-like macrophage marker CD206 (mannose receptor) and Arginase 1 (Arg1) protein expression. The expression of CD206 and Arg1 was synergistically increased by DKK1 and IL-13. We demonstrated that DKK1 utilizes STAT6 and JNK to induce Arg1 and CD206. Taken together, our study demonstrates that DKK1 promotes pulmonary fibrosis by activation of M2-like macrophages. Our study will provide new mechanistic insights into DKK1-mediated lung fibrosis pathogenesis.
Antigen presenting group 3 innate lymphoid cells orchestrate neuroinflammation
Authors: Grigg John B , Shanmugavadivu Arthi , Regen Tommy , Parkhurst Christopher N , Ahmed Anees , Joseph Ann M , Mazzucco Michael , Eberl Gerard , Vartanian Timothy , Waisman Ari , Sonnenberg Gregory F 
Published: February 2023

Abstract
Pro-inflammatory T cells in the central nervous system (CNS) are causally associated with multiple demyelinating and neurodegenerative diseases, but the pathways controlling these responses remain unclear. Here we define a unique population of group 3 innate lymphoid cells (ILC3s) that infiltrate the CNS in a mouse model of multiple sclerosis. These ILC3s are derived from the circulation, localize in proximity to infiltrating T cells in the CNS, function as antigen presenting cells that restimulate myelin-specific T cells, and are elevated in the blood of individuals with multiple sclerosis. Critically, antigen presentation by ILC3s is required to promote pro-inflammatory T cell responses in the CNS and the development of multiple sclerosis-like disease in mouse models. In contrast, conventional and tissue-resident ILC3s in the periphery do not appear to contribute to disease induction, but rather remain tolerogenic with the potential to limit autoimmune T cells and prevent multiple sclerosis-like disease when experimentally targeted to present myelin antigen. Collectively, our data define an inflammatory ILC3 population that is essential for directly promoting T cell-dependent neuroinflammation in the CNS and reveal the potential to harness peripheral tissue-resident ILC3s for the prevention of autoimmune disease.
Atherosclerotic plaque T cells produce cytokines but do not exhibit signs of T-cell receptor-mediated activation
Authors: Mulholland Megan , Jakobsson Gabriel , Sundius Lena , Ljungcrantz Irena , Rattik Sara , Bengtsson Eva , Schiopu Alexandru , Nilsson Jan , Herter Jan , Björkbacka Harry , Lichtman Andrew H , Engelbertsen Daniel 
Published: February 2023

Abstract
T-cell activation in the atherosclerotic plaque has been proposed to be a key event promoting lesion inflammation and destabilization. Although T cells and antigen-presenting cells are present in the plaque, it is unclear whether primary activation or secondary re-activation of T cells occurs in the lesion. We sought to quantify and characterize activated plaque T-cells in experimental atherosclerosis utilizing transgenic reporter mice of TCR-signalling (Nur77-GFP) or cytokine production (IFN-γ-YFP). As has been previously described, splenic Nur77hi T cells displayed markers consistent with a recently activated phenotype (PD-1+CD44+). Importantly, we observed very low levels of Nur77hi CD4+ or CD8+ T cells in the atherosclerotic aorta of Nur77-GFP-Apoe−/− mice compared to other tissues. In line with these findings, adoptive transfer of splenic Nur77-GFP CD4+ T cells to lymphodeficient atherosclerotic Rag1−/−Apoe−/− mice revealed markedly lower levels of Nur77hi T cells in plaque compared to lymphoid organs 10 weeks post-transfer, suggesting limited TCR-mediated activation in plaques. Conversely, analysis of atherosclerotic plaques from Apoe−/−IFN-γ-YFP reporter mice demonstrated robust IFN-γ production by CD4+ and CD8+ T cells. Altogether these results indicate that levels of cytokine release are above that of TCR-mediated T-cell activation, suggesting that antigen-driven activation of T cells in the plaque is not key for mediating T-cell driven atherosclerosis.
Electrical activation of vagal efferent or afferent neurons elicits two distinct mechanisms of anti-inflammatory actions.
Authors: Murray Kaitlin M , Rude Kavi M , Sladek Jessica , Reardon Colin 
Published: February 2023

Abstract
Inhibition of inflammation by reducing macrophage activation and pro-inflammatory cytokine production by electrical vagal nerve stimulation is well documented. Despite this ability to regulate inflammation, the mechanisms and intermediaries in this process are not completely understood. Vagal efferent neurons are thought to be the primary source of anti-inflammatory activity, despite the composition of the vagus nerve, which is predominantly vagal afferent neurons. Activation of vagal efferent neurons ameliorates lipopolysaccharide (LPS)-induced sepsis and is dependent on acetylcholine (ACh) derived from choline acetyltransferase (ChAT+) T-cells. Recent studies have identified vagal afferent fibers as anti-inflammatory as well, however the circuitry, including whether these vagal-mediated anti-inflammatory mechanisms converge, is unknown. Here, we show that VNS is capable of eliciting two distinct, anti-inflammatory mechanisms orchestrated by vagal efferent or afferent neurons. Using ChAT+ T-cell conditional KO mice, we show that afferent VNS reduced LPS-induced inflammation independently of T-cell derived ACh by measuring serum and lymphatic organ TNF-α and IL-6 levels. Using a highly selective β2-adrenergic receptor (β2-AR) antagonist, we show that intact, efferent, and notably afferent VNS regulates immunity in a β2-AR-dependent fashion. Together, these findings demonstrate that VNS is capable of eliciting two unique neuro-immune circuits with distinct mechanistic elements. Continued development of these circuits will inform the design of future vagal nerve stimulators, that may improve the efficacy of these devices in the regulation of immunity.
Single-cell RNA Sequencing Reveals Heterogeneity Amongst Immune Cell Subpopulations in LPS-Induced ALI Mice treated with I3C
Authors: Holloman Bryan L , Nagarkatti Mitzi , Nagarkatti Prakash , Wilson Kiesha 
Published: February 2023

Abstract
Traditionally, macrophage M1-vs-M2 dichotomy have remained fundamentally unchanged since their identification. The oversimplification of immune cell subpopulations using flow cytometric analysis fails to capture the full heterogeneity of these cells in response to disease state and treatment. However, single-cell RNA sequencing (sc-RNAseq) serves as a diagnostic tool that clusters cells based on the whole transcriptomics of individual cells, without the limitation of surface markers and transcriptional factors. In the current study, we aimed to better understand the immunomodulatory mechanism of indole-3-carbinol (I3C) on cell state. To that end, 5mg/kg of LPS was intranasally injected in C57BL/6 mice to induce ALI, and the mice were treated with 80mg/kg I3C three hours after disease induction. After 72 hours mice were euthanized. Whole lung cells were utilized for flow cytometry and sc-RNAseq. Strikingly, the traditional M1-vs-M2 separation was inadequate in classifying all macrophage clusters. LPS+I3C treated-mice had a decrease in Isg15, Ccl5, and Ly6c2 expression in M1 cluster; genes linked to inflammation. Also, the expression of monocyte chemoattractant genes (Cxcl2 and Cxcl3), arginine-associated transport gene (Slc7ac), and major histocompatibility complex (MHC) genes (H2-Ab1 and H2-K1) in M2 cluster was decreased in the diseased group following I3C treatment. In conclusion, several alterations in gene expression in myeloid immune cell subpopulations were identified following treatment with indole-3-carbinol. Thus, shedding light on several new macrophage subpopulations not identified using traditional flow cytometric analysis may offer novel mechanistic insights into disease induction.
Immunological Age Prediction in HIV-Infected, ART-Treated Individuals
Authors: de Armas Lesley , Pallikkuth Suresh , Pan Li , Rinaldi Stefano , Pahwa Rajendra , Pahwa Savita 
Published: February 2023

Abstract
Anti-retroviral therapy (ART) improves life expectancy in people living with HIV (PWH), but it remains unclear how chronic HIV infection affects normal aging of the immune system.
Plasma cell-free protein expression and immune phenotypes were assessed in blood from ART treated PWH (19–77yrs, n=106) and age-matched, HIV-negative controls (HC, n=103). Age-associated parameters were identified in HC and PWH independently by univariate Spearman correlation (p&lt;0.05) to obtain a reduced dataset for downstream statistical modeling. Machine learning algorithms were applied to generate predictive models for age as a continuous variable.
Plasma biomarker analysis resulted in 8-parameter inflammatory index that was higher in PWH compared to HC and correlated with age. Combining flow and plasma data generated 277 and 491 age-associated parameters (out of total 1,357) in HC and PWH, respectively. PWH exhibited different immunological profiles associated with age compared to HC. However, CD38 expression on T cells declined with age in both HC and PWH. Predictive modeling using age-associated parameters in HC generated a 14-parameter signature with 76.9% accuracy to predict chronological age in HC, however this model failed to predict age in PWH (18.6% accuracy) highlighting the effect of HIV infection on immunological aging. A 25-parameter model (IMmunological Age Prediction, IMAP-25) however showed 70% and 53% accuracy in HC and PWH and was used to show an accelerated aging rate in PWH by 5.6 yrs compared to HC.
We applied a statistical approach to generate immune signatures, easily monitored in human blood samples, that could be used as an indicator of one’s ‘immunological age’ during ART-treated HIV infection.
Analysis of the role of helminth TGF-β mimic in tissue repair.
Authors: Lothstein Katherine E , Smyth Danielle J , Maizels Rick , Gause William C 
Published: February 2023

Abstract
Intestinal parasites express excretory/secretory (ES) molecules, which modulate the type-2 immune response, including anti-inflammatory and tissue repair mechanisms. TGF-β mimic (TGM), an ES molecule secreted by Heligmosomoides polygyrus (Hp), binds TGF-β receptors yet lacks structural homology to TGF-β and exhibits distinct receptor interactions. Studies suggest TGM generates higher expression of immunoregulatory Foxp3+ Tregs and decreased fibrotic markers in vitro compared to TGF-β. Host TGF-β also influences wound healing. In cutaneous wounds, effective tissue repair requires rapid suppression of inflammation and production of wound healing factors. We investigated whether TGM modulates wound healing using an in vivo wound biopsy model in which TGM is injected beneath a Tegaderm® layer to mimic cutaneous wound treatment. We showed that TGM accelerates wound healing when applied to the wound at multiple doses and modulates the associated inflammatory response. LC-MS/MS analysis of TGM-treated wound exudate showed increases in proteins mediating leukocyte chemotaxis and proliferation, collagen deposition and fibrotic regulation. Gene expression analysis of TGM-treated wounds revealed enhanced immune cell infiltration of alternatively activated CD206+F4/80+ macrophages and epithelial cells concurrent with accelerated wound closure. These macrophage cell subsets are known to be essential for effective wound healing. Our findings indicate that TGM can enhance skin wound healing and associated recruitment of specific macrophage subsets, type 2 innate immune cells and their cytokine expression. This study will investigate TGM as a potential novel and effective therapeutic option for enhanced wound healing.
Mononuclear phagocytes drive Mertk-dependent T cell regulation at autoimmune and tumor sites
Authors: Whitesell Jennifer C , Lindsay Robin S , Dew Kristen , Rodriguez Erika , Tracy Dayna , Sandor Adam , Yannacone Seth , Jacobelli Jordan , Friedman Rachel Sharon 
Published: February 2023

Abstract
Understanding mechanisms of immune regulation is key to developing effective immunotherapies for autoimmunity and cancer. We examined the role of mononuclear phagocytes (MNPs) in regulating effector T cells in type 1 diabetes and melanoma. MNPs in the islets impaired T cell responsiveness to antigen by preventing T cell arrest. MNPs in the autoimmune lesion express the TAM family receptor tyrosine kinase Mertk which functions in efferocytosis. Inhibition or deficiency of Mertk led to a release from T cell regulation characterized by enhanced T cell arrest in pre-diabetic islets and at the tumor site. T cell arrest was accompanied by increased T cell-antigen presenting cell interactions in the islets. Antigen experience and effector function by T cells was increased with Mertk inhibition in the islets, but not in lymph nodes. Single cell RNA-seq analysis of islet MNPs identified multiple myeloid subsets. Inhibition of Mertk induced the most significant changes in gene expression among the islet resident macrophages including upregulation of inflammatory cytokine and adhesion genes. In the NOD mouse model, inhibition of Mertk-dependent T cell regulation culminated in the rapid acceleration of autoimmune pathology and disease. In human islets, the number of Mertk-expressing cells were increased in remaining insulin-containing islets from type 1 diabetic patients, suggesting that they might have a protective role in human disease. These data indicate that Mertk signaling in MNPs drives T cell regulation that functions specifically at the disease site in peripheral tissues through a mechanism that prevents T cell arrest and hinders response to antigen.
CD82 promotes CD8+ T cell immune responses by mediating T cell polarization and immunological synapse formation
Authors: Kim Sang-Hoon , Park Areum , Yu Jihyun , Kim Jiyoung , Song Hyun-Sup , Bae Jihong , Chae Seung Yun , Kim Seongryong , Jung Woomi , Kim You-Me 
Published: February 2023

Abstract
Tetraspanin family proteins form a rigid membrane structure called tetraspanin-enriched microdomain (TEM) on the plasma membrane and regulate multiple cellular processes. CD82, a tetraspanin protein, is highly expressed in various immune cells, but its role in immune responses has been poorly understood. In this study, we investigated the role of CD82 in T cells using CD82 knock-out (KO) mice. At steady state, CD82 KO mice had less memory CD8+ T cells in secondary lymphoid organs compared to wild type mice, which became more pronounced in aged mice. Upon in vitro T cell receptor (TCR) stimulation, CD82 KO CD8+ T cells showed defects in phosphorylation of TCR downstream signaling molecules, activation marker expression, proliferation, and cytokine production. By confocal immunofluorescence imaging, we found that TCR stimulation-induced translocation of the microtubule organizing center and formation of the immunological synapse was impaired in CD82 KO T cells. CD82 seems to recruit T cell polarity-regulating molecules such as Scribble via the PDZ domain-binding motif located in its C-terminus and mediate the T cell polarization. In association with the defective CD8+ T cell activation caused by CD82 deficiency, CD82 KO CD8+ T cells show less efficient anti-tumor immune responses than wild-type cells when transferred to tumor-bearing mice. Collectively, our study demonstrates that CD82 mediates the T cell polarization and is required for the optimal CD8+ T cell effector function.
IL-15 priming alters the regulation of IFN-γ production in NK cells
Authors: Cimpean Maria , Keppel Molly P. , Gainullina Anastasiia , Swain Amanda , Andhey Prabhakar Sairam , He Diana , Young Howard A. , Artyomov Maxim N. , Cooper Megan A. 
Published: February 2023

Abstract
Natural killer (NK) cells are innate lymphocytes important for the control of infections and tumors. Their effector functions can be triggered by inflammatory cytokines or engagement of ITAM-bearing activating receptors. We previously reported that IFN-γ production through ITAM signaling is metabolism-dependent in naïve NK cells. However, cytokine stimulation of naïve cells or priming with high-dose IL-15 prior to ITAM stimulation leads to metabolism-independent IFN-γ production. While both cytokine and receptor stimulation leads to similar IFN-γ protein production, only cytokines upregulate Ifng transcript, suggesting that protein production is translationally regulated in the receptor condition. Based on these observations, we hypothesized that IL-15 priming leads to transcriptional regulation of IFN-γ production in response to ITAM signaling. Indeed, IL-15 primed NK cells strongly upregulated Ifng transcript after receptor stimulation, rendering this receptor stimulation metabolism-independent. Inhibition of glycolysis with 2DG or mTOR with rapamycin during priming inhibited Ifng upregulation upon receptor stimulation and returned metabolism-dependent IFN-γ production. RNA-seq analysis of cytokine-, receptor-stimulated, and IL-15 cultured NK cells identified an association between glycolysis, mTORC1 signaling, and MYC targets with Ifng upregulation. Ongoing work aims to identify how ITAM signaling differs in IL-15 primed versus naïve NK cells. Our studies demonstrate distinct mechanisms of IFN-γ protein production in response to ITAM-mediated signaling between naïve and IL-15 primed NK cells.
TET2 controls differentiation of terminally exhausted CD8 T cells
Authors: Jordan Martha S , Drury Sydney , Giles Josephine R , Manne Sasikanth , Huang Hua , Chen Zeyu , Oldridge Derek , Wherry E. John , Baxter Amy E 
Published: February 2023

Abstract
CD8 T cells are critical for clearing infections and immune surveillance of cancers. However, in the setting of chronic viral infections and tumor growth, CD8 T cells become exhausted. T cell exhaustion (TEX) is characterized by a progressive increase of inhibitory receptor expression and concomitant diminishment of effector function. This diminished function renders the host unable to clear the virus or cancer. The TEX population is heterogenous and can be divided broadly into TEX progenitor and TEX terminal populations. TEX progenitor are self-renewing, responsive to PD-1 blockade and give rise to the later TEX subsets, including short-lived TEX terminal cells. Control of DNA demethylation is required in multiple settings for maintenance or loss of stem-like characteristics. We report that TET2, a methylcytosine dioxygenase that mediates active DNA demethylation, is required for TEX progenitors to differentiate fully into TEX terminal cells. TET2-deficiency during persistent viral infection resulted in a numerical loss of TEX terminal cells, while maintaining the TEX progenitor population. The TEX terminal cells that escaped this differentiation block retained some features of TEX progenitors, including decreased expression of several inhibitory receptors. TET2-deficient TEX progenitors responded to PD-1 blockade but were unable to establish expansion of TEX cells thought to be required for viral control. These data highlight the role of DNA methylation and TET2 in establishing TEX diversity.