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This article explores the role of mechano-regulated proteins YAP and TAZ in promoting gut regeneration in patients with inflammatory bowel disease (IBD). The study found that alterations in mechanotransduction can impact gut regeneration, with mechano-stimulatory drugs aiding regeneration and low mechanical treatments exacerbating gut injury. The researchers also identified the importance of smooth muscle cells' WNT4 in gut regeneration and the role of YAP/TAZ in regulating WNT4 levels. The study suggests that mechanotransduction promotes gut regeneration through the YAP/TAZ-WNT4 signaling axis. [Extracted from the article]

Background: Angiogenesis plays an important role in the occurrence and development of non‐small cell lung cancer (NSCLC). The atypical mitogen‐activated protein kinase 4 (MAPK4) has been shown to be involved in the pathogenesis of various diseases. However, the potential role of MAPK4 in the tumor angiogenesis of NSCLC remains unclear. Methods: Adult male C57BL/6 wild‐type mice were randomly divided into the control group and p‐siMAPK4 intervention group, respectively. The cell proliferation was analyzed with flow cytometry and immunofluorescence staining. The vascular density in tumor mass was analyzed by immunofluorescence staining. The expressions of MAPK4 and related signaling molecules were detected by western blot analysis and immunofluorescence staining, and so on. Results: We found that the expression of MAPK4, which was dominantly expressed in local endothelial cells (ECs), was correlated with tumor angiogenesis of NSCLC. Furthermore, MAPK4 silencing inhibited the proliferation and migration abilities of human umbilical vein ECs (HUVECs). Global gene analysis showed that MAPK4 silencing altered the expression of multiple genes related to cell cycle and angiogenesis pathways, and that MAPK4 silencing increased transduction of the extracellular regulated protein kinases 1/2 (ERK1/2) pathway but not Akt and c‐Jun n‐terminal kinase pathways. Further analysis showed that MAPK4 silencing inhibited the proliferation and migration abilities of HUVECs cultured in tumor cell supernatant, which was accompanied with increased transduction of the ERK1/2 pathway. Clinical data analysis suggested that the higher expression of MAPK4 and CD34 were associated with poor prognosis of patients with NSCLC. Targeted silencing of MAPK4 in ECs using small interfering RNA driven by the CD34 promoter effectively inhibited tumor angiogenesis and growth of NSCLC in vivo. Conclusion: Our results reveal that MAPK4 plays an important role in the angiogenesis and development of NSCLC. MAPK4 may thus represent a new target for NSCLC. [ABSTRACT FROM AUTHOR]

Coxsackievirus B3 (CVB3), a single-stranded positive RNA virus, primarily infects cardiac myocytes and is a major causative pathogen for viral myocarditis (VMC), driving cardiac inflammation and organ dysfunction. However, whether and how myocardial damage is involved in CVB3-induced VMC remains unclear. Herein, we demonstrate that the CVB3 infection of cardiac myocytes results in the release of mitochondrial DNA (mtDNA), which functions as an important driver of cardiac macrophage inflammation through the stimulator of interferon genes (STING) dependent mechanism. More specifically, the CVB3 infection of cardiac myocytes promotes the accumulation of extracellular mtDNA. Such myocardial mtDNA is indispensable for CVB3-infected myocytes in that it induces a macrophage inflammatory response. Mechanistically, a CVB3 infection upregulates the expression of the classical DNA sensor STING, which is predominantly localized within cardiac macrophages in VMC murine models. Myocardial mtDNA efficiently triggers STING signaling in those macrophages, resulting in strong NF-kB activation when inducing the inflammatory response. Accordingly, STING-deficient mice are able to resist CVB3-induced cardiac inflammation, exhibiting minimal inflammation with regard to their functional cardiac capacities, and they exhibit higher survival rates. Moreover, our findings pinpoint myocardial mtDNA as a central element driving the cardiac inflammation of CVB3-induced VMC, and we consider the DNA sensor, STING, to be a promising therapeutic target for protecting against RNA viral infections. [ABSTRACT FROM AUTHOR]

The aorta and the large conductive arteries are immunoprivileged tissues and are protected against inflammatory attack. A breakdown of immunoprivilege leads to autoimmune vasculitis, such as giant cell arteritis, in which [CD8.sup.+] Treg cells fail to contain [CD4.sup.+] T cells and macrophages, resulting in the formation of tissue-destructive granulomatous lesions. Here, we report that the molecular defect of malfunctioning [CD8.sup.+] Treg cells lies in aberrant NOTCH4 signaling that deviates endosomal trafficking and minimizes exosome production. By transcriptionally controlling the profile of RAB GTPases, NOTCH4 signaling restricted vesicular secretion of the enzyme NADPH oxidase 2 (NOX2). Specifically, [NOTCH4.sup.hi][CD8.sup.+] Treg cells increased RAB5A and RAB11A expression and suppressed RAB7A, culminating in the accumulation of early and recycling endosomes and sequestering of NOX2 in an intracellular compartment. [RAB7A.sup.lo][CD8.sup.+] Treg cells failed in the surface translocation and exosomal release of NOX2. [NOTCH4.sup.hi][RAB5A.sup.hi][RAB7A.sup.lo][RAB11A.sup.hi][CD8.sup.+] Treg cells left adaptive immunity unopposed, enabling a breakdown in tissue tolerance and aggressive vessel wall inflammation. Inhibiting NOTCH4 signaling corrected the defect and protected arteries from inflammatory insult. This study implicates NOTCH4-dependent transcriptional control of RAB proteins and intracellular vesicle trafficking in autoimmune disease and in vascular inflammation., Introduction The aorta and its major side branches are nonredundant for host survival and are protected against inflammatory attack; an immune privilege broken in the case of vasculitis (1). In [...]

Activated lymphocyte-derived DNA (ALD-DNA) has been reported to drive the polarization of macrophages toward M2b, producing inflammatory cytokines and inducing inflammation, correspondingly playing an essential role in the development of systemic lupus erythematosus (SLE). Recently, accumulating evidence has pinpointed metabolic adaptation as the crucial cell-intrinsic determinant for inflammatory response, in which glucose metabolism is the key event. However, whether and how glucose metabolism was involved in ALD-DNA-induced macrophage inflammatory response and SLE development remains unclear. Herein, we performed glucose metabolomic analyses of ALD-DNA-stimulated macrophages and uncovered increased glycolysis and diminished pentose phosphate pathway (PPP), as well as enhanced glycogenesis. In ALD-DNA-stimulated macrophages, increased glycolysis resulted in higher lactate production, whereas diminished PPP efficiently led to lower levels of nicotinamide adenine dinucleotide phosphate (NADPH) with higher levels of reactive oxygen species (ROS). While blockade of lactate generation exerted no significant effect on macrophage inflammation in response to ALD-DNA, scavenging ROS fundamentally inhibited the inflammatory response of ALD-DNA-stimulated macrophages. Further, cyclic adenosine monophosphate (cAMP), a master for regulating glycogen metabolism, was downregulated by ALD-DNA in macrophages, which subsequently imbalanced glycogen metabolism toward glycogenesis but not glycogenolysis. Administration of cAMP effectively restored glycogenolysis and enhanced PPP, which correspondingly reduced ROS levels and inhibited the inflammatory response of ALD-DNA-stimulated macrophages. Finally, blocking glucose metabolism using 2-deoxy-D-glucose (2-DG) efficiently restricted macrophage inflammatory response and alleviated ALD-DNA-induced lupus disease. Together, our findings demonstrate that ALD-DNA drives the adaptation of glucose metabolism for inducing macrophage inflammatory response in SLE, which might further our understanding of disease pathogenesis and provide clues for interventive explorations. [ABSTRACT FROM AUTHOR]

T cells are critical players in adaptive immunity, driving the tissue injury and organ damage of patients with autoimmune diseases. Consequently, investigations on T cell activation, differentiation, and function are valuable in uncovering the disease pathogenesis, thus exploring promising therapeutics for autoimmune diseases. In recent decades, accumulating studies have pinpointed immunometabolism as the fundamental determinant in controlling T cell fate. Specifically, mitochondria, as a hub of intracellular metabolism, connect glucose, lipid, and amino acid metabolic pathways. Herein, we summarize metabolic adaptations of mitochondrial oxidative phosphorylation and the relevant glucose, lipid, and amino acid metabolism during T cell activation, differentiation, and function. Further, we focused on current updates of the molecular bases for metabolic reprogramming in autoimmune T cells and advances in exploring metabolic-targeted therapeutics against autoimmune diseases. This might facilitate the in-depth understanding of autoimmune pathogeneses and the clinical management of autoimmune diseases. [ABSTRACT FROM AUTHOR]

Lung cancer is a commonly diagnosed cancer and the leading cause of cancer-related deaths, posing a serious health risk. Despite new advances in immune checkpoint and targeted therapies in recent years, the prognosis for lung cancer patients, especially those in advanced stages, remains poor. MicroRNAs (miRNAs) have been shown to modulate tumor development at multiple levels, and as such, miRNA mimics and molecules aimed at regulating miRNAs have shown promise in preclinical development. More importantly, miRNA-based therapies can also complement conventional chemoradiotherapy, immunotherapy, and targeted therapies to reverse drug resistance and increase the sensitivity of lung cancer cells. Furthermore, small interfering RNA (siRNA) and miRNA-based therapies have entered clinical trials and have shown favorable development prospects. Therefore, in this paper, we review recent advances in miRNA-based therapies in lung cancer treatment as well as adjuvant therapy and present the current state of clinical lung cancer treatment. We also discuss the challenges facing miRNA-based therapies in the clinical application of lung cancer treatment to provide new ideas for the development of novel lung cancer therapies. [ABSTRACT FROM AUTHOR]

Immune aging results in progressive loss of both protective immunity and T cell-mediated suppression, thereby conferring susceptibility to a combination of immunodeficiency and chronic inflammatory disease. Here, we determined that older individuals fail to generate immunosuppressive [CD8.sup.+][CCR7.sup.+] Tregs, a defect that is even more pronounced in the agerelated vasculitic syndrome giant cell arteritis. In young, healthy individuals, [CD8.sup.+][CCR7.sup.+] Tregs are localized in T cell zones of secondary lymphoid organs, suppress activation and expansion of CD4 T cells by inhibiting the phosphorylation of membrane-proximal signaling molecules, and effectively inhibit proliferative expansion of CD4 T cells in vitro and in vivo. We identified deficiency of NADPH oxidase 2 (NOX2) as the molecular underpinning of CD8 Treg failure in the older individuals and in patients with giant cell arteritis. CD8 Tregs suppress by releasing exosomes that carry preassembled NOX2 membrane clusters and are taken up by CD4 T cells. Overexpression of NOX2 in aged CD8 Tregs promptly restored suppressive function. Together, our data support NOX2 as a critical component of the suppressive machinery of CD8 Tregs and suggest that repairing NOX2 deficiency in these cells may protect older individuals from tissue-destructive inflammatory disease, such as large-vessel vasculitis., Introduction The immune system has evolved to protect the host against pathogens and cancerous cells, while keeping tissue-damaging inflammation at a minimum (1). Tregs serve the imperative role of dampening [...]

While previous studies have identified cancer stem‐like cells (CSCs) as a crucial driver for chemoresistance and tumor recurrence, the underlying mechanisms for populating the CSC pool remain unclear. Here, we identify hypermitophagy as a feature of human lung CSCs, promoting metabolic adaption via the Notch1‐AMPK axis to drive CSC expansion. Specifically, mitophagy is highly active in CSCs, resulting in increased mitochondrial DNA (mtDNA) content in the lysosome. Lysosomal mtDNA acts as an endogenous ligand for Toll‐like receptor 9 (TLR9) that promotes Notch1 activity. Notch1 interacts with AMPK to drive lysosomal AMPK activation by inducing metabolic stress and LKB1 phosphorylation. This TLR9‐Notch1‐AMPK axis supports mitochondrial metabolism to fuel CSC expansion. In patient‐derived xenograft chimeras, targeting mitophagy and TLR9‐dependent Notch1‐AMPK pathway restricts tumor growth and CSC expansion. Taken together, mitochondrial hemostasis is interlinked with innate immune sensing and Notch1‐AMPK activity to increase the CSC pool of human lung cancer. Synopsis: Lung cancer stem‐like cells show high levels of mitophagy, resulting in lysosomal mtDNA accumulation that activates TLR9 and Notch1‐AMPK signaling. The TLR9‐Notch1‐AMPK pathway promotes CSC expansion and can be therapeutically targeted. CSCs show mitophagic hyperactivity, resulting in the accumulation of mtDNA in lysosomes.Lysosomal mtDNA activates TLR9 and drives the expansion of lung CSCs.TLR9 interacts with Notch1, triggering Notch1 activation and subsequent AMPK phosphorylation.Blocking the TLR9‐dependent Notch1‐AMPK pathway inhibits tumor outgrowth and reduces lung CSCs. [ABSTRACT FROM AUTHOR]

Objective: Takayasu arteritis (TA) is a major type of large vessel vasculitis characterized by progressive inflammation in vascular layers. In our recent study we identified a central role of mechanistic target of rapamycin (mTOR) hyperactivity in proinflammatory T cell differentiation in TA. This study was undertaken to explore potential mechanisms underpinning T cell–intrinsic mTOR hyperactivity and vascular inflammation in TA, with a focus on Notch‐1. Methods: Notch‐1 expression and activity was determined according to Notch‐1, activated Notch‐1, and HES‐1 levels. We detected mTOR activity with intracellular expression of phosphorylated ribosomal protein S6. Differentiation of proinflammatory T cells was analyzed by detecting Th1 and Th17 lineage‐determining transcription factors. The function of Notch‐1 was evaluated using γ‐secretase inhibitor DAPT and gene knockdown using a short hairpin RNA (shRNA) strategy. We performed our translational study using humanized NSG mouse chimeras in which human vasculitis was induced using immune cells from TA patients. Results: CD4+ T cells from TA patients exerted Notch‐1high, leading to mTOR hyperactivity and spontaneous maldifferentiation of Th1 cells and Th17 cells. Blockade of Notch‐1 using DAPT and Notch‐1 shRNA efficiently abrogated mTOR complex 1 (mTORC1) activation and proinflammatory T cell differentiation. Mechanistically, Notch‐1 promoted mTOR expression, interacted with mTOR, and was associated with lysosomal localization of mTOR. Accordingly, systemic administration of DAPT and CD4+ T cell–specific gene knockdown of Notch‐1 could alleviate vascular inflammation in humanized TA chimeras. Conclusion: Expression of Notch‐1 is elevated in CD4+ T cells from TA patients, resulting in mTORC1 hyperactivity and proinflammatory T cell differentiation. Targeting Notch‐1 is a promising therapeutic strategy for the clinical management of TA. [ABSTRACT FROM AUTHOR]

Objective: Accumulating studies have identified self‐DNA as driving IgG anti–double‐stranded DNA (anti‐dsDNA) in lupus, though the underpinning mechanisms of this process remain largely undefined. Here, we explored the activity of transcription factor retinoic acid receptor–related orphan nuclear receptor γt (RORγt) in the differentiation and function of self‐DNA–specific follicular helper T (Tfh) cells in lupus. Methods: B6, TCRα–/–, CD4–/–, RORγtfl/flCD4Cre, RORγt+/+CD4Cre, Bcl‐6fl/flCD4Cre, Bcl‐6+/+CD4Cre, IL‐17–/–, and ICOS–/– mice were immunized with normal self‐DNA, immunogenic self‐DNA, and pathogen DNA to induce the production of Tfh cells and IgG anti‐dsDNA. Tfh cells with or without interleukin‐17 (IL‐17) were evaluated for their role in supporting the generation of IgG. NSG mice were reconstituted with immune cells and circulating DNA from human subjects for translational studies. IL‐17–positive Tfh cells were analyzed for their correlation with IgG anti‐dsDNA levels as well as their response to circulating self‐DNA in lupus patients. Results: Unlike normal self‐DNA, immunogenic self‐DNA and pathogen DNA efficiently induced IgG responses. Immunogenic self‐DNA induced IgG in a CD4+ T cell–dependent manner, which was abrogated by RORγt deficiency. In contrast, RORγt was not required for the generation of pathogen DNA–induced IgG. Further analyses identified RORγt as essential for the differentiation and function of Tfh cells in response to immunogenic self‐DNA, assigning IL‐17 as a feature cytokine. These IL‐17–positive Tfh cells functioned independent of inducible costimulator (ICOS), critically supporting IgG generation. Targeting immunogenic self‐DNA–specific Tfh cells by RORγ knockdown and IL‐17 blockade ameliorated IgG response and lupus nephritis in a humanized mouse model. The presence of IL‐17–positive Tfh cells was associated with IgG anti‐dsDNA levels and were expanded by circulating immunogenic self‐DNA in lupus patients. Conclusion: Immunogenic self‐DNA instructs ICOS‐dispensable IL‐17–positive Tfh cells via RORγt to produce an IgG anti‐dsDNA response. As such, IL‐17–positive Tfh cells are a promising therapeutic target for lupus patients. [ABSTRACT FROM AUTHOR]

Nef is an accessory protein encoded by human immunodeficiency virus type-1 (HIV-1) and plays important roles in regulating HIV-1 infection and viral replication. Interestingly, HIV-1 Nef can promote degradation of numerous host proteins to disrupt cellular antiviral immune response. However, how HIV-1 Nef is degraded by host factors remains largely unexplored. Here, we identified c-Cbl as a host ubiquitin E3 ligase of HIV-1 Nef. We found that c-Cbl interacts with Nef and reduces protein levels of HIV-1 Nef. Further studies demonstrated that c-Cbl promoted Lys48-linked polyubiquitination of HIV-1 Nef, thus attenuating protein stability of HIV-1 Nef. Importantly, cellular c-Cbl ubiquitinated and degraded Nef proteins produced by HIV-1 NL4-3 virions, and ultimately attenuated HIV-1 virulence for infection of THP1 cells. This study reveals a ubiquitination and proteasome-dependent degradation mechanism of HIV-1 Nef protein, and could provide potential strategies for fighting against HIV-1. [ABSTRACT FROM AUTHOR]

Objective: Takayasu arteritis (TAK) is a progressive autoimmune large vessel vasculitis with infiltration of proinflammatory T cells, with a largely unknown etiology. This study was undertaken to explore the involvement of mechanistic target of rapamycin (mTOR) in proinflammatory T cell differentiation and disease progression in TAK. Methods: Ninety‐five patients with TAK, 26 patients with small vessel vasculitis, and 40 healthy donors were enrolled. Naive and memory CD4+ T cells were activated with anti‐CD3/CD28 beads and analyzed for lineage differentiation. The mTORC1 activity was determined by quantifying intracellular phospho–S6 kinase 1 and phospho–S6 ribosomal protein. Rapamycin and lentiviral regulatory‐associated protein of mTOR short hairpin RNA were used to block mTORC1 activity. Human artery–NSG mouse chimeras representing human TAK were established for targeting mTORC1 in disease treatment. Results: TAK CD4+ T cells were selectively prepositioned with hyperactivity of mTORC1 (P < 0.001), resulting in spontaneous maldifferentiation of Th1 and Th17 cells (P < 0.001). Activity of mTORC1high in circulating CD4+ T cells predicted elevated frequencies of proinflammatory T cells and active disease in TAK patients (P < 0.001). Blockade of mTORC1 with rapamycin efficiently abrogated the maldifferentiation of Th1 and Th17 cells (P < 0.01) and ameliorated vasculitis in humanized TAK chimeras (P < 0.001). Inhibition of mTORC1 using RNA interference technology is sufficient to reduce proinflammatory T cell frequencies (P < 0.01) and restrict TAK disease progression in vivo (P < 0.01). Conclusion: Our findings indicate that hyperactivity of mTORC1 is a critical cell‐intrinsic mechanism underlying spontaneous maldifferentiation of proinflammatory T cells in TAK patients. Targeting mTORC1 is a promising therapeutic strategy against TAK. [ABSTRACT FROM AUTHOR]

Background: Autoimmune hemolytic anemia (AIHA), a life-threatening anemia with rapid onset, is caused by autoantibody directed to self red blood cells (RBCs). Currently, mechanisms underlying AIHA pathogenesis are largely undefined. Here we explored the correlation of IL-33 with AIHA disease activity and evaluated IL-33 based therapeutics in AIHA treatment.Methods: Thirty patients diagnosed with AIHA of warm-type autoantibodies without treatment were enrolled and followed up for 6 months. Levels of cytokines including IL-33, IL-4, IL-6 and IL-13 was determined with ELISA. AIHA disease activity was presented by levels of reticulocyte count, hemoglobin and lactate dehydrogenase. Serum RBC-bound IgG autoantibody was detected using anti-IgG antibody with flow cytometry. To evaluate the effect of IL-33 blockade on AIHA development, groups of B6 mice were immunized with rat RBCs plus recombinant IL-33 protein or IL-33 neutralizing antibody respectively and detected for levels of anti-RBC antibody, frequency of reticulocytes and destruction of transfused syngeneic mouse RBCs.Results: Serum level of IL-33 was higher in AIHA patients compared with healthy individuals. Of interest, serum IL-33 was positively correlated with AIHA disease activity and sensitive to their changes in AIHA patients under clinical management. Mechanistically, IL-33 could promote the production of anti-RBC autoantibody. Serum IL-33 was closely associated with serum anti-RBC autoantibody and sensitive to their changes in AIHA patients. Accordingly, blockade of IL-33 interfered with AIHA incidence and ameliorated disease activity. Vice vasa, enforced IL-33 promoted AIHA incidence and disease activity.Conclusions: IL-33 was a potential biomarker for monitoring disease activity and therapeutic response in AIHA patients. Targeting IL-33 was a promising strategy for controlling autoantibody production in AIHA patients. [ABSTRACT FROM AUTHOR]

Our recent evidence showed that prior expansion of CCR6+ Foxp3+ regulatory T cells (Tregs) was important for their dominant enrichment in tumor tissue, which was closely related to poor prognosis of breast cancer patients. However, the underlying regulation mechanism of expansion of CCR6+ Tregs in situ remains largely unknown. In this study, we reported that miR-21 was highly expressed in CCR6+ Tregs in tumor tissues from a murine breast cancer model. And silencing of miR-21 could significantly reduce the proliferation of CCR6+ Tregs in vitro. Adoptive cell-transfer assay further showed that silencing of miR-21 could alter the enrichment of CCR6+ Tregs in the tumor mass and endow effectively antitumor effect of CD8+ T cells using a murine breast cancer model. Mechanistic evidence showed that silencing of miR-21 enhanced the expression of its target phosphatase and tensin homolog deleted on chromosome ten (PTEN) and subsequently altered the activation of Akt pathway, which was ultimately responsible for reduced proliferation activity of CCR6+ Tregs. Finally, we further revealed that miR-21 was also highly expressed on CCR6+ Tregs in clinical breast cancer patients. Therefore, miR-21 can act as a fine tuner in the regulation of PTEN/Akt pathway transduction in the expansion of CCR6+ Tregs in tumor sites and provided a novel insight into the development of therapeutic strategies for promoting T-cell immunity by regulating distinct subset of Tregs through targeting specific miRNAs. [ABSTRACT FROM AUTHOR]

Background and Aims: Lupus nephritis (LN), with considerable morbidity and mortality, is one of the most severe manifestations of systemic lupus erythematosus (SLE). Yet, the pathogenic mechanisms of LN have not been clearly elucidated, and efficient therapies are still in great need. Granulin (GRN), a multifunctional protein linked to inflammatory diseases, has recently been reported to correlate with the disease activity of autoimmune diseases. However, the role of GRN in the pathogenic process of LN still remains obscure. In this study, we explored its potential role and underlying mechanism in the pathogenesis of LN. Methodology/Principal Findings: We found that serum GRN levels were significantly up-regulated and were positively correlated with the severity of LN. Overexpression of GRN in vivo by transgenic injection remarkably exacerbated LN, whereas down-regulation of GRN with shRNA ameliorated LN, firmly demonstrating the critical role of GRN in the pathogenesis of LN. Notably, macrophage phenotype analysis revealed that overexpression of GRN could enhance macrophage polarization to M2b, a key mediator of the initiation and progression of LN. On the contrary, down-regulation of GRN resulted in impaired M2b differentiation, thus ameliorating LN. Moreover, we found that MAPK signals were necessary for the effect of GRN on macrophage M2b polarization. Conclusion/Significance: We first demonstrated that GRN could aggravate lupus nephritis (LN) via promoting macrophage M2b polarization, which might provide insights into the pathogenesis of LN as well as potential therapeutic strategies against LN. [ABSTRACT FROM AUTHOR]

Lupus nephritis is one of the most serious manifestations and one of the strongest predictors of a poor outcome in systemic lupus erythematosus (SLE). Recent evidence implicated a potential role of interlukin-17 (IL-17) in the pathogenesis of lupus nephritis. However, the correlation between IL-17 expression level and the severity of lupus nephritis still remains incompletely understood. In this study, we found that serum IL-17 expression level was associated with the severity of lupus nephritis, which was evaluated by histopathology of kidney sections and urine protein. Of note, we showed that enforced expression of IL-17 using adenovirus construct that expresses IL-17 could enhance the severity of lupus nephritis, while blockade of IL-17 using neutralizing antibody resulted in decreased severity of lupus nephritis. Consistently, we observed an impaired induction of lupus nephritis in IL-17-deficient mice. Further, we revealed that IL-17 expression level was associated with immune complex deposition and complement activation in kidney. Of interest, we found that IL-17 was crucial for increasing anti-double-stranded DNA (dsDNA) antibody production in SLE. Our results suggested that IL-17 expression level positively correlated with the severity of lupus nephritis, at least in part, because of its contribution to anti-dsDNA antibody production. These findings provided a novel mechanism for how IL-17 expression level correlated with disease pathogenesis and suggested that management of IL-17 expression level was a potential and promising approach for treatment of lupus nephritis. [ABSTRACT FROM AUTHOR]

Recent evidence showed that limited activation of PI3K/Akt pathway was critical for induction and function sustainment of CD4+Foxp3+ regulatory T cells (Tregs). However, the underlying mechanism remains largely unknown. In this study, we reported that miR-126 was expressed in mouse and human Tregs. Further study showed that silencing of miR-126 using miR-126 antisense oligonucleotides ( ASO) could significantly reduce the induction of Tregs in vitro. Furthermore, miR-126 silencing could obviously reduce the expression of Foxp3 on Tregs, which was accompanied by decreased expression of CTLA-4 and GITR, as well as IL-10 and TGF-β, and impair its suppressive function. Mechanistic evidence showed that silencing of miR-126 enhanced the expression of its target p85β and subsequently altered the activation of PI3K/Akt pathway, which was ultimately responsible for reduced induction and suppressive function of Tregs. Finally, we further revealed that miR-126 silencing could impair the suppressive function of Tregs in vivo and endow effectively antitumour effect of CD8+T cells in adoptive cell transfer assay using a murine breast cancer model. Therefore, our study showed that miR-126 could act as fine-tuner in regulation of PI3K-Akt pathway transduction in the induction and sustained suppressive function of Tregs and provided a novel insight into the development of therapeutic strategies for promoting T-cell immunity by regulating Tregs through targeting specific mi RNAs. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusion To explore T cell‐intrinsic mechanisms underpinning the mal‐differentiation of tissue‐resident memory T (Trm) cells in patients with rheumatoid arthritis (RA).Circulating T cells from patient with RA and healthy individuals were used for Trm cell differentiation. The role of Hobit in Trm differentiation was investigated through targeted silencing experiments. Psmb5 expression regulation was explored by identifying BRD2 as a key transcription factor, with the interaction validated through chromatin immunoprecipitation‐quantitative polymerase chain reaction. The impact of BRD2 succinylation on Trm differentiation was examined by manipulating succinyl‐CoA levels in T cells. Humanized NSG chimeras representing synovitis provided insights into Trm infiltration in RA synovitis and were used for translational experiments.In patients with RA, a notable predisposition of CD4+ T cells toward differentiation into Trm cells was observed, demonstrating a positive correlation with the disease activity score 28. Remarkably, Hobit was a pivotal facilitator in the formation of RA CD4+ Trm cells. Mechanistic studies unveiled the dysregulation of proteasomal Psmb5 in T cells of patients with RA as the key factor contributing to elevated Hobit protein levels. The deficiency of proteasomal Psmb5 was intricately linked to BRD2, with succinylation exerting a significant impact on Psmb5 transcription and Trm cell differentiation. This heightened BRD2 succinylation was attributed to elevated levels of mitochondrial succinyl‐CoA in RA T cells. Consequently, targeting succinyl‐CoA within CD4+ T cells controlled the inflammation of synovial tissues in humanized chimeras.Mitochondrial succinyl‐CoA fosters the succinylation of BRD2, resulting in compromised transcription of proteasomal Psmb5 and the differentiation of Trm cells in RA. [ABSTRACT FROM AUTHOR]

Abstract: Accumulating data suggested that functional TLR9 was expressed in various tumor cells and TLR9 signaling could enhance the progression of tumor cells. However, the underlying mechanism of TLR9 signaling on the progression of tumors cells remains largely undefined. Our previous study demonstrated that the TLR9 agonist CpG ODNs could significantly enhance the progression of human lung cancer cells in vivo. Here we further evaluated the direct effect of CpG ODNs on the proliferation and cell cycle of human lung cancer cells. Our data showed that TLR9 agonist CpG ODNs could robustly elevate the proliferation and stimulate cell cycle entry of 95D cells in vitro, accompanied by the selectively up-regulated expression of CDK2. Furthermore, we found that down-regulation of CDK2 expression using siRNA against CDK2 could significantly inhibit the enhanced proliferation of 95D cells induced by CpG ODNs. Finally, we investigated that the CpG ODNs could selectively enhance the promoter activity of CDK2. Our findings indicated that TLR9 signaling could selectively up-regulate the expression of CDK2, which was critical for the enhanced proliferation of human lung cancer cells. Our results might provide novel insight into the understanding of functional expression of TLR9 on the progression of tumor cells. [Copyright &y& Elsevier]

The aorta and the large conductive arteries are immunoprivileged tissues and are protected against inflammatory attack. A breakdown of immunoprivilege leads to autoimmune vasculitis, such as giant cell arteritis, in which CD8+ Treg cells fail to contain CD4+ T cells and macrophages, resulting in the formation of tissue-destructive granulomatous lesions. Here, we report that the molecular defect of malfunctioning CD8+ Treg cells lies in aberrant NOTCH4 signaling that deviates endosomal trafficking and minimizes exosome production. By transcriptionally controlling the profile of RAB GTPases, NOTCH4 signaling restricted vesicular secretion of the enzyme NADPH oxidase 2 (NOX2). Specifically, NOTCH4hiCD8+ Treg cells increased RAB5A and RAB11A expression and suppressed RAB7A, culminating in the accumulation of early and recycling endosomes and sequestering of NOX2 in an intracellular compartment. RAB7AloCD8+ Treg cells failed in the surface translocation and exosomal release of NOX2. NOTCH4hiRAB5AhiRAB7AloRAB11AhiCD8+ Treg cells left adaptive immunity unopposed, enabling a breakdown in tissue tolerance and aggressive vessel wall inflammation. Inhibiting NOTCH4 signaling corrected the defect and protected arteries from inflammatory insult. This study implicates NOTCH4-dependent transcriptional control of RAB proteins and intracellular vesicle trafficking in autoimmune disease and in vascular inflammation. [ABSTRACT FROM AUTHOR]

Summary Immune aging manifests with a combination of failing adaptive immunity and insufficiently restrained inflammation. In patients with rheumatoid arthritis (RA), T cell aging occurs prematurely, but the mechanisms involved and their contribution to tissue-destructive inflammation remain unclear. We found that RA CD4 + T cells showed signs of aging during their primary immune responses and differentiated into tissue-invasive, proinflammatory effector cells. RA T cells had low expression of the double-strand-break repair nuclease MRE11A, leading to telomeric damage, juxtacentromeric heterochromatin unraveling, and senescence marker upregulation. Inhibition of MRE11A activity in healthy T cells induced the aging phenotype, whereas MRE11A overexpression in RA T cells reversed it. In human-synovium chimeric mice, MRE11A low T cells were tissue-invasive and pro-arthritogenic, and MRE11A reconstitution mitigated synovitis. Our findings link premature T cell aging and tissue-invasiveness to telomere deprotection and heterochromatin unpacking, identifying MRE11A as a therapeutic target to combat immune aging and suppress dysregulated tissue inflammation. [ABSTRACT FROM AUTHOR]

Abstract: Our previous data showed that CpG-ODNs could significantly enhance the anti-tumor efficacy of adoptively cell transfer (ACT), which was closely correlated to accumulation of Th17 cells in tumor mass. Here we further investigated that CpG-ODNs had no significant effect on the migration and proliferation capacity of Th17 cells in tumor mass. Instead, we showed that CpG-ODNs could induce the differentiation of Th17 cells via dendritic cells (DCs) in tumor infiltrating lymphocytes (TILs). Notably, we found that plasmacytoid dendritic cells (pDCs), but not myeloid dendritic cells (mDCs), were responsible for the Th17 differentiation induced by CpG-ODNs via IL-6, TGF-β and IFN-α in vitro. Finally, we revealed that CpG-ODNs could stimulate pDCs to induce the differentiation of Th17 cells in vivo, which subsequently reduced the tumor size and prolonged the survival of tumor bearing nude mice. These data provided a novel insight into the mechanism of anti-tumor efficacy of CpG-ODNs based therapeutic strategy. [Copyright &y& Elsevier]

Abstract: Chemokines play a critical role in the acute transplant rejection. In order to provide an overview of the chemokine expression during the course of acute allograft rejection, the intragraft expression profile of 11 chemokines representative of all four chemokine subfamilies was analyzed in a murine skin transplantation model of acute rejection. It was found that RANTES/CCL5, TARC/CCL17 and FKN/CX3CL1 were expressed at equivalent levels in iso- and allografts. However, the other eight chemokines expression was up-regulated to some extent in allograft compared with that in isograft. The levels of MIP-1α/CCL3, MIP-3α/CCL20 and CTACK/CCL27 were progressively increased from early stage (day 3 post-transplantation) to late stage (day 11). Mig/CXCL9, IP-10/CXCL10, I-TAC/CXCL11, CXCL16 and LTN/XCL1 expression was elevated at middle stage (day 7), and peaked at late stage. Among the up-regulated chemokines, I-TAC was the most obviously elevated chemokine. Therefore, the effect of I-TAC on the skin acute allograft rejection was evaluated. Block of I-TAC by the intradermal injection of anti-I-TAC monoclonal antibody (mAb) reduced the number of CXCR3+ cells in skin allograft and significantly prolonged the skin allograft survival. The mAb treatment did not influence the proliferation of the intragraft infiltrating cells in response to the allogeneic antigens, but significantly decreased the number of the infiltrating cells and consequently lowered the secretion of IFN-γ and TNF-α. These data indicate I-TAC might be a dominant chemokine involved in the intradermal infiltration and I-TAC-targeted intervening strategies would have potential application for the alleviation of acute transplant rejection. [Copyright &y& Elsevier]

Mitochondrial DNA (mtDNA) is frequently released from mitochondria, activating cGAS-STING signaling and inducing type I IFNs (IFN-Is) in systemic lupus erythematosus (SLE). Meanwhile, whether and how the glycolytic pathway was involved in such IFN-I responses in human SLE remain unclear. In this study, we found that monocytes from SLE patients exerted robust IFN-I generation and elevated level of cytosolic mtDNA. Transfection of mtDNA into THP-1 macrophages was efficient in inducing IFN-I responses, together with the strong glycolytic pathway that promoted lactate production, mimicking the SLE phenotype. Blockade of lactate generation abrogated such IFN-I responses and, vice versa, exogenous lactate enhanced the IFN-I generation. Mechanistically, lactate promoted the lactylation of cGAS, which inhibited its binding to E3 ubiquitination ligase MARCHF5, blocking cGAS degradation and leading to strong IFN-I responses. In accordance, targeting lactate generation alleviated disease development in humanized SLE chimeras. Collectively, cytosolic mtDNA drives metabolic adaption toward the glycolytic pathway, promoting lactylation of cGAS for licensing IFN-I responses in human SLE and thereby assigning the glycolytic pathway as a promising therapeutic target for SLE., (Copyright © 2024 by The American Association of Immunologists, Inc.)

Objectives: Patients with systemic lupus erythematosus (SLE) display heightened immune activation and elevated IgG autoantibody levels, indicating compromised regulatory T cell (Tregs) function. Our recent findings pinpoint CD8+ Tregs as crucial regulators within secondary lymphoid organs, operating in a NOX2-dependent mechanism. However, the specific involvement of CD8+ Tregs in SLE pathogenesis and the mechanisms underlying their role remain uncertain., Methods: SLE and healthy individuals were enlisted to assess the quantity and efficacy of Tregs. CD8+CD45RA+CCR7+ Tregs were generated ex vivo, and their suppressive capability was gauged by measuring pZAP70 levels in targeted T cells. Notch1 activity was evaluated by examining activated Notch1 and HES1, with manipulation of Notch1 accomplished with Notch inhibitor DAPT, Notch1 shRNA, and Notch1-ICD. To create humanized SLE chimeras, immune-deficient NSG mice were engrafted with PBMCs from SLE patients., Results: We observed a reduced frequency and impaired functionality of CD8+ Tregs in SLE patients. There was a downregulation of NOX2 in CD8+ Tregs from SLE patients, leading to a dysfunction. Mechanistically, the reduction of NOX2 in SLE CD8+ Tregs occurred at a post-translational level rather than at the transcriptional level. SLE CD8+ Tregs exhibited heightened Notch1 activity, resulting in increased expression of STUB1, an E3 ubiquitin ligase that binds to NOX2 and facilitates its ubiquitination. Consequently, restoring NOX2 levels and inhibiting Notch1 activity could alleviate the severity of the disease in humanized SLE chimeras., Conclusion: Notch1 is the cell-intrinsic mechanism underlying NOX2 deficiency and CD8+ Treg dysfunction, serving as a therapeutic target for clinical management of SLE., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objectives: Takayasu's arteritis (TAK) is a progressive autoimmune vasculitis that mainly affects the aorta and its major branches. While recent studies have identified proinflammatory T cells, including Th1 and Th17 cells, as the dominant infiltrates in the arterial adventitia, mechanisms underpinning the maintenance of such vasculogenic T cells remain obscure., Methods: 75 patients with TAK and 30 age-matched healthy controls were enrolled in this study. CD4 T cells from TAK patients were activated with anti-CD3/CD28 beads to mimic vasculogenic T cells. The survival of T cells was detected by quantifying Annexin-V+7-AAD+ fractions. Expression and activity of AMP-activated protein kinase (AMPK) were determined using phosflow cytometry and immunoblots. Specific inhibitors and shRNA were applied to block the function of AMPK and Notch1, while erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were used to reflect the disease activity of TAK patients., Results: T cells from TAK patients undergo spontaneous differentiation into vasculogenic proinflammatory T cells with prolonged survival capacity. Mechanistic explorations uncover AMPK hyperactivity in such T cells from TAK patients, promoting mitochondrial metabolism and their survival. Such AMPK hyperactivity results from the robust Notch1 activity in TAK T cells. Accordingly, T cell-intrinsic phosphor-AMPK reflects the disease activity in clinical TAK patients., Conclusions: AMPK hyperactivity is essential for maintaining the vasculogenic proinflammatory T cells in TAK patients, serving as a promising therapeutic target for TAK management.

Cancer stem-like cells (CSCs) are critically involved in cancer metastasis and chemoresistance, acting as one major obstacle in clinical practice. While accumulating studies have implicated the metabolic reprogramming of CSCs, mitochondrial dynamics in such cells remain poorly understood. Here we pinpointed OPA1hi with mitochondrial fusion as a metabolic feature of human lung CSCs, licensing their stem-like properties. Specifically, human lung CSCs exerted enhanced lipogenesis, inducing OPA1 expression via transcription factor SAM Pointed Domain containing ETS transcription Factor (SPDEF). In consequence, OPA1hi promoted mitochondrial fusion and stemness of CSCs. Such lipogenesishi, SPDEFhi, and OPA1hi metabolic adaptions were verified with primary CSCs from lung cancer patients. Accordingly, blocking lipogenesis and mitochondrial fusion efficiently impeded CSC expansion and growth of organoids derived from patients with lung cancer. Together, lipogenesis regulates mitochondrial dynamics via OPA1 for controlling CSCs in human lung cancer.

Background: Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease mainly mediated by IgG autoantibody. While follicular helper T (Tfh) cells are crucial for supporting IgG autoantibody generation in human SLE, underlying mechanisms for Tfh cell mal-differentiation remain unclear., Methods: In total, 129 SLE patients and 37 healthy donors were recruited for this study. Circulating leptin was determined by ELISA from patients with SLE and healthy individuals. CD4 T cells isolated from SLE patients and healthy donors were activated with anti-CD3/CD28 beads under cytokine-unbiased conditions in the presence or absence of recombinant leptin protein, followed by detection for Tfh cell differentiation by quantifying intracellular transcription factor Bcl-6 and cytokine IL-21. AMPK activation was assessed by analyzing phosphor-AMPK using phosflow cytometry and immunoblots. Leptin receptor expression was determined using flow cytometry and its overexpression was achieved by transfection with an expression vector. Humanized SLE chimeras were induced by injecting patients' immune cells into immune-deficient NSG mice and used for translational studies., Results: Circulating leptin was elevated in patients with SLE, inversely associated with disease activity. In healthy individuals, leptin efficiently inhibited Tfh cell differentiation through inducing AMPK activation. Meanwhile, leptin receptor deficiency was a feature of CD4 T cells in SLE patients, impairing the inhibitory effect of leptin on the differentiation of Tfh cells. As a result, we observed the coexistence of high circulating leptin and increased Tfh cell frequencies in SLE patients. Accordingly, overexpression of leptin receptor in SLE CD4 T cells abrogated Tfh cell mal-differentiation and IgG anti-dsDNA generation in humanized lupus chimeras., Conclusion: Leptin receptor deficiency blocks the inhibitory effect of leptin on SLE Tfh cell differentiation, serving as a promising therapeutic target for lupus management., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Liu, Zheng, Jia, Wang, Tang, Wen, Zhang and Yuan.)

Lupus nephritis (LN) is a severe renal disease caused by the massive deposition of the immune complexes (ICs) in renal tissue, acting as one of the significant organ manifestations of systemic lupus erythematosus (SLE) and a substantial cause of death in clinical patients. As mesangium is one of the primary sites for IC deposition, mesangial cells (MCs) constantly undergo severe damage, resulting in excessive proliferation and increased extracellular matrix (ECM) production. In addition to playing a role in organizational structure, MCs are closely related to in situ immunomodulation by phagocytosis, antigen-presenting function, and inflammatory effects, aberrantly participating in the tissue-resident immune responses and leading to immune-mediated renal lesions. Notably, such renal-resident immune responses drive a second wave of MC damage, accelerating the development of LN. This review summarized the damage mechanisms and the in situ immune regulation of MCs in LN, facilitating the current drug research for exploring clinical treatment strategies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Liu, Zhang, Wang, Hu, Wang and Wen.)

Pathogenic T cells in individuals with rheumatoid arthritis (RA) infiltrate non-lymphoid tissue sites, maneuver through extracellular matrix and form lasting inflammatory microstructures. Here we found that RA T cells abundantly express the podosome scaffolding protein TKS5, which enables them to form tissue-invasive membrane structures. TKS5 overexpression was regulated by the intracellular metabolic environment of RA T cells-specifically, by reduced glycolytic flux that led to deficiencies in ATP and pyruvate. ATP lo pyruvate lo conditions triggered fatty acid biosynthesis and the formation of cytoplasmic lipid droplets. Restoration of pyruvate production or inhibition of fatty acid synthesis corrected the tissue-invasiveness of RA T cells in vivo and reversed their proarthritogenic behavior. Thus, metabolic control of T cell locomotion provides new opportunities to interfere with T cell invasion into specific tissue sites.

Microvascular networks in the adventitia of large arteries control access of inflammatory cells to the inner wall layers (media and intima) and thus protect the immune privilege of the aorta and its major branches. In autoimmune vasculitis giant cell arteritis (GCA), CD4 T helper 1 (T H 1) and T H 17 cells invade into the wall of the aorta and large elastic arteries to form tissue-destructive granulomas. Whether the disease microenvironment provides instructive cues for vasculitogenic T cells is unknown. We report that adventitial microvascular endothelial cells (mvECs) perform immunoregulatory functions by up-regulating the expression of the Notch ligand Jagged1. Vascular endothelial growth factor (VEGF), abundantly present in GCA patients' blood, induced Jagged1 expression, allowing mvECs to regulate effector T cell induction via the Notch-mTORC1 (mammalian target of rapamycin complex 1) pathway. We found that circulating CD4 T cells in GCA patients have left the quiescent state, actively signal through the Notch pathway, and differentiate into T H 1 and T H 17 effector cells. In an in vivo model of large vessel vasculitis, exogenous VEGF functioned as an effective amplifier to recruit and activate vasculitogenic T cells. Thus, systemic VEGF co-opts endothelial Jagged1 to trigger aberrant Notch signaling, biases responsiveness of CD4 T cells, and induces pathogenic effector functions. Adventitial microvascular networks function as an instructive tissue niche, which can be exploited to target vasculitogenic immunity in large vessel vasculitis., (Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Background: Autoimmune hemolytic anemia (AIHA), a life-threatening anemia with rapid onset, is caused by autoantibody directed to self red blood cells (RBCs). Currently, mechanisms underlying AIHA pathogenesis are largely undefined. Here we explored the correlation of IL-33 with AIHA disease activity and evaluated IL-33 based therapeutics in AIHA treatment., Methods: Thirty patients diagnosed with AIHA of warm-type autoantibodies without treatment were enrolled and followed up for 6 months. Levels of cytokines including IL-33, IL-4, IL-6 and IL-13 was determined with ELISA. AIHA disease activity was presented by levels of reticulocyte count, hemoglobin and lactate dehydrogenase. Serum RBC-bound IgG autoantibody was detected using anti-IgG antibody with flow cytometry. To evaluate the effect of IL-33 blockade on AIHA development, groups of B6 mice were immunized with rat RBCs plus recombinant IL-33 protein or IL-33 neutralizing antibody respectively and detected for levels of anti-RBC antibody, frequency of reticulocytes and destruction of transfused syngeneic mouse RBCs., Results: Serum level of IL-33 was higher in AIHA patients compared with healthy individuals. Of interest, serum IL-33 was positively correlated with AIHA disease activity and sensitive to their changes in AIHA patients under clinical management. Mechanistically, IL-33 could promote the production of anti-RBC autoantibody. Serum IL-33 was closely associated with serum anti-RBC autoantibody and sensitive to their changes in AIHA patients. Accordingly, blockade of IL-33 interfered with AIHA incidence and ameliorated disease activity. Vice vasa, enforced IL-33 promoted AIHA incidence and disease activity., Conclusions: IL-33 was a potential biomarker for monitoring disease activity and therapeutic response in AIHA patients. Targeting IL-33 was a promising strategy for controlling autoantibody production in AIHA patients.