Recent studies have shown T cell cross-recognition of SARS-CoV-2 and common cold coronavirus spike proteins. However, the effect of SARS-CoV-2 vaccines on T cell responses to common cold coronaviruses remain unknown. In this study, we analyzed CD4+ T cell responses to spike peptides from SARS-CoV-2 and 3 common cold coronaviruses (HCoV-229E, HCoV-NL63, and HCoV-OC43) before and after study participants received Pfizer-BioNTech (BNT162b2) or Moderna (mRNA-1273) mRNA-based COVID-19 vaccines. Vaccine recipients made broad T cell responses to the SARS-CoV-2 spike protein and we identified 23 distinct targeted peptides in 9 participants including one peptide that was targeted by 6 individuals. Only 4 out of these 23 targeted peptides would potentially be affected by mutations in the UK (B.1.1.7) and South African (B.1.351) variants and CD4+ T cells from vaccine recipients recognized the 2 variant spike proteins as effectively as the spike protein from the ancestral virus. Interestingly, we saw a 3-fold increase in the CD4+ T cell responses to HCoV-NL63 spike peptides post-vaccination. Our results suggest that T cell responses elicited or enhanced by SARS-CoV-2 mRNA vaccines may be able to control SARS-CoV-2 variants and lead to cross-protection from some endemic coronaviruses.
Bezawit A. Woldemeskel, Caroline C. Garliss, Joel N. Blankson
Inhibitors of calcineurin phosphatase activity (CNIs) such as cyclosporin A (CsA) are widely used to treat tissue transplant rejection and acute graft-versus-host disease (aGVHD), for which inhibition of NFAT-dependent gene expression is the mechanistic paradigm. We recently reported that CNIs inhibit TCR-proximal signaling by preventing calcineurin-mediated dephosphorylation of LckS59, an inhibitory modification, raising the possibility of another mechanism by which CNIs suppress immune responses. Here we utilized T cells from mice that express LckS59A, which cannot accept a phosphate at residue 59, to initiate aGVHD. Although CsA inhibited NFAT-dependent gene upregulation in allo-aggressive T cells expressing either LckWT or LckS59A, it was ineffective in treating disease when the T cells expressed LckS59A. Two important NFAT-independent T cell functions were found to be CsA-resistant in LckS59A T cells: upregulation of the cytolytic protein perforin in tissue-infiltrating CD8+ T cells and antigen-specific T:DC (dendritic cell) adhesion and clustering in lymph nodes. These results demonstrate that effective treatment of aGVHD by CsA requires NFAT-independent inhibition of TCR signaling. Given that NFATs are widely expressed and off-target effects are a major limitation in CNI use, it is possible that targeting TCR-associated calcineurin directly may provide effective therapies with less toxicity.
Shizuka Otsuka, Nicolas Melis, Matthias M. Gaida, Debjani Dutta, Roberto Weigert, Jonathan D. Ashwell
Limiting dysfunctional neutrophilic inflammation whilst preserving effective immunity requires a better understanding of the processes that dictate neutrophil function in the tissues. Quantitative mass-spectrometry identified how inflammatory murine neutrophils regulated expression of cell surface receptors, signal transduction networks and metabolic machinery to shape neutrophil phenotypes in response to hypoxia. Through the tracing of labelled amino acids into metabolic enzymes, pro-inflammatory mediators and granule proteins we demonstrated that ongoing protein synthesis shapes the neutrophil proteome. To maintain energy supplies in the tissues, neutrophils consumed extracellular proteins to fuel central carbon metabolism. The physiological stresses of hypoxia and hypoglycaemia, characteristic of inflamed tissues, promoted this extra-cellular protein scavenging with activation of the lysosomal compartment further driving exploitation of the protein rich inflammatory milieu. This study provides a comprehensive map of neutrophil proteomes, analysis of which has led to the identification of active catabolic and anabolic pathways which enable neutrophils to sustain synthetic and effector functions in the tissues.
Emily R. Watts, Andrew J.M. Howden, Tyler Morrison, Pranvera Sadiku, Jens L. Hukelmann, Alex von Kriegsheim, Bart Ghesquière, Fiona Murphy, Ananda S. Mirchandani, Duncan C. Humphries, Robert Grecian, Eilise M. Ryan, Patricia Coelho, Giovanny Rodriguez-Blanco, Tracie M. Plant, Rebecca S. Dickinson, Andrew J. Finch, Wesley Vermaelen, Doreen A. Cantrell, Moira K.B. Whyte, Sarah R. Walmsley
Anemia in β-thalassemia is related to ineffective erythropoiesis and reduced red cell survival. Excess free heme and accumulation of unpaired α-globin chains impose substantial oxidative stress on β-thalassemic erythroblasts and erythrocytes, impacting cell metabolism. We hypothesized that increased pyruvate kinase activity induced by mitapivat (AG-348) in the Hbbth3/+ mouse model for β-thalassemia would reduce chronic hemolysis and ineffective erythropoiesis through stimulation of red cell glycolytic metabolism. Oral mitapivat administration ameliorated ineffective erythropoiesis and anemia in Hbbth3/+ mice. Increased ATP, reduced reactive oxygen species production, and reduced markers of mitochondrial dysfunction associated with improved mitochondrial clearance suggested enhanced metabolism following mitapivat administration in β-thalassemia. The amelioration of responsiveness to erythropoietin resulted in reduced soluble erythroferrone, increased liver Hamp expression, and diminished liver iron overload. Mitapivat reduced duodenal Dmt1 expression potentially by activating the pyruvate kinase M2HIF2α axis, representing a mechanism additional to Hamp in controlling iron absorption and preventing β-thalassemia–related liver iron overload. In ex vivo studies on erythroid precursors from patients with β-thalassemia, mitapivat enhanced erythropoiesis, promoted erythroid maturation, and decreased apoptosis. Overall, pyruvate kinase activation as a treatment modality for β-thalassemia in preclinical model systems had multiple beneficial effects in the erythropoietic compartment and beyond, providing a strong scientific basis for further clinical trials.
Alessandro Matte, Enrica Federti, Charles Kung, Penelope A. Kosinski, Rohini Narayanaswamy, Roberta Russo, Giorgia Federico, Francesca Carlomagno, Maria Andrea Desbats, Leonardo Salviati, Christophe Leboeuf, Maria Teresa Valenti, Francesco Turrini, Anne Janin, Shaoxia Yu, Elisabetta Beneduce, Sebastien Ronseaux, Iana Iatcenko, Lenny Dang, Tomas Ganz, Chun-Ling Jung, Achille Iolascon, Carlo Brugnara, Lucia De Franceschi
The protein kinases IKK-epsilon and TBK1 are activated in liver and fat in mouse models of obesity. We have previously demonstrated that treatment with the IKK-epsilon/TBK1 inhibitor, amlexanox, produces weight loss and relieves insulin resistance in obese animals and patients. While amlexanox treatment caused a transient reduction in food intake, long-term weight loss was attributable to increased energy expenditure via FGF21-dependent beiging of WAT. Amlexanox increased FGF21 synthesis and secretion in several tissues. Interestingly, while hepatic secretion determined circulating levels, it was dispensable for regulating energy expenditure. In contrast, adipocyte-secreted FGF21 may have acted as an autocrine factor that leads to adipose tissue browning and weight loss in obese mice. Moreover, increased energy expenditure was an important determinant of improved insulin sensitivity by amlexanox. Conversely, the immediate reductions in fasting blood glucose observed with acute amlexanox treatment were mediated by suppression of hepatic glucose production via the activation of STAT3 by adipocyte-secreted IL-6. These findings demonstrate that amlexanox improved metabolic health via FGF21 action in adipocytes to increase energy expenditure via WAT beiging, and an endocrine role of adipocyte-derived IL-6 to decrease gluconeogenesis via hepatic STAT3 activation, thereby producing a coordinated improvement in metabolic parameters.
Shannon M. Reilly, Mohammad Abu-Odeh, Magdalene Ameka, Julia H. DeLuca, Meghan C. Naber, Benyamin Dadpey, Nima Ebadat, Andrew V. Gomez, Xiaoling Peng, BreAnne Poirier, Elyse Walk, Matthew J. Potthoff, Alan R. Saltiel
BACKGROUND. Current clinical management of patients with pulmonary nodules involves either repeated LDCT/CT scans or invasive procedures yet causes significant patient misclassification. An accurate non-invasive test is needed to identify malignant nodules and reduce unnecessary invasive tests. METHOD. We developed a diagnostic model based on targeted DNA methylation sequencing of 389 pulmonary nodule patients’ plasma samples, and then validated in 140 plasma samples independently. We tested the model in different stages and subtypes of pulmonary nodules. RESULTS. A 100-feature model was developed and validated for pulmonary nodule diagnosis: the model achieved a ROC-AUC of 0.843 on 140 independent validation samples with an accuracy of 0.800. The performance was well maintained in, 1) 6-20 mm size subgroup (N=100), with a sensitivity of 1.000 and adjusted NPV of 1.000 at 10% prevalence; 2) stage I malignancy (N=90), with a sensitivity of 0.971; 3) different nodule types - solid nodules (N=78) with a sensitivity of 1.000 and adjusted NPV of 1.000, part-solid nodules (N=75) with a sensitivity of 0.947 and adjusted NPV of 0.983, and ground-glass nodules (N=67) with a sensitivity of 0.964 and adjusted NPV of 0.989 at 10% prevalence. This methylation test, called PulmoSeek, outperformed PET-CT and two clinical prediction models (Mayo and Veterans Affairs) in discriminating malignant pulmonary nodules from benign ones. CONCLUSION. This study suggests that the blood-based DNA methylation model may provide a better test for classifying pulmonary nodules, which could help facilitate the accurate diagnosis of early-stage lung cancer from pulmonary nodule patients and guide clinical decisions. FUNDING. The National Key Research and Development Program of China; Science and Technology Planning Project of Guangdong Province; The National Natural Science Foundation of China National.
Wenhua Liang, Zhiwei Chen, Caichen Li, Jun Liu, Jinsheng Tao, Xin Liu, Dezhi Zhao, Weiqiang Yin, Hanzhang Chen, Chao Cheng, Fenglei Yu, Chunfang Zhang, Lunxu Liu, Hui Tian, Kaican Cai, Xiang Liu, Zheng Wang, Ning Xu, Qing Dong, Liang Chen, Yue Yang, Xiuyi Zhi, Hui Li, Xixiang Tu, Xiangrui Cai, Zeyu Jiang, Hua Ji, Lili Mo, Jiaxuan Wang, Jian-Bing Fan, Jianxing He
Vascular stability and tone are maintained by contractile smooth muscle cells (VSMCs). However, injury-induced growth factors stimulate a contractile-synthetic phenotypic modulation which increases susceptibility to abdominal aortic aneurysm (AAA). As a regulator of embryonic VSMC differentiation, we hypothesised that Thymosin β4 (Tβ4) may function to maintain healthy vasculature throughout postnatal life. This was supported by the identification of an interaction with Low density lipoprotein receptor related protein 1 (LRP1), an endocytic regulator of PDGF-BB signalling and VSMC proliferation. LRP1 variants have been implicated by genome-wide association studies with risk of AAA and other arterial diseases. Tβ4-null mice displayed aortic VSMC and elastin defects, phenocopying LRP1 mutants, and their compromised vascular integrity predisposed to Angiotensin II-induced aneurysm formation. Aneurysmal vessels were characterised by enhanced VSMC phenotypic modulation and augmented platelet-derived growth factor (PDGF) receptor (PDGFR)β signalling. In vitro, enhanced sensitivity to PDGF-BB, upon loss of Tβ4, associated with dysregulated endocytosis, with increased recycling and reduced lysosomal targeting of LRP1-PDGFRβ. Accordingly, the exacerbated aneurysmal phenotype in Tβ4-null mice was rescued upon treatment with the PDGFRβ antagonist, Imatinib. Our study identifies Tβ4 as a key regulator of LRP1 for maintaining vascular health and provides insights into the mechanisms of growth factor-controlled VSMC phenotypic modulation underlying aortic disease progression.
Sonali Munshaw, Susann Bruche, Andia N. Redpath, Alisha Jones, Jyoti Patel, Karina N. Dubé, Regent Lee, Svenja S. Hester, Rachel Davies, Giles Neal, Ashok Handa, Michael Sattler, Roman Fischer, Keith M. Channon, Nicola Smart
Tissue-based T cells are important effectors in the prevention and control of mucosal viral infections – less is known about tissue-based B cells. We demonstrate that B cells and antibody-secreting cells (ASCs) are present in inflammatory infiltrates in skin biopsies of persons during symptomatic HSV2 reactivation and early healing. Both CD20+ B cells, most of which are antigen-inexperienced by co-expression of IgD, and ASCs, characterized by dense IgG RNA expression in combination with CD138, IRF4 and Blimp1 RNA, are seen in association with T cells. ASCs are found clustered with CD4+ T cells, suggesting potential for crosstalk. HSV2-specific antibodies to virus surface antigens are also present in tissue and increase in concentration during HSV2 reactivation and healing, unlike in serum where concentrations remain static over time. B cells, ASCs, and HSV-specific antibody were rarely detected in biopsies of unaffected skin. Evaluation of serial biopsies demonstrate that B cells and ASCs follow a more migratory than resident pattern of infiltration in HSV-affected genital skin, in contrast to T cells. Together, these observations suggest distinct phenotypes of B cells in HSV-affected tissue; dissecting their role in reactivation may reveal new therapeutic avenues to control these infections.
Emily S. Ford, Anton M. Sholukh, RuthMabel Boytz, Savanna S. Carmack, Alexis Klock, Khamsone Phasouk, Danica Shao, Raabya Rossenkhan, Paul T. Edlefsen, Tao Peng, Christine Johnston, Anna Wald, Jia Zhu, Lawrence Corey
As part of the centennial celebration of insulin’s discovery, this review summarizes the current understanding of the genetics, pathogenesis, treatment, and outcomes in type 1 diabetes (T1D). T1D results from an autoimmune response that leads to destruction of the β cells in the pancreatic islet and requires life-long insulin therapy. While much has been learned about T1D, it is now clear that there is considerable heterogeneity in T1D with regards to genetics, pathology, response to immune-based therapies, clinical course, and susceptibility to diabetes-related complications. This review highlights knowledge gaps and opportunities to improve the understanding of T1D pathogenesis and outlines emerging therapies to treat or prevent T1D and reduce the burden of T1D.
Alvin C. Powers
GDP-mannose-pyrophosphorylase-B (GMPPB) facilitates the generation of GDP-mannose, a sugar donor required for glycosylation. GMPPB defects cause muscle disease due to hypoglycosylation of α-dystroglycan (α-DG). Alpha-DG is part of a protein complex, which links the extracellular matrix with the cytoskeleton thus stabilizing myofibers. Mutations of the catalytically inactive homolog GMPPA cause AAMR syndrome, which is characterized by achalasia, alacrima, mental retardation, and muscle weakness. Here we show that Gmppa KO mice recapitulate cognitive and motor deficits. As structural correlates we found cortical layering defects, progressive neuron loss, and myopathic alterations. Increased GDP-mannose levels in skeletal muscle and in vitro assays identify GMPPA as an allosteric feedback inhibitor of GMPPB. Thus, its disruption enhances mannose incorporation into glycoproteins including α-Dg in mice and men. This increases α-Dg turnover and thereby lowers α-Dg abundance. In mice dietary mannose restriction beginning after weaning corrects α-DG hyperglycosylation and abundance, normalizes skeletal muscle morphology, and prevents neuron degeneration and the development of motor deficits. Cortical layering and cognitive performance, however, are not improved. We thus identify GMPPA defects as the first congenital disorder of glycosylation characterized by α-DG hyperglycosylation, unravel underlying disease mechanisms and point to potential dietary treatment options.
Patricia Franzka, Henriette Henze, M. Juliane Jung, Svenja C. Schüler, Sonnhild Mittag, Karina Biskup, Lutz Liebmann, Takfarinas Kentache, José Morales, Braulio Martínez, Istvan Katona, Tanja Herrmann, Antje-Kathrin Huebner, J. Christopher Hennings, Susann Groth, Lennart J. Gresing, Rüdiger Horstkorte, Thorsten Marquardt, Joachim Weis, Christoph Kaether, Osvaldo M. Mutchinick, Alessandro Ori, Otmar Huber, Véronique Blanchard, Julia von Maltzahn, Christian A. Hübner
Troponin C (TnC) is a critical regulator of skeletal muscle contraction: it binds Ca2+ to activate muscle contraction. Surprisingly, the gene encoding fast skeletal TnC (TNNC2) has not yet been implicated in muscle disease. Here, we report two families with pathogenic variants in TNNC2. Patients present with a distinct, dominantly inherited congenital muscle disease. Molecular dynamics simulations suggest that the pathomechanisms by which the variants cause muscle disease include disruption of the binding sites for Ca2+ and for troponin I. In line with these findings, physiological studies in myofibers isolated from patients’ biopsies revealed a markedly reduced force response of the sarcomeres to [Ca2+]. This pathomechanism was further confirmed in experiments in which contractile dysfunction was evoked by replacing TnC in myofibers from healthy control subjects with recombinant, mutant TnC. Conversely, the contractile dysfunction of myofibers from patients was repaired by replacing endogenous, mutant TnC with recombinant, healthy TnC. Finally, we tested the therapeutic potential of the fast skeletal muscle troponin activator tirasemtiv in patients’ myofibers and showed that the contractile dysfunction was repaired. Thus, our data reveal that pathogenic variants in TNNC2 cause congenital muscle disease, and they provide therapeutic angles to repair muscle contractility.
Martijn van de Locht, Sandra Donkervoort, Josine M. de Winter, Stefan Conijn, Leon Begthel, Benno Kusters, Payam Mohassel, Ying Hu, Livija Medne, Colin Quinn, Steven A. Moore, A. Reghan Foley, Gwimoon Seo, Darren T. Hwee, Fady I. Malik, Thomas Irving, Weikang Ma, Henk Granzier, Erik-Jan Kamsteeg, Kalyan Immadisetty, Peter Kekenes-Huskey, Jose Renato Pinto, Nicol Voermans, Carsten G. Bönnemann, Coen A.C. Ottenheijm
Cholangiopathies caused by biliary epithelial cell (BEC) injury represent a leading cause of liver failure. No effective pharmacologic therapies exist, and the underlying mechanisms remain obscure. We aimed to explore the mechanisms of bile duct repair after targeted BEC injury. Injection of intermedilysin into BEC-specific human CD59 (hCD59) transgenic mice induced acute and specific BEC death, representing a model to study the early signals that drive bile duct repair. Acute BEC injury induced cholestasis followed by CCR2+ monocyte recruitment and BEC proliferation. By using microdissection and next generation RNA sequencing, we identified five genes that were most upregulated in proliferating BECs after acute injury including Mapk8ip2, Cdkn1a, Itgb6, Rgs4, and Ccl2. Immunohistochemistry analyses confirmed robust upregulation of integrin αvβ6 (ITGβ6) expression in this BEC injury model, after bile duct ligation, and in patients with chronic cholangiopathies. Deletion of Itgb6 gene attenuated BEC proliferation post-acute bile duct injury. Macrophage depletion or Ccr2-deficiency impaired ITGβ6 expression and BEC proliferation. In vitro experiments revealed that bile-acid activated monocytes promoted BEC proliferation through ITGβ6. Our data suggest that BEC injury induces cholestasis, monocyte recruitment, and induction of ITGβ6, which work together to promote BEC proliferation, and that therefore represent potential therapeutic targets for cholangiopathies.
Adrien Guillot, Lucia Guerri, Dechun Feng, Seung-Jin Kim, Yeni Ait Ahmed, Janos Paloczi, Yong He, Kornel Schuebel, Shen Dai, Fengming Liu, Pal Pacher, Tatiana Kisseleva, Xuebin Qin, David Goldman, Frank Tacke, Bin Gao
Several COVID-19 studies have focused on neuropathology. In this issue of the JCI, Qin, Wu, and Chen, et al. focused specifically on people whose acute infection lacked obvious neurological involvement. Severely infected patients showed abnormal grey matter volumes, white matter diffusion, and cerebral blood flow compared with healthy controls and those with mild infection. The data remain associative rather than mechanistic, but correlations with systemic immune markers suggest effects of inflammation, hypercoagulation, or other aspects of disease severity. Mechanistic research is warranted. Given the lack of obvious neurological symptoms, neurocognitive assessments were not performed, but the findings suggest that such assessments may be warranted in severely affected patients, even without obvious symptoms. Further, studying CNS involvement of other disorders with overlapping pathophysiologies, such as inflammation, coagulation, hypoxia, or direct viral infection may reveal the causes for COVID-19 related neuropathology.
Amit Mahajan, Graeme F. Mason
Multisystem Inflammatory Syndrome in Children (MIS-C), a hyperinflammatory syndrome associated with SARS-CoV-2 infection, shares clinical features with toxic shock syndrome, which is triggered by bacterial superantigens. Superantigen specificity for different Vβ-chains results in Vβ-skewing, whereby T cells with specific Vβ-chains and diverse antigen specificity are overrepresented in the TCR repertoire. Here, we characterized the TCR repertoire of MIS-C patients and found a profound expansion of TCR Βeta Variable gene (TRBV)11-2, with up to 24% of clonal T cell space occupied by TRBV11-2 T cells, which correlated with MIS-C severity and serum cytokine levels. Analysis of TRBJ gene usage and CDR3 length distribution of MIS-C expanded TRBV11-2 clones revealed extensive junctional diversity. Patients with TRBV11-2 expansion showed HLA class I allele restriction to HLA-I A02, C35 and C04, indicating a novel mechanism for CDR3-independent T cell expansion. In silico modelling indicated that polyacidic residues in the Vβ chain encoded by TRBV11-2 strongly interact with the superantigen-like motif of SARS-CoV-2 spike glycoprotein, suggesting that unprocessed SARS-CoV-2 spike may directly mediate TRBV11-2 expansion. Overall, our data indicate that a CDR3-independent interaction between SARS-CoV-2 spike and TCR leads to T cell expansion and possibly activation, which may account for the clinical presentation of MIS-C.
Rebecca A. Porritt, Lisa Paschold, Magali Noval Rivas, Mary Hongying Cheng, Lael M. Yonker, Harsha Chandnani, Merrick Lopez, Donjete Simnica, Christoph Schultheiß, Chintda Santiskulvong, Jennifer van Eyk, John K. McCormick, Alessio Fasano, Ivet Bahar, Mascha Binder, Moshe Arditi
Melanomas commonly undergo a phenotype switch, from a proliferative to an invasive state. Such tumor cell plasticity contributes to immunotherapy resistance, however, the mechanisms are not completely understood and thus therapeutically unexploited. Using melanoma mouse models, we demonstrated that blocking the MNK1/2-eIF4E axis inhibited melanoma phenotype switching and sensitized melanoma to anti-PD-1 immunotherapy. We showed that phospho-eIF4E-deficient murine melanomas expressed high levels of melanocytic antigens, with similar results verified in patient melanomas. Mechanistically, we identified phospho-eIF4E-mediated translational control of NGFR, a critical effector of phenotype switching. Genetic ablation of phospho-eIF4E reprogrammed the immunosuppressive microenvironment, exemplified by lowered production of inflammatory factors, decreased PD-L1 expression on dendritic cells and MDSCs, and increased CD8+ T-cell infiltrates. Finally, dual blockade of the MNK1/2-eIF4E axis and the PD-1/PD-L1 immune checkpoint demonstrated efficacy in multiple melanoma models regardless of their genomic classification. An increase in the presence of intratumoral stem-like TCF1+PD-1+CD8+ T cells, a characteristic essential for durable anti-tumor immunity, was detected in mice administered a MNK1/2 inhibitor and anti-PD-1 therapy. Using MNK1/2 inhibitors to repress phospho-eIF4E thus offers a new strategy to inhibit melanoma plasticity and improve response to anti-PD-1 immunotherapy.
Fan Huang, Christophe Goncalves, Margarita Bartish, Joelle Rémy-Sarrazin, Mark E. Issa, Brendan Cordeiro, Qianyu Guo, Audrey Emond, Mikhael Attias, William Yang, Dany Plourde, Jie Su, Marina Godoy Gimeno, Yao Zhan, Alba Galán, Tomasz Rzymski, Milena Mazan, Magdalena Masiejczyk, Jacek Faber, Elie Khoury, Alexandre Benoit, Natascha Gagnon, David Dankort, Fabrice Journe, Ghanem Ghanem, Connie M. Krawczyk, H. Uri Saragovi, Ciriaco A. Piccirillo, Nahum Sonenberg, Ivan Topisirovic, Christopher E. Rudd, Wilson H. Miller Jr., Sonia V. del Rincón
Although cancer cells are frequently faced with nutrient- and oxygen-poor microenvironment, elevated hexosamine-biosynthesis pathway (HBP) activity and protein O-GlcNAcylation (a nutrient sensor) contribute to rapid growth of tumor and are emerging hallmarks of cancer. Inhibiting O-GlcNAcylation could be a promising anti-cancer strategy. The gluconeogenic enzymes phosphoenolpyruvate carboxykinase 1 (PCK1) was downregulated in hepatocellular carcinoma (HCC). However, little is known about the potential role of PCK1 in enhanced HBP activity and HCC carcinogenesis under glucose-limited conditions. In this study, PCK1 knockout markedly enhanced the global O-GlcNAcylation levels under low glucose condition. Mechanistically, metabolic reprogramming in PCK1-loss hepatoma cells led to oxaloacetate accumulation and increased de novo UTP synthesis contributing to uridine diphosphate-N-acetylglucosamine (UDP-GlcNAc) biosynthesis. Meanwhile, deletion of PCK1 also resulted in AMPK-GFAT1 axis inactivation promoting UDP-GlcNAc synthesis for elevated O-GlcNAcylation. Notably, lower expression of PCK1 promoted CHK2 threonine 378 O-GlcNAcylation counteracting its stability and dimer formation, increasing CHK2-dependent Rb phosphorylation and HCC cell proliferation. Moreover, aminooxyacetic acid hemihydrochloride and 6-diazo-5-oxo-L-norleucine blocked HBP-mediated O-GlcNAcylation and suppressed tumor progression in liver-specific Pck1-knockout mice. We reveal a link between PCK1 depletion and hyper-O-GlcNAcylation that underlies HCC oncogenesis and suggest therapeutic targets for HCC that act by inhibiting O-GlcNAcylation.
Jin Xiang, Chang Chen, Rui Liu, Dongmei Gou, Lei Chang, Haijun Deng, Qingzhu Gao, Wanjun Zhang, Lin Tuo, Xuanming Pan, Li Liang, Jie Xia, Luyi Huang, Ke Yao, Bohong Wang, Zeping Hu, Ailong Huang, Kai Wang, Ni Tang
X-linked adrenoleukodystrophy (ALD) is a progressive neurodegenerative disease caused by mutations in ABCD1, the peroxisomal very long-chain fatty acid (VLCFA) transporter. ABCD1 deficiency results in accumulation of saturated VLCFAs. A drug screen using a phenotypic motor assay in a zebrafish ALD model identified chloroquine as the top hit. Chloroquine increased expression of stearoyl-CoA desaturase-1 (scd1), the enzyme mediating fatty acid saturation status, suggesting that a shift towards mono-unsaturated fatty acids relieved toxicity. In human ALD fibroblasts chloroquine also increased SCD1 levels and reduced saturated VLCFAs. Conversely, pharmacological inhibition of SCD1 expression led to an increase in saturated VLCFAs, and CRISPR knockout of scd1 in zebrafish mimicked the motor phenotype of ALD zebrafish. Importantly, saturated VLCFAs caused ER stress in ALD fibroblasts whereas mono-unsaturated VLCFA did not. In parallel, we used liver X receptor (LXR) agonists to increase SCD1 expression, causing a shift from saturated towards mono-unsaturated VLCFA, and normalizing phospholipid profiles. Finally, Abcd1-/y mice receiving LXR agonist in their diet had VLCFA reductions in ALD-relevant tissues. These results suggest that metabolic rerouting of saturated to mono-unsaturated VLCFAs may alleviate lipid toxicity, a strategy that may be beneficial in ALD and other peroxisomal diseases in which VLCFAs play a key role.
Quentin Raas, Malu-Clair van de Beek, Sonja Forss-Petter, Inge M.E. Dijkstra, Abigail DeSchiffart, Briana C. Freshner, Tamara J. Stevenson, Yorrick R.J. Jaspers, Liselotte M. Nagtzaam, Ronald J.A. Wanders, Michel van Weeghel, Joo-Yeon Engelen-Lee, Marc Engelen, Florian Eichler, Johannes Berger, Joshua L. Bonkowsky, Stephan Kemp
A(H3N2) Influenza vaccine effectiveness (VE) were low during 2016-2019 seasons and varied by age. We analyzed neutralizing antibody responses to egg- and cell-propagated vaccine and circulating viruses following vaccination in 375 individuals (aged 7 months to 82 years) across all vaccine eligible age groups in 3 influenza seasons. Antibody responses to cell- compared to egg-propagated vaccine viruses were significantly reduced due to egg-adapted changes T160K, D225G, and L194P in the vaccine hemagglutinins. Vaccine egg-adaptation had differential impact on antibody responses across different age groups. Immunologically naive children immunized with egg-adapted vaccines mostly mounted antibodies targeting egg-adapted epitopes, whereas those previously primed with infection produced broader responses even when vaccinated with egg-based vaccines. In elderly, repeated boost of vaccine egg-adapted epitopes significantly reduced antibody responses to the wild type cell-grown viruses. Analysis with reverse genetics viruses suggested that the response to each egg-adapted substitution varied by age. Antibody responses did not differ in male versus female vaccinees. Here, the combination of age-specific responses to vaccine egg-adapted substitutions, diverse host immune priming histories and virus antigenic drift impacted antibody responses following vaccination and may have led to the low and variable VE against A(H3N2) viruses across different age groups.
Feng Liu, F. Liaini Gross, Stacie N. Jefferson, Crystal Holiday, Yaohui Bai, Li Wang, Bin Zhou, Min Z. Levine
BACKGROUND. Rejection is the primary barrier to broader implementation of vascularized composite allografts (VCA), including face and limb transplants. The immunologic pathways activated in face transplant rejection have not been fully characterized. METHODS. Utilizing skin biopsies prospectively collected over nine years from seven face transplant patients, we studied rejection by gene expression profiling, histology, immunostaining and T cell receptor sequencing. RESULTS. Grade 1 rejection did not differ significantly from non-rejection, suggesting that it does not represent a pathologic state and that watchful waiting is warranted. In Grade 2, there was a balanced upregulation of both pro-inflammatory T cell activation pathways and anti-inflammatory checkpoint and immunomodulatory pathways, with a net result of no tissue injury. In Grade 3, IFNγ-driven inflammation, antigen presenting cell activation and infiltration of the skin by proliferative T cells bearing markers of antigen specific activation and cytotoxic effector molecules tipped the balance towards tissue injury. Rejection of VCA and solid organ transplants had both distinct and common features. VCA rejection was uniquely associated with upregulation of immunoregulatory genes, including SOCS1, induction of lipid antigen-presenting CD1 proteins, and infiltration by T cells predicted to recognize CD1b and CD1c. CONCLUSIONS. Our findings suggest that the distinct features of VCA rejection reflect the unique immunobiology of skin and that enhancing cutaneous immunoregulatory networks may be a useful strategy in combatting rejection.
Thet Su Win, William J. Crisler, Beatrice Dyring-Andersen, Rachel Lopdrup, Jessica E. Teague, Qian Zhan, Victor Barrera, Shannan J. Ho Sui, Sotirios Tasigiorgos, Naoka Murakami, Anil Chandraker, Stefan G. Tullius, Bohdan Pomahac, Leonardo V. Riella, Rachael Clark
SUMOylation emerged as the inducer for the sorting of bioactive molecules into extracellular vesicles (EVs) triggering lymphangiogenesis, further driving tumor lymph node (LN) metastasis, but the precise mechanisms remain largely unclear. Herein, we identified that bladder cancer (BCa) cell-secreted EVs mediated the intercellular communication with human lymphatic endothelial cells (HLECs) through the transmission of a long noncoding RNA ELNAT1, and promoted lymphangiogenesis and LN metastasis in a SUMOylation-dependent manner in both cultured BCa cell lines and mouse models. Mechanistically, ELNAT1 induced UBC9 overexpression to catalyze the SUMOylation of hnRNPA1 at lysine-113 residue, which mediated the recognition of ELNAT1 by endosomal sorting complex required for transport (ESCRT) and facilitated their packaging into EVs. EV-mediated ELNAT1 was specifically transmitted into HLECs and epigenetically activated SOX18 transcription to induce lymphangiogenesis. Importantly, blocking the SUMOylation of tumor by downregulating UBC9 expression markedly reduced lymphatic metastasis in EV-mediated ELNAT1-treated BCa in vivo. Clinically, EV-mediated ELNAT1 was correlated with LN metastasis and poor prognosis of patients with BCa. These findings highlight a molecular mechanism that EV-mediated ELNAT1/UBC9/SOX18 regulatory axis promotes the lymphangiogenesis and LN metastasis of BCa in a SUMOylation-dependent manner, and implicate ELNAT1 as an attractive therapeutic target for LN metastatic BCa.
Changhao Chen, Hanhao Zheng, Yuming Luo, Yao Kong, Mingjie An, Yuting Li, Wang He, Bowen Gao, Yue Zhao, Hao Huang, Jian Huang, Tianxin Lin