A molecular signature of preclinical rheumatoid arthritis triggered by dysregulated PTPN22

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Abstract

A unique feature of rheumatoid arthritis (RA) is the presence of anti-citrullinated protein antibodies (ACPA). Several risk factors for RA are known to increase the expression or activity of peptidyl arginine deiminases (PADs), which catalyze citrullination and, when dysregulated, can result in hypercitrullination. However, the consequence of hypercitrullination is unknown and the function of each PAD has yet to be defined. Th cells of RA patients are hypoglycolytic and hyperproliferative due to impaired expression of PFKFB3 and ATM, respectively. Here, we report that these features are also observed in peripheral blood mononuclear cells (PBMCs) from healthy at-risk individuals (ARIs). PBMCs of ARIs are also hypercitrullinated and produce more IL-2 and Th17 cytokines but fewer Th2 cytokines. These abnormal features are due to impaired induction of PTPN22, a phosphatase that also suppresses citrullination independently of its phosphatase activity. Attenuated phosphatase activity of PTPN22 results in aberrant expression of IL-2, ATM, and PFKFB3, whereas diminished nonphosphatase activity of PTPN22 leads to hypercitrullination mediated by PADs. PAD2- or PAD4-mediated hypercitrullination reduces the expression of Th2 cytokines. By contrast, only PAD2-mediated hypercitrullination can increase the expression of Th17 cytokines. Taken together, our data depict a molecular signature of preclinical RA that is triggered by impaired induction of PTPN22.

Authors

Hui-Hsin Chang, Guang-Yaw Liu, Nishant Dwivedi, Bo Sun, Yuko Okamoto, Jennifer D. Kinslow, Kevin D. Deane, M. Kristen Demoruelle, Jill M. Norris, Paul R. Thompson, Jeffrey A. Sparks, Deepak A. Rao, Elizabeth W. Karlson, Hui-Chih Hung, V. Michael Holers, I-Cheng Ho

Systems biology analysis reveals role of MDM2 in diabetic nephropathy

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Abstract

To derive new insights in diabetic complications, we integrated publicly available human protein-protein interaction (PPI) networks with global metabolic networks using metabolomic data from patients with diabetic nephropathy. We focused on the participating proteins in the network that were computationally predicted to connect the urine metabolites. MDM2 had the highest significant number of PPI connections. As validation, significant downregulation of MDM2 gene expression was found in both glomerular and tubulointerstitial compartments of kidney biopsy tissue from 2 independent cohorts of patients with diabetic nephropathy. In diabetic mice, chemical inhibition of MDM2 with Nutlin-3a led to reduction in the number of podocytes, increased blood urea nitrogen, and increased mortality. Addition of Nutlin-3a decreased WT1⁺ cells in embryonic kidneys. Both podocyte- and tubule-specific MDM2-knockout mice exhibited severe glomerular and tubular dysfunction, respectively. Interestingly, the only 2 metabolites that were reduced in both podocyte and tubule-specific MDM2-knockout mice were 3-methylcrotonylglycine and uracil, both of which were also reduced in human diabetic kidney disease. Thus, our bioinformatics tool combined with multi-omics studies identified an important functional role for MDM2 in glomeruli and tubules of the diabetic nephropathic kidney and links MDM2 to a reduction in 2 key metabolite biomarkers.

Authors

Rintaro Saito, Anaïs Rocanin-Arjo, Young-Hyun You, Manjula Darshi, Benjamin Van Espen, Satoshi Miyamoto, Jessica Pham, Minya Pu, Simone Romoli, Loki Natarajan, Wenjun Ju, Matthias Kretzler, Robert Nelson, Keiichiro Ono, Dana Thomasova, Shrikant R. Mulay, Trey Ideker, Vivette D’Agati, Ergin Beyret, Juan Carlos Izpisua Belmonte, Hans Joachim Anders, Kumar Sharma

Ly6C^hi monocytes regulate T cell responses in viral hepatitis

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Abstract

Viral hepatitis remains a global health challenge despite recent progress in the development of more effective therapies. Although virus-specific CD8⁺ and CD4⁺ T cell responses are essential for viral clearance, it remains largely unknown what regulates T cell–mediated viral clearance. Thus, a better understanding of the regulation of anti-viral T cell immunity would be critical for the design of more effective therapies for viral hepatitis. Using a model of adenovirus-induced hepatitis, here we showed that adenoviral infection induced recruitment of Ly6C^hi monocytes to the liver in a CCR2-dependent manner. These recruited Ly6C^hi monocytes suppressed CD8⁺ and CD4⁺ T cell responses to adenoviral infection, leading to a delay in viral clearance. In vivo depletion of Ly6C^hi monocytes markedly enhanced anti-viral T cell responses and promoted viral clearance. Mechanistically, we showed that induction of iNOS and the production of NO by Ly6C^hi monocytes are critical for the suppression of T cell responses. In addition, a contact-dependent mechanism mediated by PD-1 and PD-L1 interaction is also required for T cell suppression by Ly6C^hi monocytes. These findings suggest a critical role for Ly6C^hi monocytes in the regulation of T cell immunity in viral hepatitis and may provide new insights into development of more effective therapies for treating viral hepatitis based on targeting the immunosuppressing monocytes.

Authors

Jiangao Zhu, Huiyao Chen, Xiaopei Huang, Songfu Jiang, Yiping Yang

The head and neck cancer immune landscape and its immunotherapeutic implications

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Abstract

Recent clinical trials have demonstrated a clear survival advantage in advanced head and neck squamous cell carcinoma (HNSCC) patients treated with immune checkpoint blockade. These emerging results reveal that HNSCC is one of the most promising frontiers for immunotherapy research. However, further progress in head and neck immuno-oncology will require a detailed understanding of the immune infiltrative landscape found in these tumors. We leveraged transcriptome data from 280 tumors profiled by The Cancer Genome Atlas (TCGA) to comprehensively characterize the immune landscape of HNSCC in order to develop a rationale for immunotherapeutic strategies in HNSCC and guide clinical investigation. We find that both HPV⁺ and HPV^– HNSCC tumors are among the most highly immune-infiltrated cancer types. Strikingly, HNSCC had the highest median Treg/CD8⁺ T cell ratio and the highest levels of CD56^dim NK cell infiltration, in our pan-cancer analysis of the most immune-infiltrated tumors. CD8⁺ T cell infiltration and CD56^dim NK cell infiltration each correlated with superior survival in HNSCC. Tumors harboring genetic smoking signatures had lower immune infiltration and were associated with poorer survival, suggesting these patients may benefit from immune agonist therapy. These findings illuminate the immune landscape of HPV⁺ and HPV^– HNSCC. Additionally, this landscape provides a potentially novel rationale for investigation of agents targeting modulators of Tregs (e.g., CTLA-4, GITR, ICOS, IDO, and VEGFA) and NK cells (e.g., KIR, TIGIT, and 4-1BB) as adjuncts to anti–PD-1 in the treatment of advanced HNSCC.

Authors

Rajarsi Mandal, Yasin Şenbabaoğlu, Alexis Desrichard, Jonathan J. Havel, Martin G. Dalin, Nadeem Riaz, Ken-Wing Lee, Ian Ganly, A. Ari Hakimi, Timothy A. Chan, Luc G.T. Morris

Anti-coreceptor therapy drives selective T cell egress by suppressing inflammation-dependent chemotactic cues

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Abstract

There continues to be a need for immunotherapies to treat type 1 diabetes in the clinic. We previously reported that nondepleting anti-CD4 and -CD8 Ab treatment effectively reverses diabetes in new-onset NOD mice. A key feature of the induction of remission is the egress of the majority of islet-resident T cells. How this occurs is undefined. Herein, the effects of coreceptor therapy on islet T cell retention were investigated. Bivalent Ab binding to CD4 and CD8 blocked TCR signaling and T cell cytokine production, while indirectly downregulating islet chemokine expression. These processes were required for T cell retention, as ectopic IFN-γ or CXCL10 inhibited Ab-mediated T cell purging. Importantly, treatment of humanized mice with nondepleting anti–human CD4 and CD8 Ab similarly reduced tissue-infiltrating human CD4⁺ and CD8⁺ T cells. These findings demonstrate that Ab binding of CD4 and CD8 interrupts a feed-forward circuit by suppressing T cell–produced cytokines needed for expression of chemotactic cues, leading to rapid T cell egress from the islets. Coreceptor therapy therefore offers a robust approach to suppress T cell–mediated pathology by purging T cells in an inflammation-dependent manner.

Authors

Aaron J. Martin, Matthew Clark, Gregory Gojanovich, Fatima Manzoor, Keith Miller, Douglas E. Kline, Y. Maurice Morillon, Bo Wang, Roland Tisch

Epithelial-macrophage interactions determine pulmonary fibrosis susceptibility in Hermansky-Pudlak syndrome

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Abstract

Alveolar epithelial cell (AEC) dysfunction underlies the pathogenesis of pulmonary fibrosis in Hermansky-Pudlak syndrome (HPS) and other genetic syndromes associated with interstitial lung disease; however, mechanisms linking AEC dysfunction and fibrotic remodeling are incompletely understood. Since increased macrophage recruitment precedes pulmonary fibrosis in HPS, we investigated whether crosstalk between AECs and macrophages determines fibrotic susceptibility. We found that AECs from HPS mice produce excessive MCP-1, which was associated with increased macrophages in the lungs of unchallenged HPS mice. Blocking MCP-1/CCR2 signaling in HPS mice with genetic deficiency of CCR2 or targeted deletion of MCP-1 in AECs normalized macrophage recruitment, decreased AEC apoptosis, and reduced lung fibrosis in these mice following treatment with low-dose bleomycin. We observed increased TGF-β production by HPS macrophages, which was eliminated by CCR2 deletion. Selective deletion of TGF-β in myeloid cells or of TGF-β signaling in AECs through deletion of TGFBR2 protected HPS mice from AEC apoptosis and bleomycin-induced fibrosis. Together, these data reveal a feedback loop in which increased MCP-1 production by dysfunctional AECs results in recruitment and activation of lung macrophages that produce TGF-β, thus amplifying the fibrotic cascade through AEC apoptosis and stimulation of fibrotic remodeling.

Authors

Lisa R. Young, Peter M. Gulleman, Chelsi W. Short, Harikrishna Tanjore, Taylor Sherrill, Aidong Qi, Andrew P. McBride, Rinat Zaynagetdinov, John T. Benjamin, William E. Lawson, Sergey V. Novitskiy, Timothy S. Blackwell

Maternal obesity reduces oxidative capacity in fetal skeletal muscle of Japanese macaques

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Abstract

Maternal obesity is proposed to alter the programming of metabolic systems in the offspring, increasing the risk for developing metabolic diseases; however, the cellular mechanisms remain poorly understood. Here, we used a nonhuman primate model to examine the impact of a maternal Western-style diet (WSD) alone, or in combination with obesity (Ob/WSD), on fetal skeletal muscle metabolism studied in the early third trimester. We find that fetal muscle responds to Ob/WSD by upregulating fatty acid metabolism, mitochondrial complex activity, and metabolic switches (CPT-1, PDK4) that promote lipid utilization over glucose oxidation. Ob/WSD fetuses also had reduced mitochondrial content, diminished oxidative capacity, and lower mitochondrial efficiency in muscle. The decrease in oxidative capacity and glucose metabolism was persistent in primary myotubes from Ob/WSD fetuses despite no additional lipid-induced stress. Switching obese mothers to a healthy diet prior to pregnancy did not improve fetal muscle mitochondrial function. Lastly, while maternal WSD alone led only to intermediary changes in fetal muscle metabolism, it was sufficient to increase oxidative damage and cellular stress. Our findings suggest that maternal obesity or WSD, alone or in combination, leads to programmed decreases in oxidative metabolism in offspring muscle. These alterations may have important implications for future health.

Authors

Carrie E. McCurdy, Simon Schenk, Byron Hetrick, Julie Houck, Brian G. Drew, Spencer Kaye, Melanie Lashbrook, Bryan C. Bergman, Diana L. Takahashi, Tyler A. Dean, Travis Nemkov, Ilya Gertsman, Kirk C. Hansen, Andrew Philp, Andrea L. Hevener, Adam J. Chicco, Kjersti M. Aagaard, Kevin L. Grove, Jacob E. Friedman

IL-3 promotes the development of experimental autoimmune encephalitis

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Abstract

Little is known about the role of IL-3 in multiple sclerosis (MS) in humans and in experimental autoimmune encephalomyelitis (EAE). Using myelin oligodendrocyte glycoprotein (MOG) peptide–induced EAE, we show that CD4⁺ T cells are the main source of IL-3 and that cerebral IL-3 expression correlates with the influx of T cells into the brain. Blockade of IL-3 with monoclonal antibodies, analysis of IL-3 deficient mice, and adoptive transfer of leukocytes demonstrate that IL-3 plays an important role for development of clinical symptoms of EAE, for migration of leukocytes into the brain, and for cerebral expression of adhesion molecules and chemokines. In contrast, injection of recombinant IL-3 exacerbates EAE symptoms and cerebral inflammation. In patients with relapsing-remitting MS (RRMS), IL-3 expression by T cells is markedly upregulated during episodes of relapse. Our data indicate that IL-3 plays an important role in EAE and may represent a new target for treatment of MS.

Authors

Kerstin Renner, Sonja Hellerbrand, Fabian Hermann, Christine Riedhammer, Yvonne Talke, Gabriela Schiechl, Manuel Rodriguez Gomez, Simone Kutzi, Dagmar Halbritter, Nicole Goebel, Hilke Brühl, Robert Weissert, Matthias Mack

NK cell activating receptor ligand expression in lymphangioleiomyomatosis is associated with lung function decline

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Abstract

Lymphangioleiomyomatosis (LAM) is a rare lung disease of women that leads to progressive cyst formation and accelerated loss of pulmonary function. Neoplastic smooth muscle cells from an unknown source metastasize to the lung and drive destructive remodeling. Given the role of NK cells in immune surveillance, we postulated that NK cell activating receptors and their cognate ligands are involved in LAM pathogenesis. We found that ligands for the NKG2D activating receptor UL-16 binding protein 2 (ULBP2) and ULBP3 are localized in cystic LAM lesions and pulmonary nodules. We found elevated soluble serum ULBP2 (mean = 575 pg/ml ± 142) in 50 of 100 subjects and ULBP3 in 30 of 100 (mean = 8,300 pg/ml ± 1,515) subjects. LAM patients had fewer circulating NKG2D⁺ NK cells and decreased NKG2D surface expression. Lung function decline was associated with soluble NKG2D ligand (sNKG2DL) detection. The greatest rate of decline forced expiratory volume in 1 second (FEV₁, –124 ± 30 ml/year) in the 48 months after enrollment (NHLBI LAM Registry) occurred in patients expressing both ULBP2 and ULBP3, whereas patients with undetectable sNKG2DL levels had the lowest rate of FEV₁ decline (–32.7 ± 10 ml/year). These data suggest a role for NK cells, sNKG2DL, and the innate immune system in LAM pathogenesis.

Authors

Andrew R. Osterburg, Rebecca L. Nelson, Benyamin Z. Yaniv, Rachel Foot, Walter R.F. Donica, Madison A. Nashu, Huan Liu, Kathryn A. Wikenheiser-Brokamp, Joel Moss, Nishant Gupta, Francis X. McCormack, Michael T. Borchers

LIM kinase/cofilin dysregulation promotes macrothrombocytopenia in severe von Willebrand disease-type 2B

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Abstract

von Willebrand disease type 2B (VWD-type 2B) is characterized by gain-of-function mutations of von Willebrand factor (vWF) that enhance its binding to platelet glycoprotein Ibα and alter the protein’s multimeric structure. Patients with VWD-type 2B display variable extents of bleeding associated with macrothrombocytopenia and sometimes with thrombopathy. Here, we addressed the molecular mechanism underlying the severe macrothrombocytopenia both in a knockin murine model for VWD-type 2B by introducing the p.V1316M mutation in the murine Vwf gene and in a patient bearing this mutation. We provide evidence of a profound defect in megakaryocyte (MK) function since: (a) the extent of proplatelet formation was drastically decreased in 2B MKs, with thick proplatelet extensions and large swellings; and (b) 2B MKs presented actin disorganization that was controlled by upregulation of the RhoA/LIM kinase (LIMK)/cofilin pathway. In vitro and in vivo inhibition of the LIMK/cofilin signaling pathway rescued actin turnover and restored normal proplatelet formation, platelet count, and platelet size. These data indicate, to our knowledge for the first time, that the severe macrothrombocytopenia in VWD-type 2B p.V1316M is due to an MK dysfunction that originates from a constitutive activation of the RhoA/LIMK/cofilin pathway and actin disorganization. This suggests a potentially new function of vWF during platelet formation that involves regulation of actin dynamics.

Authors

Alexandre Kauskot, Sonia Poirault-Chassac, Frédéric Adam, Vincent Muczynski, Gabriel Aymé, Caterina Casari, Jean-Claude Bordet, Christelle Soukaseum, Chantal Rothschild, Valérie Proulle, Audrey Pietrzyk-Nivau, Eliane Berrou, Olivier D. Christophe, Jean-Philippe Rosa, Peter J. Lenting, Marijke Bryckaert, Cécile V. Denis, Dominique Baruch