Lung inflammation is a hallmark of Coronavirus disease 2019 (COVID-19) in severely ill patients and the pathophysiology of disease is thought to be immune-mediated. Mast cells (MCs) are polyfunctional immune cells present in the airways, where they respond to certain viruses and allergens, often promoting inflammation. We observed widespread degranulation of MCs during acute and unresolved airway inflammation in SARS-CoV-2-infected mice and non-human primates. Using a mouse model of MC-deficiency, MC-dependent interstitial pneumonitis, hemorrhaging, and edema in the lung were observed during SARS-CoV-2 infection. In humans, transcriptional changes in patients requiring oxygen supplementation also implicated cells with a MC phenotype in severe disease. MC activation in humans was confirmed, through detection of MC-specific proteases, including chymase, levels of which were significantly correlated with disease severity and with biomarkers of vascular dysregulation. These results support the involvement of MCs in lung tissue damage during SARS-CoV-2 infection in animal models and the association of MC activation with severe COVID-19 in humans, suggesting potential strategies for intervention.
Janessa Yan Jun Tan, Danielle E. Anderson, Abhay P.S. Rathore, Aled O'Neill, Chinmay Kumar Mantri, Wilfried A.A. Saron, Cheryl Q.E. Lee, Wern Cui Chu, Adrian E.Z. Kang, Randy Foo, Shirin Kalimuddin, Jenny G. Low, Lena Ho, Paul Tambyah, Thomas W. Burke, Christopher W. Woods, Kuan Rong Chan, Joern Karhausen, Ashley L. St. John
Adoptive immunotherapy with Tregs is a promising approach for prevention or treatment of type 1 diabetes. Islet antigen-specific Tregs have more potent therapeutic effects than polyclonal cells, but their low frequency is a barrier for clinical application. To generate Tregs that recognize islet antigens, we engineered a chimeric antigen receptor (CAR) derived from a monoclonal antibody with specificity for the insulin B-chain 10-23 peptide presented in the context of the IAg7 MHC class II allele present in NOD mice. Peptide specificity of the resulting InsB-g7 CAR was confirmed by tetramer staining and T cell proliferation in response to recombinant or islet-derived peptide. The InsB-g7 CAR re-directed NOD Treg specificity such that insulin B 10-23-peptide stimulation enhanced suppressive function, measured via reduction of proliferation and IL-2 production by BDC2.5 T cells and CD80 and CD86 expression on dendritic cells. Co-transfer of InsB-g7 CAR Tregs prevented adoptive transfer diabetes by BDC2.5 T cells in immunodeficient NOD mice. In wild type NOD mice, InsB-g7 CAR Tregs prevented spontaneous diabetes. These results show that engineering Treg specificity for islet antigens using a T cell receptor-like CAR is a promising new therapeutic approach for the prevention of autoimmune diabetes.
Justin A. Spanier, Vivian Fung, Christine M. Wardell, Mohannad H. Alkhatib, Yixin Chen, Linnea A. Swanson, Alexander J. Dwyer, Matthew E. Weno, Nubia Silva, Jason S. Mitchell, Paul C. Orban, Majid Mojibian, C. Bruce Verchere, Brian T. Fife, Megan K. Levings
BACKGROUND. Recurrent and/or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) is often an incurable disease, with patients experiencing median survival of under ten months and significant morbidity. While immune checkpoint blockade (ICB) drugs are effective in ~20% of patients, the remaining experience limited clinical benefit and are exposed to potential adverse effects and financial costs. Clinically approved biomarkers, such as tumor mutational burden (TMB), have modest predictive value in HNSCC. METHODS. We analyze clinical and genomic features, generated using whole-exome sequencing, in 133 ICB-treated R/M HNSCC patients, of whom 69 had virus-associated and 64 had non-virus-associated tumors. RESULTS. Hierarchical clustering of genomic data revealed six molecular subtypes characterized by a wide range of objective response rates and survival after ICB therapy. The prognostic importance of these 6 subtypes was validated in an external cohort. A random forest-based predictive model, using several clinical and genomic features, predicted progression-free survival (PFS), overall survival (OS), and response with greater accuracy than a model based on TMB alone. Recursive partitioning analysis identified three features (systemic inflammatory response index, TMB, and smoking signature) that classified patients into risk groups with accurate discrimination of PFS and OS. CONCLUSION. These findings shed light on the immunogenomic characteristics of HNSCC tumors that drive differential response to ICB and identify a clinical-genomic classifier that outperforms the current clinically approved biomarker of TMB. This validated predictive tool may help with clinical risk stratification in patients with R/M HNSCC for whom ICB is being considered.
Cristina Valero, Mahdi Golkaram, Joris L. Vos, Bin Xu, Conall Fitzgerald, Mark Lee, Shannon K. Kaplan, Catherine Y Han, Xin Pei, Reith Sarkar, Lillian A. Boe, Abhinav Pandey, Elizabeth S. Koh, Charlotte L. Zuur, David B. Solit, Traci Pawlowski, Li Liu, Alan L. Ho, Diego Chowell, Nadeem Riaz, Timothy A. Chan, Luc G.T. Morris
BACKGROUND. Warts, Hypogammaglobulinemia, Infections and Myelokathexis (WHIM) syndrome is a primary immunodeficiency disorder caused by heterozygous gain-of-function CXCR4 mutations. Myelokathexis is neutropenia from neutrophil retention in bone marrow and is associated with lymphopenia and monocytopenia. The CXCR4 antagonist plerixafor mobilizes leukocytes to the blood; however, safety and efficacy in WHIM syndrome are undefined. METHODS. In this investigator-initiated, single-center, randomized, quadruple-masked phase 3 crossover trial, we compared the total infection severity score (TISS) as primary endpoint in an intent-to-treat manner in 19 WHIM patients for 12-months on plerixafor versus 12-months on G-CSF, the standard-of-care for severe congenital neutropenia. RESULTS. Plerixafor was non-superior to G-CSF for TISS (p=0.65). In exploratory endpoints, plerixafor was non-inferior to G-CSF for maintaining neutrophil counts >500 cells/microliter (p=0.023) and was superior to G-CSF for maintaining lymphocyte counts >1000 cells/microliter (p<0.0001). Complete regression of a subset of large wart areas occurred on plerixafor in 5 of 7 patients with major wart burdens at baseline. Transient rash occurred on plerixafor, and bone pain was more common on G-CSF. There were no significant differences in drug preference or quality of life, or the incidence of drug failure or serious adverse events. CONCLUSIONS. Plerixafor was not superior in WHIM patients to G-CSF for TISS, the primary endpoint. Together with wart regression and hematologic improvement, the infection severity results support continued study of plerixafor as a potential treatment for WHIM syndrome.(Funded by the Division of Intramural Research, National Institute of Allergy and Infectious Diseases; clinicaltrials.gov registration number, NCT02231879)
David H. McDermott, Daniel Velez, Elena Cho, Edward W. Cowen, John J. DiGiovanna, Diana V. Pastrana, Christopher B. Buck, Katherine R. Calvo, Pamela J. Gardner, Sergio D. Rosenzweig, Pamela Stratton, Melissa A. Merideth, H. Jeffrey Kim, Carmen Brewer, James D. Katz, Douglas B. Kuhns, Harry L. Malech, Dean Follmann, Michael P. Fay, Philip M. Murphy
Cystinosis is a lysosomal storage disease that is characterized by the accumulation of di-peptide cystine within the lumen. It is caused by mutations in the cystine exporter, cystinosin. Most of the clinically reported mutations are due to the loss of transporter function. In this study, we identified a rapidly degrading disease variant, referred to as cystinosin(7∆). We demonstrated that this mutant is retained in the endoplasmic reticulum (ER) and degraded via the ER-associated degradation (ERAD) pathway. Using genetic and chemical inhibition methods, we elucidated the role of HRD1, p97, EDEMs, and the proteasome complex in cystinosin(7∆) degradation pathway. Having understood the degradation mechanisms, we tested some chemical chaperones, previously used for treating CFTR F508∆, and demonstrated that they could facilitate the folding and trafficking of cystinosin(7∆). Strikingly, chemical chaperone treatment can reduce the lumenal cystine level by ~70%. Conclusively, our study establishes the connection between ERAD and cystinosis pathogenesis and demonstrates the possibility of using chemical chaperones to treat cystinosin(7∆).
Varsha Venkatarangan, Weichao Zhang, Xi Yang, Jess G. Thoene, Si H. Hahn, Ming Li
Negative regulation of exocytosis from secretory cells is accomplished through inhibitory signals from Gi/o G-protein-coupled-receptors by Gβγ subunit inhibition of two mechanisms: decreased calcium entry and direct interaction of Gβγ with Soluble N-ethylmaleimide-sensitive factor Attachment Protein (SNAP) Receptor (SNARE) plasma membrane fusion machinery. Previously, we disabled the second mechanism with a SNAP25 truncation (SNAP25Δ3) decreasing Gβγ affinity for the SNARE complex, leaving exocytotic fusion and modulation of calcium entry intact, and removing GPCR-Gβγ inhibition of SNARE-mediated exocytosis. Here, we report substantial metabolic benefit in mice carrying this mutation. SNAP25Δ3/Δ3 mice exhibit enhanced insulin sensitivity and beiging of white fat. Metabolic protection was amplified in SNAP25Δ3/Δ3 mice challenged with high fat diet. Glucose homeostasis, whole body insulin action, and insulin-mediated glucose uptake into white adipose tissue were improved along with resistance to diet-induced obesity. Metabolic protection in SNAP25Δ3/Δ3 mice occurred without compromising the physiological response to fasting or cold. All metabolic phenotypes were reversed at thermoneutrality, suggesting basal autonomic activity is required. Direct electrode stimulation of sympathetic neuron exocytosis from SNAP25Δ3/Δ3 inguinal adipose depots resulted in enhanced and prolonged norepinephrine release. Thus, the Gβγ-SNARE interaction represents a cellular mechanism that deserves further exploration as an additional avenue for combatting metabolic disease.
Ryan P. Ceddia, Zack Zurawski, Analisa Thompson Gray, Feyisayo Adegboye, Ainsley McDonald-Boyer, Fubiao Shi, Dianxin Liu, Jose Maldonado, Jiesi Feng, Yulong Li, Simon Alford, Julio E. Ayala, Owen P. McGuinness, Sheila Collins, Heidi E. Hamm
Biological aging can be described as accumulative, prolonged metabolic stress, and is the major risk factor for cognitive decline and Alzheimer’s disease (AD). Recently, we identified and described a quinone reductase 2 (QR2) pathway in the brain, in which QR2 acts as a removable memory constraint and metabolic buffer within neurons. QR2 becomes over-expressed with age, and is possibly a novel contributing factor to age-related metabolic stress and cognitive deficit. We found that in human cells, genetic removal of QR2 produces a shift in the proteome opposing that found in AD brains, while simultaneously reducing oxidative stress. We therefore created highly specific QR2 inhibitors (QR2i’s), enabling evaluation of chronic QR2 inhibition as a novel way to reduce biological-age related metabolic stress and cognitive decline. QR2i’s replicated results obtained by genetic removal of QR2 while local QR2i microinjection improved hippocampal and cortical dependent learning in rats and mice. Continuous consumption of QR2i’s in drinking-water improved cognition and reduced pathology in the brains of AD-model mice (5xFAD), with a noticeable between-sex effect on treatment duration. These results demonstrate the importance of QR2 activity- and pathway function in the healthy and neurodegenerative brain, and the great therapeutic potential of QR2i’s as first-in-class drugs.
Nathaniel L. Gould, Gila R. Scherer, Silvia Carvalho, Khriesto Shurrush, Haneen Kayyal, Efrat Edry, Alina Elkobi, Orit David, Maria Foqara, Darshit Thakar, Tommaso Pavesi, Vijendra Sharma, Matthew Walker, Matthew Maitland, Orly Dym, Shira Albeck, Yoav Peleg, Nicolas Germain, Ilana Babaev, Haleli Sharir, Maya Lalzar, Boris Shklyar, Neta Hazut, Mohammad Khamaisy, Maxime Lévesque, Gilles Lajoie, Massimo Avoli, Gabriel Amitai, Bruce Lefker, Chakrapani Subramanyam, Brian Shilton, Haim Barr, Kobi Rosenblum
Glial activation and inflammation coincide with neurofibrillary tangles (NFT) formation in neurons. However, the mechanism behind tau fibril and glia interaction is poorly understood. Here, we found that tau preformed fibrils (PFF) caused induction of inflammation in microglia by specifically activating the TLR2-MyD88, but not TLR4-MyD88, pathway. Accordingly, TLR2 interacting domain of MyD88 (wtTIDM) peptide inhibited tau PFF-induced activation of TLR2-MyD88-NF-κB pathway resulting in reduced inflammation. Nasal administration of wtTIDM in P301S tau-expressing PS19 mice was found to inhibit gliosis and inflammatory markers, along with reduction of pathogenic tau in the hippocampus, resulting in improved cognitive behavior in PS19 mice. The inhibitory effect of wtTIDM on tau pathology was absent in PS19 mice lacking TLR2, reinforcing the essential involvement of TLR2 in wtTIDM- mediated effects in vivo. While understanding the mechanism further, we found that tau promoter harboured a potential NF-κB binding site and that proinflammatory molecules increased the transcription of tau in neurons via NF-κB. These results suggest that tau-induced neuroinflammation and neuropathology require TLR2 and that neuroinflammation directly upregulates tau in neurons via NF-κB, highlighting a direct connection between inflammation and tauopathy.
Debashis Dutta, Malabendu Jana, Ramesh Kumar Paidi, Moumita Majumder, Sumita Raha, Sridevi Dasarathy, Kalipada Pahan
Clonal hematopoiesis of indeterminate potential (CHIP) is associated with an increased risk of cardiovascular diseases (CVD), putatively via inflammasome activation. We pursued an inflammatory gene modifier scan for CHIP-associated CVD risk among 424,651 UK Biobank participants. CHIP was identified using whole exome sequencing data of blood DNA and modeled both as a composite and for common drivers (DNMT3A, TET2, ASXL1, and JAK2) separately. We developed predicted gene expression scores for 26 inflammasome-related genes and assessed how they modify CHIP-associated CVD risk. We identify IL1RAP as a potential key molecule for CHIP-associated CVD risk across genes and increased AIM2 gene expression leading to heightened JAK2- and ASXL1-associated CVD risks. We show that CRISPR-induced Asxl1 mutated murine macrophages have a particularly heightened inflammatory response to AIM2 agonism, associated with an increased DNA damage response, as well as increased IL-10 secretion, mirroring a CVD protective effect of IL10 expression in ASXL1 CHIP. Our study supports the role of inflammasomes in CHIP-associated CVD and provides new evidence to support gene-specific strategies to address CHIP-associated CVD risk.
Zhi Yu, Trevor P. Filder, Yunfeng Ruan, Caitlyn Vlasschaert, Tetsushi Nakao, Md Mesbah Uddin, Taralynn Mack, Abhishek Niroula, J. Brett Heimlich, Seyedeh M. Zekavat, Christopher J. Gibson, Gabriel K. Griffin, Yuxuan Wang, Gina M. Peloso, Nancy Heard-Costa, Daniel Levy, Ramachandran S. Vasan, François Aguet, Kristin G. Ardlie, Kent D. Taylor, Stephen S. Rich, Jerome I. Rotter, Peter Libby, Siddhartha Jaiswal, Benjamin L. Ebert, Alexander G. Bick, Alan R. Tall, Pradeep Natarajan
The tumor extracellular matrix (ECM) critically regulates cancer progression and treatment response. Expression of the basement membrane component collagen XVIII (ColXVIII) is induced in solid tumors, but its involvement in tumorigenesis has remained elusive. We show here that ColXVIII is markedly upregulated in human breast cancer (BC) and is closely associated with a poor prognosis in high-grade BCs. We discovered a role for ColXVIII as a modulator of EGFR/ErbB receptor tyrosine kinase signaling and show that it forms a complex with EGFR, HER2 and α6 integrin to promote cancer cell proliferation in a pathway involving its N-terminal portion and the MAPK/ERK1/2 and PI3K/AKT cascades. Studies with Col18a1 mouse models crossed with the MMTV-PyMT mammary carcinogenesis model showed that ColXVIII promotes BC growth and metastasis in a tumor cell-autonomous manner. Moreover, the number of mammary cancer stem cells was significantly reduced in the MMTV-PyMT and human cell models upon ColXVIII inhibition. Finally, ablation of ColXVIII substantially improved the efficacy of ErbB-targeting therapies in both preclinical models. In summary, ColXVIII was found to sustain the stemness properties of BC cells, and tumor progression and metastasis through ErbB signaling, suggesting that targeting ColXVIII in the tumor milieu may have important therapeutic potential.
Raman Devarajan, Valerio Izzi, Hellevi Peltoketo, Gunilla Rask, Saila Kauppila, Marja-Riitta Väisänen, Heli Ruotsalainen, Guillermo A. Martinez-Nieto, Sanna-Maria Karppinen, Timo Väisänen, Inderjeet Kaur, Jussi Koivunen, Takako Sasaki, Robert Winqvist, Aki Manninen, Fredrik Wärnberg, Malin Sund, Taina Pihlajaniemi, Ritva Heljasvaara
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