Abstract
Cytotoxic T lymphocytes form a critical component of SARS-CoV-2 immunity by recognizing viral peptides bound to HLA class I molecules. Here, we identified the spike-derived peptide NYNYLYRLF448-456 (NF9) as the immunodominant HLA-A*24:02–restricted epitope in both convalescent and vaccinated donors. Across cohorts, A24/NF9-specific responses were dominated by public TCR motifs featuring TRAV12-1 paired with TRBJ2-7 and a conserved CDR3β sequence (CASSXXXGYEQYF). Using a panel of 13 TCRs, we mapped recognition of single amino acid substitutions within NF9 and identified residue 5 (L452) as the principal determinant of escape. The L452R substitution, characteristic of the Delta variant, abolished recognition across all tested TCRs despite preserved HLA binding. Crystallography of a representative public TCR (P1-15) revealed that mutation at position-5 reoriented the peptide within HLA-A*24:02, flipping the adjacent Y453 side chain into the peptide-binding groove and eliminating the dominant TCR contact. This position-5–driven conformational switch provided a structural mechanism for universal loss of NF9 recognition by HLA-A*24:02–restricted T cells. Consistent with this, Delta-infected convalescents failed to mount de novo NF9-5R–specific responses while retaining responses to the conserved A24/QI9 spike epitope. Together, these findings defined the basis of A24/NF9 recognition and showed how 1 mutation remodeled peptide presentation to abrogate TCR responses.
Authors
Takeshi Nakama, Aaron Wall, Garry Dolton, Li Rong Tan, Hannah Thomas, Hiroshi Hamana, Yoshiki Aritsu, Toong Seng Tan, Mako Toyoda, Yoshihiko Goto, Huanyu Li, Mizuki Kitamatsu, Keiko Udaka, Yusuke Miyashita, Hiroyuki Oshiumi, Kimitoshi Nakamura, Yoji Nagasaki, Rumi Minami, Hirotomo Nakata, Pierre J. Rizkallah, Hiroyuki Kishi, Takamasa Ueno, Andrew K. Sewell, Chihiro Motozono
Abstract
N6-methyladenosine (m6A) modification is the most prevalent posttranscriptional epigenetic modification in mammalian mRNAs, and it has been implicated in the regulation of nervous system development by modulating mRNA metabolism. VIRMA is the largest core subunit of the m6A methyltransferase complex and is essential for the assembly and stability of the m6A methyltransferase complex. In the retina, m6A methylation modification is widely distributed in various cellular layers and is essential for retinal homeostasis. Here, we demonstrate that VIRMA-mediated m6A modification is essential for retinal homeostasis. Loss of Virma in retinal rod cells resulted in abnormal reduction in m6A methylation levels, along with impaired photoreceptor function and degeneration. Mechanically, Virma depletion in photoreceptors dampened the m6A modification level of visual perception–associated genes, resulting compromised visual function and photoreceptors degeneration. Moreover, Virma interacted with splicing factor to regulate the alternative splicing events of retina function–related genes such as Polg2, which contributes to photoreceptor damage. Reintroduction of normal Virma expression colonially rescued photoreceptor degeneration. Collectively, our data elucidate the important role of Virma-mediated m6A modification in photoreceptor function and suggest that epigenetic modulation could serve as a potential target to treat these blinding diseases.
Authors
Wenjing Liu, Xiaojing Wu, Rong Zou, Fan Zhang, Yudi Fan, Kuanxiang Sun, Liping Yang, Jiang Hu, Lin Zhang, Xianjun Zhu
Abstract
Glucagon-like peptide-1 (GLP-1) and glucose-induced insulinotropic polypeptide (GIP) receptor agonists have revolutionized obesity therapy, but causes of obesity-associated dysregulation of endogenous incretin production remain incompletely understood. Here we show that intestinal transmembrane serine protease 2 (TMPRSS2) plays a pivotal role in deregulating anti-diabetic GLP-1 production in obesity. TMPRSS2 is widely coexpressed in intestinal epithelial cells along with its signaling target protease-activated receptor 2 (PAR2). In addition to its role in regulating coagulation protease–mediated adipose tissue inflammation, PAR2 signaling in the gut controls postprandial GIP secretion. TMPRSS2, but not the epithelial cell–expressed proteases FXa or matriptase, activates PAR2 and thereby promotes postprandial GIP release. Accordingly, a PAR2-mutant mouse resistant to TMPRSS2 cleavage is protected from GIP upregulation and diet-induced obesity. In the context of obesity, TMPRSS2 also attenuates bioavailability of the ghrelin pathway and thereby suppresses GLP-1–mediated control of glucose homeostasis. Pharmacological inhibition or genetic deletion of TMPRSS2 restores ghrelin signaling–dependent GLP-1 secretion and GLP-1’s anti-diabetic effects on nutritional glucose homeostasis. Thus, epithelial cell–expressed TMPRSS2, which critically contributes to the lung pathology in SARS-CoV-2 infection, emerges as an intestinal incretin regulator and a potential link between infection and chronic cardiometabolic diseases.
Authors
Dilraj Kaur, Sagarika Chakrabarty, Claudius Witzler, Hongjie Wang, Mengwen Wang, Romina Wolz, Petra Wilgenbus, Jens J.N. Posma, Sivaramakrishna Rachakonda, Federico Marini, Valeriya V. Zinina, Sabine Reyda, Rajinikanth Gogiraju, Claudine Graf, Fahumiya Samad, Katrin Schäfer, Christoph Reinhardt, Natalia Soshnikova, Wolfram Ruf, Thati Madhusudhan
Abstract
VIC-1911 (formerly TAS-119) is a next-generation, ATP-competitive aurora kinase A (AURKA) inhibitor with a favorable biosafety profile. However, it has not been evaluated in prostate cancer (PCa), wherein AURKA is highly expressed in advanced stages and represents a critical therapeutic target. Here, we demonstrate that VIC-1911 potently inhibits AURKA activity with high selectivity over AURKB/C across diverse PCa cell lines. Treatment with VIC-1911, even at nanomolar concentrations, substantially inhibits the growth of both androgen receptor–positive (AR-positive) and AR-negative PCa cells. VIC-1911 triggers mitotic failure, induces DNA double-strand breaks (DSBs), and activates the p53 pathway, halting cell division and inducing cell death. Notably, VIC-1911 showed synergistic effects in inhibiting PCa cell growth in vitro and xenograft tumor growth in vivo with poly (ADP-ribose) polymerase inhibitors, which have proven effective in PCa with a deficiency in homologous recombination (HR) repair. Mechanistically, VIC-1911 disabled HR-mediated repair of DSBs in otherwise HR-proficient PCa cells, leading to a “BRCAness” phenotype and pronounced accumulation of DNA damage and mitotic catastrophe. In summary, our study uncovers what we believe is a novel mechanism to induce functional BRCAness through mitotic arrest and highlights VIC-1911 as a promising therapeutic agent for advanced PCa, either as a single agent or in combination, sensitizing HR-proficient tumors to PARP inhibitors.
Authors
Galina Gritsina, Sandip Kumar Rath, Hongshun Shi, Qi Chu, Wanqing Xie, Que Thanh Waning Nguyen, Sambhavi Senthil, Thomas J. Myers, Mehmet A. Bilen, Sarah E. Fenton, Maha Hussain, David S. Yu, Jonathan C Zhao, Jindan Yu
Abstract
Maternal opioid use disorder (OUD) poses substantial risks to maternal and fetal health. These adverse outcomes are believed to be mediated, in part, by changes in placental structure and function; however, few studies have addressed this question. Here, we utilized flow cytometry, histology, and spatial and single-cell transcriptomics to uncover the impact of OUD on placental tissues. Given that half of individuals with chronic OUD contract hepatitis C (HCV), we further stratified our findings by maternal HCV status. Our results indicate that OUD leads to higher incidence of vascular malperfusion accompanied by increased levels of inflammatory markers and dysregulated secretion of placental development factors. Spatial transcriptomics revealed that OUD disrupts the communication between trophoblasts and immune cells important for placental vascular development. Additionally, CellChat analysis revealed aberrant vascular remodeling, neuropeptide, and chemotactic signaling across trophoblast, endothelial, and myeloid cells. Processes associated with tissue homeostasis and repair were also upregulated across trophoblasts and leukocytes. In addition, placental leukocytes were rewired toward regulatory/tissue surveillant phenotypes. Finally, frequencies and responses to ex vivo stimulation of decidual macrophages and cytolytic NK cells, critical for tissue remodeling and fetal tolerance, were decreased. Altogether, these results highlight substantial disruptions to placental health by maternal OUD.
Authors
Heather E. True, Brianna M. Doratt, Sheridan B. Wagner, Delphine C. Malherbe, Nathan R. Shelman, Mahdi Eskandarian Boroujeni, Cynthia Cockerham, John M. O’Brien, Ilhem Messaoudi
Abstract
Malnutrition, gut inflammation, and antibiotic-induced dysbiosis are well-recognized risk factors for poor clinical outcomes among critically ill patients. We previously showed that commercially available plant-based enteral nutrition (PBEN) preserves a commensal microbiome compared with commonly used artificial enteral nutrition (AEN). In this study, PBEN was superior to AEN in promoting recovery from antibiotic-induced dysbiosis in mice and humans. PBEN effectively mitigated anemia and leukopenia, restored naive lymphocyte populations, and reduced bone marrow myeloid expansion. Animals randomized to PBEN also exhibited improved responses to infectious gastrointestinal challenges following antibiotic exposure. A pilot clinical study validated these findings, demonstrating increased gut commensals, reduced pathogens, and improved leukocyte balance in critically ill children receiving PBEN compared with AEN. Together, these results suggest that PBEN offers a practical dietary approach to mitigate antibiotic-associated complications and potentially improve clinical outcomes among hospitalized patients requiring supplemental nutrition.
Authors
Mona Chatrizeh, Jianmin Tian, Matthew Rogers, Firuz Feturi, Guojun Wu, Brian Firek, Roman Nikonov, Lauren Cass, Alexandra Sheppeck, Lavnish Ojha, Ali Carroll, Matthew Henkel, Justin Azar, Rajesh K. Aneja, Brian Campfield, Dennis Simon, Michael J. Morowitz
Abstract
The lung alveoli are continually exposed to inhaled pathogens and environmental hazards and rely on coordinated communication between alveolar macrophages and type 2 alveolar epithelial cells (AT2s) to maintain homeostasis. Disruption of these interactions can impair immunity and repair, contributing to acute and chronic respiratory diseases. To better define these mechanisms and support therapeutic discovery, we established a human iPSC-derived air-liquid interface platform that captures key features of AT2-macrophage crosstalk. Using this system, we show that coculture enhances AT2-specific transcriptional programs including lipid synthesis, while macrophages actively phagocytose AT2-derived surfactant. iPSC-derived macrophages adopt an alveolar macrophage–like phenotype and respond to AT2-derived M-CSF. During respiratory infection, macrophages play a crucial role in modulating epithelial inflammatory responses, augmenting antiviral immunity, and limiting viral replication. We further identify a role for macrophages in epithelial repair, where VEGF-mediated signaling to macrophages increases epithelial permeability during viral infection. Together, these findings reveal dimensions of AT2-macrophage cooperation in homeostasis, infection, and repair, and demonstrate how this iPSC-derived platform can be used to dissect mechanisms that may initiate or drive the progression of respiratory diseases.
Authors
Declan L. Turner, Hannah Baric, Katelyn Patatsos, Sahel Amoozadeh, Michael See, Kathleen A. Strumila, Jack T. Murphy, Jeremy J. Wiyana, Liam Gubbels, Elizabeth S. Ng, Andrew G. Elefanty, Melanie R. Neeland, Shivanthan Shanthikumar, Sarah L. Londrigan, Mirana Ramialison, Fernando J. Rossello, Ed G. Stanley, Rhiannon B. Werder
Abstract
Methyltransferase-like 5 (METTL5) is a methyltransferase responsible for rRNA N6-methyladenosine (m6A) modification, mutations in which are associated with skeletal abnormalities and cognitive deficits. Despite METTL5’s clinical relevance, the molecular mechanisms underlying METTL5-related genetic disorders remain poorly understood. In this study, we demonstrated that Mettl5 KO led to reduced bone mass and smaller body size in mice and impaired the osteogenic differentiation of mesenchymal stem cells. Mechanistically, Mettl5 deficiency decreased the translation efficiency of oxidative stress–responsive serine-rich protein 1 mRNA, downregulated the expression of key antioxidant genes, and diminished antioxidant capacity. Importantly, administration of the antioxidant N-acetylcysteine (NAC) partially rescued skeletal defects in Mettl5-KO mice. These findings reveal a critical role for METTL5 in antioxidant defense and suggest that NAC supplementation may represent a promising therapeutic strategy for METTL5-related disorders.
Authors
Kexin Lei, Qi Yin, Qiwen Li, Qian Wang, Zhong Zhang, Fei Xue, Ruoshi Xu, Xinyi Zhou, Lin Peng, Shoichiro Kokabu, Shuibin Lin, Quan Yuan
Abstract
Lung IL-33 is involved in pathogen defense, barrier homeostasis, and development of allergic responses. We previously identified a 5 kb noncoding region within a GWAS-defined segment that regulates expression of human IL33 (hIL33) but is absent in the murine locus. To understand how this region affects IL-33 expression in vivo, we engineered 2 BAC-transgenic strains in which 166 kb of the human genome upstream of the hIL33 locus, along with a fluorescent reporter, was inserted into the murine genome, both with and without the 5 kb region. Comparison to a murine Il33 (mIl33) reporter strain revealed species-specific tropism; hIL33 reporter was mostly expressed in the endothelium, while mIl33 reporter was expressed in type 2 alveolar epithelium. hIL33 reporter expression in tracheal basal epithelium, submucosal glands, and lung microvasculature required the 5 kb region. Surprisingly, allergen and exogenous IL-33 downregulated hIL33 reporter in lung endothelium only when the 5 kb region was present. Similar IL-33–dependent downregulation of IL33 transcripts was observed in human endothelial cell lines, validating that our hIL33 reporter strain recapitulated human endothelial biology. Together, these data reveal the importance of the asthma-associated human 5 kb region in regulating human IL33 expression in a cell type– and context-dependent manner.
Authors
Maile K. Hollinger, Chanie L. Howard, Donna C. Decker, Kelly M. Blaine, Ivy Aneas, Emily M. Grayson, Tania E. Velez, Fernando A. Oliveira, Riley T. Hannan, Daniel F. Camacho, Philip A. Verhoef, Cara L. Hrusch, Rebecca S. Griffes, Jeffrey M. Sturek, Marcelo A. Nobrega, Nathan Schoettler, Anne I. Sperling
Abstract
HNF1A-MODY, the most common monogenic diabetes, exhibits progressive β cell dysfunction, but existing mouse models fail to recapitulate human disease progression, limiting understanding of pathogenic mechanisms. We developed mice with heterozygous deletion of the Hnf1a transactivation domain (Hnf1a+/Δe4-10) to model human HNF1A haploinsufficiency, conducted cross-sectional metabolic characterization, and validated our findings in HNF1A-deficient human islets. Unlike previous models, Hnf1a+/Δe4-10 mice successfully recapitulated temporal HNF1A-MODY progression. Male mice developed sequential pathophysiology: early insulin resistance in young adults (7 weeks), followed by testosterone deficiency and fasting hyperglycemia in adult mice (10 weeks). Glucose intolerance emerged in middle-aged mice (30 weeks), progressing to multi-organ dysfunction in aged mice (44–70 weeks), characterized by elevated hepatic gluconeogenesis, impaired renal glucose handling, and hepatic steatosis/fibrosis. This dual pathophysiology involving β cell dysfunction and peripheral insulin resistance was associated with dysregulated hormone secretion from both α and β cells in aged mice (40–70 weeks). Human islet studies with HNF1A knockdown confirmed translational relevance, demonstrating reduced SGLT2 protein expression and inappropriate glucagon and insulin secretion. This work established a physiologically relevant HNF1A-MODY model, identified early insulin resistance as a key mechanism triggering hormonal dysfunction, and revealed HNF1A’s role in multi-organ pathophysiology beyond traditional β cell dysfunction.
Authors
Isaline Louvet, Ana Acosta-Montalvo, Chiara Saponaro, Maria Moreno-Lopez, Sana Douffi, Abdelkrim El Karchaoui, Gianni Pasquetti, Julien Thevenet, Nathalie Delalleau, Valery Gmyr, Paolo Giacobini, Stéphanie Espiard, Julie Kerr-Conte, François Pattou, Adrian Liston, Caroline Bonner
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