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Pediatric glioma immune profiling identifies TIM3 as a therapeutic target in BRAF-Fusion pilocytic astrocytoma

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Abstract

Despite being the leading cause of childhood mortality, pediatric gliomas have been relatively understudied, and the repurposing of immunotherapies has not been successful. Whole transcriptome sequencing, single-cell sequencing, and sequential multiplex immunofluorescence were used to identify an immunotherapy strategy evaluated in multiple preclinical glioma models. MAPK-driven pediatric gliomas have a higher interferon signature relative to other molecular subgroups. Single-cell sequencing identified an activated and cytotoxic microglia population designated MG-Act in BRAF-fused MAPK-activated pilocytic astrocytoma (PA), but not in high-grade gliomas or normal brain. TIM3 is expressed on MG-Act and on the myeloid cells lining the tumor vasculature but not normal brain. TIM3 expression becomes upregulated on immune cells in the PA microenvironment and anti-TIM3 reprograms ex vivo immune cells from human PAs to a pro-inflammatory cytotoxic phenotype. In a genetically engineered murine model of MAPK-driven low-grade gliomas, anti-TIM3 treatment increased median survival over IgG and anti-PD1 treated mice. ScRNA sequencing data during the therapeutic window of anti-TIM3 demonstrates enrichment of the MG-Act population. The therapeutic activity of anti-TIM3 is abrogated in the CX3CR1 microglia knockout background. These data support the use of anti-TIM3 in clinical trials of pediatric low-grade MAPK-driven gliomas.

Authors

Shashwat Tripathi, Hinda Najem, Corey Dussold, Sebastian Pacheco, Ruochen Du, Moloud Sooreshjani, Lisa A. Hurley, James P. Chandler, Roger Stupp, Adam M. Sonabend, Craig M. Horbinski, Rimas V. Lukas, Joanne Xiu, Giselle Y. López, Theodore P. Nicolaides, Valerie Brown, Nitin R. Wadhwani, Sandi K. Lam, Charles David James, Ganesh Rao, Maria G. Castro, Amy B. Heimberger, Michael DeCuypere

Teplizumab induces persistent changes in the antigen‐specific repertoire in individuals at‐risk for type 1 diabetes

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Abstract

BACKGROUND. Teplizumab, a FcR non-binding anti-CD3 mAb, is approved to delay progression of type 1 diabetes (T1D) at-risk patients. Previous investigations described the immediate effects of the 14-day treatment, but longer-term effects of the drug remain unknown. METHODS. With an extended analysis of study participants, we found that 36% were undiagnosed or remained clinical diabetes free after 5 years suggesting operational tolerance. Using single cell RNA-seq, we compared the phenotypes, transcriptome, and repertoire of peripheral blood CD8+ T cells including autoreactive T cells from study participants before and after teplizumab and features of responders and non-responders. RESULTS. At 3 months, there were transcriptional signatures of cell activation in CD4+ and CD8+ T cells including signaling that was reversed at 18 months. At that time, there was reduced expression of genes in T cell receptor and activation pathways in clinical responders. In CD8+ T cells, we found increased expression of genes associated with exhaustion and immune regulation with teplizumab treatment. These transcriptional features were further confirmed in an independent cohort. Pseudotime analysis showed differentiation of CD8+ exhausted and memory cells with teplizumab treatment. IL7R expression was reduced and patients with lower expression of CD127 had longer diabetes free intervals. In addition, the frequency of autoantigen reactive CD8+ T cells, that expanded in the placebo group over 18 months, did not increase in the teplizumab group. CONCLUSION. These findings indicate that teplizumab promotes operational tolerance in T1D, involving activation followed by exhaustion and regulation and prevents expansion of autoreactive T cells. TRIAL REGISTRATION. ClinicalTrials.gov: NCT01030861. FUNDING. NIDDK/NIH, Juvenile Diabetes Research Foundation.

Authors

Ana Lledó-Delgado, Paula Preston-Hurlburt, Sophia Currie, Pamela Clark, Peter S. Linsley, S. Alice Long, Can Liu, Galina Koroleva, Andrew J. Martins, John S. Tsang, Kevan C. Herold

Central regulation of feeding and body weight by ciliary GPR75

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Abstract

Variants of the G protein-coupled receptor 75 (GPR75) are associated with lower BMI in large-scale human exome sequencing studies. However, how GPR75 regulates body weight remains poorly understood. Using random germline mutagenesis in mice, we identified a missense allele (Thinner) of Gpr75 that resulted in a lean phenotype and verified the decreased body weight and fat weight in Gpr75 knockout (Gpr75–/–) mice. Gpr75–/– mice displayed reduced food intake under a high-fat diet (HFD), and pair-feeding normalized their body weight. The endogenous GPR75 protein was exclusively expressed in the brains of 3xFlag tagged Gpr75 knock-in (3xFlag-Gpr75) mice, with consistent expression across different brain regions. GPR75 interacted with Gαq to activate various signaling pathways after HFD feeding. Additionally, GPR75 was localized in the primary cilia of hypothalamic cells, whereas the Thinner mutation (L144P) and human GPR75 variants with lower BMI failed to localize in the cilia. Loss of GPR75 selectively inhibited weight gain in HFD-fed mice but failed to suppress the development of obesity in Leptin ob mice and Adenylate cyclase 3 (Adcy3) mutant mice on a chow diet. Our data reveal that GPR75 is a ciliary protein expressed in the brain and plays an important role in regulating food intake.

Authors

Yiao Jiang, Yu Xun, Zhao Zhang

F¹⁸-FDG PET imaging as a diagnostic tool for immune checkpoint inhibitor-associated acute kidney injury

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Abstract

Authors

Shruti Gupta, Olivia Green-Lingren, Sudhir Bhimaniya, Aleksandra Krokhmal, Heather Jacene, Marlies Ostermann, Sugama Chicklore, Ben Sprangers, Christophe M. Deroose, Sandra M. Herrmann, Sophia L. Wells, Sarah A. Kaunfer, Jessica L. Ortega, Clara Garcia-Carro, Michael Bold, Kevin L. Chen, Meghan E. Sise, Pedram Heidari, Wai Lun Will Pak, Meghan D. Lee, Pazit Beckerman, Yael Eshet, Raymond K. Hsu, Miguel Hernandez Pampaloni, Arash Rashidi, Norbert Avril, Vicki Donley, Zain Mithani, Russ Kuker, Muhammad O Awiwi, Mindy X. Wang, Sujal I. Shah, Michael D. Weintraub, Heiko Schoder, Raad B. Chowdhury, Harish Seethapathy, Kerry L. Reynolds, Maria Jose Soler, Ala Abudayyeh, Ilya Glezerman, David E. Leaf

Hif-2α programmes oxygen chemosensitivity in chromaffin cells

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Abstract

The study of transcription factors that determine specialised neuronal functions has provided invaluable insights into the physiology of the nervous system. Peripheral chemoreceptors are neurone-like electro-physiologically excitable cells that link the oxygen content of arterial blood to the neuronal control of breathing. In the adult, this oxygen chemosensitivity is exemplified by the Type I cells of the carotid body and recent work has revealed one isoform of the transcription factor HIF, HIF-2α, to have a non-redundant role in the development and function of that organ. Here we show that the activation of HIF-2α, including isolated overexpression alone, is sufficient to induce oxygen chemosensitivity in the otherwise unresponsive adult adrenal medulla. This phenotypic change in the adrenal medulla was associated with retention of extra-adrenal paraganglioma-like tissues that resemble the foetal organ of Zuckerkandl and also manifest oxygen chemosensitivity. Acquisition of chemosensitivity was associated with changes in the adrenal medullary expression of classes of genes that are ordinarily characteristic of the carotid body, including G-protein regulators and atypical subunits of mitochondrial cytochrome oxidase. Overall, the findings suggest that, at least in certain tissues, HIF-2α acts as a phenotypic driver for cells that display oxygen chemosensitivity, thus linking two major oxygen sensing systems.

Authors

Maria Prange-Barczynska, Holly A. Jones, Yoichiro Sugimoto, Xiaotong Cheng, Joanna D.C.C Lima, Indrika Ratnayaka, Gillian Douglas, Keith J. Buckler, Peter J. Ratcliffe, Thomas P. Keeley, Tammie Bishop

NKT cells promote Th1 immune bias to dengue virus that governs long term protective antibody dynamics

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Abstract

NKT cells are innate-like T cells, recruited to the skin during viral infection, yet their contributions to long-term immune memory to viruses are unclear. We identified granzyme K, a product made by cytotoxic cells including NKT cells, is linked to induction of Th1-associated antibodies during primary dengue virus (DENV) infection in humans. We examined the role of NKT cells in vivo using DENV-infected mice lacking CD1d-dependent (CD1ddep) NKT cells. In CD1d-KO mice, Th1-polarized immunity and infection resolution were impaired, which was dependent on intrinsic NKT cell production of IFN-γ, since it was restored by adoptive transfer of WT but not IFN-γ-KO NKT cells. Furthermore, NKT cell deficiency triggered immune bias, resulting in higher levels of Th2-associated IgG1 than Th1-associated IgG2a, which failed to protect against a homologous DENV re-challenge and promoted antibody-dependent enhanced disease during secondary heterologous infections. Similarly, Th2-immunity, typified by a higher IgG4:IgG3 ratio, was associated with worsened human disease severity during secondary infections. Thus, CD1ddep NKT cells establish Th1 polarity during the early innate response to DENV, which promotes infection resolution, memory formation and long-term protection from secondary homologous and heterologous infections. These observations illustrate how early innate immune responses during primary infections can influence secondary infection outcomes.

Authors

Youngjoo Choi, Wilfried A.A. Saron, Aled O'Neill, Manouri Senanayake, Annelies Wilder-Smith, Abhay P.S. Rathore, Ashley L. St. John

Exosomal TNF-α mediates voltage-gated Na⁺ channels 1.6 overexpression and contributes to brain-tumor induced neuronal hyperexcitability

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Patients affected by glioma frequently suffer of epileptic discharges, however the causes of brain tumor-related epilepsy (BTRE) are still not completely understood. We investigated the mechanisms underlying BTRE by analyzing the effects of exosomes released by U87 glioma cells and by patient-derived glioma cells. Rat hippocampal neurons incubated for 24 h with these exosomes exhibited increased spontaneous firing, while their resting membrane potential shifted positively by 10-15 mV. Voltage clamp recordings demonstrated that the activation of the Na+ current shifted towards more hyperpolarized voltages by 10-15 mV. To understand the factors inducing hyperexcitability we focused on exosomal cytokines. Western Blot and ELISA assays show that TNF-α is present inside glioma-derived exosomes. Remarkably, incubation with TNF-α fully mimicked the phenotype induced by exosomes, with neurons firing continuously, while their resting membrane potential shifted positively. RT-PCR revealed that both exosomes and TNF-α induced over-expression of the voltage-gated Na channel Nav1.6, a low-threshold Na+ channel responsible for hyperexcitability. When neurons were preincubated with Infliximab, a specific TNF-α inhibitor, the hyperexcitability induced by exosomes and TNF-α were drastically reduced. We propose that Infliximab, an FDA approved drug to treat rheumatoid arthritis, could ameliorate the conditions of glioma patients suffering of BTRE.

Authors

Cesar Adolfo Sanchez Trivino, Renza Spelat, Federica Spada, Camilla D'Angelo, Ivana Manini, Irene Giulia Rolle, Tamara Ius, Pietro Parisse, Anna Menini, Daniela Cesselli, Miran Skrap, Fabrizia Cesca, Vincent Torre

Early ascertainment of genetic diagnoses clarifies impact on medium-term survival following neonatal congenital heart surgery

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Abstract

Authors

Benjamin J. Landis, Benjamin M. Helm, Matthew D. Durbin, Lindsey R. Helvaty, Jeremy L. Herrmann, Michael Johansen, Gabrielle C. Geddes, Stephanie M. Ware

Autism-associated neuroligin-3 deficiency in medial septum causes social deficits and sleep loss in mice

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Abstract

Patients with autism spectrum disorder (ASD) frequently experience sleep disturbance. Genetic mutations in Neuroligin-3 (NLG3) genes are highly correlative with ASD and sleep disturbance. However, the cellular and neural circuit bases of this correlation remain elusive. Here, we find the conditional knockout of NLG3 (NLG3-CKO) in the medial septum (MS) impairs social memory and reduces sleep. NLG3 knockout in MS causes hyperactivity of MS-GABA neurons during social avoidance and wakefulness. Activation of MSGABA neurons induces social memory deficits and sleep loss in C57BL/6 mice. In contrast, inactivation of these neurons ameliorates social memory deficits and sleep loss in NLG3-CKO mice. Sleep deprivation leads to social memory deficits, while social isolation causes sleep loss, both resulting in a reduction of NLG3 expression and an increase in activity of GABAergic neurons in MS from C57BL/6 mice. Furthermore, MS-GABA-innervated CA2 neurons specifically regulate social memory without impacting sleep, whereas MSGABA-innervating neurons in the preoptic area selectively control sleep without affecting social behavior. Together, these findings demonstrate that the hyperactive MS-GABA neurons impair social memory and disrupt sleep resulting from NLG3 knockout in MS, and achieve the modality specificity through their divergent downstream targets.

Authors

Haiyan Sun, Yu Shen, Pengtao Ni, Xin Liu, Yan Li, Zhentong Qiu, Jiawen Su, Yihan Wang, Miao Wu, Xiangxi Kong, Jun-Li Cao, Wei Xie, Shuming An

Hepatic lipopolysaccharide binding protein partially uncouples inflammation from fibrosis in MAFLD

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Abstract

Authors

Dan Wang, Ania Baghoomian, Zhengyi Zhang, Ya Cui, Emily C. Whang, Xiang Li, Josue Fraga, Rachel Spellman, Tien S. Dong, We Li, Arpana Gupta, Jihane N. Benhammou, Tamer Sallam

A correctable immune niche for epithelial stem-cell reprogramming and post-viral lung diseases

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Epithelial barriers are programmed for defense and repair but are also the site of long-term structural remodeling and disease. In general, this paradigm features epithelial stem cell (ESCs) that are called on to regenerate damaged tissues but can also be reprogrammed for detrimental remodeling. Here we identified a Wfdc21-dependent monocyte-derived dendritic cell (moDC) population that functioned as an early sentinel niche for basal-ESC reprogramming in mouse models of epithelial injury after respiratory viral infection. Niche function depended on moDC delivery of ligand GPNMB to basal-ESC receptor CD44 so that properly timed antibody blockade of ligand or receptor provided long-lasting correction of reprogramming and broad disease phenotypes. These same control points worked directly in mouse and human basal-ESC organoids. Together, the findings identify a mechanism to explain and modify what is otherwise a stereotyped but sometimes detrimental response to epithelial injury.

Authors

Kangyun Wu, Yong Zhang, Huiqing Yin-DeClue, Kelly Sun, Dailing Mao, Kuangying Yang, Stephen R. Austin, Erika C. Crouch, Steven L. Brody, Derek E. Byers, Christy M. Hoffmann, Michael E. Hughes, Michael J. Holtzman

Intercellular interaction between FAP⁺ fibroblasts and CD150⁺ inflammatory monocytes mediates fibro-stenosis in Crohn’s disease

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Abstract

Crohn's disease (CD) is marked by recurring intestinal inflammation and tissue injury, often resulting in fibro-stenosis and bowel obstruction, necessitating surgical intervention with high recurrence rates. To elucidate to the mechanisms underlying fibro-stenosis in CD, we analysed the transcriptome of cells isolated from the transmural ileum of CD patients, including a trio of lesions from each patient: non-affected, inflamed, and stenotic ileum samples, and compared them with samples from non-CD patients. Our computational analysis revealed that pro-fibrotic signals from a subset of monocyte-derived cells expressing CD150 induced a disease-specific fibroblast population, resulting in chronic inflammation and tissue fibrosis. The transcription factor TWIST1 was identified as a key modulator of fibroblast activation and extracellular matrix (ECM) deposition. Genetic and pharmacological inhibition of TWIST1 prevents fibroblast activation, reducing ECM production and collagen deposition. Our findings suggest that the myeloid-stromal axis may offer a promising therapeutic target to prevent fibro-stenosis in CD.

Authors

Bo-Jun Ke, Saeed Abdurahiman, Francesca Biscu, Gaia Zanella, Gabriele Dragoni, Sneha Santhosh, Veronica De Simone, Anissa Zouzaf, Lies van Baarle, Michelle Stakenborg, Veronika Bosáková, Yentl Van Rymenant, Emile Verhulst, Sare Verstockt, Elliott Klein, Gabriele Bislenghi, Albert M. Wolthuis, Jan Frič, Christine Breynaert, Andre D'Hoore, Pieter Van der Veken, Ingrid De Meester, Sara Lovisa, Lukas J.A.C. Hawinkels, Bram Verstockt, Gert De Hertogh, Séverine Vermeire, Gianluca Matteoli

Systemic and skin-limited delayed-type drug hypersensitivity reactions associate with distinct resident and recruited T cell subsets

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Abstract

Delayed-type drug hypersensitivity reactions are major causes of morbidity and mortality. The origin, phenotype and function of pathogenic T cells across the spectrum of severity requires investigation. We leveraged recent technical advancements to study skin-resident memory T cells (TRM) versus recruited T cell subsets in the pathogenesis of severe systemic forms of disease, SJS/TEN and DRESS, and skin-limited disease, morbilliform drug eruption (MDE). Microscopy, bulk transcriptional profiling and scRNAseq + CITEseq + TCRseq supported in SJS/TEN clonal expansion and recruitment of cytotoxic CD8+ T cells from circulation into skin, along with expanded and non-expanded cytotoxic CD8+ skin TRM. Comparatively, MDE displayed a cytotoxic T cell profile in skin without appreciable expansion and recruitment of cytotoxic CD8+ T cells from circulation, implicating TRM as potential protagonists in skin-limited disease. Mechanistic interrogation in patients unable to recruit T cells from circulation into skin and in a parallel mouse model supported that skin TRM were sufficient to mediate MDE. Concomitantly, SJS/TEN displayed a reduced regulatory T cell (Treg) signature compared to MDE. DRESS demonstrated recruitment of cytotoxic CD8+ T cells into skin like SJS/TEN, yet a pro-Treg signature like MDE. These findings have important implications for fundamental skin immunology and clinical care.

Authors

Pranali N. Shah, George A. Romar, Artür Manukyan, Wei-Che Ko, Pei-Chen Hsieh, Gustavo A. Velasquez, Elisa M. Schunkert, Xiaopeng Fu, Indira Guleria, Roderick T. Bronson, Kevin Wei, Abigail H. Waldman, Frank R. Vleugels, Marilyn G. Liang, Anita Giobbie-Hurder, Arash Mostaghimi, Birgitta A.R. Schmidt, Victor Barrera, Ruth K. Foreman, Manuel Garber, Sherrie J. Divito

Notch signaling suppresses neuroendocrine differentiation and alters the immune microenvironment in advanced prostate cancer

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Notch signaling can have either an oncogenic or tumor suppressive function in cancer depending on the cancer type and cellular context. While Notch can be oncogenic in early prostate cancer, we identified significant downregulation of the Notch pathway during prostate cancer progression from adenocarcinoma to neuroendocrine prostate cancer where it functions as a tumor suppressor. Activation of Notch in neuroendocrine and Rb1/Trp53-deficient prostate cancer models led to phenotypic conversion towards a more indolent non-neuroendocrine state with glandular features and expression of luminal lineage markers. This was accompanied by up-regulation of MHC and type I interferon and immune cell infiltration. Overall, these data support Notch signaling as a suppressor of neuroendocrine differentiation in advanced prostate cancer and provides insights into how Notch signaling influences lineage plasticity and the tumor microenvironment.

Authors

Sheng-Yu Ku, Yanqing Wang, Maria Mica Garcia, Yasutaka Yamada, Kei Mizuno, Mark D. Long, Spencer Rosario, Meenalakshmi Chinnam, Majd Al Assaad, Loredana Puca, Min Jin Kim, Martin K. Bakht, Varadha Balaji Venkadakrishnan, Brian D. Robinson, Andrés M. Acosta, Kristine M. Wadosky, Juan Miguel Mosquera, David W. Goodrich, Himisha Beltran

TWIST1⁺FAP⁺ fibroblasts in the pathogenesis of intestinal fibrosis in Crohn’s disease

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Intestinal fibrosis, a severe complication of Crohn’s disease (CD), is characterized by excessive extracellular matrix (ECM) deposition and induces intestinal strictures, but there are no effective anti-fibrosis drugs available for clinical application. We performed single-cell RNA sequencing (scRNA-seq) of fibrotic and non-fibrotic ileal tissues from CD patients with intestinal obstruction. Analysis revealed mesenchymal stromal cells (MSCs) as the major producers of ECM and the increased infiltration of its subset FAP+ fibroblasts in fibrotic sites, which was confirmed by immunofluorescence and flow cytometry. Single cell transcriptomic profiling of chronic Dextran Sulfate Sodium Salt (DSS) murine colitis model revealed Cd81+Pi16– fibroblasts exhibited transcriptomic and functional similarities to human FAP+ fibroblasts. Consistently, FAP+ fibroblasts were identified as the key subtype with the highest level of ECM production in fibrotic intestines. Furthermore, specific knockout or pharmacological inhibition of TWIST1, which was highly expressed by FAP+ fibroblasts, could significantly ameliorate fibrosis in mice. In addition, TWIST1 expression was induced by CXCL9+ macrophages enriched in fibrotic tissues via IL-1β and TGF-β signal. These findings suggest the inhibition of TWIST1 as a promising strategy for CD fibrosis treatment.

Authors

Yao Zhang, Jiaxin Wang, Hongxiang Sun, Zhenzhen Xun, Zirui He, Yizhou Zhao, Jingjing Qi, Sishen Sun, Qidi Yang, Yubei Gu, Ling Zhang, Chunhua Zhou, Youqiong Ye, Ningbo Wu, Duowu Zou, Bing Su

DRD2 activation inhibits choroidal neovascularization in patients with Parkinson’s disease and age-related macular degeneration

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Abstract

Neovascular age-related macular degeneration (nAMD) remains a major cause of visual impairment and puts considerable burden on patients and health care systems. L-DOPA-treated Parkinson Disease (PD) patients have been shown to be partially protected from nAMD, but the mechanism remains unknown. Using murine models, combining 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD and laser-induced nAMD, standard PD treatment of L-DOPA/DOPA-decarboxylase inhibitor, or specific dopamine receptor inhibitors, we here demonstrate that L-DOPA treatment-induced increase of dopamine mediated dopamine receptor D2 (DRD2) signaling inhibits choroidal neovascularization independently of MPTP-associated nigrostriatal pathway lesion. Analyzing a retrospective cohort of more than two hundred thousand nAMD patients receiving anti-VEGF treatment from the French nationwide insurance database, we show that DRD2-agonist treated (PD) patients have a significantly delayed age of onset for nAMD (81.4 (±7.0) vs 79.4 (±8.1) years old, respectively, p<0.0001) and reduced need for anti-VEGF therapies (-0.6 injections per 100 mg/day daily dose of DRD2 agonists the second year of treatment), similar to the L-DOPA treatment. While providing a mechanistic explanation for an intriguing epidemiological observation, our findings suggest that systemic DRD2 agonists might constitute an adjuvant therapy to delay and reduce the need for anti-VEGF therapy in nAMD patients.

Authors

Thibaud Mathis, Florian Baudin, Anne-Sophie Mariet, Sébastien Augustin, Marion Bricout, Lauriane Przegralek, Christophe Roubeix, Éric Benzenine, Guillaume Blot, Caroline Nous, Laurent Kodjikian, Martine Mauget-Faÿsse, José-Alain Sahel, Robin Plevin, Christina Zeitz, Cécile Delarasse, Xavier Guillonneau, Catherine Creuzot-Garcher, Catherine Quantin, Stéphane Hunot, Florian Sennlaub

Bi-allelic variants in RINT1 present as early-onset pure hereditary spastic paraplegia

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Authors

Vicente Quiroz, Laura Planas-Serra, Abigail Sveden, Amy Tam, Hyo M. Kim, Umar Zubair, Dario Resch, Afshin Saffari, Matt C. Danzi, Stephan Züchner, Maya Chopra, Luca Schierbaum, Aurora Pujol, Erik A. Eklund, Darius Ebrahimi-Fakhari

Randomised controlled trial reveals no benefit to a 3-month delay in COVID-19 mRNA booster vaccine

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Abstract

BACKGROUND. There is uncertainty around the timing of booster vaccination against COVID-19 in highly vaccinated populations during the present endemic phase of COVID-19. Studies focused on primary vaccination have previously suggested improved immunity after delaying immunisation. METHODS. We conducted a randomised controlled trial (Nov 2022 – Aug 2023) and assigned 52 fully vaccinated adults to an immediate or a 3-month delayed bivalent Spikevax mRNA booster vaccine. Follow-up visits were completed for 48 participants (n = 24 per arm), with saliva and plasma samples collected following each visit. RESULTS. The rise in neutralising antibody responses to ancestral and Omicron strains were almost identical between the immediate and delayed vaccination arms. Analyses of plasma and salivary antibody responses (IgG, IgA), plasma antibody-dependent phagocytic activity, and the decay kinetics of antibody responses were similar between the 2 arms. Symptomatic and asymptomatic SARS-CoV-2 infection occurred in 49% (21/49) participants over the median 11.5 months of follow up and were also similar between the 2 arms. CONCLUSIONS. Our data suggests no benefit from delaying COVID-19 mRNA booster vaccination in pre-immune populations during the present endemic phase of COVID-19 TRIAL REGISTRATION. Australian New Zealand Clinical Trials Registry number 12622000411741. FUNDING. National Health and Medical Research Council, Australia, Program Grant App1149990 and Medical Research Future Fund App2005544.

Authors

Wen Shi Lee, Jennifer Audsley, Mai-Chi Trieu, Arnold Reynaldi, L. Carissa Aurelia, Palak H. Mehta, Joanne Patterson, Helen E. Kent, Julie Nguyen, Thakshila Amarasena, Robyn Esterbauer, Ebene R. Haycroft, Pradhipa Ramanathan, Miles P. Davenport, Timothy E. Schlub, Joseph Sasadeusz, Adam K. Wheatley, Amy W. Chung, Jennifer A. Juno, Kevin J. Selva, Stephen J. Kent

A fibroblast-dependent TGFβ1/sFRP2 noncanonical Wnt signaling axis promotes epithelial metaplasia in idiopathic pulmonary fibrosis

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Reciprocal interactions between alveolar fibroblasts and epithelial cells are crucial for lung homeostasis, injury repair, and fibrogenesis, but underlying mechanisms remain unclear. To investigate, we administered the fibroblast-selective TGFβ1 signaling inhibitor, epigallocatechin gallate (EGCG), to Interstitial Lung Disease (ILD) patients undergoing diagnostic lung biopsy and conducted single-cell RNA sequencing on spare tissue. Biopsies from untreated patients showed higher fibroblast TGFβ1 signaling compared to non-disease donor or end-stage ILD tissues. In vivo, EGCG downregulated TGFβ1 signaling and several pro-inflammatory and stress pathways in biopsy samples. Notably, EGCG reduced fibroblast secreted frizzle-like receptor protein 2 (sFRP2), an unrecognized TGFβ1 fibroblast target gene induced near type II alveolar epithelial cells (AEC2s) in situ. Using AEC2-fibroblast coculture organoids and precision cut lung slices (PCLS) from non-diseased donors, we found TGFβ1 signaling promotes a spread AEC2 KRT17+ basaloid state, whereupon sFRP2 then activates a mature Krt5+ basal cell program. Wnt-receptor Frizzled 5 (Fzd5) expression and downstream calcineurin signaling were required for sFRP2-induced nuclear NFATc3 accumulation and KRT5 expression. These findings highlight stage-specific TGFβ1 signaling in ILD, the therapeutic potential of EGCG in reducing IPF-related transcriptional changes, and identify TGFβ1-non-canonical Wnt pathway crosstalk via sFRP2 as a novel mechanism for dysfunctional epithelial signaling in Idiopathic Pulmonary Fibrosis/ILD.

Authors

Max L. Cohen, Alexis N. Brumwell, Tsung Che Ho, Kiana Garakani, Genevieve Montas, Darren Leong, Vivianne W. Ding, Jeffrey A. Golden, Binh N. Trinh, David M. Jablons, Michael A. Matthay, Kirk D. Jones, Paul J. Wolters, Ying Wei, Harold A. Chapman, Claude Jourdan Le Saux

De novo monoallelic Reelin missense variants act in a dominant-negative manner causing neuronal migration disorders

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Reelin (RELN) is a secreted glycoprotein essential for cerebral cortex development. In humans, recessive RELN variants cause cortical and cerebellar malformations, while heterozygous variants were associated to epilepsy, autism and mild cortical abnormalities. However, their functional effects remain unknown. We identified inherited and de novo RELN missense variants in heterozygous patients with neuronal migration disorders (NMDs) as diverse as pachygyria and polymicrogyria. We investigated in culture and in the developing mouse cerebral cortex how different variants impacted RELN function. Polymicrogyria-associated variants behaved as gain-of-function showing an enhanced ability to induce neuronal aggregation, while those linked to pachygyria as loss-of-function leading to defective neuronal aggregation/migration. The pachygyria-associated de novo heterozygous RELN variants acted as dominant-negative by preventing wild-type RELN secretion in culture, animal models and patients, thereby causing dominant NMDs. We demonstrated how mutant RELN proteins in vitro and in vivo predict cortical malformation phenotypes, providing valuable insights into the pathogenesis of such disorders.

Authors

Martina Riva, Sofia Ferreira, Kotaro Hayashi, Yoann Saillour, Vera P. Medvedeva, Takao Honda, Kanehiro Hayashi, Claire Altersitz, Shahad Albadri, Marion Rosello, Julie Dang, Malo Serafini, Frédéric Causeret, Olivia J. Henry, Charles-Joris Roux, Céline Bellesme, Elena Freri, Dragana Josifova, Elena Parrini, Renzo Guerrini, Filippo Del Bene, Kazunori Nakajima, Nadia Bahi-Buisson, Alessandra Pierani