Fowler et al. report that neutrophils act as oxygen sinks and modify CD8+ T cell behavior in the inflamed skin. The cover art shows staining of neutrophils (Ly6G, pink) and hypoxic regions (pimonidazole, green) in murine skin following Leishmania infection.
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
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.
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
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.
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
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.
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
Amandeep Jutla, Lauren C. Shuffrey, Stephen J. Guter, Kally C. O'Reilly, George M. Anderson, James S. Sutcliffe, Edwin H. Cook, Jeremy Veenstra-VanderWeele
JCI celebrates a century of publishing scientific discoveries with a special collection highlighting major innovations in medicine and key contributing mechanistic studies.
Biological sex profoundly influences disease risk, pathogenesis, progression, and treatment, but there are persistent gaps in the study of sex differences that span all areas of medicine. Reviews in this series will examine sex as a biological variable in cancer, metabolism, cardiovascular disease, autoimmunity, and more and highlight the potential to leverage these sex differences to optimize therapies for all.
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