Infectious disease
Abstract
Authors
Karen Hoffmann, Ulrike Behrendt, Peter Pennitz, Holger Kirsten, Jessica Pohl, Elena Lopez-Rodriguez, Chantal Weissfuss, Jens Kollmeier, Mario Tönnies, Sebastian Brill, Konrad Steinestel, Martin Witzenrath, Werner Wenzel, Christian Zobel, Geraldine Nouailles
Abstract
Secondary bacterial infection, often caused by Streptococcus pneumoniae (Spn), is one of the most frequent and severe complications of influenza A virus (IAV)-induced pneumonia. Phenotyping of the pulmonary immune cell landscape after IAV infection revealed a substantial depletion of the tissue-resident alveolar macrophage (TR-AM) population at day 7, which was associated with increased susceptibility to Spn outgrowth. To elucidate the molecular mechanisms underlying TR-AM depletion, and to define putative targets for treatment, we combined single-cell transcriptomics and cell-specific PCR profiling in an unbiased manner, using in vivo models of IAV infection and IAV/Spn co-infection. The TNF superfamily 14 (TNFSF14) ligand-receptor axis was revealed as the driving force behind post-influenza TR-AM death during the early infection phase, enabling the transition to pneumococcal pneumonia, while intrapulmonary transfer of genetically modified TR-AMs and antibody-mediated neutralization of specific pathway components alleviated disease severity. With a mainly neutrophilic expression and a high abundance in the bronchoalveolar fluid (BALF) of patients with severe virus-induced ARDS, TNFSF14 emerged as a key determinant of virus-driven lung injury. Targeting the TNFSF14-mediated intercellular communication network in the virus-infected lung can, therefore, improve host defense, minimizing the risk of subsequent bacterial pneumonia, and ameliorating disease outcome.
Authors
Christina Malainou, Christin Peteranderl, Maximiliano Ruben Ferrero, Ana Ivonne Vazquez-Armendariz, Ioannis Alexopoulos, Katharina Franz, Klara Knippenberg, Julian Better, Mohammad Estiri, Cheng-Yu Wu, Hendrik Schultheis, Judith Bushe, Maria-Luisa del Rio, Jose Ignacio Rodriguez-Barbosa, Klaus Pfeffer, Stefan Günther, Mario Looso, Achim Dieter Gruber, István Vadász, Ulrich Matt, Susanne Herold
Abstract
The physiology of SARS-CoV-2 virus/host interactions is not well understood. To better understand host/virus interactions, we performed a CRISPR activation screen to identify host genes that confer resistance to authentic SARS-CoV-2. This highlighted 34 new candidate genes that may alter the course of infection. We validated that 7 of these genes can suppress authentic SARS-CoV-2 infection, including the innate immune receptor P selectin, which increases SARS-CoV-2 spike-dependent binding to cells, while protecting from infection. P selectin also promotes binding to SARS-CoV-2 variants, SARS-CoV-1, and Middle East respiratory syndrome spike proteins, suggesting a general role for P selectin in highly pathogenic coronavirus infections. Importantly, P selectin protein expression driven by synthetic mRNA can block SARS-CoV-2 infection. Naturally, P selectin is expressed on platelets, and we show that it promotes spike-mediated platelet aggregation. P selectin is also expressed on the endothelium, where SARS-CoV-2 spike interactions are also P selectin dependent. In vivo, SARS-CoV-2 uses P selectin to home to capillary beds where the virus interacts with platelets and endothelium, and blocking this interaction can clear vascular-associated pulmonary SARS-CoV-2.
Authors
Cesar L. Moreno, Fernanda V.S. Castanheira, Alberto Ospina Stella, Felicity Chung, Anupriya Aggarwal, Alexander J. Cole, Lipin Loo, Alexander Dupuy, Yvonne X. Kong, Lejla Hagimola, Jemma Fenwick, Paul R. Coleman, Rebecca Carr, Tian Y. Du, Tim Ison, Michelle Newton, Maxwell P. Bui-Marinos, Scott B. Cohen, Jennifer A. Corcoran, Daniel Hesselson, Jennifer R. Gamble, Freda H. Passam, Stuart G. Turville, Paul Kubes, G. Gregory Neely
Abstract
Clonal expansion of HIV infected CD4+ T cells is a barrier to HIV eradication. We previously described a marked reduction in the frequency of the most clonally expanded infected CD4+ T cells in an individual with elite control (ES24) after initiating chemoradiation for metastatic lung cancer with a regimen that included paclitaxel and carboplatin. We tested the hypothesis that this phenomenon was due to a higher susceptibility to the chemotherapeutic drugs of CD4+ T cell clones that were sustained by proliferation. We studied a CD4+ T cell clone with replication-competent provirus integrated into the ZNF721 gene, termed ZNF721i. We stimulated the clone with its cognate peptide and then exposed the cells to paclitaxel and/or carboplatin or the antiproliferative drug, mycophenolate mofetil. While treatment of cells with the cognate peptide alone led to a marked expansion of the ZNF721i clone, treatment with the cognate peptide followed by culture with either paclitaxel or mycophenolate mofetil abrogated this process. The drugs did not affect the proliferation of other CD4+ T cell clones that were not specific for the cognate peptide. This strategy of antigen-specific stimulation followed by treatment with an antiproliferative agent may lead to the selective elimination of clonally expanded HIV-infected cells.
Authors
Filippo Dragoni, Joel Sop, Isha Gurumurthy, Tyler P. Beckey, Kellie N. Smith, Francesco R. Simonetti, Joel N. Blankson
Abstract
Mechanisms responsible for delayed wound repair are poorly understood despite the common impact of this disorder on health. To study how Staphylococcus aureus disrupts healing, mouse and human wound repair models were evaluated after exposure to S. aureus or commensal Staphylococcus. Quorum sensing by S. aureus, but not S. hominis, delayed repair and inhibited the expression of genes responsible for lipid metabolism in keratinocytes. S. aureus with inactive accessory gene regulator (agr) did not delay healing, and the inhibition of lipid metabolism was recapitulated in vitro by synthetic phenol soluble modulin α1 (psmα1) and psmα4, genes that are under agr control. However, S. aureus strains with single deletion of psmA, psmB, alpha-hemolysin (hla), or hld gene continued to delay repair, suggesting that S. aureus used multiple agr-dependent virulence factors to disrupt healing. These observations provide insight into mechanisms for delayed wound healing, identify quorum sensing as a critical event, and highlight the role of lipid biosynthesis in wound reepithelialization.
Authors
Michelle D. Bagood, Jelena Marjanovic, Nina Jiang, Hung Chan, Tatsuya Dokoshi, Kellen J. Cavagnero, Fengwu Li, Andrea Roso-Mares, Samia Almoughrabie, Edward Liu, Irena Pastar, Marjana Tomic-Canic, Alexander R. Horswill, Richard L. Gallo
Abstract
Herein, we describe a shared surface and cell wall protein, Endoglucanase 2 (Eng2), expressed on the etiological agents that cause the endemic systemic mycoses of North America – Blastomyces, Coccidioides and Histoplasma. We demonstrate that despite sequence variation of the protein across these related fungi, exposure to Eng2 vaccinates and protects inbred and humanized HLA-DR4 strains of mice against lethal experimental infections with these fungi by eliciting adaptive immunity mediated by CD4 T cells. We also show that CD4 T cell precursors against Eng2 are detectable in naïve individuals and that patients who have recovered from these infections evince a memory and recall CD4 T cell response to Eng2 and its immunodominant epitopes that we have mapped. We create and catalogue new tools and information such as immunodominant peptide epitopes of Eng2 from each fungus recognized by inbred mice and human subjects and we engineer peptide-MHC II tetramers for tracking T cells in inbred and HLA-DR4 humanized mice that will be useful for those who study these infections in mice and humans. Lastly, because most patients demonstrate memory and recall responses against Eng2, our work offers new tools for diagnosis of this collection of infectious diseases across North America.
Authors
Uju J. Okaa, Cleison Ledesma Taira, Lucas dos Santos Dias, Hannah Dobson, Gregory C. Kujoth, Althea Campuzano, E.Jane Homan, George R. Thompson, Chiung-Yu Hung, George S. Deepe, Marcel Wüthrich, Bruce S. Klein
Abstract
Bacterial infections, particularly uropathogenic E. coli (UPEC), contribute substantially to male infertility through tissue damage and subsequent fibrosis in the testis and epididymis. The role of testicular macrophages (TMs), a diverse cell population integral to tissue maintenance and immune balance, in fibrosis is not fully understood. Here, we used single-cell RNA sequencing in a murine model of epididymo-orchitis to analyze TM dynamics during UPEC infection. Our study identified a marked increase in S100a4+ macrophages, originating from monocytes, strongly associated with fibrotic changes. This association was validated in human testicular and epididymal samples. We further demonstrated that S100a4+ macrophages transition to a myofibroblast-like phenotype, producing extracellular matrix proteins such as collagen I and fibronectin. S100a4, both extracellular and intracellular, activated collagen synthesis through the TGF-β/STAT3 signaling pathway, highlighting this pathway as a therapeutic target. Inhibition of S100a4 with niclosamide or macrophage-specific S100a4 KO markedly reduced immune infiltration, tissue damage, and fibrosis in infected murine models. Our findings establish the critical role of S100a4+ macrophages in fibrosis during UPEC-induced epididymo-orchitis and propose them as potential targets for antifibrotic therapy development.
Authors
Ming Wang, Xu Chu, Zhongyu Fan, Lin Chen, Huafei Wang, Peng Wang, Zihao Wang, Yiming Zhang, Yihao Du, Sudhanshu Bhushan, Zhengguo Zhang
Abstract
Molnupiravir is an antiviral medicine that induces lethal copying errors during SARS-CoV-2 RNA replication. Molnupiravir reduced hospitalization in one pivotal trial by 50% and had variable effects on reducing viral RNA levels in three separate trials. We used mathematical models to simulate these trials and closely recapitulated their virologic outcomes. Model simulations suggest lower antiviral potency against pre-omicron SARS-CoV-2 variants than against omicron. We estimate that in vitro assays underestimate in vivo potency 6-7 fold against omicron variants. Our model suggests that because polymerase chain reaction detects molnupiravir mutated variants, the true reduction in non-mutated viral RNA is underestimated by ~0.4 log10 in the two trials conducted while omicron variants dominated. Viral area under the curve estimates differ significantly between non-mutated and mutated viral RNA. Our results reinforce past work suggesting that in vitro assays are unreliable for estimating in vivo antiviral drug potency and suggest that virologic endpoints for respiratory virus clinical trials should be catered to the drug mechanism of action.
Authors
Shadisadat Esmaeili, Katherine Owens, Ugo Avila-Ponce de Leon, Joseph F. Standing, David M. Lowe, Shengyuan Zhang, James A. Watson, William H.K. Schilling, Jessica Wagoner, Stephen J. Polyak, Joshua T. Schiffer
Abstract
Background. Following SARS-CoV-2 infection, ~10-35% of COVID-19 patients experience long COVID (LC), in which debilitating symptoms persist for at least three months. Elucidating biologic underpinnings of LC could identify therapeutic opportunities. Methods. We utilized machine learning methods on biologic analytes provided over 12-months after hospital discharge from >500 COVID-19 patients in the IMPACC cohort to identify a multi-omics “recovery factor”, trained on patient-reported physical function survey scores. Immune profiling data included PBMC transcriptomics, serum O-link and plasma proteomics, plasma metabolomics, and blood CyTOF protein levels. Recovery factor scores were tested for association with LC, disease severity, clinical parameters, and immune subset frequencies. Enrichment analyses identified biologic pathways associated with recovery factor scores. Results. LC participants had lower recovery factor scores compared to recovered participants. Recovery factor scores predicted LC as early as hospital admission, irrespective of acute COVID-19 severity. Biologic characterization revealed increased inflammatory mediators, elevated signatures of heme metabolism, and decreased androgenic steroids as predictive and ongoing biomarkers of LC. Lower recovery factor scores were associated with reduced lymphocyte and increased myeloid cell frequencies. The observed signatures are consistent with persistent inflammation driving anemia and stress erythropoiesis as major biologic underpinnings of LC. Conclusion. The multi-omics recovery factor identifies patients at risk of LC early after SARS-CoV-2 infection and reveals LC biomarkers and potential treatment targets. Trial Registration. ClinicalTrials.gov NCT04378777. Funding. This study was funded by NIH, NIAID and NSF.
Authors
Gisela Gabernet, Jessica Maciuch, Jeremy P. Gygi, John F. Moore, Annmarie Hoch, Caitlin Syphurs, Tianyi Chu, Naresh Doni Jayavelu, David B. Corry, Farrah Kheradmand, Lindsey R. Baden, Rafick-Pierre Sekaly, Grace A. McComsey, Elias K. Haddad, Charles B. Cairns, Nadine Rouphael, Ana Fernandez-Sesma, Viviana Simon, Jordan P. Metcalf, Nelson I. Agudelo Higuita, Catherine L. Hough, William B. Messer, Mark M. Davis, Kari C. Nadeau, Bali Pulendran, Monica Kraft, Chris Bime, Elaine F. Reed, Joanna Schaenman, David J. Erle, Carolyn S. Calfee, Mark A. Atkinson, Scott C. Brakenridge, Esther Melamed, Albert C. Shaw, David A. Hafler, Alison D. Augustine, Patrice M. Becker, Al Ozonoff, Steven E. Bosinger, Walter Eckalbar, Holden T. Maecker, Seunghee Kim-Schulze, Hanno Steen, Florian Krammer, Kerstin Westendorf, IMPACC Network, Bjoern Peters, Slim Fourati, Matthew C. Altman, Ofer Levy, Kinga K. Smolen, Ruth R. Montgomery, Joann Diray-Arce, Steven H. Kleinstein, Leying Guan, Lauren I.R. Ehrlich
Abstract
The persistent challenge of sepsis-related mortality underscores the necessity for deeper insights, with our multi-center cross-age cohort study identifying insulin-like growth factor binding protein 6 (IGFBP6) as a critical regulator in sepsis diagnosis, prognosis, and mortality risk evaluation. Mechanistically, IGFBP6 engages in IGF-independent binding to prohibitin2 (PHB2) on epithelial cells, driving PHB2 tyrosine phosphorylation during sepsis. This process disrupts STAT1 phosphorylation, nuclear translocation, and its recruitment to the CCL2 promoter, ultimately impairing CCL2 transcription and macrophage chemotaxis. Crucially, PHB2 silencing via siPHB2 and STAT1 activation using 2-NP restored CCL2 expression in vitro and in vivo, improving bacterial clearance and survival in septic mice. Concurrently, IGFBP6 compromises macrophage bactericidal activity by inhibiting Akt phosphorylation, reducing ROS/IL-1β production and phagocytic capacity – defects reversible by Akt agonist SC79. Collectively, IGFBP6 emerges as an endogenous driver of sepsis pathogenesis, positioning it as a dual diagnostic biomarker and therapeutic target. Intervention strategies targeting IGFBP6-mediated signaling may offer transformative approaches for sepsis management.
Authors
Kai Chen, Ying Hu, Xiaoyan Yu, Hong Tang, Yanting Ruan, Yue Li, Xun Gao, Qing Zhao, Hong Wang, Xuemei Zhang, David Paul Molloy, Yibing Yin, Dapeng Chen, Zhixin Song
No posts were found with this tag.
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)