Biology subjects

Kenney, A.

Publications and source records attributed to Kenney, A..

9 recordsLinked to original sources

bioRxiv2025

Caspase-11 Mediated Hyperinflammation Impairs CD8⁺ T Cell Immunity and Viral Clearance in Severe SARS-CoV-2 Infection

Severe SARS-CoV-2 infection is characterized by lung hyperinflammation, impaired interferon responses, and defective T-cell activation, yet the molecular drivers of these immune dysregulations remain incompletely understood. Caspase-11 (CASP11), a key mediator of the non-canonical inflammasome, has been shown to mediate an innate hyperinflammatory response and cytokine release in a non-severe, non-lethal SARS-CoV-2 infection model. However, the role played by CASP11 in severe SARS-CoV-2 disease and how it impacts adaptive immunity is not identified. Here, we newly discover that CASP11 exacerbates severe SARS-CoV-2 pathogenesis by amplifying early innate immune responses while concurrently impairing antiviral CD8 T-cell immunity. Using global knockouts, reciprocal bone marrow chimeras, and phagocyte-monocyte system (PMS) cell-specific CASP11 deletion models, we show that CASP11 deletion in monocyte-derived cells reduces lung inflammation, enhances type I and II interferon signaling, and promotes robust virus-specific effector CD8 T-cell response. This was associated with enhanced viral clearance and improved survival, even under lethal infection conditions. Importantly, CASP11 KO mice also exhibited faster resolution of post-viral inflammation, suggesting a role in long-term immune remodeling. These findings position CASP11 as a promising immunomodulatory target for acute and delayed manifestations of severe SARS-CoV-2.

microbiology↗

bioRxiv2023

Loss of Gasdermin D is protective against influenza virus-induced inflammation and mortality

Influenza virus activates cellular inflammasome pathways, which can be either beneficial or detrimental to infection outcomes. Here, we investigated the role of the inflammasome-activated pore-forming protein gasdermin D (GSDMD) during infection. Ablation of GSDMD in knockout (KO) mice significantly attenuated virus-induced weight loss, lung dysfunction, lung histopathology, and mortality compared with wild type (WT) mice, despite similar viral loads. Infected GSDMD KO mice exhibited decreased inflammatory gene signatures revealed by lung transcriptomics, which also implicated a diminished neutrophil response. Importantly, neutrophil depletion in infected WT mice recapitulated the reduced mortality and lung inflammation observed in GSDMD KO animals, while having no additional protective effects in GSDMD KOs. These findings reveal a new function for GSDMD in promoting lung neutrophil responses that amplify influenza virus-induced inflammation and pathogenesis. Targeting the GSDMD/neutrophil axis may provide a new therapeutic avenue for treating severe influenza.

immunology↗

bioRxiv2022

Prime-pull immunization of mice with a BcfA-adjuvanted vaccine elicits mucosal immunity and prevents SARS CoV-2 infection and pathology

Vaccines against SARS-CoV-2 that induce mucosal immunity capable of preventing infection and disease remain urgently needed. We show that intramuscular priming of mice with an alum and BcfA-adjuvanted Spike subunit vaccine, followed by a BcfA-adjuvanted mucosal booster, generated Th17 polarized tissue resident CD4+ T cells, and mucosal and serum antibodies. The serum antibodies efficiently neutralized SARS-CoV-2 and its Delta variant, suggesting cross-protection against a recent variant of concern (VOC). Immunization with this heterologous vaccine prevented weight loss following challenge with mouse-adapted SARS-CoV-2 and reduced viral replication in the nose and lungs. Histopathology showed a strong leukocyte and polymorphonuclear (PMN) cell infiltrate without epithelial damage in mice immunized with BcfA-containing vaccines. In contrast, viral load was not reduced in the upper respiratory tract of IL-17 knockout mice immunized with the same formulation, suggesting that the Th17 polarized T cell responses are critical for protection. We show that vaccines adjuvanted with alum and BcfA, delivered through a heterologous prime-pull regimen, protect against SARS-CoV-2 infection without causing enhanced respiratory disease. SIGNIFICANCEThere remains a need for SARS CoV-2 booster vaccines that generate mucosal immunity and prevent transmission. We show that systemic priming followed by a mucosal booster with a BcfA-adjuvanted subunit vaccine generates neutralizing antibodies and Th17 polarized systemic and tissue-resident immune responses that provide sterilizing immunity against wildtype SARS CoV-2, and a variant of concern. Importantly, in contrast to alum alone, the addition of BcfA prevents respiratory pathology. These results suggest that a BcfA-adjuvanted mucosal booster may elicit mucosal immunity in individuals previously immunized systemically with approved vaccines. This foundational study in mice sets the stage for testing our vaccine regimen in larger animal models as a booster vaccine.

immunology↗

bioRxiv2021

Interferon-induced transmembrane protein 3 (IFITM3) limits lethality of SARS-CoV-2 in mice

Interferon-induced transmembrane protein 3 (IFITM3) is a host antiviral protein that alters cell membranes to block fusion of viruses. Published reports have identified conflicting pro- and antiviral effects of IFITM3 on SARS-CoV-2 in cultured cells, and its impact on viral pathogenesis in vivo remains unclear. Here, we show that IFITM3 knockout (KO) mice infected with mouse-adapted SARS-CoV-2 experienced extreme weight loss and lethality, while wild type (WT) mice lost minimal weight and recovered. KO mice had higher lung viral titers and increases in lung inflammatory cytokine levels, CD45-positive immune cell infiltration, and histopathology, compared to WT mice. Mechanistically, we observed disseminated viral antigen staining throughout the lung tissue and pulmonary vasculature in KO mice, while staining was observed in confined regions in WT lungs. Global transcriptomic analysis of infected lungs identified upregulation of gene signatures associated with interferons, inflammation, and angiogenesis in KO versus WT animals, highlighting changes in lung gene expression programs that precede severe lung pathology and fatality. Corroborating the protective effect of IFITM3 in vivo, K18-hACE2/IFITM3 KO mice infected with non-adapted SARS-CoV-2 showed enhanced, rapid weight loss and early death compared to control mice. Increased heart infection was observed in both mouse models in the absence of IFITM3, indicating that IFITM3 constrains extrapulmonary dissemination of SARS-CoV-2. Our results establish IFITM3 KO mice as a new animal model for studying severe SARS-CoV-2 infection of the lung and cardiovascular system, and overall demonstrate that IFITM3 is protective in SARS-CoV-2 infections of mice.

immunology↗

bioRxiv2021

Caspase-4/11 exacerbates disease severity in SARS-CoV-2 infection by promoting inflammation and thrombosis

SARS-CoV-2 is a worldwide health concern, and new treatment strategies are needed 1. Targeting inflammatory innate immunity pathways holds therapeutic promise, but effective molecular targets remain elusive. Here, we show that human caspase-4 (CASP4), and its mouse homologue, caspase-11 (CASP11), are upregulated in SARS-CoV-2 infections, and that CASP4 expression correlates with severity of SARS-CoV-2 infection in humans. SARS-CoV-2-infected Casp11-/- mice were protected from severe weight loss and lung pathology, including blood vessel damage, compared to wild-type (WT) and gasdermin-D knock out (Gsdmd-/-) mice. GSDMD is a downstream effector of CASP11 and CASP1. Notably, viral titers were similar in the three genotypes. Global transcriptomics of SARS-CoV-2-infected WT, Casp11-/- and Gsdmd-/- lungs identified restrained expression of inflammatory molecules and altered neutrophil gene signatures in Casp11-/- mice. We confirmed that protein levels of inflammatory mediators IL-1{beta}, IL6, and CXCL1, and neutrophil functions, were reduced in Casp11-/- lungs. Additionally, Casp11-/- lungs accumulated less von Willebrand factor, a marker for endothelial damage, but expressed more Kruppel-Like Factor 2, a transcription factor that maintains vascular integrity. Overall, our results demonstrate that CASP4/11, promotes detrimental SARS-CoV-2-associated inflammation and coagulopathy, largely independently of GSDMD, identifying CASP4/11 as a promising drug target for treatment and prevention of severe COVID-19.

immunology↗

bioRxiv2020

IWS1 phosphorylation by AKT kinase controls the nucleocytoplasmic export of type I IFNs and the sensitivity of lung adenocarcinoma cells to oncolytic viral infection, through U2AF2 RNA splicing.

The authors have withdrawn their manuscript. While attempting to reproduce the data on the alternative splicing of exon 2 of U2AF2, they observed that the proposed splicing mechanism could not give rise to a functional U2AF2 protein. In addition, they observed evidence of manipulation in the electropherogram of the splicing junction between exons 1 and 3 and in the primary data on which this electropherogram was based, which were deposited in Mendeley by the first author. These observations raise questions on the integrity of the reported results. In light of this information, the authors have no confidence in the key findings of the paper, and therefore, do not wish it to be cited. If you have any questions, please contact the corresponding author.

cancer biology↗

bioRxiv2020

Short chain fatty acid butyrate promotes virus infection by repressing interferon stimulated genes

Butyrate is an abundant metabolite produced by the gut microbiota and is known to modulate multiple immune system pathways and inflammatory diseases. However, studies of its effects on virus infection of cells are limited and enigmatic. We found that butyrate increases cellular infection and virus replication in influenza virus, reovirus, and human immunodeficiency virus infections. Further exploring this phenomenon, we found that addition of butyrate to cells deficient in type I interferon (IFN) signaling did not increase susceptibility to virus infection. Accordingly, we discovered that butyrate suppressed levels of specific IFN stimulated gene (ISG) products in human and mouse cells. Butyrate did not inhibit IFN-induced phosphorylation of transcription factors STAT1 and STAT2 or their translocation to the nucleus, indicating that IFN signaling was not disrupted. Rather, our data are suggestive of a role for inhibition of histone deacetylase activity by butyrate in limiting ISG induction. Global transcript analysis revealed that butyrate increases expression of more than 800 cellular genes, but represses IFN-induced expression of 60% of ISGs. Overall, we identify a new mechanism by which butyrate promotes virus infection via repression of ISGs. Our findings also add to the growing body of evidence showing that individual ISGs respond differently to type I IFN induction depending on the cellular environment, including the presence of butyrate. ImportanceButyrate is a lipid produced by intestinal bacteria that can regulate inflammation throughout the body. Here we show for the first time that butyrate influences the innate antiviral immune response mediated by type I IFNs. A majority of antiviral genes induced by type I IFNs were repressed in the presence of butyrate, resulting in increased virus infection and replication in cells. This suggests that butyrate could be broadly used as a tool to increase growth of virus stocks for research and for the generation of vaccines. Our research also indicates that metabolites produced by the gut microbiome can have complex effects on cellular physiology as demonstrated by the dampening of an inflammatory innate immune pathway by butyrate resulting in a pro-viral cellular environment.

microbiology↗

bioRxiv2019

IFITMs Inhibit Cell Fusion Mediated by Trophoblast Syncytins

Type I interferon (IFN) induced by virus infections during pregnancy causes placental damage, though the mechanisms and identities of IFN-stimulated genes that are involved remain under investigation. The IFN-induced transmembrane proteins (IFITMs) inhibit virus infections by preventing virus membrane fusion with cells and by inhibiting fusion of infected cells (syncytialization). Fusion of placental trophoblasts via expression of endogenous retroviral fusogens known as Syncytins forms the syncytiotrophoblast, a multinucleated cell structure essential for fetal development. We found that IFN blocks fusion of BeWo human placental trophoblasts. Stably-expressed IFITMs 1, 2, and 3 also blocked fusion of these trophoblasts, while making them more resistant to virus infections. Conversely, stable knockdown of IFITMs in BeWo trophoblasts increased their spontaneous fusion and allowed fusion in the presence of IFN, while also making the cells more susceptible to virus infection. Overall, our data demonstrate that IFITMs are anti-viral and anti-fusogenic in trophoblasts.

immunology↗

bioRxiv2019

IFITM3 protects the heart during influenza virus infection

Influenza virus primarily targets the lungs, but dissemination and damage to heart tissue is also known to occur in severe infections. Despite this knowledge, influenza virus-induced cardiac pathogenesis and its underlying mechanisms have been difficult to study due to a lack of small animal models. In humans, polymorphisms in the gene encoding interferon-induced transmembrane protein 3 (IFITM3), an antiviral restriction factor, are associated with susceptibility to severe influenza, but whether IFITM3 deficiencies contribute to other aspects of pathogenesis, including cardiac dysfunction, is unknown. We now show that IFITM3 deficiency in a newly generated knockout (KO) mouse model exacerbates illness and mortality following influenza A virus infection. Enhanced pathogenesis correlated with increased replication of virus in the lungs, spleens, and hearts of KO mice relative to wildtype (WT) mice. IFITM3 KO mice exhibited normal cardiac function at baseline, but developed severely aberrant electrical activity upon infection, including decreased heart rate and irregular, arrhythmic RR (interbeat) intervals. In contrast, WT mice exhibited a mild decrease in heart rate without irregularity of RR intervals. Heightened cardiac virus titers and electrical dysfunction in KO animals was accompanied by increased activation of fibrotic pathways and fibrotic lesions in the heart. Our findings reveal an essential role for IFITM3 in controlling influenza virus replication and pathogenesis in heart tissue and establish IFITM3 KO mice as a powerful model to study virus-induced cardiac dysfunction.

immunology↗