Biology subjects

Looney, M.

Publications and source records attributed to Looney, M..

3 recordsLinked to original sources

bioRxiv2025

Fibroblast orchestration of inflammaging via NF-kB activation

Aged tissue is characterized by chronic inflammation known as "inflammaging". While this aging immune phenotype supposedly drives some of the most common diseases affecting the elderly, little is known about the structural drivers of inflammaging. In this study, we demonstrate that age-dependent activation of NF-kB in tissue fibroblasts remodels the immune architecture, promoting the emergence of an exhausted T cell population (GZMK+/CD8+) recently identified in normal aging, as well as autoimmunity and cancer. Fibroblast-specific NF-kB activation triggered a fibroblast-macrophage-T cell circuit to form tertiary lymphoid structures in the lung and promoted the emergence of exhausted GZMK+ T cells. Fibroblastic activation of NF-kB increased host susceptibility to acute lung injury and mimics severe pneumonia commonly seen in elderly patients, which was alleviated by deletion of GZMK+ T cells. Our data provide a structural basis for inflammaging, where fibroblasts orchestrate the complex immune aging phenotype in non-immune tissues, increasing susceptibility to age-related diseases. Highlights- Bronchus-associated lymphoid tissue (BALT) enriched for GZMK+ T cells develop with age - Lung adventitial fibroblasts demonstrate increased NF-kB activation with age. - Fibroblast activation of NF-kB in young animals recapitulates multiple features of normal lung immune aging - Depletion of GZMK+ cells decreases lung inflammation in a mouse model of acute respiratory distress syndrome (ARDS)

immunology↗

bioRxiv2021

Sex differences in lung imaging and SARS-CoV-2 antibody responses in a COVID-19 golden Syrian hamster model

In the ongoing coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), more severe outcomes are reported in males compared with females, including hospitalizations and deaths. Animal models can provide an opportunity to mechanistically interrogate causes of sex differences in the pathogenesis of SARS-CoV-2. Adult male and female golden Syrian hamsters (8-10 weeks of age) were inoculated intranasally with 105 TCID50 of SARS-CoV-2/USA-WA1/2020 and euthanized at several time points during the acute (i.e., virus actively replicating) and recovery (i.e., after the infectious virus has been cleared) phases of infection. There was no mortality, but infected male hamsters experienced greater morbidity, losing a greater percentage of body mass, developing more extensive pneumonia as noted on chest computed tomography, and recovering more slowly than females. Treatment of male hamsters with estradiol did not alter pulmonary damage. Virus titers in respiratory tissues, including nasal turbinates, trachea, and lungs, and pulmonary cytokine concentrations, including IFN{beta} and TNF, were comparable between the sexes. However, during the recovery phase of infection, females mounted two-fold greater IgM, IgG, and IgA responses against the receptor-binding domain of the spike protein (S-RBD) in both plasma and respiratory tissues. Female hamsters also had significantly greater IgG antibodies against whole inactivated SARS-CoV-2 and mutant S-RBDs, as well as virus neutralizing antibodies in plasma. The development of an animal model to study COVID-19 sex differences will allow for a greater mechanistic understanding of the SARS-CoV-2 associated sex differences seen in the human population. ImportanceMen experience more severe outcomes from COVID-19 than women. Golden Syrian hamsters were used to explore sex differences in the pathogenesis of a human clinical isolate of SARS-CoV-2. After inoculation, male hamsters experienced greater sickness, developed more severe lung pathology, and recovered more slowly than females. Sex differences in disease could not be reversed by estradiol treatment in males and were not explained by either virus replication kinetics or the concentrations of inflammatory cytokines in the lungs. During the recovery period, antiviral antibody responses in the respiratory tract and plasma, including to newly emerging SARS-CoV-2 variants, were greater in females than male hamsters. Greater lung pathology during the acute phase combined with reduced antiviral antibody responses during the recovery phase of infection in males than females illustrate the utility of golden Syrian hamsters as a model to explore sex differences in the pathogenesis of SARS-CoV-2 and vaccine-induced immunity and protection. One Sentence SummaryFollowing SARS-CoV-2 infection, male hamsters experience worse clinical disease and have lower antiviral antibody responses than females.

microbiology↗

bioRxiv2019

Modulating pathogenesis with Mobile-CRISPRi

Pathogens express a set of proteins required for establishing and maintaining an infection, termed virulence life-style genes (VLGs). Due to their outsized importance in pathogenesis, VLG products are attractive targets for the next generation of antimicrobials. However, precise manipulation of VLG expression in the context of infection is technically challenging, limiting our ability to understand the roles of VLGs in pathogenesis and accordingly design effective inhibitors. We previously developed a suite of gene knockdown tools that are transferred by conjugation and stably integrate into pathogen genomes that we call \"Mobile-CRISPRi\". Here we show the efficacy of Mobile-CRISPRi in controlling VLG expression in a murine infection model. We optimize Mobile-CRISPRi in Pseudomonas aeruginosa for use in a murine model of pneumonia by tuning the expression of CRISPRi components to avoid non-specific toxicity. As a proof of principle, we demonstrate that knockdown of a VLG encoding the type III secretion system (T3SS) activator ExsA blocks effector protein secretion in culture and attenuates virulence in mice. We anticipate that Mobile-CRISPRi will be a valuable tool to probe the function of VLGs across many bacterial species and pathogenesis models.\n\nImportanceAntibiotic resistance is a growing threat to global health. To optimize the use of our existing antibiotics and identify new targets for future inhibitors, understanding the fundamental drivers of bacterial growth in the context of the host immune response is paramount. Historically these genetic drivers have been difficult to manipulate, as they are requisite for pathogen survival. Here, we provide the first application of Mobile-CRISPRi to study virulence life-style genes in mouse models of lung infection through partial gene perturbation. We envision the use of Mobile-CRISPRi in future pathogenesis models and antibiotic target discovery efforts.

microbiology↗