Biology subjects

Crossland, N. A.

Publications and source records attributed to Crossland, N. A..

4 recordsLinked to original sources

bioRxiv2021

Macrophages govern antiviral responses in human lung tissues protected from SARS-CoV-2 infection

The majority of SARS-CoV-2 infections among healthy individuals result in asymptomatic to mild disease. However, the immunological mechanisms defining effective lung tissue protection from SARS-CoV-2 infection remain elusive. Unlike mice solely engrafted with human fetal lung xenograft (fLX), mice co-engrafted with fLX and a myeloid-enhanced human immune system (HNFL mice) are protected against SARS-CoV-2 infection, severe inflammation, and histopathology. Effective control of viral infection in HNFL mice associated with significant macrophage infiltration, and the induction of a potent macrophage-mediated interferon response. The pronounced upregulation of the USP18-ISG15 axis (a negative regulator of IFN responses), by macrophages was unique to HNFL mice and represented a prominent correlate of reduced inflammation and histopathology. Altogether, our work shed light on unique cellular and molecular correlates of lung tissue protection during SARS-CoV-2 infection, and underscores macrophage IFN responses as prime targets for developing immunotherapies against coronavirus respiratory diseases. HIGHLIGHTSO_LIMice engrafted with human fetal lung xenografts (fLX-mice) are highly susceptible to SARS-CoV-2. C_LIO_LICo-engraftment with a human myeloid-enriched immune system protected fLX-mice against infection. C_LIO_LITissue protection was defined by a potent and well-balanced antiviral response mediated by infiltrating macrophages. C_LIO_LIProtective IFN response was dominated by the upregulation of the USP18-ISG15 axis. C_LI

microbiology↗

bioRxiv2021

Dissemination and progression of pulmonary Mycobacterium avium infection in mouse model are associated with type 2 macrophage activation

Pulmonary infections caused by the group of nontuberculosis mycobacteria (NTM), Mycobacterium avium complex (MAC), are increasing worldwide and a growing public health concern. Pulmonary granulomas are the hallmark of MAC lung infection, yet reliable correlates of granuloma progression and susceptibility in immunocompetent hosts are poorly defined. The development of mouse models that recapitulate the diversity of granulomas seen in MAC pulmonary disease in humans is crucial to study mechanisms of susceptibility in humans and for preclinical evaluation of therapeutics. Unlike widely used inbred mouse strains, mice that carry the mutant allele at the genetic locus sst1 develop human-like pulmonary tuberculosis featuring well-organized caseating granulomas. These mice became instrumental in pre-clinical testing of novel interventions. In this study we tested whether the B6.Sst1S that carries the sst1 mutant allele on standard B6 background develop more advanced pulmonary infection with NTM M. avium spp. hominissuis (M.av). To assess pulmonary disease progression, we utilized traditional semi-quantitative histomorphological evaluation and fluorescent multiplex immunohistochemistry (fmIHC) in combination with whole slide imaging and digital image analysis. After infection with the laboratory M.av strain 101, the B6.Sst1S pulmonary lesions progressed 12 - 20 weeks post infection, although we did not observe the formation of necrotic granulomas during this interval. Using fmIHC, we determined that the disease progression was associated with a steadily increasing proportion of mycobacteria infected Arg1+ and double positive iNOS+/Arg1+ macrophages. The B6.Sst1S granulomas had a greater proportion of Arg1+ and double positive iNOS+/Arg1+ macrophages, and decreased T cell density, as compared to wild type B6 mice. Thus, the genetic composition of the B6.Sst1S mice renders them more susceptible to pulmonary M.av infection. In combination with more virulent clinical isolates of M.av these mice could provide an improved mouse model that recapitulates more severe pulmonary disease in humans. The Arg1 macrophage expression in this model combined with automated fmIHC could serve as a sensitive biomarker for the unbiased assessment of medical countermeasures against NTM infection.

pathology↗

bioRxiv2021

Inhalable Nanobody (PiN-21) prevents and treats SARS-CoV-2 infections in Syrian hamsters at ultra-low doses

Globally there is an urgency to develop effective, low-cost therapeutic interventions for coronavirus disease 2019 (COVID-19). We previously generated the stable and ultrapotent homotrimeric Pittsburgh inhalable Nanobody 21 (PiN-21). Using Syrian hamsters that model moderate to severe COVID-19 disease, we demonstrate the high efficacy of PiN-21 to prevent and treat SARS-CoV-2 infection. Intranasal delivery of PiN-21 at 0.6 mg/kg protects infected animals from weight loss and substantially reduces viral burdens in both lower and upper airways compared to control. Aerosol delivery of PiN-21 facilitates deposition throughout the respiratory tract and dose minimization to 0.2 mg/kg. Inhalation treatment quickly reverses animals weight loss post-infection and decreases lung viral titers by 6 logs leading to drastically mitigated lung pathology and prevents viral pneumonia. Combined with the marked stability and low production cost, this novel therapy may provide a convenient and cost-effective option to mitigate the ongoing pandemic.

microbiology↗

bioRxiv2020

SARS-CoV-2 desensitizes host cells to interferon through inhibition of the JAK-STAT pathway

SARS-CoV-2 can infect multiple organs, including lung, intestine, kidney, heart, liver, and brain. The molecular details of how the virus navigates through diverse cellular environments and establishes replication are poorly defined. Here, we performed global proteomic analysis of the virus-host interface in a newly established panel of phenotypically diverse, SARS-CoV-2-infectable human cell lines representing different body organs. This revealed universal inhibition of interferon signaling across cell types following SARS-CoV-2 infection. We performed systematic analyses of the JAK-STAT pathway in a broad range of cellular systems, including immortalized cell lines and primary-like cardiomyocytes, and found that several pathway components were targeted by SARS-CoV-2 leading to cellular desensitization to interferon. These findings indicate that the suppression of interferon signaling is a mechanism widely used by SARS-CoV-2 in diverse tissues to evade antiviral innate immunity, and that targeting the viral mediators of immune evasion may help block virus replication in patients with COVID-19.

microbiology↗