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Reagin KL, Lee RL, Cocciolone L, Funk KE. Antigen non-specific CD8 + T cells accelerate cognitive decline in aged mice following respiratory coronavirus infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.02.573675. [PMID: 38260669 PMCID: PMC10802364 DOI: 10.1101/2024.01.02.573675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Primarily a respiratory infection, numerous patients infected with SARS-CoV-2 present with neurologic symptoms, some continuing long after viral clearance as a persistent symptomatic phase termed "long COVID". Advanced age increases the risk of severe disease, as well as incidence of long COVID. We hypothesized that perturbations in the aged immune response predispose elderly individuals to severe coronavirus infection and post-infectious sequelae. Using a murine model of respiratory coronavirus, mouse hepatitis virus strain A59 (MHV-A59), we found that aging increased clinical illness and lethality to MHV infection, with aged animals harboring increased virus in the brain during acute infection. This was coupled with an unexpected increase in activated CD8+ T cells within the brains of aged animals but reduced antigen specificity of those CD8+ T cells. Aged animals demonstrated spatial learning impairment following MHV infection, which correlated with increased neuronal cell death and reduced neuronal regeneration in aged hippocampus. Using primary cell culture, we demonstrated that activated CD8+ T cells induce neuronal death, independent of antigen-specificity. Specifically, higher levels of CD8+ T cell-derived IFN-γ correlated with neuronal death. These results support the evidence that CD8+ T cells in the brain directly contribute to cognitive dysfunction following coronavirus infection in aged individuals.
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Affiliation(s)
- Katie L. Reagin
- Department of Biological Sciences, University of North Carolina at Charlotte
| | - Rae-Ling Lee
- Department of Biological Sciences, University of North Carolina at Charlotte
| | - Loren Cocciolone
- Department of Biological Sciences, University of North Carolina at Charlotte
| | - Kristen E. Funk
- Department of Biological Sciences, University of North Carolina at Charlotte
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Wessel AW, Dowd KA, Biering SB, Zhang P, Edeling MA, Nelson CA, Funk KE, DeMaso CR, Klein RS, Smith JL, Cao TM, Kuhn RJ, Fremont DH, Harris E, Pierson TC, Diamond MS. Levels of Circulating NS1 Impact West Nile Virus Spread to the Brain. J Virol 2021; 95:e0084421. [PMID: 34346770 PMCID: PMC8475509 DOI: 10.1128/jvi.00844-21] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 07/28/2021] [Indexed: 12/15/2022] Open
Abstract
Dengue virus (DENV) and West Nile virus (WNV) are arthropod-transmitted flaviviruses that cause systemic vascular leakage and encephalitis syndromes, respectively, in humans. However, the viral factors contributing to these specific clinical disorders are not completely understood. Flavivirus nonstructural protein 1 (NS1) is required for replication, expressed on the cell surface, and secreted as a soluble glycoprotein, reaching high levels in the blood of infected individuals. Extracellular DENV NS1 and WNV NS1 interact with host proteins and cells, have immune evasion functions, and promote endothelial dysfunction in a tissue-specific manner. To characterize how differences in DENV NS1 and WNV NS1 might function in pathogenesis, we generated WNV NS1 variants with substitutions corresponding to residues found in DENV NS1. We discovered that the substitution NS1-P101K led to reduced WNV infectivity in the brain and attenuated lethality in infected mice, although the virus replicated efficiently in cell culture and peripheral organs and bound at wild-type levels to brain endothelial cells and complement components. The P101K substitution resulted in reduced NS1 antigenemia in mice, and this was associated with reduced WNV spread to the brain. Because exogenous administration of NS1 protein rescued WNV brain infectivity in mice, we conclude that circulating WNV NS1 facilitates viral dissemination into the central nervous system and impacts disease outcomes. IMPORTANCE Flavivirus NS1 serves as an essential scaffolding molecule during virus replication but also is expressed on the cell surface and is secreted as a soluble glycoprotein that circulates in the blood of infected individuals. Although extracellular forms of NS1 are implicated in immune modulation and in promoting endothelial dysfunction at blood-tissue barriers, it has been challenging to study specific effects of NS1 on pathogenesis without disrupting its key role in virus replication. Here, we assessed WNV NS1 variants that do not affect virus replication and evaluated their effects on pathogenesis in mice. Our characterization of WNV NS1-P101K suggests that the levels of NS1 in the circulation facilitate WNV dissemination to the brain and affect disease outcomes. Our findings facilitate understanding of the role of NS1 during flavivirus infection and support antiviral strategies for targeting circulating forms of NS1.
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Affiliation(s)
- Alex W. Wessel
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Kimberly A. Dowd
- Viral Pathogenesis Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Scott B. Biering
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, California, USA
| | - Ping Zhang
- Department of Immunology, Key Laboratory of Tropical Diseases Control, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Melissa A. Edeling
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Christopher A. Nelson
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Kristen E. Funk
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Christina R. DeMaso
- Viral Pathogenesis Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Robyn S. Klein
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Neuroscience, Washington University School of Medicine, St. Louis, Missouri, USA
- Center for Neuroimmunology and Neuroinfectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Janet L. Smith
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, USA
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Thu Minh Cao
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, Indiana, USA
| | - Richard J. Kuhn
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, Indiana, USA
| | - Daved H. Fremont
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Eva Harris
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, California, USA
| | - Theodore C. Pierson
- Viral Pathogenesis Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Michael S. Diamond
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
- The Andrew M. and Jane M. Bursky Center for Human Immunology and Immunotherapy Programs, Washington University School of Medicine, St. Louis, Missouri, USA
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