Defects in Antiviral T Cell Responses Inflicted by Aging-Associated miR-181a Deficiency

Publication date: 19 November 2019Source: Cell Reports, Volume 29, Issue 8Author(s): Chulwoo Kim, Rohit R. Jadhav, Claire E. Gustafson, Megan J. Smithey, Alec J. Hirsch, Jennifer L. Uhrlaub, William H. Hildebrand, Janko Nikolich-Žugich, Cornelia M. Weyand, Jörg J. GoronzySummaryGeneration of protective immunity to infections and vaccinations declines with age. Studies in healthy individuals have implicated reduced miR-181a expression in T cells as contributing to this defect. To understand the impact of miR-181a expression on antiviral responses, we examined LCMV infection in mice with miR-181ab1-deficient T cells. We found that miR-181a deficiency delays viral clearance, thereby biasing the immune response in favor of CD4 over CD8 T cells. Antigen-specific CD4 T cells in mice with miR-181a-deficient T cells expand more and have a broader TCR repertoire with preferential expansion of high-affinity T cells than in wild-type mice. Importantly, generation of antigen-specific miR-181a-deficient CD8 effector T cells is particularly impaired, resulting in lower frequencies of CD8 T cells in the liver even at time points when the infection has been cleared. Consistent with the mouse model, CD4 memory T cells in individuals infected with West Nile virus at older ages tend to be more frequent and of higher affinity.Graphical Abstract
Source: Cell Reports - Category: Cytology Source Type: research

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Publication date: Available online 2 January 2020Source: Veterinary MicrobiologyAuthor(s): John Baird, Birthe Tegtmeyer, Luis Arroyo, Alexander Stang, Yannick Brüggemann, Murray Hazlett, Eike SteinmannAbstractTheiler’s disease was confirmed within a group horses located on a farm in southwestern Ontario during the summer and autumn of 2005. Five sudden deaths occurred between 3 July and 21 August, 2005, none of which were necropsied, however two of the horses showed clinical signs compatible with hepatic encephalopathy prior to death. No horse on the farm had received a biologic product of equine blood origin in...
Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research
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Source: Viruses - Category: Virology Authors: Tags: Review Source Type: research
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Source: Vaccine - Category: Allergy & Immunology Authors: Tags: Vaccine Source Type: research
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Source: Viruses - Category: Virology Authors: Tags: Review Source Type: research
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Source: Health News: - Category: Consumer Health News Source Type: news
CONCLUSIONS: The co-circulation of those viruses in the same area represents a risk for the development of severe infections if they spread throughout the country. Successive flavivirus infections may have an impact on disease pathogenesis, as well as on the development of safe vaccine strategies. PMID: 31411310 [PubMed - in process]
Source: Memorias do Instituto Oswaldo Cruz - Category: Infectious Diseases Authors: Tags: Mem Inst Oswaldo Cruz Source Type: research
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Source: Viruses - Category: Virology Authors: Tags: Article Source Type: research
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Source: Viruses - Category: Virology Authors: Tags: Article Source Type: research
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Source: Comparative immunology, microbiology and infectious diseases. - Category: Allergy & Immunology Authors: Tags: Comp Immunol Microbiol Infect Dis Source Type: research
Source: Human Vaccines and Immunotherapeutics - Category: Allergy & Immunology Authors: Source Type: research
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