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
ave;s Leblond Pierre Tritz Neurological disorders represent an important sanitary and economic threat for the equine industry worldwide. Among nervous diseases, viral encephalitis is of growing concern, due to the emergence of arboviruses and to the high contagiosity of herpesvirus-infected horses. The nature, severity and duration of the clinical signs could be different depending on the etiological agent and its virulence. However, definite diagnosis generally requires the implementation of combinations of direct and/or indirect screening assays in specialized laboratories. The equine practitioner, involved in a mi...
Source: Viruses - Category: Virology Authors: Tags: Review Source Type: research
In this report, NS5-K61A, NS5-E218A, and a double mutant encoding both mutations (NS5-K61A/E218A) were compared both in vitro and in vivo. Each single mutant was strongly attenuated in highly susceptible outbred mice, whereas the double mutant unexpectedly was not attenuated. Sequencing analysis demonstrated that the double mutant was capable of reversion at both residues NS5-61 and NS5-218, whereas the genotype of the single mutants did not show evidence of reversion. Overall, either NS5-K61A or NS5-E218A methyltransferase mutations could be potential mutations to include in a candidate live WNV vaccine; however, multiple...
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: CBSNews.com - 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
Abstract Japanese encephalitis virus (JEV) and West Nile virus (WNV) are two major mosquito borne flaviviruses belonging to same serocomplex. JEV is transmitted by Culex mosquitoes and the reservoir host for the virus is pigs and/or water birds. WNV is also transmitted by Culex mosquitoes and reservoir host in this case is birds. It can also be transmitted through contact with other infected animals, their blood, or other tissues. The envelope protein of these viruses is the major source of epitopes and provides protective immunity. Bioinformatics tools were used to identify conserved epitopes in the envelope prot...
Source: Comparative immunology, microbiology and infectious diseases. - Category: Allergy & Immunology Authors: Tags: Comp Immunol Microbiol Infect Dis Source Type: research
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Source: Human Vaccines and Immunotherapeutics - Category: Allergy & Immunology Authors: Source Type: research
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