Ifit2 deficiency restricts microglial activation and leukocyte migration following murine coronavirus (m-CoV) CNS infection

• Published in: PLoS pathogens 2020-11, Vol.16 (11), p.e1009034-e1009034
• Main Authors: Das Sarma, Jayasri, Burrows, Amy, Rayman, Patricia, Hwang, Mi-Hyun, Kundu, Soumya, Sharma, Nikhil, Bergmann, Cornelia, Sen, Ganes C
• Format: Article
• Language: English
• Subjects: AMP; Analysis; Animal models; Animals; Antiviral activity; Apoptosis Regulatory Proteins - deficiency; Apoptosis Regulatory Proteins - metabolism; Biology and Life Sciences; Brain; Causes of; Cell activation; Cell Movement - immunology; Chemokines; Control; Coronavirus infections; Coronavirus Infections - immunology; Coronavirus Infections - virology; Coronaviruses; CX3CR1 protein; Cyclic GMP; Cytokines; Cytokines - metabolism; Disease; Encephalitis; Endothelial cells; Genes; Genetic engineering; Homeostasis; Infections; Inflammation; Influence; Interferon; Interferon inducers; Interferons - metabolism; Leukocyte disorders; Leukocyte migration; Leukocytes; Leukocytes - cytology; Leukocytes - metabolism; Leukocytes - virology; Lymphocytes B; Lyssavirus; Medicine and Health Sciences; Mice, Inbred C57BL; Microglia; Microglia - metabolism; Mortality; Murine hepatitis virus - metabolism; Murine hepatitis virus - pathogenicity; NF-κB protein; Pathogenesis; Protein deficiency; Proteins; Rabies; Receptors; Research and Analysis Methods; RNA-Binding Proteins - metabolism; Rodents; Stimulators; Stomatitis; Toll-like receptors; Transcription factors; Vector-borne diseases; Viral infections; Virus Replication - immunology; Viruses; West Nile virus; α-Interferon
• ISSN: 1553-7374; 1553-7366; 1553-7374
• DOI: 10.1371/journal.ppat.1009034

The interferon-induced tetratricopeptide repeat protein (Ifit2) protects mice from lethal neurotropic viruses. Neurotropic coronavirus MHV-RSA59 infection of Ifit2-/- mice caused pronounced morbidity and mortality accompanied by rampant virus replication and spread throughout the brain. In spite of the higher virus load, induction of many cytokines and chemokines in the brains of infected Ifit2-/- mice were similar to that in wild-type mice. In contrast, infected Ifit2-/- mice revealed significantly impaired microglial activation as well as reduced recruitment of NK1.1 T cells and CD4 T cells to the brain, possibly contributing to the lack of viral clearance. These two deficiencies were associated with a lower level of microglial expression of CX3CR1, the receptor of the CX3CL1 (Fractalkine) chemokine, which plays a critical role in both microglial activation and leukocyte recruitment. The above results uncovered a new potential role of an interferon-induced protein in immune protection.