title: Murine gamma herpesvirus 68 hijacks MAVS and IKKβ to abrogate NFκB activation and antiviral cytokine production.
abstract: Upon viral infection, mitochondrial antiviral signaling (MAVS) protein serves as a key adaptor to promote cytokine production. We report here that murine gamma herpesvirus 68 (γHV68), a model virus for oncogenic human gamma herpesviruses, subverts cytokine production via the MAVS adaptor. During early infection, γHV68 hijacks MAVS and IKKβ to induce the site-specific phosphorylation of RelA, a crucial subunit of the transcriptionally active NFκB dimer, which primes RelA for the proteasome-mediated degradation. As such, γHV68 efficiently abrogated NFκB activation and cytokine gene expression. Conversely, uncoupling RelA degradation from γHV68 infection promoted NFκB activation and elevated cytokine production. Loss of MAVS increased cytokine production and immune cell infiltration in the lungs of γHV68-infected mice. Moreover, exogenous expression of the phosphorylation- and degradation-resistant RelA variant restored γHV68-induced cytokine production. Our findings uncover an intricate strategy whereby signaling via the upstream MAVS adaptor is intercepted by a pathogen to nullify the immediate downstream effector, RelA, of the innate immune pathway.
authors: Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
authors: Xiaonan
authors: X
authors: Dong
authors: Pinghui
authors: P
authors: Feng
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D016207:Cytokines / Q000378:metabolism*; D004195:Disease Models, Animal; D006566:Herpesviridae Infections / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D051550:I-kappa B Kinase / Q000378:metabolism*; D007113:Immunity, Innate / Q000502:physiology; D008168:Lung / Q000378:metabolism / Q000473:pathology / Q000821:virology; D051379:Mice; D018345:Mice, Knockout; D016328:NF-kappa B / Q000378:metabolism*; D041681:NIH 3T3 Cells; D010766:Phosphorylation; D018144:Rhadinovirus / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D051996:Transcription Factor RelA / Q000378:metabolism; D014412:Tumor Virus Infections / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D016207:Cytokines; D051550:I-kappa B Kinase; D016328:NF-kappa B; D051996:Transcription Factor RelA; C512612:MAVS protein, mouse; C498144:Rela protein, mouse