ABSTRACT
Tripartite motif (TRIM) family proteins are important effectors of innate immunity against viral infections. Here we identified TRIM35 as a regulator of TRAF3 activation. Deficiency in or inhibition of TRIM35 suppressed the production of type I interferon (IFN) in response to viral infection. Trim35-deficient mice were more susceptible to influenza A virus (IAV) infection than were wild-type mice. TRIM35 promoted the RIG-I-mediated signaling by catalyzing Lys63-linked polyubiquitination of TRAF3 and the subsequent formation of a signaling complex with VISA and TBK1. IAV PB2 polymerase countered the innate antiviral immune response by impeding the Lys63-linked polyubiquitination and activation of TRAF3. TRIM35 mediated Lys48-linked polyubiquitination and proteasomal degradation of IAV PB2, thereby antagonizing its suppression of TRAF3 activation. Our in vitro and in vivo findings thus reveal novel roles of TRIM35, through catalyzing Lys63- or Lys48-linked polyubiquitination, in RIG-I antiviral immunity and mechanism of defense against IAV infection.
Subject(s)
Animals , Dogs , Humans , Mice , A549 Cells , Apoptosis Regulatory Proteins/immunology , DEAD Box Protein 58/immunology , HEK293 Cells , Influenza A Virus, H1N1 Subtype/immunology , Madin Darby Canine Kidney Cells , Mice, Knockout , Orthomyxoviridae Infections/pathology , Proteolysis , Signal Transduction/immunology , THP-1 Cells , TNF Receptor-Associated Factor 3/immunology , Ubiquitination/immunology , Viral Proteins/immunologyABSTRACT
According to 45 hemagglutinin (HA) gene sequences of H7 subtype of avian influenza virus (AIV), a pair of specific oligonucleotide primers was designed. We developed one step RT-PCR for detecting AIV subtype H7. Sensitivity to detection of allantoic fluid by one step RT-PCR reached 10(5.5) EID50/mL and detection of swab samples reached 10(3) EID50/mL. We simultaneity detected the tissue and swab samples infected with H7 subtypes AIV by one step RT-PCR and virus isolation method. The results showed that the sensitivity of the assay gave an excellent correlation with the conventional virus isolation method. H1-H15 subtypes of avian influenza and other avian diseases were detected by the one step RT-PCR. The results showed the assays were high specific, without cross-reaction with other subtypes or other avian diseases. Development of one step RT-PCR will provide effective technical support for the rapid diagnosis and surveillance of molecular epidemiology of AIV subtype H7.