Src family kinase inhibitors block translation of alphavirus subgenomic mRNAs

Alphaviruses are arthropod-transmitted RNA viruses that can cause arthralgia, myalgia, and encephalitis in humans. Since the role of cellular kinases in alphavirus replication is unknown, we profiled kinetic changes in host kinase abundance and phosphorylation following chikungunya virus (CHIKV) infection of fibroblasts. Based upon the results of this study, we treated CHIKV-infected cells with kinase inhibitors targeting the Src family kinase (SFK)–phosphatidylinositol 3-kinase (PI3K)–AKT–mTORC signaling pathways. Treatment of cells with SFK inhibitors blocked the replication of CHIKV as well as multiple other alphaviruses, including Mayaro virus, O’nyong-nyong virus, Ross River virus, and Venezuelan equine encephalitis virus. Dissecting the effect of SFK inhibition on alphavirus replication, we found that viral structural protein levels were significantly reduced, but synthesis of viral genomic and subgenomic RNAs was unaffected. By measuring the association of viral RNA with polyribosomes, we found that the SFK inhibitor dasatinib blocks alphavirus subgenomic RNA translation. Our results demonstrate a role for SFK signaling in alphavirus subgenomic RNA translation and replication. Targeting host factors involved in alphavirus replication represents an innovative, perhaps paradigm-shifting, strategy for exploring the replication of CHIKV and other alphaviruses while promoting antiviral therapeutic development

Src Family Kinase Inhibitors Block Translation of Alphavirus Subgenomic mRNAs

Alphaviruses are arthropod-transmitted RNA viruses that can cause arthralgia, myalgia, and encephalitis in humans. Since the role of cellular kinases in alphavirus replication is unknown, we profiled kinetic changes in host kinase abundance and phosphorylation following chikungunya virus (CHIKV) infection of fibroblasts. Based upon the results of this study, we treated CHIKV-infected cells with kinase inhibitors targeting the Src family kinase (SFK)–phosphatidylinositol 3-kinase (PI3K)–AKT–mTORC signaling pathways. Treatment of cells with SFK inhibitors blocked the replication of CHIKV as well as multiple other alphaviruses, including Mayaro virus, O’nyong-nyong virus, Ross River virus, and Venezuelan equine encephalitis virus. Dissecting the effect of SFK inhibition on alphavirus replication, we found that viral structural protein levels were significantly reduced, but synthesis of viral genomic and subgenomic RNAs was unaffected. By measuring the association of viral RNA with polyribosomes, we found that the SFK inhibitor dasatinib blocks alphavirus subgenomic RNA translation. Our results demonstrate a role for SFK signaling in alphavirus subgenomic RNA translation and replication. Targeting host factors involved in alphavirus replication represents an innovative, perhaps paradigmshifting, strategy for exploring the replication of CHIKV and other alphaviruses while promoting antiviral therapeutic development

Non-replicating adenovirus based Mayaro virus vaccine elicits protective immune responses and cross protects against other alphaviruses.

Mayaro virus (MAYV) is an alphavirus endemic to South and Central America associated with sporadic outbreaks in humans. MAYV infection causes severe joint and muscle pain that can persist for weeks to months. Currently, there are no approved vaccines or therapeutics to prevent MAYV infection or treat the debilitating musculoskeletal inflammatory disease. In the current study, a prophylactic MAYV vaccine expressing the complete viral structural polyprotein was developed based on a non-replicating human adenovirus V (AdV) platform. Vaccination with AdV-MAYV elicited potent neutralizing antibodies that protected WT mice against MAYV challenge by preventing viremia, reducing viral dissemination to tissues and mitigating viral disease. The vaccine also prevented viral-mediated demise in IFN⍺R1-/- mice. Passive transfer of immune serum from vaccinated animals similarly prevented infection and disease in WT mice as well as virus-induced demise of IFN⍺R1-/- mice, indicating that antiviral antibodies are protective. Immunization with AdV-MAYV also generated cross-neutralizing antibodies against two related arthritogenic alphaviruses-chikungunya and Una viruses. These cross-neutralizing antibodies were protective against lethal infection in IFN⍺R1-/- mice following challenge with these heterotypic alphaviruses. These results indicate AdV-MAYV elicits protective immune responses with substantial cross-reactivity and protective efficacy against other arthritogenic alphaviruses. Our findings also highlight the potential for development of a multi-virus targeting vaccine against alphaviruses with endemic and epidemic potential in the Americas