Differential activities of alpha/beta IFN subtypes against influenza virus in vivo and enhancement of specific immune responses in DNA vaccinated mice expressing haemagglutinin and nucleoprotein
VACCINE
Authors: James, Cassandra M.; Abdad, Mohammad Y.; Mansfield, Josephine P.; Jacobsen, Hege K.; Vind, Azita Rezazadeh; Stumbles, Philip A.; Bartlett, Emmalene J.
Abstract
Vaccines are urgently needed to elicit immunity to different influenza virus strains. DNA vaccines can elicit partial protective immunity, however their efficacy requires improvement. We assessed the capacity of individual type I IFN multigene family members as subtype transgenes to abrogate influenza virus replication in a vaccination/challenge mouse model. Differences in antiviral efficacy were found among the subtypes with IFNA5 and IFNA6 being most effective, while IFNA1 was the least effective in reducing lung virus replication. Mice vaccinated with combinatorial HA/IFNA6 or NP/IFNA6 showed reduced lung viral titres, clinical score, body weight loss, and pulmonary tissue damage compared to IFNA6, HA, or NP viral vaccination alone. In addition, IFNA6 increased IaG2a titres with upregulation of IFNgamma response in the respiratory tract. We conclude that IFN-alpha 6 has antiviral and immunomodulatory effects, which improve efficacy of DNA vaccines for enhanced control of influenza. (c) 2006 Elsevier Ltd. All rights reserved.
Infectious pancreatic necrosis virus proteins VP2, VP3, VP4 and VP5 antagonize IFNa1 promoter activation while VP1 induces IFNa1
VIRUS RESEARCH
Authors: Lauksund, Silje; Greiner-Tollersrud, Linn; Chang, Chia-Jung; Robertsen, Borre
Abstract
Infectious pancreatic necrosis virus (IPNV) is one of the major viral pathogens causing disease in farmed Atlantic salmon worldwide. In the present work we show that several of the IPN proteins have powerful antagonistic properties against type I IFN induction in Atlantic salmon. Each of the five IPNV genes cloned into an expression vector were tested for the ability to influence activation of the Atlantic salmon IFNa1 promoter by the interferon promoter inducing protein one (IPS-1) or interferon regulatory factors (IRF). This showed that preVP2, VP3 and VP5 inhibited activation of both promoters, while VP4 only antagonized activation of the IFNa1 promoter. The viral protease VP4 was the most potent inhibitor of IFN induction, apparently targeting the IRF1 and IRF3 branch of the signaling cascade. VP4 antagonism is independent of its protease activity since the catalytically dead mutant VP4K674A inhibited activation of the IFNa1 promoter to a similar extent as wild type VP4. In contrast to the other IPNV proteins, the RNA-dependent RNA polymerase VP1 activated the IFNa1 promoter. The ability to activate the IFN response was disrupted in the mutant VP1S163A, which has lost the ability to produce dsRNA. VP1 also exhibited synergistic effects with IRF1 and IRF3 in inducing an IFNa1-dependent antiviral state in cells. Taken together these results suggest that IPNV has developed multiple IFN antagonistic properties to prevent IFN-induction by VP1 and its dsRNA genome. (C) 2014 The Authors. Published by Elsevier B.V.