[Source: PLoS ONE, full text: (LINK). Abstract, edited.]
MDA5 Can Be Exploited as Efficacious Genetic Adjuvant for DNA Vaccination against Lethal H5N1 Influenza Virus Infection in Chickens
Matthias Liniger, Artur Summerfield, Nicolas Ruggli*
Research Department, Institute of Virology and Immunoprophylaxis (IVI), Mittelhäusern, Switzerland
Chickens lack the retinoic acid-inducible gene I (RIG-I) and sense avian influenza virus (AIV) infections by means of the melanoma differentiation-associated gene 5 product (chMDA5). Plasmid-driven expression of the N-terminal half of chMDA5 containing the caspase activation and recruitment domains [chMDA5(1-483)] triggers interferon-β responses in chicken cells. We hypothesized that mimicking virus infection by chMDA5(1-483) expression may enhance vaccine-induced adaptive immunity. In order to test this, the potential genetic adjuvant properties of chMDA5(1-483) were evaluated in vivo in combination with a suboptimal quantity of a plasmid DNA vaccine expressing haemagglutinin (HA) of H5N1 AIV. Co-administration of the HA plasmid with plasmid DNA for chMDA5(1-483) expression resulted in approximately 10-fold higher HA-specific antibody responses than injection of the HA plasmid mixed with empty vector DNA as control. Accordingly, compared with HA DNA vaccination alone, the chMDA5(1-483)-adjuvanted HA DNA vaccine mediated enhanced protection against a lethal H5N1 challenge infection in chickens, with reduced clinical signs and cloacal virus shedding. These data demonstrate that innate immune activation by expression of signaling domains of RIG-I-like receptors can be exploited to enhance vaccine efficacy.
Citation: Liniger M, Summerfield A, Ruggli N (2012) MDA5 Can Be Exploited as Efficacious Genetic Adjuvant for DNA Vaccination against Lethal H5N1 Influenza Virus Infection in Chickens. PLoS ONE 7(12): e49952. doi:10.1371/journal.pone.0049952
Editor: Gourapura J. Renukaradhya, The Ohio State University, United States of America
Received: June 15, 2012; Accepted: October 18, 2012; Published: December 5, 2012
Copyright: © 2012 Liniger et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work was funded by the Swiss Federal Veterinary Office (grant number 1.07.09; www.bvet.admin.ch) and by the EU FP6 project FUPATH (grant number 044220; cordis.europa.eu). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: email@example.com