Thanks to Greg Folkers for sending the link to this Antiviral Research article, available at ScienceDirect.com: Protection against Chikungunya virus induced arthralgia following prophylactic treatment with adenovirus vectored interferon (mDEF201). The abstract:
Recent outbreaks of Chikungunya virus (CHIKV) infection have resulted in millions of cases of disease with significant morbidity. No approved antiviral treatments exist for the prevention or treatment of this viral disease.
Infection with CHIKV results in a high rate of symptomatic disease that primarily includes a debilitating arthralgia. To model this cardinal disease manifestation, adult DBA/1J mice were challenged with CHIKV by footpad injection. Viremia and hind limb virus titers increased ∼100-fold while spleen virus increased >1000-fold within 1 day post-virus infection (dpi).
Footpad swelling was measured over a 10-day period, with peak swelling observed between 6 and 7 dpi. Histology of the hind leg at the site of virus challenge showed evidence of myositis and synovitis starting on 5 dpi. Cytokine profiling of the hind limb at the site of inoculation revealed a biphasic inflammatory response represented by an increase in IL-6, MCP-1, IFN-γ, MIP-1α, RANTES, and IL-17.
To investigate the prophylactic capacity of IFN, mice were treated with mDEF201, an adenovirus-vectored IFN-α. Intranasal administration of a single 107 pfu/ml dose of mDEF201 administered 21 days to 24 h prior to infection, significantly reduced footpad swelling, virus titers in the hind leg and spleen, and several inflammatory cytokines. Efficacy was not observed when treatment was initiated 24 h after virus challenge.
This arthralgia model of CHIKV recapitulates relevant disease features commonly observed in human disease making it applicable to preclinical testing of therapies that target both viral replication and the associated joint disease.