Effective Treatment of Respiratory Alphaherpesvirus Infection Using RNA Interference

Abstract

BackgroundEquine herpesvirus type 1 (EHV-1), a member of the Alphaherpesvirinae, is spread via nasal secretions and causes respiratory disease, neurological disorders and abortions. The virus is a significant equine pathogen, but current EHV-1 vaccines are only partially protective and effective metaphylactic and therapeutic agents are not available. Small interfering RNAs (siRNA's), delivered intranasally, could prove a valuable alternative for infection control. siRNA's against two essential EHV-1 genes, encoding the viral helicase (Ori) and glycoprotein B, were evaluated for their potential to decrease EHV-1 infection in a mouse model.Methodology/Principal FndingssiRNA therapy in vitro significantly reduced virus production and plaque size. Viral titers were reduced 80-fold with 37.5 pmol of a single siRNA or with as little as 6.25 pmol of each siRNA when used in combination. siRNA therapy in vivo significantly reduced viral replication and clinical signs. Intranasal treatment did not require a transport vehicle and proved effective when given up to 12 h before or after infection.Conclusions/SignificancesiRNA treatment has potential for both prevention and early treatment of EHV-1 infections.

Cationic polyaspartamide-based nanocomplexes mediate siRNA entry and down-regulation of the pro-inflammatory mediator high mobility group box 1 in airway epithelial cells

“…These complexes were characterized by a size of almost 400 nm and a zeta potential of À8 mV. siRNA delivery has been attempted in vivo to the lung in the absence of carrying molecules and nevertheless obtaining positive results (Fulton et al, 2009;Gutbier et al, 2010;Rosas-Taraco et al, 2009;Senoo et al, 2010), with some reports showing no significant difference in gene silencing efficiency between naked siRNA and the use of delivery vectors (Bitko et al, 2005;Fulton et al, 2009). It has been hypothesized that the siRNA modifications transfection or the damage of the airway epithelium caused by viral infection, or by other pathological processes, may have caused increased internalization of naked siRNAs (Fujita et al, 2013).…”

Immunological and hematological toxicities challenging clinical translation of nucleic acid-based therapeutics

“…The majority of studies utilizing siRNA were designed to avoid systemic administration. The routes of administration in these studies were subcutaneous [120], intradermal [121], intraocular [122], intralesional [123], intranasal [124][125][126], intratracheal [127,128], intrathecal [129][130][131], intracerebral [132,133], intratumoral [134][135][136][137], intravaginal [138,139], intrarectal [140], transdermal [141] and topical [142].…”

The effect of siRNA treatment on experimental equine herpesvirus type 1 (EHV-1) infection in horses

“…For equine viruses, in vitro studies have shown that siRNA can reduce viral titers in cell cultures infected with equine arteritis virus (Heinrich et al, 2009), African horse sickness virus (Stassen et al, 2007) or Venezuelan equine encephalitis virus (O'Brien, 2007). More specifically for EHV-1, RNA interference has been effective both in vitro and in vivo, as assessed by a reduction in plaque formation in cell cultures and a reduction in clinical signs (weight loss) and viral replication within lung tissue in a murine model of EHV-1 infection (Fulton et al, 2009).…”