title: Double-stranded RNA against white spot syndrome virus (WSSV) vp28 or vp26 reduced susceptibility of Litopenaeus vannamei to WSSV, and survivors exhibited decreased susceptibility in subsequent re-infections.
abstract: The antiviral effect of vp28 or vp26 double-stranded (ds) RNA upon single or consecutive white spot syndrome virus (WSSV) intramuscular challenges with a high infectious dose was evaluated. The vp28 dsRNA showed the highest protection both in single (LT(50)=145h at 10d and 98h at 20d post treatment [dpt]) or consecutive (LT(50)=765h) WSSV challenges compared to vp26 dsRNA (LT(50)=126h at 10 d and 57h at 20dpt vs. consecutive challenge LT(50)=751h). Single WSSV challenges showed that animals treated with vp28 or vp26 dsRNA gradually lost the antiviral effect as virus challenge occurred at 10dpt (cumulative mortality 63% vs. 80%, respectively) or 20dpt (87% vs. 100%, respectively). In contrast, animals treated with vp28 or vp26 dsRNA and consecutively challenged with WSSV showed and extended lower susceptibility to WSSV. All dead animals were WSSV-positive by one-step PCR, whereas all surviving shrimp from single or continuous challenges were WSSV-negative as determined by reverse transcription (RT)-PCR. In conclusion, shrimp treated with a single administration of vp28 or vp26 dsRNA and consecutively challenged with WSSV showed a stronger and longer antiviral response than shrimp exposed once to WSSV at 10 or 20dpt.
authors.affiliation: Centro de Investigaciones Biológicas del Noroeste, S.C. Mar Bermejo No. 195, Colonia Playa Palo de Santa Rita, Código Postal 23090, La Paz, Baja California Sur, Mexico.
authors.forename: Claudio Humberto
authors.initials: CH
authors.lastname: Mejía-Ruíz
authors.forename: Sergio
authors.initials: S
authors.lastname: Vega-Peña
authors.forename: Píndaro
authors.initials: P
authors.lastname: Alvarez-Ruiz
authors.forename: César Marcial
authors.initials: CM
authors.lastname: Escobedo-Bonilla
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000627:therapeutic use*; D015316:Genetic Therapy / Q000379:methods*; D033561:Penaeidae / Q000187:drug effects / Q000821:virology*; D016133:Polymerase Chain Reaction; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000235:genetics / Q000627:therapeutic use*; D012367:RNA, Viral / Q000235:genetics / Q000627:therapeutic use; D014759:Viral Envelope Proteins / Q000235:genetics*; D046848:White spot syndrome virus 1 / Q000235:genetics*
chemical_list: D000998:Antiviral Agents; D012330:RNA, Double-Stranded; D012367:RNA, Viral; C548473:VP28 protein, white spot syndrome virus; D014759:Viral Envelope Proteins