Innate immunomodulation with recombinant interferon-alpha enhances resistance of rainbow trout (Oncorhynchus mykiss) to infectious hematopoietic necrosis virus.
We examined the in vivo immunostimulatory effects of a recombinant Atlantic salmon (Salmo salar) interferon-alpha2 (rSasaIFN-alpha2). The mature rSasaIFN-alpha2, expressed and purified from Escherichia coli, was administered to rainbow trout (Oncorhynchus mykiss) via the oral, immersion, or intraperitoneal (IP) injection route. Injection of rSasaIFN-alpha2 at 0.1microg/g fish gave significantly greater protection than a phosphate buffered saline (PBS) injection against a lethal challenge of infectious hematopoietic necrosis virus (IHNV), with a relative percent survival of 39%. Relative percent survival (RPS) increased significantly to 92% when the fish were injected with rSasaIFN-alpha2 at 1microg/g fish. Antiviral protection was evident for up to 7 days post-injection of rSasaIFN-alpha2. Administration of rSasaIFN-alpha2 by the oral or immersion route was not protective, and the fish succumbed to virus infection. The level of systemic IFN-induced expression of the Mx1 gene was significantly greater (p<0.01) in the IFN-injected group than in the PBS-injected group, and this was correlated with the fish survival rates in the challenge study. We used relative quantitative real-time polymerase chain reactions to examine the systemic expression of several other IFN-induced genes (including genes for IFN1, IFN regulatory factors 1 and 2, MHC-I, STAT1, vig-1, and GBP) and found that their expression was significantly increased 1-day post-rSasaIFN-alpha2 injection. Expression of the IFN-gamma and interleukin-1beta genes was not significantly increased. Thus, a salmonid rIFN-alpha can modulate the innate immune response of rainbow trout and mediate early antiviral protection against IHNV.
Ooi
Ei Lin
EL
Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Shirokanedai 4-6-1, Minato, Tokyo 108-8639, Japan.
Verjan
Noel
N
Haraguchi
Ikumi
I
Oshima
Takeo
T
Kondo
Hidehiro
H
Hirono
Ikuo
I
Aoki
Takashi
T
Kiyono
Hiroshi
H
Yuki
Yoshikazu
Y
D000818:Animals; D005786:Gene Expression Regulation / Q000187:drug effects; D007108:Immune Tolerance / Q000187:drug effects / Q000276:immunology*; D007113:Immunity, Innate / Q000187:drug effects / Q000276:immunology*; D029142:Infectious hematopoietic necrosis virus / Q000276:immunology*; D007370:Interferon Type I / Q000008:administration & dosage / Q000276:immunology* / Q000494:pharmacology; D017686:Oncorhynchus mykiss / Q000276:immunology* / Q000821:virology*; D011994:Recombinant Proteins; D018353:Rhabdoviridae Infections / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D015996:Survival Rate
D007370:Interferon Type I; D011994:Recombinant Proteins