Chicken interferon type I inhibits infectious bronchitis virus replication and associated respiratory illness.
Infectious bronchitis virus (IBV) causes an economically important respiratory disease in poultry worldwide. Previous studies have shown that CD8(+) cytotoxic T lymphocytes (CTL) are critical in controlling acute IBV infection, but the role of innate immunity is unknown. This study describes the in vitro and in vivo anti-IBV activity of natural spleen cell-derived and recombinant chicken interferon type I (rChIFN-alpha). Both natural and rChIFN-alpha inhibited replication of the Beaudette strain of IBV in chicken kidney cells (CKC) in a dose-dependent manner, with the antiviral activity of the former accounted for entirely by its content of type I IFN. IFN at 100 U/ml reduced viral replication by 50% as measured by syncytia formation. In addition, the spleen cell-derived supernatants (natural IFN) inhibited tracheal ring ciliostasis mediated by the Gray strain of IBV. Optimal protection against IBV-induced respiratory disease was obtained after intravenous or oral administration of ChIFN given 1 day before virus challenge and each of 5 days thereafter. ChIFN-I protected chicks from clinical illness by delaying the onset of the disease and decreasing the severity of illness, demonstrating its potential as an immune enhancer.
Pei
J
J
Department of Veterinary Pathobiology, Texas A&M University, College Station, TX 77843-4467, USA.
Sekellick
M J
MJ
Marcus
P I
PI
Choi
I S
IS
Collisson
E W
EW
D000818:Animals; D000998:Antiviral Agents / Q000378:metabolism / Q000494:pharmacology / Q000627:therapeutic use*; D002478:Cells, Cultured; D002645:Chickens; D018352:Coronavirus Infections / Q000517:prevention & control*; D046508:Culture Techniques; D001351:Infectious bronchitis virus / Q000187:drug effects* / Q000254:growth & development; D007370:Interferon Type I / Q000096:biosynthesis / Q000494:pharmacology / Q000627:therapeutic use*; D007371:Interferon-gamma / Q000096:biosynthesis; D007668:Kidney / Q000821:virology; D007700:Kinetics; D012120:Respiration Disorders / Q000517:prevention & control* / Q000821:virology; D013154:Spleen / Q000276:immunology; D014132:Trachea / Q000821:virology; D014779:Virus Replication / Q000187:drug effects
D000998:Antiviral Agents; D007370:Interferon Type I; D007371:Interferon-gamma