Antiviral effect of Saccharomyces cerevisiae beta-glucan to swine influenza virus by increased production of interferon-gamma and nitric oxide.
The aim of these experiments was to investigate the potential antiviral effect of Saccharomyces cerevisiae beta-glucan on the pneumonia induced by swine influenza virus (SIV). Forty colostrum-deprived 5-day-old piglets were randomly divided into four groups of 10. The 20 pigs in groups 1 and 2 were administered Saccharomyces cerevisiae beta-glucan orally (50 mg/day/pig; En-Bio Technology Co., Ltd) for 3 days before SIV infection and those in groups 3 and 4 were given culture medium/diluent alone. Groups 1 and 3 were inoculated intranasally with 3 ml of tissue culture fluid containing 2 x 10(6) tissue culture infective doses 50% (TCID(50))/ml of SIV and those in groups 2 and 4 were exposed in the same manner to uninfected cell culture supernatant. The microscopic lung lesions induced by SIV infection (group 1 pigs) were significantly more severe than those induced by infection in animals pre-administered beta-glucan (group 3) (P < 0.05). Significantly more SIV nucleic acid was detected in the lungs of pigs experimentally infected with SIV only (group 1) at 5, 7 and 10 days post-inoculation (dpi) compared with lungs from pigs pre-administered beta-glucan and infected with SIV (group 3) (P < 0.05). The concentrations of interferon-gamma (IFN-gamma) and nitric oxide (NO) in bronchoalveolar lavage fluid from pigs pre-administered beta-glucan and infected with SIV (group 3) were significantly higher than for any other group at 7 and 10 dpi for IFN-gamma, and at 5, 7 and 10 dpi for NO (P < 0.05). Saccharomyces cerevisiae beta-glucan reduced the pulmonary lesion score and viral replication rate in SIV-infected pigs. These findings support the potential application of beta-glucan as prophylactic/treatment agent in influenza virus infection.
Jung
K
K
Department of Veterinary Pathology, College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University, Building no. 85, San 56-1, Shillim-dong, Kwanak-Gu 151-742.
Ha
Y
Y
Ha
S-K
SK
Han
D U
DU
Kim
D-W
DW
Moon
W K
WK
Chae
C
C
D000284:Administration, Oral; D000818:Animals; D000831:Animals, Newborn; D000998:Antiviral Agents / Q000008:administration & dosage*; D005936:Glucans / Q000008:administration & dosage*; D009980:Influenza A virus / Q000472:pathogenicity*; D007371:Interferon-gamma / Q000096:biosynthesis; D008168:Lung / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis; D009976:Orthomyxoviridae Infections / Q000517:prevention & control / Q000662:veterinary*; D012441:Saccharomyces cerevisiae; D013552:Swine; D013553:Swine Diseases / Q000517:prevention & control* / Q000821:virology; D014612:Vaccines / Q000276:immunology*
D000998:Antiviral Agents; D005936:Glucans; D014612:Vaccines; D009569:Nitric Oxide; D007371:Interferon-gamma