Oral administration of heat-killed Lactobacillus plantarum L-137 enhances protection against influenza virus infection by stimulation of type I interferon production in mice.
We have previously reported that heat-killed Lactobacillus plantarum L-137 (HK-LP) stimulates macrophage/dendritic cells to produce T helper (Th) 1-related cytokines in vitro and in vivo in mice. We here examined the effect of oral administration of HK-LP on protection against influenza virus infection in mice. C57BL/6 mice were orally given HK-LP from day -7 to 7 and intranasally infected with influenza virus A/FM/1/47 (H1N1, a mouse-adapted strain) at 100 pfu on day 0. The survival time was significantly prolonged in mice treated with HK-LP than that in mice treated with PBS as controls. The viral titers in the lung were significantly lower in mice treated with HK-LP than controls at the early stage after influenza virus infection. An appreciable level of interferon (IFN)-beta was detected in the serum of mice treated with HK-LP, while no IFN-beta was detected in controls after influenza infection. Our results suggest that HK-LP, a potent IFN-beta inducer, is useful for prevention against influenza infection.
Research Center for Prevention of Infectious Diseases, Medical Institute of Bioregulation, Kyushu University, Maidashi, Higashi-ku, Fukuoka, Japan.
Naoyoshi
N
Maeda
Risa
R
Nakamura
Yoshitaka
Y
Hirose
Shinji
S
Murosaki
Yoshihiro
Y
Yamamoto
Tetsuo
T
Kase
Yasunobu
Y
Yoshikai
D000284:Administration, Oral; D000818:Animals; D005260:Female; D007252:Influenza Vaccines / Q000008:administration & dosage; D007370:Interferon Type I / Q000097:blood*; D048191:Lactiplantibacillus plantarum / Q000276:immunology*; D008168:Lung / Q000473:pathology / Q000821:virology; D051379:Mice; D008810:Mice, Inbred C57BL; D009975:Orthomyxoviridae / Q000276:immunology*; D009976:Orthomyxoviridae Infections / Q000097:blood / Q000276:immunology* / Q000517:prevention & control*; D019936:Probiotics / Q000008:administration & dosage; D015164:Vaccines, Inactivated / Q000008:administration & dosage; D019562:Viral Load
D007252:Influenza Vaccines; D007370:Interferon Type I; D015164:Vaccines, Inactivated