Inactivation and morphological changes of avian influenza virus by copper ions.
The infectivity of the H9N2 virus to MDCK cells was time-dependently inhibited by Cu(2+) at concentrations of 2.5-250 microM. In 25 microM Cu(2+) solution, the virus titer decreased by approximately 3 and 4 log within 3 and 6 h, respectively. Compared to Cu(2+), Zn(2+) was much less effective in virus inactivation. The H9N2 virus hemagglutinin activity was not affected by 2.5-250 microM Cu(2+). The H9N2 virus neuraminidase (NA) activity was drastically reduced by 25 mM Cu(2+), marginally reduced by 250 microM Cu(2+), and not affected by 25 microM Cu(2+). Thus, we found that copper ions suppress the infectivity of influenza virus at lower concentrations at which neither NA nor hemagglutination inhibition occurs. Electron microscopic analysis revealed morphological abnormalities of the Cu(2+)-treated H9N2 virus. Additional studies should be undertaken to clarify the mechanism underlying the antiviral effect of copper ions on influenza virus.
Horie
M
M
Department of Virology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
Ogawa
H
H
Yoshida
Y
Y
Yamada
K
K
Hara
A
A
Ozawa
K
K
Matsuda
S
S
Mizota
C
C
Tani
M
M
Yamamoto
Y
Y
Yamada
M
M
Nakamura
K
K
Imai
K
K
D000818:Animals; D001717:Birds; D003300:Copper / Q000494:pharmacology*; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000378:metabolism; D053127:Influenza A Virus, H9N2 Subtype / Q000737:chemistry / Q000187:drug effects* / Q000276:immunology / Q000472:pathogenicity; D005585:Influenza in Birds / Q000821:virology; D008854:Microscopy, Electron; D009439:Neuraminidase / Q000037:antagonists & inhibitors*; D009976:Orthomyxoviridae Infections / Q000821:virology; D014407:Tumor Cells, Cultured
D019267:Hemagglutinin Glycoproteins, Influenza Virus; D003300:Copper; D009439:Neuraminidase