In vitro antiviral activity of lactoferrin and ribavirin upon hantavirus.
Bovine lactoferrin (LF) and ribavirin (Rbv) were tested as antiviral agents against Seoul type hantavirus (SR-11 strain) in vitro. Hantaviral foci number in Vero E6 cells infected with SR-11 was reduced with LF treatment by 5 days post infection to obtain a 50% effective dose (ED50) of 2500 microg/ml, while pretreatment with LF was highly efficacious having an ED50 of 39 microg/ml. Conversely, 1 h pretreatment with Rbv revealed no inhibition of viral focus formation but could significantly reduce the number of viral foci (ED50: 10 microg/ml) when used from the time of viral infection. One hour pre-treatment of the cell monolayer with LF and subsequent addition of Rbv revealed a synergistic anti-hantaviral effect against SR-11, <20 FFU/ml as compared to 10(5) foci/ml in the control. One hour treatment of SR-11 with LF prior to cell inoculation gave an ED50 of 312.5 microg/ml. Whereas, washing the LF-pretreated cell monolayer with PBS demonstrated minimal focus reduction, suggesting LF lightly adheres to cells. These results indicate that LF has anti-hantaviral activity in vitro and inhibition of virus adsorption to cells which play an important role in revealing the anti-hantaviral activity of LF. This paper reports for the first time the anti-hantaviral effect of LF.
Murphy
M E
ME
Laboratory of Public Health, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
Kariwa
H
H
Mizutani
T
T
Yoshimatsu
K
K
Arikawa
J
J
Takashima
I
I
D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002417:Cattle; D002522:Chlorocebus aethiops; D004305:Dose-Response Relationship, Drug; D006476:Orthohantavirus / Q000187:drug effects*; D007781:Lactoferrin / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D012254:Ribavirin / Q000494:pharmacology*; D013997:Time Factors; D014709:Vero Cells
D000998:Antiviral Agents; D012254:Ribavirin; D007781:Lactoferrin