Inhibition of epidemic isolates of coxsackievirus type A 24 by recombinant and natural interferon alpha and interferon beta

Natural human interferons (IFN) and recombinant human IFNs (rIFN-alpha and rIFN-beta) inhibited the production of virus in Chang's human conjunctival cell cultures infected with epidemic isolates of acute hemorrhagic conjunctivitis virus, Coxsackievirus type A 24 (CA24). Generally, natural and rIFN-alpha and rIFN-beta were equally effective in inhibiting CA24 infection. However, rIFN-alpha A was more effective than rIFN-alpha C, D, I, J, and K in reducing virus infection, cytopathogenesis, and virus production. Recombinant IFN-alpha J was least effective in inhibiting CA24 in human conjunctival cell cultures. Also, the IFN titer was reduced 10- to 1,000-fold when cells were infected with greater than or equal to 0.3-0.5 CA24/cell, suggesting a dose-dependent IFN resistance by CA24. These results suggest that the antiviral activity of IFN against acute hemorrhagic conjunctivitis in vivo may vary with the CA24 isolates, the MOI, the type of IFN, and the time of infection with respect to beginning IFN treatment.