Interferons

Interferons are antiviral proteins made by animal cells in response to viral infections. (Figure 1)

These are low molecular weight proteins that prevent viral multipliation.

They are not virus specific but they are host specific.

Production of interferons is induced by exposure of the cell to live virus, inactivated viral, viral nucleic acids or synthetic double-stranded RNA. Because ds RNA does not occur in cells unless they are infected by virus, it may serve as a signal for viral infection.

Highly virulent viruses usually do not induce interferon synthesis because they inhibit host cell transcription and/or translation before interferon can be made.

Interferons can be released and act on neighboring cells.

Inhibits viral-directed RNA synthesis