virus interference

virus interference [′vī·rəs ‚in·tər′fir·əns]

(microbiology)

A phenomenon which may be defined as protection of host cells against one virus, conferred as a result of prior infection with a different virus.

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Virus interference

Inhibition of the replication of a virus by a previous infection with another virus. The two viruses may be unrelated, related, or identical. In some cases, virus interference may take place even if the first virus was inactivated. The term mutual exclusion has been applied to this phenomenon in bacterial viruses.

Several mechanisms of interference can be distinguished: (1) Inactivation of cell receptors by one virus may prevent subsequent adsorption and penetration by another virus. (2) The first virus may inhibit or modify cellular enzymes or proteins required for replication of the superinfecting virus. (3) The first virus may generate destructive enzymes or induce the cell to synthesize protective substances which prevent superinfection. (4) The first virus may generate defective interfering particles or mutants which may inhibit the replication of the infecting virus by competing with it for a protein (or enzyme) available in limited quantities; this type of viral interference has been called autointerference, and depends on a greater replicative efficiency of the defective interfering particles or mutants, compared to the infecting virus. See Animal virus, Virulence, Virus, Virus, defective