Virokines

Virokines are receptor molecules secreted or produced by viruses. In effect, they inhibit the elicitation of an immune response capable of destroying the virus or virus infected cells. Select viral species secrete interleukin recep tors (Doherty, 1995). Members of the poxvirus family produce and secrete a molecule having structural homologies to the B chain of the IL-1 receptor. Binding of free IL-1 to the protein prevents the activity of the major proinflammatory cytokine and allows viral replication within the cells. Rabbit myxovirus and vaccinia (a member of the poxvirus family) secrete IFN receptors (Moss-man et al., 1995). Binding of IFN-a and -B inhibits the normal activation of NK and LAK cells. Finally, some herpesvirus strains secrete receptors for IL-8 and IL-17 (Ahuja et al., 1994). If these chemokines do not react with their normal targets, immunosuppression occurs within the localized area infected with the viruses.

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