True about interferon is:

Ans. (b) Inhibits viral replication in cells Rt,11 itlii ilallarayl111 CO, p p Iiii i tC,i :;r, p Interferon (host coded protein) has no direct action on viruses but inhibit viral replication by selectively inhibiting translation of viral m-RNA without affecting cellular m-RNA. IFN are not virus specific but species specific. It is of 3 types: Type Cell source. Cell target Biological ctivity IFN a (protein) or leukocyte IFN All cells All cells Antiviral activity; stimulates T L.ell, macrophages and NK cell activity IFN 13 (glycoprotein) or Fibroblast IFN All cells All cells Direct antitumor effects Upregulates MHC class I antigen expression. Used therepeutically in viral and autoimmune disease * IFNy (glycoprotein) or immune IFN T cells All cells Regulates macrophage and NK cells activation NK cells Stimulates Ig secretion by B cells Induction of class II histocompatibility antigens TH1 T cell differentiation