Microinjection of Interferon and 2', 5'-Oligoadenylate into Mouse L Cells and Their Effects on Virus Growth

Abstract

By means of a new type of microinjection apparatus, which has a micropipette located in a hole through the optical axis of the condenser lens, we injected interferon (IFN) or 2', 5'-oligoadenylate (2-5 A) into mouse L cells, and observed their antiviral effects on the multiplication of vesicular stomatitis virus (VSV). After injection, cells were infected with VSV, and labeled with [³H] uridine in the presence of actinomycin D. The proportion of cells infected with VSV which carried radioactive virus-RNA was determined by autoradiography. IFN introduced directly into L cells had no effect on the virus growth. This result supports the idea that IFN molecules exert their effect from outside the cell membrane without penetrating into the cytoplasm. 2-5 A, on the other hand, was able to inhibit the growth of VSV effectively when injected into L cells. The antiviral effect was dependent on the dose of 2-5 A injected, and moreover the effect was transient, since it disappeared completely after 24-h incubation.