The mechanism of interference between an avian leukosis virus and rous sarcoma virus: I. Establishment of interference

Abstract

The adsorption of high concentrations of RAV-1 to chick embryo cells renders the cells resistant to infection by the pseudotype of Rous sarcoma virus designated RSV(RAV-1) which contains the RSV genome and the RAV-1 outer coat. The interfering RAV-1 particles may be added directly to the cell culture in high concentrations (early interference) or may be produced by the RAV-1 infected cells themselves (late interference). The degree of resistance can be reduced by treatment of cells with RAV-1 antibody or at pH 2.2 at all stages of RAV-1 infection. Early interference can be established by RAV-1 at temperatures low enough (4–8 °) to block penetration of the cell by the interfering virus. RAV-1 heated to 54 ° for 15 minutes loses its infectivity, but retains its capacity to induce early interference. After a 15-minute treatment of RAV-1 at higher temperatures both properties are lost, and at lower temperatures neither is lost.