Interferon inducing activity of (A)n.(U)n complexes of varying chain length

Evidence is presented that the interferon-inducing activity of (A)n.(U)n in primary rabbit kidney cells with respect to the chain length of the constituting (A)n and (U)n strands is governed by the following criteria: (1) the activity increases with the length of the uninterrupted double-stranded segment in the complex whereby both chains are equally important and the number of such segments for complex molecule is without effect, (2) at a constant total concentration of constituting nucleotides, the activity increases with the number of double-stranded molecular entities available to the cell, and (3) complexes with the (U)n strand considerably overlapping the (A)n strand are inactive due to the formation of triple stranded structures.