Priming of L cells by murine immune interferon

Partially purified murine immune interferon (IFN gamma) was found to be equivalent to IFN alpha/beta in its ability to enhance the production of IFN alpha/beta by L-929 cells. While crude preparations were also able to prime, it was apparent that such preparations of IFN contained 'blocking factors' that reduced the priming efficiency of IFN. Exposing IFN gamma to heat, low pH or its specific antibody readily destroyed its ability to prime, providing evidence that IFN gamma itself was responsible for priming.