Growth Inhibition of Human Lymphoblastoid Cells by Interferon Preparations, Obtained from Human Leukocytes

Abstract

The growth inhibition of human lymphoblastoid cells by human interferon preparations (HIF) and a mock-interferon preparation (Mock-IF) was studied. HIF was induced in suspensions of primary human leukocytes by Newcastle Disease Virus. Mock-IF was prepared from uninduced cell suspension of a comparable batch. The highest degree of inhibition of cell propagation was ob­ tained on the EBV producer line P3HR1, the inhibition of the cell lines Raji and SKL 1 was significantly lower, no effect was observed on the cell line RPMI 1788 originating from a healthy donor. Mock-IF also caused a growth inhibition but to a lower degree as HIF. HIF and Mock-IF are similar in the following properties: 1. Stability at pH 2 at 4 °C for four days, 2. sensitivity to tryptic digestion, and 3. molecular weights in the range between 5,000 and 40,000 daltons