Induced and down-regulated proteins in the human cultured hairy cell leukemia line JOK-1 and the Burkitt's lymphoma cell line Daudi during incubation with interferon-alpha: a kinetic study.

Abstract

To elucidate the mechanism of action of interferon-alpha (IFN-alpha), the effect on cell proliferation and protein synthesis in the human hairy cell leukemia line JOK-1 and the Burkitt's lymphoma cell line Daudi were investigated. While Daudi cells were inhibited in proliferation and in total protein synthesis, no effect was seen on JOK-1 cells. However, high-resolution two-dimensional gel electrophoresis showed that four polypeptides were induced in JOK-1 cells after IFN-alpha incubation, while an additional 11 were induced and two down-regulated in Daudi cells. Kinetic studies revealed that the changes in JOK-1 cells were only temporary (within 8-16 h) and small to moderate in magnitude (less than four-fold). In Daudi cells, the changes for two of these polypeptides were early (within 2 h), for most of them prolonged (at least 24 h), and for three of them of great magnitude (between 6- and 30-fold). Quantitative analytical assessments indicated that four IFN-alpha-inducible polypeptides, present in low amounts of untreated cells, were highly expressed only in sensitive Daudi cells upon IFN-alpha treatment. This observation might indicate a role for these polypeptides in the inhibition of cell proliferation in Daudi cells. Furthermore, six of the other IFN-alpha-modulated polypeptides were synthesized constitutively in JOK-1 cells at levels comparable to those achieved in IFN-alpha-treated Daudi cells.(ABSTRACT TRUNCATED AT 250 WORDS)