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-α: 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)

Comparative study of the structural and functional properties of a bovine plasma C-type lectin, collectin-43, with other collectins

“…Cells were biosynthetically labelled with [35S]methionine. The major proteins in the cell lysate have previously been compared proteins of known molecular masses and pl values and these were used as internal standards (Madsen et al, 1992). Briefly, the first-dimension run was isoelectric focusing (i.e.f.)…”

The biology of hairy cell leukemia

“…The IFN-a receptors seem to fbnction normally on HC. Thus, the binding of IFN-a induces a rapid down-regulation of the receptor (201) and incubation of PBMNC from leukemic HCL patients or HCL cell lines in vitro with IFN (94,202) and PBMNC from IFN treated HCL patients in vivo (1,94,203,204) have uniformly shown a rapid induction of synthesis of some intracellular proteins and a down-regulation of others. This has been taken as evidence for a direct mechanism of action of IFN in HCL (94), and even though it is in agreement with a direct effect, the mere induction of changes in protein synthesis and activity perse is not necessarily connected to a growth inhibition.…”

“…This has been taken as evidence for a direct mechanism of action of IFN in HCL (94), and even though it is in agreement with a direct effect, the mere induction of changes in protein synthesis and activity perse is not necessarily connected to a growth inhibition. This is entirely dependent of the proteins induced, and even though some of these like 2-5A (178) and the human Mx homolog (179) are known, the nature of most of these proteins are unknown (1, 94,202,203). Underscoring this objection is the fact that induction of novel proteins is also seen with IFN-y, which is ineffective in HCL (94), and that IFN have been shown to induce proteins in other cell types without affecting their growth (205).…”