Regulation of B-cell growth and immunoglobulin gene transcription by interleukin-6

Abstract

Interleukin-6 (IL-6) stimulates growth and immunoglobulin (Ig) secretion in Epstein-Barr virus (EBV)-infected B cells. In this study, we demonstrate that B-cell activation by IL-6 is associated with an initial induction of c-myc, a gene believed to act as a competence factor for increased RNA transcription and DNA replication, and by increases in DNA, RNA, and protein synthesis, as well as cell number. IL-6 increased the levels of Ig mRNA per cell in comparison to a non-cycle-dependent cellular mRNA, tubulin. However, two other cell cycle-dependent cellular mRNAs, c-myc and actin, were also induced by IL-6 comparable to Ig mRNAs. Increased levels of Ig mRNA were not due to significant changes in RNA turnover, but appeared to reflect increased levels of RNA transcription. Together, these findings support the notion that IL-6 plays an important role as a stimulator of DNA and RNA synthesis in EBV-activated B cells. © 1992 by The American Society of Hematology.