Expression of interleukin 6 and its specific receptor by untreated and PMA-stimulated human erythroid and megakaryocytic cell lines.
Different human hematopoietic cell lines were analyzed for the presence of interleukin 6 (IL-6) and IL-6 receptor (IL-6-R). Both IL-6 mRNA and secreted active IL-6 protein were detectable in untreated cell lines with erythroid or megakaryoblastic features (K562, HEL, KU 812, MEG-01, and Dami), but they were not expressed constitutively in other leukemic cell lines (KG1, HL60, and U937). IL-6-R production, studied by the presence of its mRNA and specific binding sites for iodinated recombinant IL-6, was detected in most cell lines except K562, HEL, and Dami. Therefore, only KU 812 and MEG-01 coexpress both IL-6 and IL-6-R. After phorbol ester myristate acetate (PMA) treatment, all the cell lines studied expressed or overexpressed IL-6. In the erythroid K562 cell line, IL-6-R was not detectable before induction, but was promptly expressed after stimulation with PMA, suggesting that some of the new features of K562 cells induced by PMA may be mediated by IL-6. However, neutralizing antibodies against IL-6 did not block either the growth arrest or the loss of the erythroid phenotype induced by PMA. The presence of IL-6 and IL-6-R in erythroid and megakaryocytic leukemic cell lines suggests that their synthesis may occur during normal hematopoietic differentiation.
Navarro
S
S
CNRS UPR 37, IRSC, Villejuif, France.
Mitjavila
M T
MT
Katz
A
A
Doly
J
J
Vainchenker
W
W
D000906:Antibodies / Q000276:immunology; D002460:Cell Line; D015672:Erythroid Precursor Cells / Q000378:metabolism*; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D008533:Megakaryocytes / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism*; D019947:Receptors, Interleukin-6; D011994:Recombinant Proteins; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D000906:Antibodies; D015850:Interleukin-6; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D019947:Receptors, Interleukin-6; D011994:Recombinant Proteins; D013755:Tetradecanoylphorbol Acetate