Characterization of a human eosinophil proteoglycan, and augmentation of its biosynthesis and size by interleukin 3, interleukin 5, and granulocyte/macrophage colony stimulating factor

M. E. Rothenberger, Joel L Pomerantz, W. F. Owen, S. Avraham, R. J. Soberman, K. F. Austen, R. L. Stevens

Research output: Contribution to journalArticle


Human eosinophils were cultured for up to 7 days in enriched medium in the absence or presence of recombinant human interleukin (IL) 3, mouse IL 5, or recombinant human granulocyte/macrophage colony stimulating factor (GM-CSF) and then were radiolabeled with [35S]sulfate to characterize their cell-associated proteoglycans. Freshly isolated eosinophils that were not exposed to any of these cytokines synthesized M(r) ~ 80,000 Pronase-resistant 35S-labeled proteoglycans which contained M(r) ~ 8,000 glycosaminoglycans. RNA blot analysis of total eosinophil RNA, probed with a cDNA that encodes a proteoglycan peptide core of the promyelocytic leukemia HL-60 cell, revealed that the mRNA which encodes the analogous molecule in eosinophils was ~ 1.3 kilobases, like that in HL-60 cells. When eosinophils were cultured for 1 day or longer in the presence of 10 pM IL 3, 1 pM IL 5, or 10 pM GM-CSF, the rates of [35S]sulfate incorporation were increased ~ 2-fold, and the synthesized M(r) ~ 300,000 Pronase-resistant 35S-labeled proteoglycans which contained M(r) ~ 30,000 35S-labeled glycosaminoglycans. Approximately 93% of the 35S-labeled glycosaminoglycans bound to the proteoglycans synthesized by noncytokine- and cytokine-treated eosinophils were susceptible to degradation by chondroitinase ABC. As assessed by high performance liquid chromatography, 6-16% of these chondroitinase ABC-generated 35S-labeled disaccharides were disulfated disaccharides derived from chondroitin sulfate E; the remainder were monosulfated disaccharides derived from chondroitin sulfate A. Utilizing GM-CSF as a model of the cytokines, it was demonstrated that the GM-CSF-treated cells synthesized larger glycosaminoglycans onto β-D-xyloside than the noncytokine-treated cells. Thus, IL 3, IL 5, and GM-CSF induce human eosinophils to augment proteoglycan biosynthesis by increasing the size of the newly synthesized proteoglycans and their individual chondroitin sulfate chains.

Original languageEnglish (US)
Pages (from-to)13901-13908
Number of pages8
JournalJournal of Biological Chemistry
Issue number27
Publication statusPublished - 1988
Externally publishedYes


ASJC Scopus subject areas

  • Biochemistry

Cite this