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

• Published in: The Journal of biological chemistry 1988-09, Vol.263 (27), p.13901-13908
• Main Authors: Rothenberg, M E, Pomerantz, J L, Owen, W F, Avraham, S, Soberman, R J, Austen, K F, Stevens, R L
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Cell physiology; Cells, Cultured; Chondroitin Lyases - metabolism; Chondroitin Sulfates - metabolism; Chromatography, High Pressure Liquid; Colony-Stimulating Factors - pharmacology; Deoxyglucose - metabolism; DNA - genetics; Eosinophils - drug effects; Eosinophils - metabolism; Fundamental and applied biological sciences. Psychology; Glycosaminoglycans - metabolism; Glycosides - pharmacology; Granulocyte-Macrophage Colony-Stimulating Factor; Growth Substances - pharmacology; Humans; Interleukin-3 - pharmacology; Interleukin-5; Interleukins - pharmacology; Molecular and cellular biology; Molecular Weight; Nucleic Acid Hybridization; Pronase - metabolism; Proteoglycans - blood; Proteoglycans - genetics; Responses to growth factors, tumor promotors, other factors; RNA - genetics; RNA, Messenger - genetics; Sulfates - metabolism
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)68329-2

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 Mr approximately 80,000 Pronase-resistant 35S-labeled proteoglycans which contained Mr approximately 80,000 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 approximately 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 approximately 2-fold, and the cells synthesized Mr approximately 300,000 Pronase-resistant 35S-labeled proteoglycans which contained Mr approximately 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 beta-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.