Characterization of a human eosinophil proteoglycan, and augmentation of its biosynthesis and size by interleukin 3, interleukin 5, and granulocyte/macrophage colony stimulating factor.
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.
Rothenberg
M E
ME
Department of Medicine, Harvard Medical School, Boston, Massachusetts.
Pomerantz
J L
JL
Owen
W F
WF
Avraham
S
S
Soberman
R J
RJ
Austen
K F
KF
Stevens
R L
RL
D002478:Cells, Cultured; D002808:Chondroitin Lyases / Q000378:metabolism; D002809:Chondroitin Sulfates / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003115:Colony-Stimulating Factors / Q000494:pharmacology*; D004247:DNA / Q000235:genetics; D003847:Deoxyglucose / Q000378:metabolism; D004804:Eosinophils / Q000187:drug effects / Q000378:metabolism*; D006025:Glycosaminoglycans / Q000378:metabolism; D006027:Glycosides / Q000494:pharmacology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D006133:Growth Substances / Q000494:pharmacology*; D006801:Humans; D007377:Interleukin-3 / Q000494:pharmacology*; D015848:Interleukin-5; D007378:Interleukins / Q000494:pharmacology*; D008970:Molecular Weight; D009693:Nucleic Acid Hybridization; D011402:Pronase / Q000378:metabolism; D011509:Proteoglycans / Q000097:blood* / Q000235:genetics; D012313:RNA / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D013431:Sulfates / Q000378:metabolism
D003115:Colony-Stimulating Factors; D006025:Glycosaminoglycans; D006027:Glycosides; D006133:Growth Substances; D007377:Interleukin-3; D015848:Interleukin-5; D007378:Interleukins; D011509:Proteoglycans; D012333:RNA, Messenger; D013431:Sulfates; C010807:xylosides; D012313:RNA; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D002809:Chondroitin Sulfates; D004247:DNA; D003847:Deoxyglucose; D011402:Pronase; D002808:Chondroitin Lyases