Microheterogeneity of human interleukin 6 synthesized by transfected NIH/3T3 cells: comparison with human monocytes, fibroblasts and endothelial cells.
A cDNA containing the entire coding region of human interleukin 6 (IL 6) was stably expressed in murine NIH/3T3 fibroblasts using a bovine papilloma virus-based expression vector with a metallothionein promoter. Expression of IL 6 in transfected cells was highly inducible by heavy metals like cadmium as measured at mRNA and protein levels. Cadmium-stimulated transfected NIH/3T3 cells synthesized and exported biologically active IL 6 (1.7 x 10(4) U/10(6) cells/24 h). IL 6 from the culture medium of transfected NIH/3T3 cells exhibited at least eight bands on Western blots after sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that human IL 6 expressed in NIH/3T3 cells shows a complex glycosylation pattern. Using glycosidases and the N-glycosylation inhibitor tunicamycin it was possible to discriminate between five species carrying N-linked carbohydrate side chains and two species carrying only O-linked side chains. In addition, a substantial amount of unglycosylated IL 5 was observed. IL 6 from transfected NIH/3T3 cells differed markedly in its glycosylation pattern from those of stimulated human monocytes, fibroblasts and endothelial cells.
Schiel
X
X
Institut für Biochemie der RWTH Aachen, FRG.
Rose-John
S
S
Dufhues
G
G
Schooltink
H
H
Gross
V
V
Heinrich
P C
PC
D000818:Animals; D002478:Cells, Cultured; D004727:Endothelium / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D009000:Monocytes / Q000378:metabolism*; D014162:Transfection
D015850:Interleukin-6