High-level expression of a bioengineered, cysteine-free hepatocyte-stimulating factor (interleukin 6)-like protein.
Hepatocyte-stimulating factor, interferon-beta 2, B-cell stimulation factor 2, and hybridoma/plasmacytoma growth factor are identical proteins presently referred to as interleukin 6 (IL-6). Through the use of synthetic oligonucleotide technology, we have constructed a biologically active recombinant IL-6 (rIL-6) gene based on the sequence of a human IL-6 cDNA. The synthetic gene encodes a cysteine-free, bioengineered rIL-6 protein that is expressed at high levels in Escherichia coli as a tripartite fusion protein. Cleavage of the fusion protein with collagenase releases a 23-kDa rIL-6 protein that can be easily purified to homogeneity. We show that the rIL-6 protein displays a range of biological activities similar to those of natural human IL-6, as demonstrated by its ability to (i) protect cells from viral infection, (ii) stimulate the synthesis of fibrinogen in rat FAZA 967 cells, and (iii) induce the terminal differentiation of B cells, resulting in elevated secretion of immunoglobulin.
Jambou
R C
RC
Department of Pathology, University of North Carolina, Chapel Hill 27599.
Snouwaert
J N
JN
Bishop
G A
GA
Stebbins
J R
JR
Frelinger
J A
JA
Fowlkes
D M
DM
D000595:Amino Acid Sequence; D000818:Animals; D000998:Antiviral Agents; D001402:B-Lymphocytes / Q000187:drug effects; D001483:Base Sequence; D003545:Cysteine; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D015850:Interleukin-6; D007378:Interleukins / Q000032:analysis / Q000235:genetics* / Q000494:pharmacology; D008099:Liver / Q000187:drug effects; D008969:Molecular Sequence Data; D051381:Rats; D011994:Recombinant Proteins / Q000032:analysis
D000998:Antiviral Agents; D015850:Interleukin-6; D007378:Interleukins; D011994:Recombinant Proteins; D003545:Cysteine