Woodchuck interleukin-6 gene: structure, characterization, and biologic activity.
Woodchuck is an important animal model for studying human hepatitis B virus (HBV) infection. Within the cytokine network, interleukin-6 (IL-6) plays an important role in immune responses that may lead to viral clearance. To further understand woodchuck IL-6 biology, we cloned and characterized the IL-6 gene from white blood cells. The complete woodchuck IL-6 gene is about 7 kb and consists of five exons and four introns. The IL-6 gene organization of the woodchuck is similar to those of the human, rat, and mouse. Also several elements are highly conserved in the 300 bp promoter region of the IL-6 gene, including a nuclear factor kappa B (NF-kappaB) binding site. The woodchuck IL-6 gene encodes a polypeptide of 207 amino acids in a precursor form and 189 amino acids in the mature form. The expressed protein was 23 kDa according to SDS-PAGE. To demonstrate biologic activity, we expressed woodchuck IL-6 and showed that the purified recombinant protein induced terminal differentiation, as reflected by upregulation of Fcgamma receptor expression, and substantially inhibited proliferation of M1 cells, a murine myeloid leukemia cell line. The inhibitory effect of woodchuck IL-6 on M1 cells was blocked by an anti-gp130 monoclonal antibody, suggesting that woodchuck IL-6 activity is specifically mediated by signaling through the IL-6 receptor complex. Cloning of the woodchuck IL-6 gene and demonstrating biologic activity of the gene product will facilitate studies of human hepatitis B virus using the woodchuck model.
Li
Daniel H
DH
Division of Immunology and Rheumatology, Department of Medicine, Stanford University School of Medicine, 269 W. Campus Drive, CCSR Building 2230, Stanford, CA 94305-5166, USA. dhli@leland.stanford.edu
Kumanogoh
Atsushi
A
Cao
Thai M
TM
Parnes
Jane R
JR
Cullen
John M
JM
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D005091:Exons; D005796:Genes / Q000235:genetics; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D007438:Introns; D008392:Marmota / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics; D011994:Recombinant Proteins / Q000378:metabolism / Q000494:pharmacology; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors / Q000378:metabolism
D018076:DNA, Complementary; D015850:Interleukin-6; D011994:Recombinant Proteins; D014157:Transcription Factors