Hormonal regulation of complement biosynthesis in human cell lines--II. Upregulation of the biosynthesis of complement components C3, factor B and C1 inhibitor by interleukin-6 and interleukin-1 in human hepatoma cell line.
The effect of interleukin (IL)-6 and IL-1 on the biosynthesis of complement components C3, factor B, C2, C4 and C1 inhibitor (C1 inh), as well as that of albumin, was studied in vitro in human hepatoma-derived cell line, HepG2. Measuring the amounts of secreted complement proteins we detected a significant upregulation of C3 by both hormones. The enhancement of the factor B and especially that of C1 inh production was predominant by IL-6. In our experimental system neither IL-1 nor IL-6 affected the biosynthesis of C2 and C4. Albumin secretion was significantly decreased only in the simultaneous presence of IL-1 and IL-6. Detection of the changes in the amounts of C3- and factor B-specific mRNA of HepG2 cells suggests a pretranslational regulation by these cytokines. The secretion of C3 and factor B was markedly potentiated when IL-1 and IL-6 were added together. However only the gene expression of factor B, but not of C3, was found to reveal synergism. IL-6 enhanced the in vitro production of C3 in mouse hepatocytes as well. This effect was greatly potentiated in the presence of histamine.
Falus
A
A
Department of Immunology, National Institute of Rheumatology and Physiotherapy, Budapest, Hungary.
Rokita
H
H
Walcz
E
E
Brozik
M
M
Hidvégi
T
T
Merétey
K
K
D006528:Carcinoma, Hepatocellular; D002460:Cell Line; D003174:Complement C1 Inactivator Proteins / Q000096:biosynthesis* / Q000235:genetics; D003176:Complement C3 / Q000096:biosynthesis* / Q000235:genetics; D011415:Complement Factor B / Q000096:biosynthesis* / Q000235:genetics; D004792:Enzyme Precursors / Q000096:biosynthesis*; D005786:Gene Expression Regulation; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D015850:Interleukin-6 / Q000494:pharmacology*; D008113:Liver Neoplasms; D011994:Recombinant Proteins / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
D003174:Complement C1 Inactivator Proteins; D003176:Complement C3; D004792:Enzyme Precursors; D007375:Interleukin-1; D015850:Interleukin-6; D011994:Recombinant Proteins; D011415:Complement Factor B