Open AccessSynovial fibroblast‐like cells synthesize seven proteins of the complement system
Author(s) -
Katz Yitzhak,
Strunk Robert C.
Publication year - 1988
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/art.1780311104
Subject(s) - fibroblast , gel electrophoresis , microbiology and biotechnology , protein subunit , lipopolysaccharide , polyacrylamide gel electrophoresis , immunoprecipitation , chemistry , complement system , methionine , immunology , biology , biochemistry , antibody , gene , in vitro , amino acid , enzyme
Fibroblast‐like cells from synovial tissue obtained during arthroscopy in 4 young adults with recent knee trauma were biosynthetically labeled with 35 S‐methionine, and protein production was quantitated by immunoprecipitation and sodium dodecyl sulfate—polyacrylamide gel electrophoresis. Synovial fibroblast‐like cells synthesized C1r, C1s, C1 inhibitor, C2, C3, factor B, and factor H, all with the same sizes and subunit structures as the proteins synthesized in skin fibroblasts. The capacity to synthesize these proteins was not lost with passages or freeze‐thawing. Gamma‐interferon stimulation increased synthesis of all 7 proteins. Lipopolysaccharide increased synthesis of only C3 and factor B. Unlike in whole rheumatoid tissue, C4 and C5 were not detected. Synovial lining cells may be an important source of local complement for participation in local defense or development of pathologic states.