La/SSB ribonucleoprotein levels increased in transformed cells.
Autoantibodies to the La/SSB ribonucleoprotein are commonly found in patients with Sjögren's syndrome. Previous studies have shown that La/SSB accumulates in cells shortly after viral infection. We have extended these studies by investigating levels of the La/SSB antigen in virally and spontaneously transformed cell lines (contact-insensitive and tumourigenic) relative to their non-transformed counterpart cell lines (contact-sensitive and non-tumourigenic). Transformed BALB/3T12-3 and KNRK fibroblasts were visibly brighter by immunofluorescence assay than non-transformed BALB/3T3 and NRK fibroblasts respectively, when reacted with anti-La/SSB specific sera. This was confirmed by flow cytometry, as La/SSB levels were elevated in the transformed counterparts of the same cell lines. An anti-Sm monoclonal antibody and normal human serum reacted with these cell lines failed to show a significant increase by flow cytometry. Finally, a two-fold increase in the La/SSB antigen was demonstrated in cell lysates of these cell lines by a capture ELISA. These data show that La/SSB is elevated in transformed cell lines compared with non-transformed counterpart cell lines and suggest that this increase is not restricted to viral transformation.
Rother
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RP
Arthritis/Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City 73104.
Thomas
P S
PS
D000818:Animals; D001324:Autoantigens / Q000096:biosynthesis*; D002461:Cell Line, Transformed / Q000378:metabolism*; D002472:Cell Transformation, Viral / Q000502:physiology; D004797:Enzyme-Linked Immunosorbent Assay; D005347:Fibroblasts / Q000378:metabolism; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D051379:Mice; D051381:Rats; D012261:Ribonucleoproteins / Q000096:biosynthesis*; D009053:Sarcoma Viruses, Murine; D000097585:SS-B Antigen
D001324:Autoantigens; D012261:Ribonucleoproteins; D000097585:SS-B Antigen