La/SSB ribonucleoprotein levels increased in transformed cells

• Published in: Clinical and experimental immunology Vol. 83; no. 3; pp. 369 - 374
• Main Authors: ROTHER, R. P., THOMAS, P. S.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-03-1991; Blackwell
• Subjects: Animals; Autoantigens - biosynthesis; Biological and medical sciences; Cell Line, Transformed - metabolism; Cell physiology; Cell transformation and carcinogenesis. Action of oncogenes and antioncogenes; Cell Transformation, Viral - physiology; Enzyme-Linked Immunosorbent Assay; Fibroblasts - metabolism; Flow Cytometry; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; La/SSB; Mice; Molecular and cellular biology; Rats; Ribonucleoproteins - biosynthesis; Sarcoma Viruses, Murine; Sjögren's syndrome; SS-B Antigen; Flow cytometry; Ribonucleoprotein; Transformed cell; Rodentia; Autoantibody; Vertebrata; Immunoprecipitation reaction; Mammalia; Cell line; Mouse; Ratio; Sjogren syndrome; Fibroblast; Comparative study
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/j.1365-2249.1991.tb05645.x

SUMMARY
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 immunofluorcscence 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.