Autoantibodies to a Novel Early Endosome Antigen 1

• Published in: Clinical immunology and immunopathology Vol. 86; no. 1; pp. 81 - 87
• Main Authors: Waite, Rochelle L., Sentry, John W., Stenmark, Harald, Toh, Ban-Hock
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.01.1998; New York, NY Academic Press; Boston
• Subjects: Aged; Aged, 80 and over; Antibody Specificity; Arthralgia - blood; Arthralgia - immunology; Arthritis - blood; Arthritis - immunology; Arthritis, Rheumatoid - blood; Arthritis, Rheumatoid - immunology; autoantibodies; Autoantibodies - blood; Autoantibodies - immunology; autoimmune disease; Autoimmune Diseases - blood; Autoimmune Diseases - immunology; Biological and medical sciences; Biomarkers; early endosome antigen 1 (EEA1); Endosomes - immunology; Enzyme-Linked Immunosorbent Assay; Female; Fluorescent Antibody Technique, Indirect; HeLa Cells; Humans; Immunoglobulin G - blood; Immunoglobulin G - immunology; Immunoglobulin M - blood; Immunoglobulin M - immunology; Joint Diseases - blood; Joint Diseases - immunology; Male; Medical sciences; Membrane Proteins - immunology; polyarticular disease; Receptors, Transferrin - analysis; Recombinant Fusion Proteins - immunology; Rheumatoid Factor - analysis; Sarcoidosis. Granulomatous diseases of unproved etiology. Connective tissue diseases. Elastic tissue diseases. Vasculitis; subacute cutaneous lupus erythematosus; Vesicular Transport Proteins; polyarticular disease; early endosome antigen 1 (EEA1); subacute cutaneous lupus erythematosus; autoimmune disease; autoantibodies; Human; Immunopathology; Connective tissue disease; Cell compartment; Skin disease; Immunoglobulins; Antibody; Autoantibody; Autoimmune disease; Hela cell line; Antigen; Characterization; Autoantigen; Systemic disease; Lupus erythematosus; Localization; Endosome
• ISSN: 0090-1229; 1090-2341
• DOI: 10.1006/clin.1997.4455

Autoantibodies to EEA1, an antigen on early endosomes, were first reported in the serum of a patient with subacute cutaneous lupus erythematosus (SCLE). Here we have examined 38 sera selected for investigation of autoantibodies to EEA1 on the basis of cytoplasmic vesicle-like reactivity by immunofluorescence. Ten of the sera were reactive to a HeLa cell protein of approximately the sameMras human EEA1. Eight of these sera belonged to the IgG1subclass. Five of the sera reacted with fusion proteins incorporating either the amino (from amino acids 1 to 209) or the carboxyl (incorporating the most C-terminal 300 amino acids) terminus of the human EEA1 protein. Antigens reactive with these 5 sera colocalized with internalized transferrin receptors, indicating their association with early endosomes. The other 5 sera which did not react to both fusion proteins did not colocalize with internalized transferrin receptors. We conclude that 5 of the 38 patients (13%) have autoantibodies to EEA1. None of these patients have SCLE, but have generalized joint pain, polyarthritis, rheumatoid arthritis, or circulating rheumatoid factors.