Autoimmune response directed against conserved determinants of nuclear envelope proteins in a patient with linear scleroderma.

Abstract

We have studied the autoantibodies in the serum of a patient with linear scleroderma that specifically recognize the nuclear envelope of cultured cells. These antibodies bind to conserved determinants of nuclear lamins, the predominant mammalian nuclear envelope proteins. Of the three mammalian nuclear lamin proteins (P70, P68, and P60), only P70 and P60 bind the autoantibodies. In addition, two proteins of the Drosophila embryonic nuclear matrix, P70 and P68, bind these autoantibodies. We have used nuclear matrices to isolate the autoantibodies from the patient's serum that react to the nuclear lamins. At least three different IgG heavy chains were found to be involved in this autoimmune response to nuclear lamins, indicating that this response is not due to the expansion of a single B-cell clone.A strong correlation exists between systemic rheumatic diseases and the presence of circulating autoantibodies to proteinnucleic acid complexes (1). The targets of these autoantibodies include nuclear ribonucleoprotein particles (2), nucleosomes (3), nucleoli (4), kinetochores (5), and others. The range of targets for particular disease syndromes are often limited; for example, systemic lupus erythematosis is often associated with autoantibodies to nuclear ribonucleoprotein particles (2), whereas most scleroderma CREST patients produce autoantibodies to centromeric regions of chromosomes (kinetochores; ref. 5). Surprisingly, little is known of the autoimmune responses or their targets on a molecular level.In an attempt to associate the immunofluorescence pattern of sera from patients with specific autoimmune diseases, we discovered a high-titer serum directed against the nuclear envelope in a patient with linear scleroderma. We designate this serum as LS-1. We have chosen here to characterize this autoimmune response more precisely by identifying the antigens recognized by this serum and by determining the nature and complexity of the antibody response. We have found that this autoimmune response is polyclonal and directed against two of the three predominant polypeptides of the nuclear envelope, known as nuclear lamins (6).Using immunofluorescence and immunotransfers of NaDodSO4 gels, we also have detected nuclear lamins in Drosophila melanogaster embryonic nuclear matrices. This demonstrates that nuclear lamins are present in invertebrates and that these autoantibodies from LS-1 serum must be directed against highly conserved determinants. at 26°C in Echalier's medium (7).Immunofluorescence Microscopy. CHO and Kc cells were grown on glass coverslips (12-mm diameter, Corning), fixed in 1% formaldehyde in phosphate-buffered saline (Pi/NaCl) for 5 min at 22°C, and made permeable to antibodies by washing in 0.1% Triton X-100 (Sigma) in Pi/NaCl. The cells were first exposed to LS-1 serum diluted 1:200 and subsequently to a rhodamine-conjugated goat anti-human IgG (Cappel Laboratories, Cochranville, PA). Cells were photographed with a Zeiss photomicroscope with a X 100 planapo objective.Immunohistochemical Microsc...

A novel autoantibody causing a peripheral fluorescent antinuclear antibody pattern is specific for nuclear pore complexes

“…The punctate fluorescence of nuclear pore complexes was not apparent on rat liver sections used for routine ANA detection. The autoantibody produced a continuous peripheral (rim) labeling, similar to the fluorescence patterns reported for antibodies to DNA and to lamins (1)(2)(3)(4)(5)(6). However, on cultured cells, the peripheral fluorescence was punctate, and thus, it could not be confused with the continuous labeling associated with these antibodies.…”

Anti‐DNA topoisomerase IIα autoantibodies in localized scleroderma

“…Therefore, antitopo II␣ antibody can be regarded as one of the anti-nuclear matrix autoantibodies. Consistently, autoantibodies to nuclear lamin, one of components of nuclear matrix, are also detected in localized scleroderma (15). Since nuclear matrix is the protein framework involved in the organization of chromatin, autoimmune responses in localized scleroderma may be directed toward not only native chromatin, but also its framework (nuclear matrix), including topo II␣.…”

Autoantibodies to Nuclear Lamin C in the Eosinophilia—Myalgia Syndrome Associated with L‐Tryptophan Ingestion

“…Human autoantibodies reacting with the lamins were originally described in a patient with linear scleroderma, but these antibodies are distinctly uncommon (8). We and others have reported the detection of antilamin antibodies in the sera of patients with systemic lupus erythematosus (SLE) (6), rheumatoid arthritis (9), and a chronic autoimmune syndrome characterized by hepatitis, cytopenias, and vasculitis (10).…”