title: Specific antibodies to moesin, a membrane-cytoskeleton linker protein, are frequently detected in patients with acquired aplastic anemia.
abstract: To identify novel autoantibodies in acquired aplastic anemia (AA), we screened the sera of patients with AA possessing small populations of paroxysmal nocturnal hemoglobinuria (PNH)-type cells for the presence of antibodies (Abs) which recognize proteins derived from a leukemia cell line, UT-7. Immunoblotting using proteins derived from lysates or culture supernatants of UT-7 cells revealed the presence of IgG Abs specific to an 80-kDa protein. Peptide mass fingerprinting identified this 80-kDa protein as moesin. Enzyme-linked immunosorbent assay (ELISA) using recombinant moesin showed high titers of antimoesin Abs in 25 (37%) of 67 patients with AA. Moesin was secreted from several myeloid leukemia cell lines other than UT-7, such as OUN-1 and K562, as an exosomal protein. The presence of antimoesin Abs was significantly correlated with the presence of PNH-type cells and antidiazepam-binding inhibitor-related protein-1 (DRS-1) Abs. Patients with AA that did not show any of these 3 markers tended to respond poorly to immunosuppressive therapy. These findings suggest that a B-cell response to moesin, possibly derived from hematopoietic cells, frequently occurs in patients with AA and that detection of antimoesin Abs in combination with other markers may be useful in diagnosing immune pathophysiology in patients with AA.
authors.affiliation: Cellular Transplantation Biology, Division of Cancer Medicine, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takamatsu
authors.forename: Xingmin
authors.initials: X
authors.lastname: Feng
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Chuhjo
authors.forename: Xuzhang
authors.initials: X
authors.lastname: Lu
authors.forename: Chiharu
authors.initials: C
authors.lastname: Sugimori
authors.forename: Katsuya
authors.initials: K
authors.lastname: Okawa
authors.forename: Miyuki
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Shoichi
authors.initials: S
authors.lastname: Iseki
authors.forename: Shinji
authors.initials: S
authors.lastname: Nakao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000741:Anemia, Aplastic / Q000097:blood* / Q000453:epidemiology / Q000276:immunology* / Q000628:therapy; D000906:Antibodies / Q000097:blood / Q000276:immunology*; D018941:Antigens, CD19 / Q000378:metabolism; D018952:Antigens, CD34 / Q000378:metabolism; D001172:Arthritis, Rheumatoid / Q000276:immunology; D015415:Biomarkers; D017252:CD3 Complex / Q000378:metabolism; D002460:Cell Line; D003599:Cytoskeleton / Q000378:metabolism*; D000939:Epitopes / Q000276:immunology; D005260:Female; D006801:Humans; D007167:Immunotherapy; D007938:Leukemia; D008297:Male; D008840:Microfilament Proteins / Q000276:immunology* / Q000378:metabolism*; D008875:Middle Aged; D008970:Molecular Weight; D009190:Myelodysplastic Syndromes / Q000453:epidemiology / Q000276:immunology / Q000378:metabolism; D015995:Prevalence
chemical_list: D000906:Antibodies; D018941:Antigens, CD19; D018952:Antigens, CD34; D015415:Biomarkers; D017252:CD3 Complex; D000939:Epitopes; D008840:Microfilament Proteins; C071058:moesin