title: SS-A/Ro52, an autoantigen involved in CD28-mediated IL-2 production.
abstract: An autoantibody against SS-A/Ro52 (Ro52) is most frequently found in the sera of patients with Sjögren's syndrome, systemic lupus erythematosus, and congenital heart block from anti-Ro52 Ab-positive mother. However, the physiological function of the autoantigen SS-A/Ro52 has not yet been elucidated. In this study, we describe the role of Ro52 protein in T cell activation. Overexpression of SS-A/Ro52 in Jurkat T cell resulted in enhanced IL-2 production following CD28 stimulation. Furthermore, transfection of anti-Ro52-specific small RNA duplexes partially blocked the expression of native and overexpressed Ro52 in Jurkat T cell, resulting in decreased IL-2 production via CD28 pathway in these cells. Finally, intracellular localization of Ro52 dramatically changed following CD28 stimulation. Our data reveal a novel function of Ro52 in CD28-mediated pathway, which eventually contributes to cytokine production and expression of the T cell biological programs.
authors.affiliation: Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Ishii
authors.forename: Kei
authors.initials: K
authors.lastname: Ohnuma
authors.forename: Akikazu
authors.initials: A
authors.lastname: Murakami
authors.forename: Naruhiko
authors.initials: N
authors.lastname: Takasawa
authors.forename: Tadanori
authors.initials: T
authors.lastname: Yamochi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Iwata
authors.forename: Masahiko
authors.initials: M
authors.lastname: Uchiyama
authors.forename: Nam H
authors.initials: NH
authors.lastname: Dang
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Tanaka
authors.forename: Chikao
authors.initials: C
authors.lastname: Morimoto
mesh_terms: D000276:Adjuvants, Immunologic / Q000235:genetics / Q000502:physiology; D001324:Autoantigens / Q000235:genetics / Q000502:physiology*; D018106:CD28 Antigens / Q000502:physiology*; D015536:Down-Regulation / Q000235:genetics / Q000276:immunology; D049452:Green Fluorescent Proteins; D006801:Humans; D007376:Interleukin-2 / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D019169:Jurkat Cells; D008164:Luminescent Proteins / Q000235:genetics; D008213:Lymphocyte Activation; D034622:RNA Interference / Q000276:immunology; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology; D013347:Subcellular Fractions / Q000276:immunology / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D014162:Transfection; D000099207:SS-A Antigen
chemical_list: D000276:Adjuvants, Immunologic; D001324:Autoantigens; D018106:CD28 Antigens; D049452:Green Fluorescent Proteins; D007376:Interleukin-2; D008164:Luminescent Proteins; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins; D000099207:SS-A Antigen; C116006:RO60 protein, human