title: What is the evidence for Sjögren's syndrome being triggered by viral infection? Subplot: infections that cause clinical features of Sjögren's syndrome.
abstract: OBJECTIVE
  To clarify the involvement of viral infections in the pathogenesis of Sjögren's syndrome and to discuss whether viruses can be a trigger for the development of Sjögren's syndrome.
  
  
  RESULTS
  Although some viruses are candidate triggers of Sjögren's syndrome, we focus on human T lymphotropic virus type I (HTLV-I). Clinicoepidemiological studies show a relationship between HTLV-I and Sjögren's syndrome with a low frequency of salivary gland damage in magnetic resonance imaging, autoantibody production and ectopic germinal center in HTLV-I-associated myelopathy (HAM) patients with Sjögren's syndrome. Our recent study showed that HTLV-I has the potential to infect salivary gland epithelial cells (SGECs). After a coculture of HCT-5 (an HTLV-I-infected T-cell line derived from the cerebrospinal fluid) of an HAM patient and SGECs, we observed time-dependent increases in the levels of soluble intracellular adhesion molecule1, interferon gamma-induced protein 10 kDa and regulated on activation, normal T-cell expressed and secreted. In addition, SGECs themselves express these molecules along with the expression of HTLV-I proteins.
  
  
  CONCLUSIONS
  HTLV-I is involved in the pathogenesis of HTLV-I-seropositive patients with Sjögren's syndrome. By infecting CD4 T cells in vivo, HTLV-I induces specific clinicopathological conditions. In addition, HTLV-I-infected SGECs have the potential to augment the expression of molecules involved in cell adhesion, inflammation and migration.
authors.affiliation: Unit of Translational Medicine, Department of Immunology and Rheumatology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Nakamura
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kawakami
mesh_terms: D001323:Autoantibodies / Q000096:biosynthesis; D004847:Epithelial Cells / Q000821:virology; D005260:Female; D015490:HTLV-I Infections / Q000150:complications* / Q000453:epidemiology / Q000276:immunology; D015368:Human T-lymphotropic virus 1 / Q000472:pathogenicity; D006801:Humans; D012469:Salivary Glands / Q000276:immunology / Q000821:virology; D012859:Sjogren's Syndrome / Q000453:epidemiology / Q000276:immunology / Q000821:virology*; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D001323:Autoantibodies