51. IL-10+ T follicular regulatory cells are associated with the pathogenesis of IgG4-related disease
- Author
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Hiromi Takaki, Tetsuo Himi, Katsunori Shigehara, Ryuta Kamekura, Ippei Ikegami, Kenichi Takano, Fumie Ito, Hiroki Takahashi, Shingo Ichimiya, Motohisa Yamamoto, and Hayato Yabe
- Subjects
0301 basic medicine ,medicine.medical_treatment ,Immunology ,Disease ,Pathogenesis ,03 medical and health sciences ,0302 clinical medicine ,parasitic diseases ,Follicular phase ,medicine ,Immunology and Allergy ,skin and connective tissue diseases ,B cell ,integumentary system ,business.industry ,fungi ,Immunosenescence ,medicine.disease ,Interleukin 10 ,030104 developmental biology ,Cytokine ,medicine.anatomical_structure ,IgG4-related disease ,business ,030215 immunology - Abstract
IgG4-related disease (IgG4-RD) is a chronic fibroinflammatory disease characterized by elevation of serum IgG4 level as well as infiltration of IgG4+ plasma cells in various affected organs. The etiology of IgG4-RD is still not fully understood. Since IgG4-RD is more prevalent in the elderly, aging in itself is considered to be an important risk factor of IgG4-RD. However, the relationship between the pathogenesis of IgG4-RD and immunosenescence remains unknown. To clarify age-related features underlying IgG4-RD, we focused on T follicular regulatory (Tfr) cells, which share forkhead box P3 with regulatory T cells, since the percentage of Tfr cells is known to depend on age. Studies of blood specimens from patients with IgG4-RD and from healthy volunteers demonstrated a marked elevation of circulating Tfr (cTfr) cells in patients with IgG4-RD. Moreover, the percentage of cTfr cells was significantly correlated with various clinical parameters including the level of serum IgG4 and the number of involved organs in IgG4-RD patients. The percentages of tonsillar and blood Tfr cells were increased with aging in healthy volunteers, whereas the suppressive effect of cTfr cells on B cell function in elderly subjects was impaired in comparison with that in young subjects due to a defect in the production of a regulatory cytokine, IL-10. Given that the number of IL-10-producing cTfr cells in IgG4-RD patients was markedly increased compared with that in healthy elderly subjects, these findings suggest that an abnormal aging process of Tfr cells may be related to the pathogenesis of IgG4-RD.
- Published
- 2019