Alternative TitleIgA腎症における扁桃細菌叢に対する異常粘膜免疫応答
Note (General)Background. Immunoglobulin A nephropathy (IgAN) is the most common glomerulonephritis worldwide, characterized by mesangial polymeric IgA1 deposition. IgAN is believed to develop owing to aberrant mucosal immunoreaction against commensals in the tonsils. However, the exact interrelation between pathogenic IgA and mucosal microbiota in IgAN patients is unclear. Methods. Biopsy-proven IgAN or recurrent tonsillitis (RT) patients who had undergone tonsillectomy were enrolled. We used 16S ribosomal RNA gene amplicon sequencing with a flow cytometry-based bacterial cell sorting technique) and immunoglobulin repertoire sequencing of the IgA heavy chain to characterize IgA-coated bacteria of the tonsillar microbiota (IgA-SEQ) and their corresponding IgA repertoire. Furthermore, we fractionated patient serum using gelfiltration chromatography and performed flow cytometry-based analysis of IgA binding to bacteria cultured from incised tonsils. Results. Tonsillar proliferation-inducing ligand and B-cell activating factor levels were significantly higher in IgAN than in RT patients. IgA-SEQ for tonsillar microbiota revealed the preferential binding ability of IgA to Bacteroidetes in IgAN tonsils compared with those from RT patients. Expression of immunoglobulin heavy (IGH) constant alpha 1 with IGH variable 3–30 was significantly higher in IgAN than that in RT, and positively correlated with the IgA-coated enrichment score of Bacteroidetes. Serum polymeric IgA, comprising high levels of GdIgA1, exhibited considerable binding to Bacteroidetes strains cultured from the tonsils of IgAN patients. Conclusions. These findings provide evidence that aberrant mucosal immune responses to tonsillar anaerobic microbiota, primarily consisting of members of the phylum Bacteroidetes, are involved in IgAN pathophysiology.
Nephrology Dialysis Transplantation. 2021, 36(1), 75–86.
新大院博(医)第998号
Collection (particular)国立国会図書館デジタルコレクション > デジタル化資料 > 博士論文
Date Accepted (W3CDTF)2022-05-09T11:57:37+09:00
Data Provider (Database)国立国会図書館 : 国立国会図書館デジタルコレクション