Identification and analysis of novel inherited dysregulation of interferon

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K08754
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 53050:Dermatology-related
• Research Institution: Wakayama Medical University
• Principal Investigator: Kunimoto Kayo 和歌山県立医科大学, 医学部, 講師 (10438278)
• Co-Investigator(Kenkyū-buntansha): 金澤 伸雄 兵庫医科大学, 医学部, 教授 (90343227) ; 邊見 弘明 岡山理科大学, 獣医学部, 教授 (20451924)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 凍瘡様皮疹 / インターフェロン制御異常症 / 新規遺伝子変異 / 自己炎症性疾患

Outline of Final Research Achievements

Intracellular STAT1 phosphorylation after IFNγ stimulation of cells from affected children and parents with a compound heterozygous mutation of paternal Xa and maternal Xb was enhanced in immortalized B cells in the father and affected children. Expression of type I IFN response genes in peripheral blood mononuclear cells was higher in affected children and father by qRT-PCR. Immunohistological examination of the skin rash showed positive expression of pSTAT1 in both the affected child and the father. Expression of X in wild-type X and Xa and Xb mutant 293T cells, and reporter assays for ISRE and GAS after IFNγ stimulation in 293T cells and X-deficient HAP1 cells showed no difference due to mutation.
Activation of the Ifna4 promoter in 293T cells overexpressing TRIF and IRF3 also did not differ by mutation.

Free Research Field

自己炎症性疾患

Academic Significance and Societal Importance of the Research Achievements

患者由来不死化B細胞などで観察された、IFN刺激後のSTAT1リン酸化の亢進が、293T細胞やHAP1細胞に遺伝子を過剰発現させた系では再現できず、X変異の機能的意義を示すことができなかったため、変異マウスの作成やタンパク質の作成ができていない。しかし、XaとXb変異はマウスでもよく保存されていることから、それらの生体内での意義を明らかにし、X欠損マウスと異なるI型IFN異常症モデルを得ることを目標に、CRSPAR/Cas9システムを用いて Xa変異マウスとXb変異マウスを作成し、かけあわせて複合ヘテロ変異マウスを得るよう進めていく。