Purpose

Patients with STAT1 gain-of-function (GOF) mutations often exhibit autoimmune features. The JAK1/2 inhibitor ruxolitinib can be administered to alleviate autoimmune symptoms; however, it is unclear how immune cells are molecularly changed by ruxolitinib treatment. Then, we aimed to investigate the trnscriptional and epigenetic status of immune cells before and after ruxolitinib treatment in a patient with STAT1 GOF.

Methods

A patient with a heterozygous STAT1 GOF variant (p.Ala267Val), exhibiting autoimmune features, was treated with ruxolitinib, and peripheral blood mononuclear cells (PBMCs) were longitudinally collected. PBMCs were transcriptionally analyzed by single-cell cellular indexing of the transcriptomes and epitopes by sequencing (CITE-seq), and epigenetically analyzed by assay of transposase-accessible chromatin sequencing (ATAC-seq).

Results

CITE-seq analysis revealed that before treatment, the patient’s PBMCs exhibited aberrantly activated inflammatory features, especially IFN-related features. In particular, monocytes showed high expression levels of a subset of IFN-stimulated genes (ISGs). Ruxolitinib treatment substantially downregulated aberrantly overexpressed ISGs, and improved autoimmune features. However, epigenetic analysis demonstrated that genetic regions of ISGs—e.g., STAT1, IRF1, MX1, and OAS1—were highly accessible even after ruxolitinib treatment. When ruxolitinib was temporarily discontinued, the patient’s autoimmune features were aggravated, which is in line with sustained epigenetic abnormality.

Conclusions

In a patient with STAT1 GOF, ruxolitinib treatment improved autoimmune features and downregulated aberrantly overexpressed ISGs, but did not correct epigenetic abnormality of ISGs.

中文翻译：

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Ruxolitinib 可改善 STAT1 GOF 患者的免疫失调特征，但不能改善表观遗传异常

目的

具有 STAT1 功能获得性 (GOF) 突变的患者通常表现出自身免疫特征。 JAK1/2抑制剂ruxolitinib可用于缓解自身免疫症状；然而，尚不清楚鲁索替尼治疗如何在分子上改变免疫细胞。然后，我们旨在研究 STAT1 GOF 患者接受鲁索替尼治疗前后免疫细胞的转录和表观遗传状态。

方法

一名具有杂合 STAT1 GOF 变异 (p.Ala267Val) 且表现出自身免疫特征的患者接受鲁索替尼治疗，并纵向收集外周血单核细胞 (PBMC)。通过测序 (CITE-seq) 对转录组和表位进行单细胞细胞索引，对 PBMC 进行转录分析，并通过转座酶可及染色质测序 (ATAC-seq) 进行表观遗传学分析。

结果

CITE-seq 分析显示，在治疗前，患者的 PBMC 表现出异常激活的炎症特征，尤其是 IFN 相关特征。特别是，单核细胞显示出 IFN 刺激基因 (ISG) 子集的高表达水平。鲁索替尼治疗显着下调了异常过度表达的 ISG，并改善了自身免疫特征。然而，表观遗传学分析表明，即使在鲁索替尼治疗后，ISG 的遗传区域（例如STAT1、IRF1、MX1和OAS1）也很容易接近。当鲁索替尼暂时停用时，患者的自身免疫特征加重，这与持续的表观遗传异常相符。

结论

在 STAT1 GOF 患者中，鲁索替尼治疗改善了自身免疫特征并下调了异常过度表达的 ISG，但没有纠正 ISG 的表观遗传异常。