Nakazawa Maho, Suzuki Katsuya, Takeshita Masaru, Inamo Jun, Kamata Hirofumi, Ishii Makoto, Oyamada Yoshitaka, Oshima Hisaji, Takeuchi Tsutomu
Keio University School of Medicine, Tokyo, Japan.
National Hospital Organization Tokyo Medical Center, Tokyo, Japan.
Arthritis Rheumatol. 2021 Apr;73(4):576-586. doi: 10.1002/art.41554. Epub 2021 Feb 15.
To identify immunologic factors in the lungs of patients with rheumatoid arthritis-associated interstitial lung disease (RA-ILD) and patients with idiopathic inflammatory myopathy-associated ILD (IIM-ILD) and to examine their pathologic mechanisms.
Eleven patients with RA-ILD, 16 with IIM-ILD, 6 with drug-induced ILD (DI-ILD), and 8 healthy controls were enrolled. Peripheral blood (PB) and bronchoalveolar lavage (BAL) fluid were immunophenotyped by flow cytometry. Alveolar macrophages (AMs) were analyzed by coculture assay with PB naive CD4+ T cells from healthy individuals and RNA sequencing.
Several coinhibitory molecules were coexpressed on BAL fluid T cells (CTLA-4, programmed death 1 [PD-1], T cell immunoglobulin and mucin domain-containing protein 3 [TIM-3], and lymphocyte activation gene 3 protein, from most to least), whereas only PD-1 was expressed on PB T cells. CTLA-4+PD-1+CD4+ T cells were characteristic of RA-ILD, whereas CTLA-4+PD-1+TIM-3+CD8+ T cells were characteristic of IIM-ILD. BAL fluid PD-1+CD4+ T cells rarely expressed CXCR5, but their levels correlated with levels of plasmablasts and plasma cells (ρ = 0.57, P = 0.006), indicating that most of them would be considered peripheral helper T cells. In coculture experiments, AMs from patients with RA-ILD and IIM-ILD induced more PD-1 and TIM-3 on T cells (P < 0.05), suggesting that coinhibitory molecule expression on BAL fluid T cells was partly due to AMs. RNA sequencing showed significant down-regulation of PD ligand 1/2 genes in AMs from patients with RA-ILD compared to those with DI-ILD.
We have identified differences in coinhibitory molecule expression between patients with RA-ILD and those with IIM-ILD. PD-1 on T cells in RA-ILD and TIM-3 on CD8+ T cells in IIM-ILD might be key factors in the disease process. Evaluation of coinhibitory molecules on BAL fluid T cells could be clinically useful.
鉴定类风湿关节炎相关间质性肺疾病（RA-ILD）患者和特发性炎性肌病相关ILD（IIM-ILD）患者肺内的免疫因素，并研究其病理机制。
纳入11例RA-ILD患者、16例IIM-ILD患者、6例药物性ILD（DI-ILD）患者和8名健康对照者。通过流式细胞术对外周血（PB）和支气管肺泡灌洗（BAL）液进行免疫表型分析。通过与健康个体的PB初始CD4+T细胞共培养试验和RNA测序分析肺泡巨噬细胞（AM）。
几种共抑制分子在BAL液T细胞上共表达（从多到少依次为细胞毒性T淋巴细胞相关蛋白4 [CTLA-4]、程序性死亡蛋白1 [PD-1]、含T细胞免疫球蛋白和粘蛋白结构域蛋白3 [TIM-3]以及淋巴细胞活化基因3蛋白），而仅PD-1在PB T细胞上表达。CTLA-4+PD-1+CD4+T细胞是RA-ILD的特征，而CTLA-4+PD-1+TIM-3+CD8+T细胞是IIM-ILD的特征。BAL液PD-1+CD4+T细胞很少表达趋化因子受体CXCR5，但其水平与成浆细胞和浆细胞水平相关（ρ = 0.57，P = 0.006），表明其中大多数可被视为外周辅助性T细胞。在共培养实验中，RA-ILD和IIM-ILD患者的AM在T细胞上诱导更多的PD-1和TIM-3（P < 0.05），提示BAL液T细胞上共抑制分子的表达部分归因于AM。RNA测序显示，与DI-ILD患者相比，RA-ILD患者的AM中PD配体1/2基因显著下调。
我们已确定RA-ILD患者和IIM-ILD患者在共抑制分子表达上存在差异。RA-ILD中T细胞上的PD-1和IIM-ILD中CD8+T细胞上的TIM-3可能是疾病进程中的关键因素。评估BAL液T细胞上的共抑制分子可能具有临床应用价值。
