Inhibition of ABL1 tyrosine kinase reduces HTLV-1 proviral loads in peripheral blood mononuclear cells from patients with HTLV-1-associated myelopathy/tropical spastic paraparesis
Inhibition of ABL1 tyrosine kinase reduces HTLV-1 proviral loads in peripheral blood mononuclear cells from patients with HTLV-1-associated myelopathy/tropical spastic paraparesis
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DOI：
10.1371/journal.pntd.0008361
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发表时间：
2020-07-01
影响因子：
3.8
通讯作者：
Izumo, Shuji
中科院分区：
文献类型：
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作者：
Kodama, Daisuke;Tanaka, Masakazu;Izumo, Shuji
人类T细胞白血病病毒1型（HTLV-1）可导致无法治愈的成人T细胞白血病和HTLV-1相关的脊髓病/热带痉挛性下肢轻瘫（HAM/TSP）。与无症状HTLV-1携带者相比，HAM/TSP患者的HTLV-1感染细胞水平增加。然而，细胞基因在HTLV-1感染的CD 4 + T细胞中的作用有待发现。我们对HAM/TSP患者的CD 4 + T细胞进行了微阵列分析，发现ABL 1是HAM/TSP中的重要基因。ABL 1是已知的T和B淋巴细胞的存活因子，并且是已知负责慢性髓细胞性白血病（CML）的融合基因（BCR-ABL）的一部分。ABL 1酪氨酸激酶抑制剂（TKI），包括伊马替尼、尼洛替尼和达沙替尼，在临床上用于治疗CML。为了评估ABL 1是否确实对HAM/TSP很重要，我们研究了TKI对HTLV-1感染细胞的影响。我们开发了一种单叠氮丙啶-HTLV-1活力定量PCR检测方法，该方法可以区分DNA与活细胞和死细胞。使用该方法，我们能够在HAM/TSP病例的外周血单核细胞（PBMC）接受TKI治疗时单独测量活细胞中的HTLV-1前病毒载量（PVL）。用尼洛替尼或达沙替尼处理PBMC可诱导活细胞中PVL显著降低（分别为21.0%和17.5%）。此外，ABL 1 siRNA转染降低了HTLV-1感染细胞系的细胞活力，但在未感染的细胞系中没有。一项基于我们临床记录的回顾性调查发现了一个罕见的HAM/TSP病例，他也患有CML。患者在接受伊马替尼治疗CML后显示PVL减少84.2%。我们的结论是，抑制ABL 1酪氨酸激酶特异性地减少了HAM/TSP患者PBMC中的PVL，提示ABL 1是HTLV-1感染细胞存活的重要基因，TKI可能是HAM/TSP的潜在治疗剂。作者总结人T细胞白血病病毒1型（HTLV-1）作为前病毒整合在主要为CD 4+的基因组DNA中。感染者的T细胞数量。HTLV-1感染的CD 4 + T细胞通过母乳、精液和输血传播。HTLV-1在日本、中东、非洲、加勒比海岛屿以及中美洲和南美洲流行。一小部分感染者会发展成成人T细胞白血病、HTLV-1相关性脊髓病/热带痉挛性下肢轻瘫（HAM/TSP）和其他疾病。HAM/TSP是一种慢性神经炎性疾病，以痉挛性轻瘫和排尿障碍为特征。HTLV-1感染的CD 4 + T细胞浸润脊髓并引起炎症，导致这种神经症状。我们已经确定了酪氨酸激酶基因ABL 1作为一个基因，经常发现在HTLV-1感染的CD 4 + T细胞的信号转导途径。因此，ABL 1在HAM/TSP的发病机制中起重要作用。用酪氨酸激酶抑制剂（TKI）抑制ABL 1，这是用于慢性粒细胞白血病（CML），减少了前病毒负荷（PVL）在体外。根据我们的临床记录，我们发现一例HAM/TSP和CML患者的罕见病例，该患者在TKI治疗CML后显示PVL降低。因此，TKI是HAM/TSP的潜在治疗药物。
Human T-cell leukemia virus type 1 (HTLV-1) causes incurable adult T-cell leukemia and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Patients with HAM/TSP have increased levels of HTLV-1-infected cells compared with asymptomatic HTLV-1 carriers. However, the roles of cellular genes in HTLV-1-infected CD4+ T cells await discovery. We performed microarray analysis of CD4+ T cells from HAM/TSP patients and found that theABL1is an important gene in HAM/TSP.ABL1is a known survival factor for T- and B-lymphocytes and is part of the fused gene (BCR-ABL) known to be responsible for chronic myelogenous leukemia (CML). ABL1 tyrosine kinase inhibitors (TKIs), including imatinib, nilotinib, and dasatinib, are used clinically for treating CML. To evaluate whetherABL1is indeed important for HAM/TSP, we investigated the effect of TKIs on HTLV-1-infected cells. We developed a propidium monoazide-HTLV-1 viability quantitative PCR assay, which distinguishes DNA from live cells and dead cells. Using this method, we were able to measure the HTLV-1 proviral load (PVL) in live cells alone when peripheral blood mononuclear cells (PBMCs) from HAM/TSP cases were treated with TKIs. Treating the PBMCs with nilotinib or dasatinib induced significant reductions in PVL (21.0% and 17.5%, respectively) in live cells. Furthermore,ABL1siRNA transfection reduced cell viability in HTLV-1-infected cell lines, but not in uninfected cell lines. A retrospective survey based on our clinical records found a rare case of HAM/TSP who also suffered from CML. The patient showed an 84.2% PVL reduction after CML treatment with imatinib. We conclude that inhibiting the ABL1 tyrosine kinase specifically reduced the PVL in PBMCs from patients with HAM/TSP, suggesting thatABL1is an important gene for the survival of HTLV-1-infected cells and that TKIs may be potential therapeutic agents for HAM/TSP.Author summary Human T-cell leukemia virus type 1 (HTLV-1) is integrated as a provirus in the genomic DNA mainly of CD4+ T cell population in the infected people. HTLV-1-infected CD4+ T cells are transmitted via breast milk, semen, and blood transfusions. HTLV-1 is endemic in Japan, the Middle East, Africa, Caribbean islands, and Central and South America. A small proportion of infected people develop adult T-cell leukemia, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and other diseases. HAM/TSP, a chronic neuroinflammatory disorder, is characterized by spastic paraparesis and urinary disturbance. HTLV-1-infected CD4+ T cells infiltrate the spinal cord and cause inflammation, which results in such neurological symptoms. We have identified the tyrosine kinase geneABL1as a gene frequently found in the signal transduction pathways in HTLV-1-infected CD4+ T cells. Therefore,ABL1appears to be important in the pathogenesis of HAM/TSP. Inhibiting ABL1 with tyrosine kinase inhibitors (TKIs), which is used for chronic myelogenous leukemia (CML), reduced the proviral load (PVL)in vitro. We found a rare case of a patient with HAM/TSP and CML by our clinical records, who showed a decrease in PVL after TKI treatment for CML. Hence, TKIs are potential therapeutic agents for HAM/TSP.