PTPN21-CDSlong isoform inhibits the response of acute lymphoblastic leukemia cells to NK-mediated lysis via the KIR/HLA-I axis
PTPN21-CDSlong isoform inhibits the response of acute lymphoblastic leukemia cells to NK-mediated lysis via the KIR/HLA-I axis
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PTPN21-CDSlong 亚型通过 KIR/HLA-I 轴抑制急性淋巴细胞白血病细胞对 NK 介导的裂解反应
DOI：
10.1002/jcb.29601
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发表时间：
2020
影响因子：
4
通讯作者：
Huang He
中科院分区：
文献类型：
--
作者：
Wang Huafang;Zhu Ni;Ye Xiaohang;Wang Limengmeng;Wang Binsheng;Shan Wei;Lai Xiaoyu;Tan Yamin;Fu Shan;Xiao Haowen;Huang He
蛋白酪氨酸磷酸酶21(PTPN21)是非受体酪氨酸磷酸酶家族的成员。我们发现，在异基因造血干细胞移植后复发的费城染色体阴性急性淋巴细胞白血病(ALL)中，PTPN21发生了突变。根据编码蛋白质的长度，PTPN21由三种类型的异构体组成。然而，不同亚型在白血病细胞中的作用尚未阐明。本研究通过逆转录聚合酶链式反应结合Sanger测序鉴定了5株ALL细胞中PTPN21亚型的组成，并通过CRISPR-Cas9技术敲除不同亚型的PTPN21亚型，进一步探讨了PTPN21亚型与自然杀伤(NK)细胞介导的杀伤敏感性之间的关系。随后，我们通过RNA测序和验证性实验对其作用机制进行了探讨。结果表明，PTPN21亚型在所有细胞中均被敲除，但PTPN21-CDSlong敲除的NALM6细胞(NALM6-PTPN21(Lk))对NK介导的杀伤的敏感性显著增加。全转录组测序和进一步的验证测试表明，NALM6-PTPN21(Lk)细胞中人类白细胞抗原I类(HLA-I)分子显著减少，并伴随着抗原提呈相关伴侣蛋白的表达显著下调。我们的结果揭示了一个先前未知的机制，即PTPN21-CDSlong和CDSort亚型在所有细胞的NK介导的杀伤中可能发挥相反的作用，并表明内源性PTPN21-CDSlong亚型通过调节KIR-HLA-I轴抑制所有细胞对NK细胞介导的杀伤。
Protein tyrosine phosphatase non-receptor type 21 (PTPN21) is a member of the non-receptor tyrosine phosphatase family. We have found that PTPN21 is mutated in relapsed Philadelphia chromosome-negative acute lymphoblastic leukemia (ALL) after allogeneic hematopoietic stem cell transplantation. PTPN21 consists of three types of isoforms according to the length of the protein encoded. However, the roles of different isoforms in leukemic cells have not been elucidated. In the study, PTPN21 isoform constitution in five ALL cell lines were identified by transcriptome polymerase chain reaction combined with Sanger sequencing, and the relationship between PTPN21 isoforms and sensitivity to natural killer (NK) cells mediated killing in ALL cell lines were further assessed by knock-out of different isoforms of PTPN21 using CRISPR-Cas9 technique. Subsequently, we explored the functional mechanisms through RNA sequencing and confirmatory testing. The results showed that there was no significant change when all PTPN21 isoforms were knocked out in ALL cells, but the sensitivity of NALM6 cells with PTPN21-CDSlong knock-out (NALM6-PTPN21(lk)) to NK-mediated killing was significantly increased. Whole transcriptome sequencing and further validation testing showed that human leukocyte antigen class I (HLA-I) molecules were significantly decreased, accompanied by a significantly downregulated expression of antigen presenting-related chaperones in NALM6-PTPN21(lk) cells. Our results uncovered a previously unknown mechanism that PTPN21-CDSlong and CDSshort isoforms may play opposite roles in NK-mediated killing in ALL cells, and showed that the endogenous PTPN21-CDSlong isoform inhibited ALL cells to NK cell-mediated lysis by regulating the KIR-HLA-I axis.