Identification of an overexpressed gene, HSPA4L, the product of which can provoke prevalent humoral immune responses in leukemia patients
Identification of an overexpressed gene, HSPA4L, the product of which can provoke prevalent humoral immune responses in leukemia patients
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DOI：
10.1016/j.exphem.2007.03.015
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发表时间：
2007-07-01
影响因子：
2.6
通讯作者：
Aizawa, Yoshifusa
中科院分区：
文献类型：
--
作者：
Takahashi, Hidenobu;Furukawa, Tatsuo;Aizawa, Yoshifusa
目标。为了鉴定白血病相关抗原，我们应用重组表达克隆(SEREX)方法对1例对干扰素-α有细胞遗传学反应的慢性粒细胞白血病(CML)患者进行了抗原的血清学鉴定。用1例慢性粒细胞白血病患者的血清对文库进行免疫筛选。用两种分离的抗原通过Northern印迹分析和定量逆转录聚合酶链式反应来评价表达模式。采用Western blotting和酶联免疫吸附试验进行血清学分析。我们鉴定了14个阳性克隆，分别代表5种不同的抗原。在这些基因中，有两个基因被进一步验证。其中一个克隆(克隆70)是人多核苷酸核苷酸转移酶1(PNPT1)，它是I型干扰素(α/β反应基因)。克隆70的mRNA在正常人体组织中普遍表达。另一个基因(克隆57)是类热休克蛋白(HSPA4L)，属于热休克蛋白110家族成员，其mRNA在正常人睾丸中高表达，在白血病细胞中高表达。9例急性髓系白血病患者中有6例检测到HSPA4L抗体，10例急性淋巴细胞白血病患者中有4例检测到HSPA4L抗体，11例CML患者中有9例检测到HSPA4L抗体，10例健康志愿者中未检测到HSPA4L抗体。白血病患者抗该蛋白抗体效价高于健康志愿者。这些结果表明，HSPA4L是热休克蛋白的一员，在白血病细胞中高度表达，并能诱导白血病患者产生体液免疫反应，可能成为抗白血病治疗和白血病抗原特异性免疫治疗的潜在靶点。
Objective. To identify leukemia-associated antigens, we applied the serological identification of antigens by the recombinant expression cloning (SEREX) method to a chronic myelogenous leukemia (CML) patient who achieved a cytogenetic response to interferon-alpha.Materials and Methods. Immunoscreening of the cDNA library was performed with sera from a CML patient. Two isolated antigens were used to evaluate the expression pattern using Northern blot analysis and quantitative reverse transcriptase polymerase chain reaction. Western blotting and enzyme-linked immunosorbent assay were also performed for serological analysis.Results. We identified 14 positive clones, representing five different antigens. Of these, two genes were further validated. One (clone 70) was the human polyribonucleotide nucleotidyltransferase 1 (PNPT1), which is the type I interferon (alpha/beta-responsive gene). The mRNA of clone 70 was ubiquitously expressed in normal human tissues. The other gene (clone 57) was the heat shock 70-kDa protein 4-like (HSPA4L), which is a member of the heat shock protein 110 family, whose mRNA is strongly expressed in normal human testis and overexpressed in leukemia cells. Seroactivity against HSPA4L was detected in 6 of 9 acute myeloid leukemia patients, 4 of 10 acute lymphoblastic leukemia patients, 9 of 11 CML patients, and none of 10 healthy volunteers. Leukemia patients had higher titer of the antibodies against the protein than healthy volunteers.Conclusions. These results suggest that HSPA4L, a member of heat shock protein, is highly expressed by leukemia cells, and elicit humoral immune responses in leukemia patients, and it might be a potential target for antileukemia therapy and an antigen-specific immunotherapy for leukemia.