Screening for deficits in DNA repair by the response of irradiated human lymphocytes to phytohemagglutinin.
Screening for deficits in DNA repair by the response of irradiated human lymphocytes to phytohemagglutinin.
复制标题
通过受辐射的人类淋巴细胞对植物血凝素的反应来筛选 DNA 修复缺陷。
作者：
S. Agarwal;D. Brown;E. Katz;L. Loeb
已经开发出一种测定人类淋巴细胞修复DNA损伤的能力的方法。在这个实验中，纯化的人淋巴细胞暴露在分级剂量的辐射中，然后用植物血凝素刺激进行DNA复制。在第二轮和随后的DNA复制过程中，胸腺嘧啶在受照射淋巴细胞中的掺入率被认为是细胞修复DNA损伤能力的指标。在正常人淋巴细胞中，剂量为100至800拉德的x射线照射可抑制植物血凝素刺激的胸苷结合，与辐射剂量成正比，而不会减少DNA聚合酶的诱导。在暴露于分级剂量的x射线照射后，发现色素性干皮病患者淋巴细胞对植物血凝素的反应与正常对照相似，而紫外线照射后的反应明显受损。相反，共济失调毛细血管扩张患者的淋巴细胞对x射线照射敏感。这些临床综合征的数据支持这种测定方法测量DNA修复的观点，并表明使用这种方法筛选DNA修复遗传缺陷个体的可行性。
An assay has been developed to measure the ability of human lymphocytes to repair damage to DNA. In this assay, purified human lymphocytes are exposed to graded doses of radiation and then stimulated with phytohemagglutinin to undergo DNA replication. The rate of incorporation of thymidine in irradiated lymphocytes during the second and subsequent rounds of DNA replication is taken to be indicative of the ability of the cells to repair damage to DNA. In lymphocytes from normal individuals, X-irradiation with doses of 100 to 800 rads was found to inhibit phytohemagglutinin-stimulated thymidine incorporation proportionally to the dose of radiation without curtailing the induction of DNA polymerase. The response to phytohemagglutinin of lymphocytes from a patient with xeroderma pigmentosum after exposure to graded doses of X-irradiation was found to be similar to that of the normal controls, whereas the response after ultraviolet irradiation was markedly impaired. In contrast, lymphocytes from patients with ataxia telangiectasia were hypersensitive to X-irradiation. The data on these clinical syndromes support the idea that this assay measures DNA repair and indicates the feasibility of using this method for screening individuals for genetic deficits in DNA repair.