Norimura T, Maher V M, McCormick J J
Department of Microbiology, Michigan State University, East Lansing 48824-1316.
Mutagenesis. 1990 Sep;5(5):447-51. doi: 10.1093/mutage/5.5.447.
The cytotoxic and mutagenic effects of a series of carcinogenic mutagens in human peripheral blood T cells exposed in culture were determined and compared with results obtained previously with diploid human skin fibroblasts. The mutagens studied were: ethylnitrosourea (ENU), (+/-)-7 beta,8 alpha-dihydroxy-9 alpha,10 alpha-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE) and UV (254 nm) radiation. Resistance to 6-thioguanine (TG) served as the genetic marker. The T lymphocytes, cultured in the presence of 10% fetal bovine serum, T cell growth factor and lethally-irradiated B lymphoblastoid cells (allogeneic stimulators), exhibited population doubling times of 22 h for as long as tested, i.e. greater than 40 days, and cloning efficiencies between 30 and 50%. The T cells were exposed to the mutagens in exponential growth, 3 days after being isolated and primed to begin blast formation, using doses that reduced cell survival to between 80 and 25% of the untreated control. The background frequency of TG-resistant cells in the 14 independent populations assayed ranged from 1.2 x 10(-6) to 10.6 x 10(-6), with an average of 5.1 x 10(-6) +/- 2.8 x 10(-6). Each agent induced a dose-dependent increase in TG-resistant cells, reaching 85 x 10(-6) for UV, 260 x 10(-6) for ENU and 70 x 10(-6) for BPDE. When compared on the basis of fluence or applied concentration, T cells were 1.5-times more sensitive than fibroblasts to the cytotoxic effects of ENU, but equally as sensitive as fibroblasts to its mutagenic effects.(ABSTRACT TRUNCATED AT 250 WORDS)
测定了一系列致癌诱变剂在体外培养的人外周血T细胞中的细胞毒性和诱变效应，并与之前用人二倍体皮肤成纤维细胞获得的结果进行了比较。所研究的诱变剂有：乙基亚硝基脲（ENU）、（±）-7β，8α-二羟基-9α，10α-环氧-7，8，9，10-四氢苯并[a]芘（BPDE）和紫外线（254nm）辐射。对6-硫代鸟嘌呤（TG）的抗性作为遗传标记。在10%胎牛血清、T细胞生长因子和经致死剂量照射的B淋巴母细胞（同种异体刺激物）存在的情况下培养的T淋巴细胞，在长达40多天的测试期内群体倍增时间为22小时，克隆效率在30%至50%之间。T细胞在分离并启动转化为母细胞3天后处于指数生长期时暴露于诱变剂，使用的剂量可使细胞存活率降至未处理对照的80%至25%。在测定的14个独立群体中，对TG耐药细胞的背景频率范围为1.2×10⁻⁶至10.6×10⁻⁶，平均为5.1×10⁻⁶±2.8×10⁻⁶。每种诱变剂都诱导了对TG耐药细胞的剂量依赖性增加，紫外线诱导的达到85×10⁻⁶，ENU诱导的达到260×10⁻⁶，BPDE诱导的达到70×10⁻⁶。基于通量或应用浓度进行比较时，T细胞对ENU细胞毒性作用的敏感性比成纤维细胞高1.5倍，但对其诱变作用的敏感性与成纤维细胞相同。（摘要截于250字）
