Castellanos G, Owens T, Rudd C, Bladon T, Kaplan J G
Can J Biochem. 1982 Sep;60(9):854-60. doi: 10.1139/o82-108.
Low doses (30-84 ergs/mm2, 1 erg = 10(7) J) of ultraviolet radiation (UV) caused severe inhibition of the proliferation of human lymphocytes in vitro. Greatest inhibition was produced when resting cells were irradiated immediately prior to stimulation with concanavalin A (Con A); this was true whether activation was measured by the incorporation of labelled leucine, uridine, or thymidine. If UV was applied at 44 h after culture in presence of Con A, the incorporation of [3H]thymidine measured 4 h later was seen to be inhibited but transcription and translation were scarcely affected. UV, applied after the appearance of the Con A induced thymidine transport system, did not inhibit its function. The disaggregation of chromatin and increase in nuclear volume characteristic of, and essential to, the proliferative response of lymphocytes were completely inhibited if the cells were irradiated before mitogen was added to the cultures, but were unaffected if irradiation occurred after 16 h of culture in presence of Con A. Cells irradiated with 84 ergs/mm2 at the onset of culture with mitogen did not show the early increase of cation pump function which is a characteristic of stimulated lymphocytes, when this was measured by means of 86Rb uptake after 2-4 h culture. The mitogen-stimulated activation of cation pump function has previously been shown to be unaffected by concentrations of cycloheximide and actinomycin D which produce virtually complete inhibition of protein and RNA synthesis, respectively. The major inhibitory effect of UV treatment of lymphocytes at onset of culture with Con A is therefore not on DNA or on DNA synthesis, but on some component(s) of the early activation process, possibly at the cell periphery; inactivation of this component prevents cells from proceeding into later stages of the proliferative pathway.
低剂量（30 - 84尔格/平方毫米，1尔格 = 10⁻⁷焦耳）的紫外线辐射（UV）在体外会严重抑制人淋巴细胞的增殖。当静止细胞在用伴刀豆球蛋白A（Con A）刺激前立即受到照射时，抑制作用最强；无论通过标记亮氨酸、尿苷或胸苷的掺入来测量激活情况，都是如此。如果在Con A存在下培养44小时后施加UV，4小时后测量的[³H]胸苷掺入受到抑制，但转录和翻译几乎不受影响。在Con A诱导的胸苷转运系统出现后施加UV，并不抑制其功能。如果在向培养物中添加促有丝分裂原之前照射细胞，淋巴细胞增殖反应所特有的染色质解聚和核体积增加会被完全抑制，但如果在Con A存在下培养16小时后进行照射，则不受影响。在用促有丝分裂原开始培养时用84尔格/平方毫米照射的细胞，在培养2 - 4小时后通过⁸⁶Rb摄取测量时，未显示出受刺激淋巴细胞特有的阳离子泵功能早期增加。先前已表明，促有丝分裂原刺激的阳离子泵功能激活不受环己酰亚胺和放线菌素D浓度的影响，而这两种物质分别几乎完全抑制蛋白质和RNA合成。因此，在用Con A开始培养时对淋巴细胞进行UV处理的主要抑制作用不是对DNA或DNA合成，而是对早期激活过程的某些成分，可能是在细胞周边；该成分的失活阻止细胞进入增殖途径的后期阶段。
