Holán V, Lipoldová M, Takác M, Cerná J, Vancatová A, Cechová D, Veselský L, Hasek M
Immunology. 1985 Oct;56(2):275-83.
A permanent cell line designated SL4c has been established from a primary culture of murine BALB/c spleen cells regularly stimulated with large doses of irradiated allogeneic cells plus exogenous interleukin-2(IL-2). After 8 months of cultivation, the cells of the SL4c line proliferate spontaneously and do not respond with an increase in proliferation to alloantigenic stimulation. The cells have the Lyt 1.2+, Lyt 2.2-, L3T4a+, Thy 1.2+ phenotype and exert a strong suppressive effect upon stimulation with freshly explanted cells. The SL4c line produces a suppressor factor (SF4c), which inhibits the mitogen-induced proliferation of normal lymphoid cells but does not suppress the proliferation of fibroblasts and sarcoma cells. The suppression is antigen non-specific, is not limited by H-2 restriction nor by interspecies barrier, and is not due to cytotoxic effect. However, the suppression is only detectable if the SF4c is added to the stimulated cells during the early stages of mitogen-induced proliferation. A tentative characterization of the relative molecular weight (MW) of the suppressor molecule based upon fractionation of SF4c supernatant on a Sepharose 6B column shows that the inhibitory activity is confined to the high MW fractions (300,000-350,000). Translation material obtained from Xenopus laevis oocytes, which were injected with RNA preparations isolated from SL4c cells, also shows the suppressive effect.
一个名为SL4c的永久性细胞系是从小鼠BALB/c脾细胞的原代培养物中建立的，该原代培养物用大剂量经辐照的同种异体细胞加外源性白细胞介素-2（IL-2）定期刺激。培养8个月后，SL4c系细胞自发增殖，对同种抗原刺激不再出现增殖增加反应。这些细胞具有Lyt 1.2+、Lyt 2.2-、L3T4a+、Thy 1.2+表型，对新鲜分离的细胞刺激具有强烈的抑制作用。SL4c系产生一种抑制因子（SF4c），它能抑制正常淋巴细胞由丝裂原诱导的增殖，但不抑制成纤维细胞和肉瘤细胞的增殖。这种抑制作用是非抗原特异性的，不受H-2限制，也不受种间屏障限制，且不是由细胞毒性作用引起的。然而，只有在丝裂原诱导增殖的早期阶段将SF4c加入受刺激细胞时，才能检测到这种抑制作用。基于在琼脂糖6B柱上对SF4c上清液进行分级分离对抑制分子相对分子量（MW）的初步表征表明，抑制活性局限于高分子量组分（300,000 - 350,000）。从注射了从SL4c细胞分离的RNA制剂的非洲爪蟾卵母细胞获得的翻译产物也显示出抑制作用。
