Macfarlane D E, Manzel L, Krieg A M
Department of Medicine, Veterans Administration Hospital, USA.
Immunology. 1997 Aug;91(4):586-93. doi: 10.1046/j.1365-2567.1997.00301.x.
Certain oligodeoxynucleotides (ODN) containing cytosine followed by guanosine (CpG) protect B cells from apoptosis, and induce B-cell proliferation and cytokine production. We investigated the effect of phosphorothioate CpG-containing ODNs (5'-ATAATCGACGTTCAAGCAAG-3' or 5'-TCCATGACGTTCCTGACGTT-3') and control ODNs (which did not contain CpG) on apoptosis and cell growth in WEHI 231 murine B lymphoma cells. Anti-surface (alpha-s)IgM antibody induces 40-60% DNA degradation and growth arrest of WEHI 231 cells in 24 h. Both of these effects were substantially reversed by 30 ng/ml CpG-ODN added up to 8 hr after alpha-sIgM. Control ODNs not containing the CpG motif were without effect. We explored various hypotheses to account for these effects. The phorbol ester, 12-O-tetradecanoyl phorbol-13-acetate, inhibits apoptosis induced by alpha-sIgM, but the anti-apoptotic effect of CpG-ODN was not affected by inhibitors of protein kinase C, indicating that CpG-ODN does not act via protein kinase C. CpG-ODN inhibited apoptosis and growth arrest induced by C2- and C8-ceramide, sphingomyelinase and an intracellular Ca2+ pump inhibitor thapsigargin, indicating that inhibition is not mediated via suppression of the ceramide cycle or suppression of Ca2+ mobilization. CpG-ODN partially inhibited apoptosis induced by okadaic acid, a protein phosphatase inhibitor, and by menadione, a free radical generator. CpG-ODN also inhibited apoptosis and growth arrest induced by ultraviolet-irradiation, glucocorticoid, vinca alkaloids, and doxorubicin. CpG-ODN significantly protected cells from DNA fragmentation induced by alpha-sIgM in the presence of cycloheximide, but cycloheximide itself induces apoptosis which was unaffected by CpG-ODN. These results suggest that CpG-ODNs powerfully modulate the process by which immune cells are committed to death or proliferation by a mechanism acting on distal cell signalling events. CpG-ODNs may be able to decrease immunosuppression in patients undergoing cancer chemotherapy.
某些含有胞嘧啶后接鸟苷（CpG）的寡脱氧核苷酸（ODN）可保护B细胞免于凋亡，并诱导B细胞增殖和细胞因子产生。我们研究了含硫代磷酸酯CpG的ODN（5'-ATAATCGACGTTCAAGCAAG-3'或5'-TCCATGACGTTCCTGACGTT-3'）和对照ODN（不含CpG）对WEHI 231小鼠B淋巴瘤细胞凋亡和细胞生长的影响。抗表面（α-s）IgM抗体在24小时内可诱导40-60%的WEHI 231细胞DNA降解和生长停滞。在α-sIgM作用后长达8小时添加30 ng/ml的CpG-ODN可使这两种效应显著逆转。不含CpG基序的对照ODN则无此作用。我们探讨了各种假说来解释这些效应。佛波酯12-O-十四酰佛波醇-13-乙酸酯可抑制α-sIgM诱导的凋亡，但CpG-ODN的抗凋亡作用不受蛋白激酶C抑制剂的影响，这表明CpG-ODN并非通过蛋白激酶C起作用。CpG-ODN可抑制由C2-和C8-神经酰胺、鞘磷脂酶及细胞内Ca2+泵抑制剂毒胡萝卜素诱导的凋亡和生长停滞，这表明其抑制作用并非通过抑制神经酰胺循环或抑制Ca2+动员介导。CpG-ODN可部分抑制蛋白磷酸酶抑制剂冈田酸及自由基生成剂甲萘醌诱导的凋亡。CpG-ODN还可抑制紫外线照射、糖皮质激素、长春花生物碱及阿霉素诱导的凋亡和生长停滞。在存在环己酰亚胺的情况下，CpG-ODN可显著保护细胞免受α-sIgM诱导的DNA片段化，但环己酰亚胺本身诱导的凋亡不受CpG-ODN影响。这些结果表明，CpG-ODN通过作用于远端细胞信号事件的机制，有力地调节免疫细胞走向死亡或增殖的过程。CpG-ODN或许能够减轻接受癌症化疗患者的免疫抑制。
