K562细胞导入IL-2基因后的细胞凋亡

应用逆转录病毒载体介导人白细胞介素2(IL-2)基因转入人红白血病细胞系K562并获得表达。IL-2基因修饰的细胞发生了明显的形态学改变,胞质空泡化,胞浆嗜碱性减弱,核出现分叶现象,同时可见部分细胞核染色质凝集于核内膜处,核膜完整,细胞器保存完好,并可见细胞的发疱现象,提示IL-2基因转导可诱导K562细胞凋亡。

APOPTOSIS OF K562 CELLS TRANSDUCED WITH IL-2 GENE

Human interleukin-2 gene was transferred into human erythroleukemic cell line K562 by retroviral vector. Integration of the foreign gene was confirmed by PCR amplification with neo gene. Using MTT method and IL-2-dependent cell line CTLL-2, IL-2 specific activity was detected as 5-10 units/ 106 cells/24hr in the supernatant of the transduced K562 cell culture. The IL-2 gene-modified K562 celis showed striking morphological changes with their increased celi size. Condensation and margination of chromatin along with cytoplasmic vacuolization and blebbing followed by nuclear lobulation were remarkable under electron microscope while mitbtic figures were very rare. A typical DNA ladder from transduced celis was found in electrophoresis. The results suggested that apoptosis in the transduced K562 cells would be induced by IL-2 gene transfer. Other than the drastic morphological changes, the immunophenotypic change might be involved as well in the celis fonvards apoptosis which prob-ably prevented the IL-2 gene-modified K562 celis from being recognized by LAK cells in our experiments. The transduced celis showed low susceptibility to LAK activity.