过量表达XBP1对于重组CHO细胞中HBsAg分泌的影响

考察了过量表达CHO细胞的内源性XBP1(X-box binding protein 1)对于重组CHO细胞中乙肝表面抗原(HBsAg)分泌的影响。结果表明:XBP1无法改善DMSO作用下CHO细胞中HBsAg的分泌,但能促进DTT作用下的HBsAg的分泌。进一步研究发现,细胞在DTT作用下形成了内质网分泌压力,而在DMSO作用下,没有形成内质网分泌压力。由此推断在内质网成为分泌限制部位的情况下,XBP1能够促进HBsAg的分泌;而DMSO通过促进二硫键的形成促进了HBsAg在内质网中的分泌,使得分泌限制部位发生在分泌过程中的其他细胞器。

Effects of XBP1 Overexpression on HBsAg Secretion in Recombinant CHO Cells

The effects of endogenous XBP1 (X-box binding protein 1) overexpression on HBsAg secretion in CHO cells were first tested.However, no improvement was observed with DMSO.But HBsAg secretion was significantly enhanced with DTT, an inducer of ER stress response.Further analysis showed that DMSO did not trigger the ER stress response.The function of XBP1 in facilitating protein secretion depended on whether the protein expression resulted in secretory saturation in ER.On the contrary, the presence of DMSO was able to improve HBsAg folding and facilitate it passing through ER, and caused secretory saturation in other organelle of secretory pathway.