Intracellular single-chain antibody inhibits integrin VLA-4 maturation and function.
Intracellular single-chain antibody inhibits integrin VLA-4 maturation and function.
复制标题
细胞内单链抗体抑制整合素 VLA-4 的成熟和功能。
DOI：
10.1042/bj3180591
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Hemler,ME
中科院分区：
文献类型：
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作者：
Yuan,Q;Strauch,KL;Lobb,RR;Hemler,ME
制备含有抗（整联蛋白α4）抗体HP 1/2的VHand VL区、链间接头和KDEL内质网滞留序列的单链抗体构建体。相对于模拟转染子，该单链抗体的细胞内表达导致选定RD细胞上α4β 1整合素的细胞表面表达降低80%，选定Jurkat细胞上α4β 1整合素的细胞表面表达降低65-100%。单链抗体转染细胞的免疫沉淀显示单链抗体与整合素α 4和β 1亚基形成复合物，α 4和β 1亚基的减少与成熟受损一致。此外，RD和Jurkat细胞与α4β 1配体[VCAM-1（血管细胞粘附分子-1），FN 40（纤连蛋白的40 kDa糜蛋白酶片段）和CS 1]的粘附大大受损，固定化FN 40蛋白上的细胞铺展几乎完全消除。因此，我们得出结论，细胞内单链抗体可用于减少或消除特定整合素的细胞表面表达，具有特定的功能后果。这种方法应该普遍适用于其他整合素亚基。
A single-chain antibody construct was prepared containing the VHand VLregions of anti-(integrin α4) antibody HP1/2, an interchain linker and a KDEL endoplasmic reticulum retention sequence. Intracellular expression of this single-chain antibody caused cell-surface expression of α4β1integrin to be decreased by 80% on selected RD cells and by 65–100% on selected Jurkat cells, relative to mock transfectants. Immunoprecipitation from single-chain-antibody-transfected cells showed that the single-chain antibody was complexed with the integrin α4and β1subunits, and the diminished sizes of α4and β1were consistent with impaired maturation. Furthermore, cell adhesion to α4β1ligands [VCAM-1 (vascular cell adhesion molecule-1), FN40 (40 kDa chymotryptic fragment of fibronectin) and CS1] was greatly impaired in both RD and Jurkat cells, and cell spreading on immobilized FN40 protein was almost completely eliminated. Thus we conclude that intracellular single-chain antibodies may be used to reduce or eliminate cell-surface expression of a specific integrin, with specific functional consequences. This approach should be generally applicable to other integrin subunits.