人胎肝FLT3配基膜外区基因的克隆及其在COS-7细胞中的表达

Cloning of cDNA for Putative Extracellular Region of Human FLT3 Ligand from Fetal Liver and Its Expression in COS - 7 Cells

FLT3是表达于造血干、祖细胞及胎盘、脑和睾丸等组织的一种Ⅲ型酪氨酸激酶受体。FLT3配基(FL)对造血祖细胞有协同刺激作用。本研究用反转录-聚合酶链反应(RT-PCR)方法从胎肝组织克隆了FL膜外片段cDNA,其序列与从T淋巴细胞系及胸腺基质细胞系中获得的FL克隆序列完全相同。用真核细胞表达载体pCMV4在COS-7细胞中表达了FL膜外片段。重组人FL(rhFL)可协同GM-CSF增加骨髓细胞中CFU-GM的产率。

The FLT3 receptor tyrosine kinase is present mainly on primitive hematopoietic cell populations, brain, placenta and testis. The ligand for FLT3/FLK2 (FL) stimulates, the proliferation of primitive hematopoietic celis. By using reverse transcription- PCR approaches, cDNA for putative extracellular region of human FL was cloned from fetal li ver. The sequence of the clone is identi cal with its counter-part form from T lymphocytes and thymic stromal celis. The FL cDNA was cloned into pCMV4 ex-pression vector and expressed in COS - 7 cells. Recombinant human FL (rhFL) increased both the number and size of CFU - GM colonies stimulated by GM - CSF.