重组人粒细胞集落刺激因子

G-CSF is a pleiotropic cytokine best known for its specific effects on the proliferation, differentiation, and activation of hematopoietic cells of the neutrophilic granulocyte lineage. It is produced mainly by monocytes and macrophages upon activation by endotoxin, TNF-a and IFN-g. Other cell types including fibroblasts, endothelial cells, astrocytes and bone marrow stromal cells can also secrete G-CSF after LPS, IL-1 or TNF-a activation. In addition, various carcinoma cell lines and myeloblastic leukemia cells can express G-CSF constitutively. In humans, two distinct cDNA clones for G-CSF, encoding 207 and 204 amino acid precursor proteins, have been isolated. Both proteins have a 30 amino acid signal peptide and have identical amino acid sequences except for a three amino acid insertion (deletion) at the 35th amino acid residue from the N-terminus of the mature protein. Human G-CSF is 73% identical at the amino acid level to murine G-CSF and the two proteins show species cross-reactivity.

G-CSF是一种具有多效性的细胞因子，主要因其对中性粒细胞谱系造血细胞的增殖、分化及活化的特异性调控作用而广为人知。G-CSF主要由单核细胞和巨噬细胞在内毒素、TNF-α和IFN-γ刺激下产生。除上述细胞外，成纤维细胞、内皮细胞、星形胶质细胞以及骨髓基质细胞等，在LPS、IL-1或TNF-α刺激下也可分泌G-CSF。此外，多种癌细胞系及髓母细胞性白血病细胞亦可持续表达G-CSF。

在人类中，已分离获得两种不同的G-CSF cDNA克隆，分别编码207个和204个氨基酸的前体蛋白。这两种蛋白均含有30个氨基酸的信号肽，其成熟蛋白序列仅在N端第35位氨基酸处存在3个氨基酸的插入（或缺失）差异。人源G-CSF与小鼠G-CSF在氨基酸序列上具有约73%的同源性，并且两者之间存在跨物种反应性。