Danielpour D, Dart L L, Flanders K C, Roberts A B, Sporn M B
Laboratory of Chemoprevention, National Cancer Institute, Bethesda, Maryland 20892.
J Cell Physiol. 1989 Jan;138(1):79-86. doi: 10.1002/jcp.1041380112.
Transforming growth factor beta (TGF-beta), a potent modulator of cell growth, differentiation, and the expression of extracellular matrix components in a variety of cell types, exists as two distinct homodimers (TGF-beta 1 and TGF-beta 2), sharing 71% sequence homology. Radioreceptor and previously described radioimmunological assays using rabbit antibodies have not been able to distinguish between these two forms. We have developed antisera in turkeys against native TGF-beta 1 and TGF-beta 2, each of which specifically blocks both the receptor binding and biological activity of each of these peptides. With these immunological reagents we describe sensitive and specific immunological assays for TGF-beta 1 and TGF-beta 2 in complex biological fluids. Using these assays we show that both TGF-beta 1 and TGF-beta 2 are secreted by a variety of cultured cells, but that some cells secrete predominantly either TGF-beta 1 or TGF-beta 2 while others secrete both peptides in nearly equal amounts. Our results demonstrate that the expression of each of the two forms of TGF-beta is independently regulated.
转化生长因子β（TGF-β）是细胞生长、分化以及多种细胞类型中细胞外基质成分表达的强效调节剂，它以两种不同的同二聚体（TGF-β1和TGF-β2）形式存在，序列同源性为71%。放射性受体以及先前使用兔抗体描述的放射免疫测定法无法区分这两种形式。我们已在火鸡中制备了针对天然TGF-β1和TGF-β2的抗血清，其中每一种都能特异性阻断这些肽各自的受体结合和生物学活性。利用这些免疫试剂，我们描述了用于复杂生物流体中TGF-β1和TGF-β2的灵敏且特异的免疫测定法。使用这些测定法，我们表明TGF-β1和TGF-β2均由多种培养细胞分泌，但有些细胞主要分泌TGF-β1或TGF-β2，而其他细胞则以几乎相等的量分泌这两种肽。我们的结果表明，TGF-β两种形式各自的表达是独立调节的。
