Overproduction of recombinant human transforming growth factor beta 3 in Chinese hamster ovary cells

Transforming growth factor beta 3 (TGFβ3) is an important cytokine, functioning in cell proliferation and differentiation, and has been considered to have therapeutic potential for treating various diseases and for scar reduction in adult wound healing. In the current study, a Chinese hamster ovary (CHO) cell line overexpressing recombinant human TGFβ3 (rhTGFβ3) was established. Through a 15-day fed-batch culture process in a 7.5-l bioreactor (5-l working volume) using chemically defined medium, the established cells could produce over 133mg/l of rhTGFβ3 protein. The rhTGFβ3 was purified to homogeneity from the culture supernatant using a two-step chromatographic procedure, resulting in a recovery rate of approximately 65%, with protein purity greater than 97%. The N-terminal amino acid sequences of the purified rhTGFβ3 were confirmed by N-terminal sequencing analysis. The purified rhTGFβ3 was further demonstrated to be functionally active by measuring the inhibition of growth of HT-2 cells, revealing a half-maximal effective concentration of 42.11pg/ml and specific activity of 1.84×10(7)U/mg.