Increasing therapeutic applications for recombinant human interferon-γ (rhIFN-γ), an antiviral proinflammatory cytokine, has broadened interest in optimizing methods for its production and purification. We describe a reversed phase chromatography (RPC) procedure using Source-30 ™ matrix in the purification of rhIFN-γ from Escherichia coli that results in a higher yield than previously reported. The purified rhIFN-γ monomer from the RPC column is refolded in Tris buffer. Optimal refolding occurs at protein concentrations between 50-100 μg/ml. This method yields greater than 90% of the dimer form with a yield of 40 mg g −1 cell mass. Greater than 99% purity is achieved with further purification over a Superdex G-75 column to obtain specific activities of from 2 to 4 × 10 7 IU/mg protein as determined via cytopathic antiviral assay. The improved yield of rhIFN-γ in a simple chromatographic purification procedure promises to enhance the development and therapeutic application of this biologically potent molecule.

Fibrosis of the lung is a common endpoint for a variety of diseases. Current available treatments have been mostly ineffective. Proliferation of pulmonary fibroblasts, enhanced production of extracellular matrix components by these cells, and differentiation of fibroblasts to myofibroblasts results in tissue fibrosis. Curcumin, a component of the widely used Ayurvedic compound turmeric, is a potent biological molecule. Numerous studies have characterized its effects on a wide variety of cellular processes and diseases. Its potential role as a therapy for pulmonary fibrosis, however, remains undefined. In this study, we show that treatment of both normal human lung fibroblasts and those obtained from patients with idiopathic interstitial pneumonias (IIPs) results in inhibition of proliferative responses and induces cell cycle arrest. In addition, curcumin inhibits transforming growth factor (TGF)‐β1‐induced myofibroblast differentiation and collagen production. The effects of curcumin were demonstrated to occur, in part, through binding and activation of the nuclear receptor, peroxisome proliferator‐activated receptor‐γ (PPAR‐γ). These observations suggest a role for curcumin as a novel agent in the treatment of fibrotic lung diseases. Supported by NIH Grants HL70068, HL57243, and PO50HL60289.