Gene cloning of a novel fungal immunomodulatory protein from Chroogomphis rutilus and its expression in Pichia pastoris

BACKGROUND: Fungal immunomodulatory proteins (FlPs) are a newly identified protein family that exhibits immunomodulation and antitumor activities. However, little is known about the FlPs from Gomphidiaceae species. In this study, a novel FIP gene termed FIP-cru was cloned from Chroogomphis rutilus, analyzed, and functionally expressed in Pichia pastoris GS115.In addtion, the bioactivity of rFIP-cru was examined including hemagglutination, cytotoxicity, and interleukin-2 assays in vitro. RESULTS: FIP-cru comprised 342 bp and encoded a peptide of 113 amino acids, which shared a high homology to other FlPs. rFIP-cru was obtained by expressing the recombinant gene in P. pastoris GS115, with a yield of 148.5 mg L-1, and then purified via ammonium sulfate precipitation and agarose nickel magnetic nanobeads. The bioactivity assay showed that rFIP-cru can agglutinate mouse and sheep red blood cells but not human cells. Additionally, rFIP-cru can stimulate the proliferation of murine splenocytes and enhance the secretion of interleukin-2. CONCLUSION: FIP-cru is a novel fungal immunomodulatory protein. The use of P. pastoris as an expression system will provide a feasible production method to obtain large amounts of rFIP-cru to study its potential application in therapeutic and medical studies. (C) 2016 Society of Chemical Industry