High level expression of C-terminal truncated recombinant chicken interferon-γ in baculovirus vector system

Abstract

Chicken interferon-γ (ChIFN-γ) was expressed by baculovirus in a C-terminal truncated form, namely ChIFN-γT, to accelerate the secretion of the expressed protein. It is also expressed as ChIFN-γT bearing poly His tag, ChIFN-γTHis, for easy purification. The expressed proteins were detected by SDS-PAGE analysis with Coomassie brilliant blue staining. The purified ChIFN-γTHis with nickel chelated column showed anti-viral activity in vitro and stimulation of the secretion of nitrogen intermediates such as nitric oxide in chicken peripheral blood mononuclear cells. Antiserum against ChIFN-γTHis recognized the 15 kDa, 16 kDa, and 32 kDa bands that seemed to be an unglycosylated monomer, a glycosylated monomer, and a homodimer of ChIFN-γTHis in the culture supernatant, respectively. The anti-serum also recognized around 14 kDa and 28 kDa bands in the sera of chickens or concanavalin A stimulated spleen cell culture supernatants that seemed to be monomeric and dimeric forms of a natural ChIFN-γ, respectively.