Cloning and Expression of the Chicken Interferon-γ Gene

Abstract

We have cloned the gene for chicken interferon-gamma (ChIFN-gamma) from a cDNA expression library generated from a T cell line (CC8.1h) that produces high levels of IFN-gamma activity. CC8.1h constitutively produces IFN activity that shares physiochemical properties with mammalian IFN-gamma. ChIFN-gamma, when secreted by CC8.1h or expressed in transfected COS cells, is heat labile, inactivated by exposure to pH 2, and capable of inducing nitrite production by chicken macrophages. These properties clearly distinguish it from chicken and mammalian type I IFN. The ChIFN-gamma gene codes for a predicted mature protein of 145 amino acids with a molecular mass of 16.8 kD. There are two potential N-glycosylation sites located near the N terminus. ChIFN-gamma protein shares significant amino acid homology with mammalian IFN-gamma proteins; in particular it also contains the highly conserved motifs that are present in all mammalian IFN-gamma proteins. ChIFN-gamma is 35 and 32% identical to the equine and human counterparts, respectively, but shares only 15% homology with chicken type I IFN. These findings show that the emergence of the two principal types of IFN predates the divergence of avians and mammals that occurred some 350 million years ago.

Control of poultry coccidiosis: changing trends

“…Interferon gamma, the important cytokine of Th1 pathway is considered to have adjuvant effect with an anti-coccidial vaccine. Chicken IFNc has been cloned and expressed (Digby and Lowenthal 1995), and treatment with recombinant IFNc alone has been shown to help in preventing reductions in body weight gain as well as oocysts output with E. acervulina and E. tenella infections. However, application of cytokines is not free from limitation and the cytokines are subjected to rapid degradation and clearance in vivo.…”

Differential Cytokine Responses following Marek's Disease Virus Infection of Chickens Differing in Resistance to Marek's Disease

“…This provides an opportunity to investigate the involvement of key cytokines in MD pathogenesis in the context of resistant and susceptible chicken genotypes. Chicken orthologues of the Th1 cytokines IFN-␥, IL-2, and IL-18 (18,50,56) and the proinflammatory cytokines IL-1␤ (61) and IL-6 (51) have been cloned and sequenced. IL-15 (37), which is closely related to IL-2, and the chemokine IL-8 (5, 55) have also been cloned and sequenced.…”

Cytokines and prevention of infectious diseases in poultry: A review

“…However, IFN-g is a pleiotropic molecule that has some involvement in most stages of the inflammatory and immune responses (Baron et al, 1987;Grossber, 1987;Farrar & Schreiber, 1993). Both type I and type II IFN have been cloned from the chicken (Sekellick et al, 1994;Digby & Lowenthal, 1995).…”

“…Because of the low level of sequence similarities between chicken and mammalian cytokine lack of avian bioassays and lack of cross-reactivity with antibodies to mammalian cytokines, only nine chicken cytokine genes have been cloned to date: type I (IFN-a/b) and type II (IFN-g) IFN (Sekellick et al, 1994;Digby & Lowenthal, 1995), IL-8 (Sugano et al, 1987;Bedard et al, 1993;, IL-2 (Sundick & Gill-Dixon, 1997; Kaiser & Mariani, 1999;Stepaniak et al, 1999), IL-15 (Sundick & Jones, 1996), the transforming growth factor family (Jakowlew et al, 1988a(Jakowlew et al, ,b,c, 1990, stem cell factor (Zhou et al, 1993;Bartunek et al, 1996), IL-1b (Weining et al, 1998), and myelomonocytic growth factor (cMGF) (Leutz et al, 1989). Of these, only IFN-a, IFN-g, and cMGF have been used in disease protection studies.…”