Recombinant Human IFN-gamma

Interon-gamma (IFN-gamma), also known as type II or immune interferon, exerts a wide range of immunoregulatory activities and is considered to be the prototype proinflammatory cytokine ^{[1, 2]}. Mature human IFN-gamma exists as a non-covalently linked homodimer of 20-25 kDa variably glycosylated subunits ^[3]. It shares 90% amino acid (aa) sequence identity with rhesus IFN-gamma, 59%-64% with bovine, canine, equine, feline, and porcine IFN-gamma, and 37%-43% with cotton rat, mouse, and rat IFN-gamma. IFN-gamma dimers bind to IFN-gamma RI (alpha subunits) which then interact with IFN-gamma RII (beta subunits) to form the functional receptor complex of two alpha and two beta subunits. Inclusion of IFN-gamma RII increases the binding affinity for ligand and the efficiency of signal transduction ^{[4, 5]}.  IFN-gamma is produced by a variety of immune cells under inflammatory conditions, notably by T cells and NK cells ^[6]. It plays a key role in host defense by promoting the development and activation of Th1 cells, chemoattraction and activation of monocytes and macrophages, up-regulation of antigen presentation molecules, and immunoglobulin class switching in B cells. It also exhibits antiviral, antiproliferative, and apoptotic effects ^{[6, 7]}. In addition, IFN-gamma functions as an anti-inflammatory mediator by promoting the development of regulatory T cells and inhibiting Th17 cell differentiation ^{[8, 9]}. The pleiotropic effects of IFN-gamma contribute to the development of multiple aspects of atherosclerosis ^[7].

Reference

[1]. Billiau, A. and P. Matthys (2009) Cytokine Growth Factor Rev. 20:97.

[2]. Pestka, S. et al. (2004) Immunol. Rev. 202:8.

[3]. Gray, P.W. and D.V. Goeddel (1982) Nature 298:859.

[4]. Marsters, S.A. et al. (1995) Proc. Natl. Acad. Sci. 92:5401.

[5]. Krause, C.D. et al. (2000) J. Biol. Chem. 275:22995.

[6]. Schroder, K. et al. (2004) J. Leukoc. Biol. 75:163.

[7]. McLaren, J.E. and D.P. Ramji (2009) Cytokine Growth Factor Rev. 20:125.

[8]. Muhl, H. and J. Pfeilschifter (2003) Int. Immunopharmacol. 3:1247.

[9]. Kelchtermans, H. et al. (2008) Trends Immunol. 29:479.