2. Lactoferrin
Lactoferrin (Lf) is a highly conserved pleiotropic iron-binding glycoprotein of the transferrin family that is expressed and secreted by glandular cells and found in most body fluids (Levay & Viljoen, 1995)⁠. It appears in especially high concentrations in mammalian milk and was first identified in bovine milk (Soerensen, M, 1939)⁠ and subsequently isolated from human milk (Johanson et al., 1960). It has been found to be a 80-kDa glycoprotein containing 703 amino acid residues, and its primary structure has been well characterized (Jolles et al., 1984).
Since its discovery, Lf and its related peptides are mainly considered to be important non-specific host defense molecules against a variety of pathogens including a spectrum of viruses (Bruni et al., 2016). More recently, Lf’s anti-inflammatory and immunomodulatory role has captured increasing scientific interest, since it appears to be able to moderate host response to infections and has the dual ability to stimulate the immune system to counteract pathogenic invasion while simultaneously preventing harmful host immune and inflammatory responses.