Lactoferrin, a versatile natural antimicrobial glycoprotein that modulates the host's innate immunity

Lactoferrin is a multifunctional protein found in the secretions of mammals. The antimicrobial activity of lactoferrin was the first to be discovered and was assumed to be solely dependent on its iron-chelating ability. However, lactoferrin has been reported to display proteolytic activity towards bacterial virulence factors and to modulate the host defence by stimulating the immune system and balancing pathogen-induced inflammation. Here, we review the current understandings of the antimicrobial effect, interaction with host cells, and innate immune modulation of lactoferrin, and put forward this moonlighting protein as a possible alternative for antibiotics. Key words: lactoferrin, antimicrobial, proteolytic activity, immunomodulation. La lactoferrine est une proteine multifonctionnelle presente dans les secretions des mammiferes. L'activite antimicrobienne de la lactoferrine a ete la premiere a etre decouverte et on a presume qu'elle dependait uniquement de sa capacite a chelater le fer. Cependant, il s'est avere que la lactoferrine presentait une activite proteolytique envers des facteurs de virulence bacteriens et qu'elle modulait la defense de l'hote en stimulant le systeme immunitaire et en equilibrant l'inflammation induite par les agents pathogenes. Les auteurs font ici la synthese des connaissances actuelles sur l'effet antimicrobien, l'interaction avec les cellules de l'hote et la modulation immunitaire innee de la lactoferrine, et presentent cette proteine aux activites secondaires multiples comme solution de rechange possible aux antibiotiques. [Traduit par la Redaction] Mots-cles : lactoferrine, antimicrobien, activite proteolytique, immunomodulation.
Introduction The discovery and development of antibiotics has greatly reduced morbidity and mortality from bacterial infections. However, extensive use and even misuse of these antibiotics in medicine and in agriculture [...]