The first function attributed to lactoferrin (Lf), an iron binding protein belonging to the non-immune natural defences, was antimicrobial activity that depended on its capacity to sequester iron. Lactoferrin is found in milk, tears and leukocytes. Lactoferrin also attenuates the pathogenic potential of H. influenzae by proteolytic degradation of the Hap adhesin. While lactoferrin may aid in the the transmission of human T cell leukemia virus type 1, lactoferrin inhibits HIV-1 replication at the level of viral fusion and entry into cells.
