The Immunomodulatory Effects of Lactoferrin on the Neutrophil Functions

Abstract

Abstract

                Lactoferrin is a multifunctional glycoprotein that binds to iron and is found in mammalian milk, other external secretions such as saliva, tears, semen, mucosal surface of the respiratory and intestinal tracts, and the secondary granules of neutrophils. The wide localization of lactoferrin in the body, especially in neutrophils, mostly characterizes its biological functions. The secreted form of lactoferrin is thought to be involved in the host defense against microbial infection at mucosal sites and another neutrophilic form of lactoferrin has notable immunomodulatory function. Neutrophils are the first responder against microbe invasion and a deficiency in their function leads to severe recurrent bacterial and fungal infection and inflammatory lesions. These lesions often affect the respiratory tract, oral mucosa and skin. It was shown that the oral administration of lactoferrin induced an anti-inflammatory effect in the cats with chronic inflammation, by modulating neutrophil functions. In addition, the oral administration of lactoferrin increased the expression of β2 integrin on the surface of neutrophils in canine leukocyte adhesion deficiency (CLAD) dogs, and as a result of this modulating effect, a clinical improvement was observed. Therefore, lactoferrin might be a treatment target for congenital neutrophil dysfunction based on its ability to modulate neutrophil functions. In this review article, we will discuss the modulating effects of lactoferrin on the neutrophil functions, especially in the congenital neutrophil dysfunction.