Pattern of lactoferrin anti-influenza virus inhibitory activity

Abstract

Active antigenic drift allows the influenza virus to partially or completely avoid recognition by the immune system. For treatment, inhibitors of the proton-selective ion channel M2 and inhibitors of neuraminidase are used, which have undesirable side effects and provoke the emergence of treatment-resistant strains of the virus. This justifies the need to search for new therapeutic agents. Lactoferrin (LF) is a glycoprotein with a molecular mass of 75—80 kDa, capable for binding metal ions. The highest concentrations of LF are detected in colostrum and milk, a significant amount is deposited in neutrophil granules. The structure of the LF domains of human milk, cow, goat, pig, horse, camel, buffalo is homologous. LF interacts with both specific receptors and endocytosis receptors (LRP), Toll-like, signal receptors on the surface of various cell types. Lactoferrin of humans and animals has a high antiviral activity. This glycoprotein modulates the immune system, including the humoral and cellular immune responses, and regulates redox reactions. However, literature data on the role of this protein in the prevention and treatment of influenza are few. LF inhibitory activity against influenza A and B viruses has been described, including H1N1, H5N1, H7N1, H3N2 strains. It has been established that LF binds virus hemagglutinin, preventing interaction with the cell, blocks programmed cell death through interaction with caspase 3 for preventing the spread of the virus at the later stages of the infection, and blocks virus assembly. Peptides synthesized on the basis of LF C-domain structure demonstrate high inhibitory activity against virus. The use of LF as an adjuvant for vaccines is more effective than of aluminum oxide. Further study of LF effects on influenza virus and on the immune response during infection is necessary to develop new methods of prevention and treatment.