Viruses and Lactoferrin
LF has strong antiviral activity against a broad spectrum of both naked and enveloped DNA and RNA viruses (99, 149–151). LF inhibits the entry of viral particles into host cells, either by direct attachment to the viral particles or by blocking their cellular receptors (discussed in previous paragraphs) (149). Some of the viruses that LF prevents from entering host cells e.g., Herpes simplex virus (162), human papillomavirus (163), human immunodeficiency virus (HIV) (164), and rotavirus (165). These viruses typically utilize common molecules on the cell membrane to facilitate their invasion into cells, including HSPGs (Figure 1). HSPGs provide the first anchoring sites on the host cell surface, and help the virus make primary contact with these cells (99, 162). HSPGs can be either membrane bound, or in secretory vesicles and in the extracellular matrix (86). It has been shown that LF is able to prevent the internalization of some viruses by binding to HSPGs (86).