ANTIROTAVIRAL ACTIVITY OF MILK-PROTEINS - LACTOFERRIN PREVENTS ROTAVIRUS INFECTION IN THE ENTEROCYTE-LIKE CELL-LINE HT-29

Different milk proteins were analyzed for their inhibitory effect on e ither rotavirus-mediated agglutination of human erythrocytes or rotavi rus infection of the human enterocyte-like cell line HT-29. Proteins i nvestigated were alpha-lactalbumin, beta-lactoglobulin, apo-lactoferri n, and Fe3+-lactoferrin, and their antiviral action was compared with the activity of mucin, a milk glycoprotein known to affect rotavirus i nfection. Results obtained demonstrated that beta-lactoglobulin, apo- and Fe3+-lactoferrin are able to inhibit the replication of rotavirus in a dose-dependent manner, apo-lactoferrin being the most active. It was shown that apo-lactoferrin hinders virus attachment to cell recept ors since it is able to bind the viral particles and to prevent both r otavirus haemagglutination and viral binding to susceptible cells. Mor eover, this protein markedly inhibited rotavirus antigen synthesis and yield in HT-29 cells when added during the viral adsorption step or w hen it was present in the first hours of infection, suggesting that th is protein interferes with the early phases of rotavirus infection.