ANTIVIRAL EFFECT OF BOVINE LACTOFERRIN SATURATED WITH METAL-IONS ON EARLY STEPS OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 INFECTION

Lactoferrin is a mammalian iron-binding glycoprotein present in many b iological secretions, such as milk, tears, semen and plasma and a majo r component of the specific granules of polymorphonuclear leucocytes. The effect of bovine lactoferrin (BLf) in apo-form or saturated with f erric, manganese or zinc ions, on human immunodeficiency virus type 1 (HIV-1) infection in the C8166 T-cell line was studied. Both HIV-1 rep lication and syncytium formation were efficiently inhibited, in a dose -dependent manner, by lactoferrins. BLf in apo and saturated forms mar kedly inhibited HIV-1 replication when added prior to HIV infection or during the virus adsorption step, thus suggesting a mechanism of acti on on the HIV binding to or entry into C8166 cells. Likewise, the addi tion of Fe3+ BLf prior to HIV infection and during the attachment step resulted in a marked reduction of the HIV-1 DNA in C8166 cells 20 h a fter infection. The potent antiviral effect and the high selectivity i ndex exhibited by BLf suggest for this protein, in apo or saturated fo rms, an important role in inhibiting the early HIV-cell interaction, e ven though a post adsorption effect cannot. be ruled out. (C) 1998 Els evier Science Ltd. All rights reserved.