Effect of 3-hydroxyphthaloyl-beta-lactoglobulin on vaginal transmission ofsimian immunodeficiency virus in rhesus monkeys

Heterosexual transmission of human immunodeficiency virus type 1 (HIV-1) is the major cause of the ongoing AIDS epidemic. Application of chemical barr ier methods is expected to contribute to the worldwide control of this epid emic. Bovine P-lactoglobulin modified by 3-hydroxyphthalic anhydride (3-hyd roxyphthaloyl-beta-lactoglobulin [3HP-beta-LG]) was shown to inhibit HIV-1, HIV-2, simian immunodeficiency virus (SIV), herpes simplex virus type 1 an d 2, and Chlamydia trachomatis infection in vitro. Here, we show that 3HP-b eta-LG not formulated into any vehicle protected three of six rhesus monkey s against vaginal infection by SIV. Incorporation of the compound into an a ppropriate vehicle is expected to increase the degree of protection. 3HP-be ta-LG may be effective as a vaginal inhibitor of HIV-1 infection in humans.