CD8(+) T lymphocytes have been shown to produce unidentified soluble factor
s active in suppressing HIV-1 replication. In this study, we purified an HI
V-1 suppressing activity from the culture supernatant of an immortalized CD
8(+) T cell clone, derived from an HIV-1 infected long-term nonprogressor,
and identified this activity as the amino-terminal fragment (ATF) of urokin
ase-type plasminogen activator (uPA), ATF is catalytically inactive, but su
ppresses the release of viral particles from the HIV-1 infected cell lines
via binding to its receptor CD87, In contrast, cell proliferation and the s
ecretion of an HIV-1 LTR driven reporter gene product were not affected by
ATF. These findings suggest that ATF may inhibit the assembly and budding o
f HIV-1, which provides a novel therapeutic strategy for AIDS. (C) 2001 Aca
demic Press.