K. Konopka et al., Secretory leukocyte protease inhibitor (SLPI): Oxidation of SLPI does not explain its variable anti-HIV activity, J DENT RES, 78(12), 1999, pp. 1773-1776
Secretory leukocyte protease inhibitor (SLPI) has been proposed as a potent
ial inhibitor of HIV-1 infection in human saliva. Although the ability of r
ecombinant (r) SLPI to inhibit HIV-1 infection of macrophages and primary T
-cells has been demonstrated by two independent laboratories, evidence to t
he contrary has also been reported. This study re-examines the anti-HIV eff
ect of rSLPI and investigates the effects of repeated freeze-thawing and ox
idation on the anti-HIV activity of rSLPI. rSLPI inhibited HIV-1(BaL) infec
tion of human macrophages in a highly variable manner. HPLC and electrospra
y ionization mass spectrometry (ESI) analyses indicated that variability in
our inhibition data could not be attributed to the degradation or oxidatio
n of rSLPI. These results suggest that the variable anti-HIV effect of rSLP
I may be due to differential expression of the cell-surface molecule(s) to
which SLPI binds rather than to changes in the rSLPI molecule.