Anti-HIV activity of newly cloned secretory leukocyte protease inhibitor (SLPI) in human macrophages


Nejat Düzgüneş: 0000-0001-6159-1391


Biomedical Sciences

Document Type

Conference Presentation

Conference Title

32nd Annual Meeting of the American Association for Dental Research


San Antonio, TX

Conference Dates

March 12-15, 2003

Date of Presentation


Journal Title

Journal of Dental Research

Journal ISSN


Journal Volume Number

82 (special issue A)

First Page



Objectives: Secretory leukocyte protease inhibitor (SLPI), a serine protease inhibitor present in saliva, has been shown to inhibit HIV infection of macrophages and primary T-cells (McNeely et al., J. Clin. Invest. 1995; 96:456; Blood 1997; 90:1141; Shugars et al., Oral. Dis. 1997; 3 (Suppl.1):S70). However, contradictory results have also been published (Turpin et al., Antiviral Res. 1996; 29:269) and variable results were observed in our laboratory (Konopka et al., J. Dent. Res. 1999; 78: 1773). All these studies have been performed using the same, commercially available, preparation of recombinant (r) SLPI obtained from Synergen and/or R&D Systems. In this study we examined the anti-HIV activity of a newly cloned SLPI using monocyte-derived macrophages. Methods: The SLPI gene was synthesized by a PCR-based strategy using long oligonucleotides, and the protein was overexpressed in E. coli, purified, and successfully refolded. Macrophages were infected with HIV-1Ba-L on day 10 or 14 post-isolation, in the absence or presence of SLPI. Cells were incubated with SLPI for 30 min at 37°C prior to addition of the virus. SLPI was also present during the 2 h infection period. Virus production in culture supernatants was monitored by p24 ELISA. Results: Over 90% inhibition of p24 production was observed in macrophages infected in the presence of 5, 10 or 20 µg/ml of SLPI. At 0.5 or 1 µg/ml, SLPI reduced the p24 levels by ~70 to 80%. This potent inhibition of virus production was sustained for 2 weeks of culture. Conclusions: (i) the newly cloned SLPI effectively blocks HIV-1 infection in macrophages, and (ii) the availability of an active rSLPI will enable the investigation of the biochemical and structural basis for the anti-HIV activity of SLPI. Partially supported by Pacific Dental Research Foundation Grant 518, and funds from the University of the Pacific School of Dentistry.

This document is currently not available here.