Infection and Immunity, June 2001, p. 3883-3890, Vol. 69, No. 6
0019-9567/01/$04.00+0 DOI: 10.1128/IAI.69.6.3883-3890.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
Department of Oral Surgery, Kochi Medical School, Kohasu, Nankoku-city, Kochi 783-8505, Japan
Received 20 October 2000/Returned for modification 27 December 2000/Accepted 20 March 2001
To develop a new strategy to control candidiasis, we examined in vivo the anticandidal effects of a synthetic lactoferrin peptide, FKCRRWQWRM (peptide 2) and the peptide that mimics it, FKARRWQWRM (peptide 2'). Although all mice that underwent intraperitoneal injection of 5 × 108 Candida cells with or without peptide 2' died within 8 or 7 days, respectively, the survival times of mice treated with 5 to 100 µg of intravenous peptide 2 per day for 5 days after the candidal inoculation were prolonged between 8.4 ± 2.9 and 22.4 ± 3.6 days, depending on the dose of peptide 2. The prolongation of survival by peptide 2 was also observed in mice that were infected with 1.0 × 109 Candida albicans cells (3.2 ± 1.3 days in control mice versus 8.2 ± 2.4 days in the mice injected with 10 µg of peptide 2 per day). In the high-dose inoculation, a combination of peptide 2 (10 µg/day) with amphotericin B (0.1 µg/day) and granulocyte-macrophage colony-stimulating factor (GM-CSF) (0.1 µg/day) brought prolonged survival. With a combination of these agents, 60% of the mice were alive for more than 22 days. Correspondingly, peptide 2 activated phagocytes inducing inducible NO synthase and the expression of p47phox and p67phox, and peptide 2 increased phagocyte Candida-killing activities up to 1.5-fold of the control levels upregulating the generation of superoxide, lactoferrin, and defensin from neutrophils and macrophages. These findings indicated that the anticandidal effects of peptide 2 depend not only on the direct Candida cell growth-inhibitory activity, but also on the phagocytes' upregulatory activity, and that combinations of peptide 2 with GM-CSF and antifungal drugs will help in the development of new strategies for control of candidiasis.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|