Title
Antimicrobial peptide LL-37 and its truncated forms, GI-20 and GF-17, exert spermicidal effects and microbicidal activity against Neisseria gonorrhoeae
Author
Wongsakorn Kiattiburut, Ruina Zhi, Seung Gee Lee, Alexander C. Foo, Duane R. Hickling, Jeffrey W. Keillor, Natalie K. Goto, Weihua Li, Wayne Conlan, Jonathan B. Angel, Guangshun Wang, Nongnuj Tanphaichitr
Year
2018
Journal
Human Reproduction
Abstract
The plasma membrane integrity of peptide-treated sperm was assessed by cellular exclusion of Sytox Green, a membrane impermeable fluorescent DNA dye. Successful mouse in vitro fertilization was revealed by the presence of two pronuclei in oocytes following co-incubation with capacitated untreated/peptide-pretreated sperm. Sperm plus each peptide were transcervically injected into female mice and the success of in vivo fertilization was scored by the formation of 2–4 cell embryos 42 h afterward. Reproductive tract tissues of peptide pre-exposed females were then assessed histologically for any damage. Minimal inhibitory/ bactericidal concentrations of LL-37, GI-20 and GF-17 on N. gonorrhoeae were determined by a standard method. Like LL-37, treatment of sperm with GI-20 and GF-17 resulted in dose-dependent increases in sperm plasma membrane permeabilization, reaching the maximum at 18 and 3.6 μM for human and mouse sperm, respectively (P < 0.0001, as compared with untreated sperm). Mouse sperm treated with 3.6 μM GI-20 or GF-17 did not fertilize oocytes either in vitro or in vivo. Moreover, reproductive tract tissues of female mice pre-exposed to 3.6 μM GI-20 or GF-17 remained intact with no lesions, erosions or ulcerations. At 1.8–7.2 μM, LL-37, GI-20 and GF-17 exerted bactericidal effects on N. gonorrhoeae
Instrument
J-815
Keywords
Circular dichroism, Secondary structure, Biochemistry