Antimicrobial Activity of the Peptide LfcinB15 against Candida albicans

Abstract

Lactoferricin (Lfcin) is an amphipathic, cationic peptide derived from proteolytic cleavage of the N-lobe of lactoferrin (Lf). Lfcin and its derivatives possess broad-spectrum antibacterial and antifungal activities. However, unlike their antibacterial functions, the modes of action of Lfcin and its derivatives against pathogenic fungi are less well understood. In this study, the mechanisms of LfcinB15, a derivative of bovine Lfcin, against Candida albicans were, therefore, extensively investigated. LfcinB15 exhibited inhibitory activity against planktonic cells, biofilm cells, and clinical isolates of C. albicans and non-albicans Candida species. We further demonstrated that LfcinB15 is localized on the cell surface and vacuoles of C. albicans cells. Moreover, LfcinB15 uses several different methods to kill C. albicans, including disturbing the cell membrane, inducing reactive oxygen species (ROS) generation, and causing mitochondrial dysfunction. Finally, the Hog1 and Mkc1 mitogen-activated protein kinases were both activated in C. albicans cells in response to LfcinB15. These findings help us to obtain more insight into the complex mechanisms used by LfcinB15 and other Lfcin-derived peptides to fight fungal pathogens.

Membrane Permeabilization and Antimicrobial Activity of Recombinant Defensin-d2 and Actifensin against Multidrug-Resistant Pseudomonas aeruginosa and Candida albicans

“…To measure differences in the ROS production between treated and untreated cells, P. aeruginosa and C. albicans were grown in MHB at 37 °C until OD 600 reached 0.5 [ 75 ]. The cells were incubated with 10 μM of 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA) for 1 h in the dark.…”

WMR Peptide as Antifungal and Antibiofilm against Albicans and Non-Albicans Candida Species: Shreds of Evidence on the Mechanism of Action

“…Cells were harvested, washed with 12.5 mM sodium acetate, treated with or without different concentrations of WMR, (50.0 µM for C. albicans and 10.0 µM for C. parapsilosis) and incubated at 37 • C for 1 h. Cells were then plated on TSB agar plates and incubated overnight at 37 • C, and the number of CFUs from cells treated was counted and normalized to that of the untreated control. The results were reported as percentages of survival using the following formula: [(CFU of the sample treated with the agent)/(CFU of non-treated control) × 100] [47]. The data represent the mean ± standard deviation for three independent experiments.…”

Chimeric Peptides Derived from Bovine Lactoferricin and Buforin II: Antifungal Activity against Reference Strains and Clinical Isolates of Candida spp.

“…The results above described are in agreement with previous reports, in which peptides containing the minimal motif of LfcinB presented MICs between 0.8 and 400 µg/mL for C. albicans [ 35 ]. In addition, Chang et al [ 36 ] reported that the viability of cells treated with LfcinB decreased as the concentration of LfcinB increased; similarly, the antifungal activity of the chimera was concentration dependent. Furthermore, Jang et al [ 37 ] reported that peptides containing the minimum motif of BFII showed antifungal activity, with MIC values of 32 to >64 μg/mL in strains of C. albicans and Cryptococcus neoformans .…”