Host defence peptides identified in human apolipoprotein B as promising antifungal agents.

Affiliation

Dell'Olmo E(1)(2), Gaglione R(1)(3), Cesaro A(1), Cafaro V(4), Teertstra WR(5), de Cock H(5), Notomista E(4), Haagsman HP(2), Veldhuizen EJA(6), Arciello A(7)(8).
Author information:
(1)Department of Chemical Sciences, University of Naples Federico II, 80126, Naples, Italy.
(2)Department of Biomolecular Health Sciences, Division of Infectious Diseases and Immunology, Section Molecular Host Defence, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
(3)Istituto Nazionale di Biostrutture e Biosistemi
(INBB), Rome, Italy.
(4)Department of Biology, University of Naples Federico II, 80126, Naples, Italy.
(5)Molecular Microbiology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands.
(6)Department of Biomolecular Health Sciences, Division of Infectious Diseases and Immunology, Section Molecular Host Defence, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands. [Email]
(7)Department of Chemical Sciences, University of Naples Federico II, 80126, Naples, Italy. [Email]
(8)Istituto Nazionale di Biostrutture e Biosistemi
(INBB), Rome, Italy. [Email]

Abstract

Therapeutic options to treat invasive fungal infections are still limited. This makes the development of novel antifungal agents highly desirable. Naturally occurring antifungal peptides represent valid candidates, since they are not harmful for human cells and are endowed with a wide range of activities and their mechanism of action is different from that of conventional antifungal drugs. Here, we characterized for the first time the antifungal properties of novel peptides identified in human apolipoprotein B. ApoB-derived peptides, here named r(P)ApoBLPro, r(P)ApoBLAla and r(P)ApoBSPro, were found to have significant fungicidal activity towards Candida albicans (C. albicans) cells. Peptides were also found to be able to slow down metabolic activity of Aspergillus niger (A. niger) spores. In addition, experiments were carried out to clarify the mechanism of fungicidal activity of ApoB-derived peptides. Peptides immediately interacted with C. albicans cell surfaces, as indicated by fluorescence live cell imaging analyses, and induced severe membrane damage, as indicated by propidium iodide uptake induced upon treatment of C. albicans cells with ApoB-derived peptides. ApoB-derived peptides were also tested on A. niger swollen spores, initial hyphae and branched mycelium. The effects of peptides were found to be more severe on swollen spores and initial hyphae compared to mycelium. Fluorescence live cell imaging analyses confirmed peptide internalization into swollen spores with a consequent accumulation into hyphae. Altogether, these findings open interesting perspectives to the application of ApoB-derived peptides as effective antifungal agents. KEY POINTS: Human cryptides identified in ApoB are effective antifungal agents. ApoB-derived cryptides exert fungicidal effects towards C. albicans cells. ApoB-derived cryptides affect different stages of growth of A. niger. Graphical abstract.