In Vivo Applicability of Neosartorya fischeri Antifungal Protein 2 (NFAP2) in Treatment of Vulvovaginal Candidiasis

Abstract

As a consequence of emerging numbers of vulvovaginitis cases caused by azole-resistant and biofilm-forming Candida species, fast and efficient treatment of this infection has become challenging. The problem is further exacerbated by the severe side effects of azoles as long-term-use medications in the recurrent form. There is therefore an increasing demand for novel and safely applicable effective antifungal therapeutic strategies. The small, cysteine-rich, and cationic antifungal proteins from filamentous ascomycetes are potential candidates, as they inhibit the growth of several Candida spp. in vitro; however, no information is available about their in vivo antifungal potency against yeasts. In the present study, we investigated the possible therapeutic application of one of their representatives in the treatment of vulvovaginal candidiasis, Neosartorya fischeri antifungal protein 2 (NFAP2). NFAP2 inhibited the growth of a fluconazole (FLC)-resistant Candida albicans strain isolated from a vulvovaginal infection, and it was effective against both planktonic cells and biofilm in vitro. We observed that the fungal cell-killing activity of NFAP2 is connected to its pore-forming ability in the cell membrane. NFAP2 did not exert cytotoxic effects on primary human keratinocytes and dermal fibroblasts at the MIC in vitro. In vivo murine vulvovaginitis model experiments showed that NFAP2 significantly decreases the number of FLC-resistant C. albicans cells, and combined application with FLC enhances the efficacy. These results suggest that NFAP2 provides a feasible base for the development of a fundamental new, safely applicable mono- or polytherapeutic topical agent for the treatment of superficial candidiasis.

Two small, cysteine-rich and cationic antifungal proteins from Penicillium chrysogenum: A comparative study of PAF and PAFB

“…Similar to the findings with PAF, the efficacy could also be further improved in this model by combining NFAP2 with fluconazole [77]. Other examples for the combinatorial efficacy of AMPs with licensed drugs, e.g.…”

Nutrient Excess Triggers the Expression of the Penicillium chrysogenum Antifungal Protein PAFB

“…Extensively studied examples are AMPs from Penicillium chrysogenum (P. chrysogenum antifungal protein (PAF) and P. chrysogenum antifungal protein B (PAFB)) [6,7], Neosartorya fischeri (N. fischeri antifungal protein (NFAP) and N. fischeri antifungal protein 2 (NFAP2)) [8,9], Penicillium digitatum (P. digidatum antifungal protein B (AfpB)) [10], Penicillium expansum (P. expansum antifungal proteins A, B, C (PeAfpA, PeAfpB and PeAfpC)) [11], Aspergillus giganteus (A. giganteus antifungal protein (AFP)) [12,13] and Aspergillus niger (A. niger antifungal protein (AnAFP)) [14]. Most of them show no cytotoxicity to mammalian cells in vitro [10,11,[15][16][17][18] and in vivo [16,19].…”

Cysteine‐Rich Antifungal Proteins from Filamentous Fungi are Promising Bioactive Natural Compounds in Anti‐Candida Therapy

“…[64] A murine vulvovaginitis model proved that NFAP2 significantly decreases the cell number of fluconazole-resistant C. albicans during the infection; furthermore its combination with fluconazole enhances the activity. [60] These results promise a safe in vivo administration of crAFPs as mono-or polytherapeutic agents in treatment of fungal infection. However, the cation-sensitivity discussed above combined with poor bioavailability could diminish their potential application as systemic agents in an anti-Candida therapy.…”

“…Several studies unambiguously demonstrated the fungal selectivity of crAFPs as these proteins exhibit neither hemolytic nor cytotoxic effects on mammalian cells in vitro. [26,28,60,62,63] Intranasal and topical application of PAF proved to be safe in a toxicity testing in mice: no adverse effects were detected when the protein was administered at its highest in vitro inhibitory concentration for Aspergillus fumigatus. [59] In a subsequent study the in vivo antifungal potency of intraperitoneally administered PAF was demonstrated with a murine pulmonary aspergillosis model.…”

“…[50] The applicability of crAFPs in vivo was further shown in a mouse infection model, where the synergistic anti-Candida efficacy of NFAP2 in combination with fluconazole was proven recently. [60] In contrast, no antagonistic mode of actions have been observed so far, which underlines the potential of crAFPs for anti-Candida polytherapy. [27,50]…”