No abstract

The small antifungal protein secreted by Penicillium chrysogenum (PAF) inhibits the growth of important zoo pathogenic filamentous fungi, including members of the Aspergillus family.It was shown previously that PAF has no toxic effects on mammalian cells in vitro. We carried out safety experiments by investigating the in vivo effects of PAF by inoculating adult C57/B16 mice with PAF intranasally. Animals were randomly divided into six groups and subjected to different PAF concentrations, up to 54 µg, either once a week for up to 8 weeks or once every day for two weeks. Animals neither died due to the treatment nor were any side effects observed. Histological examinations did not find any pathological reaction in the liver, in the mucous membrane of the nose, and in the lungs, even in the highest concentration used.Mass spectrometry revealed that ZZZ. The effect of the drug on the skin was examined in an irritative dermatitis model by measuring the thickness of the ears. This proved to be the same following PAF application as in control (23.8±9.2 vs. 22.5±5.0 µm, respectively) and significantly less than when treated with phorbol-12-myristate-13-acetate (PMA; 57.5±29.2 µm) used as positive control. Histological changes relative to control were present only in the case of PMA. Positron emission tomography was used to follow potential inflammation of the lungs. Neither the application of control saline nor that of PAF induced any inflammation while the positive control lipopolysaccharide did. Since no toxic effects of PAF were found either in intranasal application or in local external treatment, our result is the first step for introducing PAF as potential antifungal drug in human therapy.

PAF, a small antifungal protein from Penicillium chrysogenum, inhibits the growth of several pathogenic filamentous fungi, including members of the Aspergillus genus. PAF has been proven to have no toxic effects in vivo in mice by intranasal application. To test its efficacy against invasive pulmonary aspergillosis (IPA), experiments were carried out in mice suffering from IPA. Adult mice were immunosuppressed and then infected with Aspergillus fumigatus. After stable infection, the animals were inoculated with PAF intranasally at a concentration of 2.7 mg/kg twice per day. At this concentration—which is highly toxic in vitro to A. fumigatus—the mortality of the animals was slightly delayed but finally all animals died. Histological examinations revealed massive fungal infections in the lungs of both PAF-treated and untreated animal groups. Because intranasally administered PAF was unable to overcome IPA, modified and combined therapies were introduced. The intraperitoneal application of PAF in animals with IPA prolonged the survival of the animals only 1 day. Similar results were obtained with amphotericin B (AMB), with PAF and AMB being equally effective. Combined therapy with AMB and PAF—which are synergistic in vitro—was found to be more effective than either AMB or PAF treatment alone. As no toxic effects of PAF in mammals have been described thus far, and, moreover, there are so far no A. fumigatus strains with reported inherent or acquired PAF resistance, it is worth carrying out further studies to introduce PAF as a potential antifungal drug in human therapy.

No abstract

Merkel cell carcinoma (MCC) is a rare, high-grade, aggressive cutaneous neuroendocrine malignancy most commonly associated with sun-exposed areas of older individuals. A relatively newly identified human virus, the Merkel cell polyomavirus (MCPyV) has been implicated in the pathogenesis of MCC. Our study aimed to examine nine MCC cases and randomly selected 60 melanoma cases to identify MCPyV status and to elucidate genetic differences between virus-positive and -negative cases. Altogether, seven MCPyV-positive MCC samples and four melanoma samples were analyzed. In MCPyV-positive MCC RB1, TP53, FBXW7, CTNNB1, and HNF1A pathogenic variants were identified, while in virus-negative cases only benign variants were found. In MCPyV-positive melanoma cases, besides BRAF mutations the following genes were also affected: PIK3CA, STK11, CDKN2A, SMAD4, and APC. In contrast to studies found in the literature, a higher tumor burden was detected in virus-associated MCC compared to MCPyV-negative cases. No association was identified between virus infection and tumor burden in melanoma samples. We concluded that analyzing the key morphologic and immunohistological features of MCC is critical to avoid confusion with other cutaneous malignancies. Molecular genetic investigations such as next-generation sequencing (NGS) enable molecular stratification, which may have future clinical impact.