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Amphotericin B formulations possess diverse immunomodulatory properties that may contribute to the activity of phagocytes against invasive aspergillosis. In this work we provide a novel set of data on different gene transcriptional profiles of monocytes exposed to the combination of Aspergillus fumigatus and amphotericin B formulations. We used pathway-specific microarray analysis, RT-PCR analysis and enzyme-linked immunosorbent assays to compare the effects of amphotericin B deoxycholate (DAMB) at 1 μg/ml and amphotericin B lipid complex (ABLC) at 5 μg/ml to assess gene expression of immune molecules of THP-1 cells exposed to A. fumigatus hyphae (AF) for 4 h. A. fumigatus hyphae at effector/target ratio 10/1 induced mostly chemotactic factors for monocyte recruitment. DAMB at 1 μg/ml in the presence or absence of AF induced the most pronounced changes in pro-inflammatory and chemokine gene expression, while ABLC under the same conditions caused less dramatic effect. There was a reciprocal response of increased expression of the genes encoding IL-1β and IL-20 and decreased expression of IL-10, IL-2 and IL-3 in response of monocytes to both the hyphae and antifungal agents. These results demonstrate that amphotericin B formulations exert differential effects on genes encoding pro-inflammatory molecules, immunoregulatory molecules and chemokines by human monocytes during response to A. fumigatus and that these molecules may affect antifungal activity.

Objectives: To investigate the activities of two newer triazoles and two echinocandins combined with human phagocytes against Candida parapsilosis biofilms. Methods: An in vitro model of C. parapsilosis biofilms was used. Biofilms were grown on silicone elastomer discs in 96-well plates at 37°C for 72 h. Biofilms or planktonic cells were incubated with voriconazole, posaconazole, caspofungin or anidulafungin, at clinically relevant concentrations, and human phagocytes (neutrophils or monocytes) alone or in combination with each of the antifungal agents for a further 22 h. Fungal damage induced by antifungal agents and/or phagocytes was determined by XTT [2,3-bis(2-methoxy-4-nitro-5-sulfo-phenyl)2H-tetrazolium-5-carboxanilide] metabolic assay. Results: Each of the antifungal agents alone and in combination with human phagocytes induced less damage against C. parapsilosis biofilms compared with planktonic cells. No antagonistic interactions between antifungal agents and phagocytes were found. Furthermore, anidulafungin, but not caspofungin, and neutrophils exerted additive activity against C. porapsilosis biofilms. Conclusions: Besides a lack of antagonistic interactions between newer antifungal agents and phagocytes, anidulafungin exerts additive immunopharmacological activity against C. parapsilosis biofilms.

Among Zygomycetes, Cunninghamella bertholletiae occurs less frequently as the etiologic agent of human disease but causes more aggressive, refractory, and fatal infections despite antifungal therapy. Little is known about the differential innate host response against Cunninghamella and other Zygomycetes in the presence of antifungal agents. We therefore studied the activity of human neutrophils (PMNs) alone or in combination with caspofungin, posaconazole (PSC), and voriconazole (VRC) against hyphae of Rhizopus oryzae, Rhizopus microsporus and C. bertholletiae. Hyphal damage was measured by XTT metabolic assay and release of IL-6, IL-8 and TNF-alpha from PMNs by ELISA. Cunninghamella bertholletiae was more resistant to PMN-induced hyphal damage than either Rhizopus spp. at effector:target (E:T) ratios of 1:1, 5:1 and 10:1 (P < 0.05). The hyphal damage caused by caspofungin at 0.1 microg/ml or PSC and VRC at 0.5 microg/ml with C. bertholletiae and R. oryzae and by caspofungin against R. microsporus ranged from 18-29%. The PMN-induced hyphal damage was not modulated by combination with antifungal agents. Cunninghamella bertholletiae induced significantly decreased IL-8 (P < 0.05), but increased TNF-alpha release from PMNs compared to both Rhizopus spp. (P < 0.01). No IL-6 was released from PMNs exposed to the three Zygomycetes. In comparison to R. oryzae and R. microsporus, C. bertholletiae is more resistant to PMN-induced hyphal damage with or without antifungal therapy and is more capable of suppressing release of IL-8.

Candida albicans is a leading cause of biofilm-related infections. As Candida biofilms are recalcitrant to host defenses, we sought to determine the effects of interferon-γ and granulocyte colony-stimulating factor, two pro-inflammatory cytokines, on the antifungal activities of human polymorphonuclear neutrophils (PMNs) against C. albicans biofilms, using an in vitro biofilm model. Priming of PMNs by these cytokines augmented fungal damage of planktonic cells; however, priming of PMNs did not have the same effect against Candida biofilms. Biofilm phenotype appears to play an important role in protecting C. albicans from the innate immune system.