interleukin-8 and Dermatomycoses

Topics: beta-Defensins; Dermatomycoses; Epigenesis, Genetic; Humans; Interleukin-8; Keratinocytes; Malassezia

The mechanisms involved in the establishment of the specific immune response against dermatophytes remain unknown. Polymorphonuclear neutrophils (PMNs) are recruited early during the infection process and participate in the elimination of dermatophytes. They could therefore be involved in the induction of the immune response during dermatophytoses by producing specific cytokines. The aim of this work was to assess the in vitro cytokine production by feline PMNs exposed to living arthroconidia from the dermatophyte species Microsporum canis or stimulated with either a secreted or a structural component of M. canis, the latter consisting of heat-killed arthroconidia. The levels of specific cytokines produced by PMNs were determined by capture ELISA and/or quantitative RT-PCR. Results showed that PMNs secrete TNFα, IL-1β and IL-8 following exposure to M. canis living arthroconidia and stimulation with both a secreted component and heat-killed arthroconidia. The level of IL-8 mRNA was also increased in PMNs stimulated with M. canis living arthroconidia. In conclusion, infective M. canis arthroconidia induce the production of pro-inflammatory cytokines by feline PMNs that can be activated either by secreted or structural fungal components. Our results suggest that these granulocytes are involved in the initiation of the immune response against M. canis.

Topics: Animals; Cat Diseases; Cats; Cells, Cultured; Cytokines; Dermatomycoses; Enzyme-Linked Immunosorbent Assay; Female; Interleukin-1beta; Interleukin-8; Male; Microsporum; Neutrophils; RNA, Messenger; Spores, Fungal; Tumor Necrosis Factor-alpha

The lipophilic fungus Malassezia furfur (M. furfur) is a commensal microbe associated with several chronic diseases such as pityriasis versicolor, folliculitis, and seborrheic dermatitis. Because M. furfur-related diseases are difficult to treat and require prolonged use of medications, the treatment for M. furfur-related skin diseases is supposed to gain control over M. furfur growth and the inflammation associated with it, as well as to prevent secondary infections. In this study, we investigated the antifungal and anti-inflammatory effects of cecropin A(1-8)-magainin 2(1-12) hybrid peptide analog P5 on M. furfur. The minimal inhibitory concentration of P5 against M. furfur was 0.39 μM, making it 3-4 times more potent than commonly used antifungal agents such as ketoconazole (1.5 μM) or itraconazole (1.14 μM). P5 efficiently inhibited the expression of IL-8 and Toll-like receptor 2 in M. furfur-infected human keratinocytes without eukaryotic cytotoxicity at its fungicidal concentration. Moreover, P5 significantly downregulated NF-κB activation and intracellular calcium fluctuation, which are closely related with enhanced responses of keratinocyte inflammation induced by M. furfur infection. Taken together, these observations suggest P5 may be a potential therapeutic agent for M. furfur-associated human skin diseases because of its distinct antifungal and anti-inflammatory action.

Topics: Antifungal Agents; Antimicrobial Cationic Peptides; Calcium; Calcium Signaling; Cell Nucleus; Cells, Cultured; Dermatomycoses; Dose-Response Relationship, Drug; Humans; Interleukin-8; Keratinocytes; Malassezia; Microbial Sensitivity Tests; NF-kappa B

Toll-like receptors (TLRs) are crucial players in the innate immune response to microbial invaders. The lipophilic yeast Malassezia furfur has been implicated in the triggering of scalp lesions in psoriasis. The aim of the present study was to assess the role of TLRs in the defence against M. furfur infection. The expression of the myeloid differentiation factor 88 (MyD88) gene, which is involved in the signalling pathway of many TLRs, was also analysed. In addition, a possible correlation of antimicrobial peptides of the beta-defensin family to TLRs was tested. Human keratinocytes infected with M. furfur and a variety of M. furfur-positive psoriatic skin biopsies were analysed by RT-PCR, for TLRs, MyD88, human beta-defensin 2 (HBD-2), HBD-3 and interleukin-8 (IL-8) mRNA expression. When keratinocytes were infected with M. furfur, an up-regulation for TLR2, MyD88, HBD-2, HBD-3 and IL-8 mRNA was demonstrated, compared to the untreated cells. The same results were obtained when psoriatic skin biopsies were analysed. The M. furfur-induced increase in HBD-2 and IL-8 gene expression is inhibited by anti-TLR2 neutralising antibodies, suggesting that TLR2 is involved in the M. furfur-induced expression of these molecules. These findings suggest the importance of TLRs in skin protection against fungi and the importance of keratinocytes as a component of innate immunity.

Topics: Adaptor Proteins, Signal Transducing; beta-Defensins; Biopsy; Cell Proliferation; Cells, Cultured; Dermatomycoses; Gene Expression Regulation; Humans; Interleukin-8; Keratinocytes; Malassezia; Myeloid Differentiation Factor 88; Psoriasis; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Skin; Toll-Like Receptor 2

The characteristic pathological feature of dermatomycosis is numerous neutrophilic infiltrates within the epidermis. However, the precise mechanism of this infiltration remains unknown. In this study, interleukins 1 beta, 6, and 8, monocyte chemotactic protein-1 (MCP-1), and tumor necrosis factor (TNF)-alpha levels in the medium where keratinocytes were co-cultured with Candida albicans, Malassezia and Trichophyton mentagrophytes, were determined by enzyme-linked immunosorbent assays (ELISAs) in order to estimate the effect of these fungi on the cytokine production from human keratinocytes. The IL-8 level in the supernatants increased with 1 to 14 hours of co-culture in response to live C. albicans, but the other cytokines were undetectable. Furthermore, the mRNA of IL- 8 in keratinocytes was also confirmed to increased. This data suggested that C. albicans directly induce interleukin 8 production from human keratinocytes without activated macrophages. The IL-6, IL-8, and TNF-alpha levels in the culture supernatants increased with 1 to 24 hours of co-culture with keratinocytes and Malassezia species but the MCP-1 level was undetectable. The IL-8 and TNF-alpha levels in the culture supernatants increased with 1 to 24 hours of co-culture with keratinocytes and Trichophyton mentagrophytes but the other cytokine levels were undetectable. The ELISA analysis of cytokine production by human keratinocytes will provide useful information in understanding the pathogenesis of dermatomycosis.

Topics: Candidiasis; Chemokine CCL2; Coculture Techniques; Cytokines; Dermatomycoses; Humans; Interleukin-1; Interleukin-6; Interleukin-8; Keratinocytes; Malassezia; Tinea Versicolor; Tumor Necrosis Factor-alpha

Topics: Cells, Cultured; Dermatomycoses; Humans; Interleukin-8; Keratinocytes; Skin; Trichophytin