RESUMEN
Analysing culture supernatants of yeast and hyphal cells of Candida albicans, we found two close homologues of pathogenesis-related (PR-) 1 proteins, Rbe1p and Rbt4p, in the secretome. Due to sequence homology, three additional, yet not characterized open reading frames, ORF19.6200, ORF19.2787 and ORF19.2336, together with RBE1 and RBT4 were assigned to a novel family of CaPRY proteins. In a Δrbe1/Δrbt4 deletion strain, genome-wide transcriptional analysis revealed differential transcription of only a limited set of genes implicated in virulence and oxidative stress response. Single deletion of RBE1 or RBT4 in a clinical C. albicans isolate resulted in a moderate but significant attenuation in virulence in a mouse model for disseminated candidiasis. However, a synergistic effect was observed in a Δrbe1/Δrbt4 double deletion strain, where virulence was strongly affected. Remarkably, transcription of RBT4 and RBE1 was each upregulated in blastospores of Δrbe1 or hyphae of Δrbt4 deletion strains respectively, indicating functional complementation thereby compensating a potential virulence defect in the single deletion strains. Furthermore, the double deletion strain showed increased sensitivity to attack by polymorphonuclear leucocytes. Therefore, the crucial contribution of both C. albicans pathogenesis-related proteins to virulence might be vested in protection against phagocyte attack.
Asunto(s)
Candida albicans/genética , Candida albicans/patogenicidad , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Secuencia de Aminoácidos , Animales , Candida albicans/metabolismo , ADN de Hongos/genética , Perfilación de la Expresión Génica , Regulación Fúngica de la Expresión Génica , Genoma Fúngico , Ratones , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Estrés Oxidativo/genética , Fenotipo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Alineación de Secuencia , Eliminación de Secuencia , Virulencia/genéticaRESUMEN
A 31-year-old woman presented with a cough, pain on the left side on deep inspiration, dyspnea, and fever. A chest x-ray showed pneumonic infiltration of the left middle and lower lung and decreased left hemithorax volume. A computed tomography (CT) revealed an occlusion of the left main bronchus by an intraluminal tumour. Bronchoscopic biopsy specimens suggested an endobronchial hamartoma. Therefore, we resected the tumour endobronchially using a bronchoscopic electrosurgical snare and argon plasma coagulation.