stained with crystal violet (CV) and observed under a light microscope. of expression of two stress-related genes (DDR48 and em SOD5 /em ), and a modulated expression of -glucan epitopes, but no gross changes in cell wall polysaccharide composition. Interestingly, the em mp65 /em mutant displayed a marked reduction in adhesion to BEC and Caco-2 cells and severe defects in biofilm formation when compared to the wild type. All of the pointed out properties were totally or partially recovered in a revertant strain, demonstrating the specificity of gene deletion. Conclusions We demonstrate that this em MP65 /em gene of em Candida albicans /em plays a significant role in maintaining cell wall integrity, as well as in adherence to epithelia and biofilm formation, which are major virulence attributes of this fungus. Background em Candida albicans /em is usually both a commensal and a pathogenic yeast, which is responsible for severe infections in humans, particularly in immunocompromised persons, such as AIDS and malignancy patients, diabetics, newborns and the elderly [1,2]. Although several anti- em Candida /em brokers are currently available, such as amphotericin B, azoles and echinocandins, there is clearly a need for new specific anti-fungal brokers and drug-targets [3]. The cell wall of em C. albicans /em is an essential organelle that helps to withstand osmotic pressure and determines the shape of the cell. The cell wall is usually a plastic and dynamic structure, whose macromolecular composition, molecular business and thickness can greatly vary depending on environmental conditions. The cell wall construction is also tightly controlled in space and time by many genes [4]. Within a host-parasite relationship, the cell wall of em C. albicans /em lies at the crossroads of pathogenicity and therapeutics. It contributes to pathogenicity through adherence and invasion, and it is the target of both pharmacological and immunological antifungal therapy [5,6]. The cell wall comprises two main layers. The inner layer consists of a network of 1 1,3-glucan molecules, accounting for approximately 40% of the cell-wall mass, to which 1,6-glucan (about 20%) and chitin (2-4%) are covalently attached [7]. The outer layer is composed of a dense layer of mannoproteins, termed “cell wall proteins” (CWP), which account for 35-40% of the cell-wall mass. Based on their linkage to other cell wall polysaccharides, two classes of CWPs can be distinguished. One class, which constitutes the majority of the CWPs, consists of CWPs that are covalently linked to 1,6-glucan via a remnant of a GPI anchor [8,9]. The other class consists of the so-called “alkali sensitive linkage” Succinyl phosphonate trisodium salt (ASL)-CWPs, which are covalently linked to the 1,3-glucan network (without an interconnecting 1,6-glucan molecule) through an unknown linkage that is sensitive to moderate alkaline conditions [10]. The best-described ASL-CWPs are the family of Pir-proteins (proteins with internal repeats). Pir-proteins are thought to be pre-proteins that are processed at Kex2 endoprotease acknowledgement sites CTLA4 [11]; the N-terminal a part of mature proteins contains conserved internal tandem repeats, and the C-terminal half shares a high sequence similarity including four conserved cysteines. The em MP65 /em gene encodes a cell wall mannoprotein (Mp65p) of em C. albicans /em . In a previous study [12-14], our research group identified, generated, and intensely analyzed native and recombinant forms of Mp65p and found that it is a major target of immune response in humans and mice [15-17]; we also found that Mp65p is usually a critical determinant of pathogenicity in experimental models of systemic contamination in mice and vaginal contamination in rats [18-21]. Mp65p is usually a putative -glucanase adhesin with one N- and multiple potential O-glycosylation sites, homologous to Scw10p of em S. cerevisiae /em , a member of the GH17 glycosyl-hydrolase family [14,21,22]. Moreover, it contains a putative Succinyl phosphonate trisodium salt Kex2 peptidase (KR) site [23], where Succinyl phosphonate trisodium salt the protein is usually cleaved for secretion and an RGD motif that characterizes numerous proteins of eukaryotic organisms involved in adhesion mechanisms, as both adhesins and adhesin receptors [24,25]. Furthermore, we found that the em MP65 /em gene can be used as a diagnostic marker for systemic em C. albicans /em and non em -albicans /em infections [26]. In another study [21], we explained the construction of the em mp65 /em mutants and some of.
