scholarly journals Secretory Aspartyl Proteinases Cause Vaginitis and Can Mediate Vaginitis Caused by Candida albicans in Mice

mBio ◽  
2015 ◽  
Vol 6 (3) ◽  
Author(s):  
Eva Pericolini ◽  
Elena Gabrielli ◽  
Mario Amacker ◽  
Lydia Kasper ◽  
Elena Roselletti ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Epithelial Cells ◽  
Inflammatory Response ◽  
Common Disease ◽  
Content Type ◽  
Neutrophil Influx ◽  
Caspase 1 ◽  
Vaginal Epithelial Cells ◽  
Pepstatin A ◽  
Aspartyl Proteinases

ABSTRACTVaginal inflammation (vaginitis) is the most common disease caused by the human-pathogenic fungusCandida albicans. Secretory aspartyl proteinases (Sap) are major virulence traits ofC. albicansthat have been suggested to play a role in vaginitis. To dissect the mechanisms by which Sap play this role, Sap2, a dominantly expressed member of the Sap family and a putative constituent of an anti-Candidavaccine, was used. Injection of full-length Sap2 into the mouse vagina caused local neutrophil influx and accumulation of the inflammasome-dependent interleukin-1β (IL-1β) but not of inflammasome-independent tumor necrosis factor alpha. Sap2 could be replaced by other Sap, while no inflammation was induced by the vaccine antigen, the N-terminal-truncated, enzymatically inactive tSap2. Anti-Sap2 antibodies, in particular Fab from a human combinatorial antibody library, inhibited or abolished the inflammatory response, provided the antibodies were able, like the Sap inhibitor Pepstatin A, to inhibit Sap enzyme activity. The same antibodies and Pepstatin A also inhibited neutrophil influx and cytokine production stimulated byC. albicansintravaginal injection, and a mutant strain lackingSAP1,SAP2, andSAP3was unable to cause vaginal inflammation. Sap2 induced expression of activated caspase-1 in murine and human vaginal epithelial cells. Caspase-1 inhibition downregulated IL-1β and IL-18 production by vaginal epithelial cells, and blockade of the IL-1β receptor strongly reduced neutrophil influx. Overall, the data suggest that some Sap, particularly Sap2, are proinflammatory proteinsin vivoand can mediate the inflammasome-dependent, acute inflammatory response of vaginal epithelial cells toC. albicans. These findings support the notion that vaccine-induced or passively administered anti-Sap antibodies could contribute to control vaginitis.IMPORTANCECandidal vaginitis is an acute inflammatory disease that affects many women of fertile age, with no definitive cure and, in its recurrent forms, causing true devastation of quality of life. Unraveling the fungal factors causing inflammation is important to be able to devise novel tools to fight the disease. In an experimental murine model, we have discovered that aspartyl proteinases, particularly Sap2, may cause the same inflammatory signs of vaginitis caused by the fungus and that anti-Sap antibodies and the protease inhibitor Pepstatin A almost equally inhibit Sap- andC. albicans-induced inflammation. Sap-induced vaginitis is an early event during vaginal infection, is uncoupled from fungal growth, and requires Sap and caspase-1 enzymatic activities to occur, suggesting that Sap or products of Sap activity activate an inflammasome sensor of epithelial cells. Our data support the notion that anti-Sap antibodies could help control the essence of candidal vaginitis, i.e., the inflammatory response.

scholarly journals Induction of Caspase-11 by Aspartyl Proteinases of Candida albicans and Implication in Promoting Inflammatory Response

2015 ◽  
Vol 83 (5) ◽  
pp. 1940-1948 ◽  
Author(s):  
Elena Gabrielli ◽  
Eva Pericolini ◽  
Eugenio Luciano ◽  
Samuele Sabbatini ◽  
Elena Roselletti ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Inflammatory Response ◽  
Nlrp3 Inflammasome ◽  
Type I Interferon ◽  
Inflammasome Activation ◽  
Type I ◽  
Subsequent Increase ◽  
Content Type ◽  
Caspase 1 ◽  
Aspartyl Proteinases

We recently demonstrated that the secreted aspartyl proteinases (Saps), Sap2 and Sap6, ofCandida albicanshave the potential to induce the canonical activation of the NLRP3 inflammasome, leading to the secretion of interleukin-1β (IL-1β) and IL-18 via caspase-1 activation. We also observed that the activation of caspase-1 is partially independent from the NLRP3 activation pathway. In this study, we examined whether Sap2 and Sap6 are also able to activate the noncanonical inflammasome pathway in murine macrophages. Our data show that both Sap2 and Sap6 can activate caspase-11 through type I interferon (IFN) production. Caspase-11 cooperates to activate caspase-1, with a subsequent increase of IL-1β secretion. Endocytosis and internalization of Saps are required for the induction of type I IFN production, which is essential for induction of noncanonical inflammasome activation. Our study indicates a sophisticated interplay between caspase-1 and caspase-11 that connects the canonical and noncanonical pathways of inflammasome activation in response toC. albicansSaps.

scholarly journals Candida albicans Adhesion to and Invasion and Damage of Vaginal Epithelial Cells: Stage-Specific Inhibition by Clotrimazole and Bifonazole

2011 ◽  
Vol 55 (9) ◽  
pp. 4436-4439 ◽  
Author(s):  
Betty Wächtler ◽  
Duncan Wilson ◽  
Bernhard Hube
Keyword(s):  
Candida Albicans ◽  
Epithelial Cells ◽  
Antifungal Agents ◽  
Vaginal Epithelium ◽  
Specific Inhibition ◽  
Content Type ◽  
Vaginal Epithelial Cells ◽  
Specific Activities ◽  
Low Levels ◽  
Adhesion And Invasion

ABSTRACTClotrimazole and bifonazole are highly effective antifungal agents against mucosalCandida albicansinfections. Here we examined the effects of low levels of clotrimazole and bifonazole on the ability ofC. albicansto adhere, invade, and damage vaginal epithelial cells. Although adhesion and invasion were not affected, damage was greatly reduced upon azole treatment. This clearly indicates that low levels of azoles influence specific activities ofC. albicansduring distinct stages of vaginal epithelium infections.

scholarly journals Vaginal Epithelial Cell-Derived S100 Alarmins Induced by Candida albicans via Pattern Recognition Receptor Interactions Are Sufficient but Not Necessary for the Acute Neutrophil Response during Experimental Vaginal Candidiasis

2013 ◽  
Vol 82 (2) ◽  
pp. 783-792 ◽  
Author(s):  
Junko Yano ◽  
Glen E. Palmer ◽  
Karen E. Eberle ◽  
Brian M. Peters ◽  
Thomas Vogl ◽  
...  
Keyword(s):  
Pattern Recognition ◽  
Candida Albicans ◽  
Epithelial Cells ◽  
Biologically Active ◽  
Polymorphonuclear Neutrophil ◽  
Vaginal Candidiasis ◽  
Content Type ◽  
Vaginal Epithelial Cells

ABSTRACTVulvovaginal candidiasis (VVC), caused byCandida albicans, affects women worldwide. Animal and clinical studies suggest that the immunopathogenic inflammatory condition of VVC is initiated by S100 alarmins in response toC. albicans, which stimulate polymorphonuclear neutrophil (PMN) migration to the vagina. The purpose of this study was to extend previousin vitrodata and determine the requirement for the alarmin S100A8 in the PMN response and to evaluate pattern recognition receptors (PRRs) that initiate the response. For the former, PMN migration was evaluatedin vitroorin vivoin the presence or absence of S100 alarmins initiated by several approaches. For the latter, vaginal epithelial cells were evaluated for PRR expression andC. albicans-induced S100A8 and S100A9 mRNAs, followed by evaluation of the PMN response in inoculated PRR-deficient mice. Results revealed that, consistent with previously reportedin vitrodata, eukaryote-derived S100A8, but not prokaryote-derived recombinant S100A8, induced significant PMN chemotaxisin vivo. Conversely, a lack of biologically active S100A8 alarmin, achieved by antibody neutralization or by using S100A9−/−mice, had no effect on the PMN responsein vivo. In PRR analyses, whereas Toll-like receptor 4 (TLR4)- and SIGNR1-deficient vaginal epithelial cells showed a dramatic reduction inC. albicans-induced S100A8/S100A9 mRNAsin vitro, inoculated mice deficient in these PRRs showed PMN migration similar to that in wild-type controls. These results suggest that S100A8 alarmin is sufficient, but not necessary, to induce PMN migration during VVC and that the vaginal PMN response toC. albicansinvolves PRRs in addition to SIGNR1 and TLR4, or other induction pathways.

scholarly journals Novel Aggregation Properties of Candida albicans Secreted Aspartyl Proteinase Sap6 Mediate Virulence in Oral Candidiasis

2015 ◽  
Vol 83 (7) ◽  
pp. 2614-2626 ◽  
Author(s):  
Rohitashw Kumar ◽  
Darpan Saraswat ◽  
Swetha Tati ◽  
Mira Edgerton
Keyword(s):  
Candida Albicans ◽  
Epithelial Cells ◽  
Oral Candidiasis ◽  
Oral Microbiome ◽  
Proteinase Activity ◽  
Adhesion Properties ◽  
Content Type ◽  
Oral Epithelial Cells ◽  
Oral Epithelial ◽  
Cell Cell

Candida albicans, a commensal fungus of the oral microbiome, causes oral candidiasis in humans with localized or systemic immune deficiencies. Secreted aspartic proteinases (Saps) are a family of 10 related proteases and are virulence factors due to their proteolytic activity, as well as their roles in adherence and colonization of host tissues. We found that mice infected sublingually withC. albicanscells overexpressing Sap6 (SAP6OE and a Δsap8strain) had thicker fungal plaques and more severe oral infection, while infection with the Δsap6strain was attenuated. These hypervirulent strains had highly aggregative colony structurein vitroand higher secreted proteinase activity; however, the levels of proteinase activity ofC. albicansSaps did not uniformly match their abilities to damage cultured oral epithelial cells (SCC-15 cells). Hyphal induction in cells overexpressing Sap6 (SAP6OE and Δsap8cells) resulted in formation of large cell-cell aggregates. These aggregates could be produced in germinated wild-type cells by addition of native or heat-inactivated Sap6. Sap6 bound only to germinated cells and increasedC. albicansadhesion to oral epithelial cells. The adhesion properties of Sap6 were lost upon deletion of its integrin-binding motif (RGD) and could be inhibited by addition of RGD peptide or anti-integrin antibodies. Thus, Sap6 (but not Sap5) has an alternative novel function in cell-cell aggregation, independent of its proteinase activity, to promote infection and virulence in oral candidiasis.

scholarly journals The Inflammatory Response Induced by Aspartic Proteases of Candida albicans Is Independent of Proteolytic Activity

2010 ◽  
Vol 78 (11) ◽  
pp. 4754-4762 ◽  
Author(s):  
Donatella Pietrella ◽  
Anna Rachini ◽  
Neelam Pandey ◽  
Lydia Schild ◽  
Mihai Netea ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Inflammatory Response ◽  
Proteolytic Activity ◽  
Necrosis Factor Alpha ◽  
Pathogenic Yeast ◽  
Aspartic Proteases ◽  
Akt Activation ◽  
Tnf Α ◽  
Factor Alpha ◽  
Pepstatin A

ABSTRACT The secretion of aspartic proteases (Saps) has long been recognized as a virulence-associated trait of the pathogenic yeast Candida albicans. In this study, we report that different recombinant Saps, including Sap1, Sap2, Sap3, and Sap6, have differing abilities to induce secretion of proinflammatory cytokines by human monocytes. In particular Sap1, Sap2, and Sap6 significantly induced interleukin-1β (IL-1β), tumor necrosis factor alpha (TNF-α), and IL-6 production. Sap3 was able to stimulate the secretion of IL-1β and TNF-α. All Saps tested were able to induce Ca2+ influx in monocytes. Treatment of these Saps with pepstatin A did not have any effect on cytokine secretion, indicating that their stimulatory potential was independent from their proteolytic activity. The capacity of Saps to induce inflammatory cytokine production was also independent from protease-activated receptor (PAR) activation and from the optimal pH for individual Sap activity. The interaction of Saps with monocytes induced Akt activation and phosphorylation of IκBα, which mediates translocation of NF-κB into the nucleus. Overall, these results suggest that individual Sap proteins can induce an inflammatory response and that this phenomenon is independent from the pH of a specific host niche and from Sap enzymatic activity. The inflammatory response is partially dependent on Sap denaturation and is triggered by the Akt/NF-κB activation pathway. Our data suggest a novel, activity-independent aspect of Saps during interactions of C. albicans with the host.

scholarly journals The Toll Interleukin-1 Receptor (IL-1R) 8/Single Ig Domain IL-1R-Related Molecule Modulates the Renal Response to Bacterial Infection

2012 ◽  
Vol 80 (11) ◽  
pp. 3812-3820 ◽  
Author(s):  
Jaklien C. Leemans ◽  
Loes M. Butter ◽  
Gwendoline J. D. Teske ◽  
Ingrid Stroo ◽  
Wilco P. Pulskens ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Inflammatory Response ◽  
Host Response ◽  
Interleukin 1 ◽  
Negative Regulator ◽  
Tubular Epithelial Cells ◽  
Content Type ◽  
Related Molecule ◽  
E Coli ◽  
Ig Domain

ABSTRACTOur immune system has to constantly strike a balance between activation and inhibition of an inflammatory response to combat invading pathogens and avoid inflammation-induced collateral tissue damage. Toll interleukin-1 receptor 8 (IL-1R-8)/single Ig domain IL-1R-related molecule (TIR8/SIGIRR) is an inhibitor of Toll-like receptor (TLR)/IL-1R signaling, which is predominantly expressed in the kidney. The biological role of renal TIR8 during infection is, however, unknown. We therefore evaluated renal TIR8 expression duringEscherichia colipyelonephritis and explored its role in host defense using TIR8−/−versus TIR8+/+mice. We found that TIR8 protein is abundantly present in the majority of cortical tubular epithelial cells. Pyelonephritis resulted in a significant downregulation of TIR8 mRNA in kidneys of TIR8+/+mice. TIR8 inhibited an effective host response againstE. coli, as indicated by diminished renal bacterial outgrowth and dysfunction in TIR8−/−mice. This correlated with increased amounts of circulating and intrarenal neutrophils at the early phase of infection. TIR8−/−tubular epithelial cells had increased cytokine/chemokine production when stimulated with lipopolysaccharide (LPS) or heat-killedE. coli, suggesting that TIR8 played an anti-inflammatory role during pathogen stimulation by inhibiting LPS signaling. These data suggest that TIR8 is an important negative regulator of an LPS-mediated inflammatory response in tubular epithelial cells and dampens an effective antibacterial host response during pyelonephritis caused by uropathogenicE. coli.

scholarly journals Effect of antimycotic agents on the activity of aspartyl proteinases secreted by Candida albicans

2003 ◽  
Vol 52 (3) ◽  
pp. 247-249 ◽  
Author(s):  
Martin Schaller ◽  
Nikola Krnjaic ◽  
Markus Niewerth ◽  
Gerald Hamm ◽  
Bernhard Hube ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Amphotericin B ◽  
Proteinase Inhibitors ◽  
Inhibitory Effect ◽  
Antifungal Drugs ◽  
Immunodeficiency Virus ◽  
Antimycotic Agent ◽  
Pepstatin A ◽  
Aspartyl Proteinases

The inhibitory effect of human immunodeficiency virus (HIV) proteinase inhibitors amprenavir and saquinavir and antifungal agents terbinafine, ketoconazole, amphotericin B and ciclopiroxolamine on aspartyl proteinases (Saps) secreted by Candida albicans was tested in an in vitro spectophotometric assay. As expected, both HIV proteinase inhibitors showed a significant inhibitory effect on Sap activity, which was comparable to that of the classical aspartyl proteinase inhibitor pepstatin A (P < 0.001). Antifungal drugs such as ketoconazole, terbinafine and amphotericin B had no, or only minor, inhibitory effects on proteolytic activity. In contrast, a significant reduction in Sap activity could be demonstrated during treatment with the antifungal agent ciclopiroxolamine (P < 0.001). These results point to a multiple effect of this antimycotic agent and might explain the reduced adherence of C. albicans to human epithelial cells at subinhibitory doses.

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