LL37 and hBD-3 elevate the β-1,3-exoglucanase activity of Candida albicans Xog1p, resulting in reduced fungal adhesion to plastic

2012 ◽  
Vol 441 (3) ◽  
pp. 963-970 ◽  
Author(s):  
Hao-Teng Chang ◽  
Pei-Wen Tsai ◽  
Hsin-Hui Huang ◽  
Yu-Shu Liu ◽  
Tzu-Shan Chien ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Antimicrobial Peptides ◽  
Organ Transplant ◽  
Vaginal Candidiasis ◽  
Immunocompromised Patients ◽  
Fungal Adhesion ◽  
Oral Thrush ◽  
Dose Dependent

The opportunistic fungus Candida albicans causes oral thrush and vaginal candidiasis, as well as candidaemia in immunocompromised patients including those undergoing cancer chemotherapy, organ transplant and those with AIDS. We previously found that the AMPs (antimicrobial peptides) LL37 and hBD-3 (human β-defensin-3) inhibited C. albicans viability and its adhesion to plastic. For the present study, the mechanism by which LL37 and hBD-3 reduced C. albicans adhesion was investigated. After AMP treatment, C. albicans adhesion to plastic was reduced by up to ~60% and was dose-dependent. Our previous study indicated that LL37 might interact with the cell-wall β-1,3-exoglucanase Xog1p, which is involved in cell-wall β-glucan metabolism, and consequently the binding of LL37 or hBD-3 to Xog1p might cause the decrease in adhesion. For the present study, Xog1p(41–438)-6H, an N-terminally truncated, active, recombinant construct of Xog1p and Xog1p fragments were produced and used in pull-down assays and ELISA in vitro, which demonstrated that all constructs interacted with both AMPs. Enzymatic analyses showed that LL37 and hBD-3 enhanced the β-1,3-exoglucanase activity of Xog1p(41–438)-6H approximately 2-fold. Therefore elevated Xog1p activity might compromise cell-wall integrity and decrease C. albicans adhesion. To test this hypothesis, C. albicans was treated with 1.3 μM Xog1p(41–438)-6H and C. albicans adhesion to plastic decreased 47.7%. Taken together, the evidence suggests that Xog1p is one of the LL37/hBD-3 targets, and elevated β-1,3-exoglucanase activity reduces C. albicans adhesion to plastic.

scholarly journals Effect of β-1,6-Glucan Inhibitors on the Invasion Process of Candida albicans: Potential Mechanism of Their In Vivo Efficacy

2009 ◽  
Vol 53 (9) ◽  
pp. 3963-3971 ◽  
Author(s):  
Akihiro Kitamura ◽  
Saito Higuchi ◽  
Masato Hata ◽  
Katsuhiro Kawakami ◽  
Kumi Yoshida ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Critical Role ◽  
Vaginal Candidiasis ◽  
Specific Cell ◽  
Cell Wall Proteins ◽  
Invasion Process ◽  
In Vivo Efficacy

ABSTRACT β-1,6-Glucan is a fungus-specific cell wall component that is essential for the retention of many cell wall proteins. We recently reported the discovery of a small molecule inhibitor of β-1,6-glucan biosynthesis in yeasts. In the course of our study of its derivatives, we found a unique feature in their antifungal profile. D21-6076, one of these compounds, exhibited potent in vitro and in vivo antifungal activities against Candida glabrata. Interestingly, although it only weakly reduced the growth of Candida albicans in conventional media, it significantly prolonged the survival of mice infected by the pathogen. Biochemical evaluation of D21-6076 indicated that it inhibited β-1,6-glucan synthesis of C. albicans, leading the cell wall proteins, which play a critical role in its virulence, to be released from the cell. Correspondingly, adhesion of C. albicans cells to mammalian cells and their hyphal elongation were strongly reduced by the drug treatment. The results of the experiment using an in vitro model of vaginal candidiasis showed that D21-6076 strongly inhibited the invasion process of C. albicans without a significant reduction in its growth in the medium. These evidences suggested that D21-6076 probably exhibited in vivo efficacy against C. albicans by inhibiting its invasion process.

Interaction of Candida albicans with genital mucosa: effect of sex hormones on adherence of yeasts in vitro

1988 ◽  
Vol 34 (3) ◽  
pp. 224-228 ◽  
Author(s):  
Aliza Kalo ◽  
Esther Segal
Keyword(s):  
Candida Albicans ◽  
Hela Cell ◽  
Sex Hormones ◽  
Hela Cells ◽  
Cell Types ◽  
Vaginal Candidiasis ◽  
Genital Mucosa ◽  
Hela Cell Lines ◽  
I Cells

Findings from our previous studies revealed a correlation between the level of adherence in vitro of Candida albicans to human exfoliated vaginal epithelial cells (VEC) and the hormonal status of the cell donors. In the present study we investigated the effect of the sex hormones estradiol, estriol, progesterone, and testosterone on the binding of the yeasts to HeLa cell lines and VEC in vitro. Monolayers of HeLa cells were exposed to the hormones and yeasts under controlled conditions. The number of adherent yeasts per square millimetre of HeLa cell monolayers and the percentage of VEC with adherent yeasts was estimated by microscopic counts. The results showed that the tested sex hormones affected at various degrees the adhesion of yeasts to HeLa cells or VEC. Progesterone had the most marked effect, leading to a significant increase in the number of adherent yeasts to HeLa cells or in the percentage of adhesion of VEC. In addition, VEC were separated on Percoll gradients into the two cell types: superficial (S) and intermediate (I), cell types which appear physiologically under increased serum levels of estradiol or progesterone, respectively. Adhesion assays with the separated cell populations revealed an increased binding capacity of the I cells. The finding that progesterone increased the adherence of yeasts to genital mucosa and that VEC of the I type have a higher capacity to adhere the yeasts is compatible with our previous observation that increased numbers of I cells, appearing under high level of progesterone, are found in situations known to have predisposition to vaginal candidiasis. Thus, our data point to a possible involvement of the hormone progesterone in the adherence of C. albicans to genital epithelium.

Spilanthol as a promising antifungal alkylamide for the treatment of vulvovaginal candidiasis

2021 ◽  
Author(s):  
Rodrigo L Fabri ◽  
Jhamine C O Freitas ◽  
Ari S O Lemos ◽  
Lara M Campos ◽  
Irley O M Diniz ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Cell Membrane ◽  
Multidrug Resistant ◽  
Fungal Strain ◽  
Vulvovaginal Candidiasis ◽  
Biofilm Matrix

Abstract Spilanthol is a bioactive alkylamide from the native Amazon plant species, Acmella oleracea. However, antifungal activities of spilanthol and its application to the therapeutic treatment of candidiasis remains to be explored. This study sought to evaluate the in vitro and in vivo antifungal activity of spilanthol previously isolated from A. oleracea (spilanthol(AcO)) against Candida albicans ATCC® 10231™, a multidrug-resistant fungal strain. Microdilution methods were used to determine inhibitory and fungicidal concentrations of spilanthol(AcO). In planktonic cultures, the fungal growth kinetics, yeast cell metabolic activity, cell membrane permeability and cell wall integrity were investigated. The effect of spilanthol(AcO) on the proliferation and adhesion of fungal biofilms was evaluated by whole slide imaging and scanning electron microscopy. The biochemical composition of the biofilm matrix was also analyzed. In parallel, spilanthol(AcO) was tested in vivo in an experimental vulvovaginal candidiasis model. Our in vitro analyses in C. albicans planktonic cultures detected a significant inhibitory effect of spilanthol(AcO), which affects both yeast cell membrane and cell wall integrity, interfering with the fungus growth. C. albicans biofilm proliferation and adhesion, as well as, carbohydrates and DNA in biofilm matrix were reduced after spilanthol(AcO) treatment. Moreover, infected rats treated with spilanthol(AcO) showed consistent reduction of both fungal burden and inflammatory processes compared to the untreated animals. Altogether, our findings demonstrated that spilanthol(AcO) is an bioactive compound against planktonic and biofilm forms of a multidrug resistant C. albicans strain. Furthermore, spilanthol(AcO) can be potentially considered for therapeutical treatment of vulvovaginal candidiasis caused by C. albicans. Lay Abstract This study sought to evaluate the antifungal activity of spilanthol against Candida albicans ATCC® 10 231™, a multidrug-resistant fungal strain. Our findings demonstrated that spilanthol(AcO) can be potentially considered for therapeutical treatment of vulvovaginal candidiasis caused by C. albicans.

scholarly journals Hepatitis E Virus Immunopathogenesis

Pathogens ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1180
Author(s):  
Kush Kumar Yadav ◽  
Scott P. Kenney
Keyword(s):  
Hepatitis E Virus ◽  
Organ Transplant ◽  
Hepatitis E ◽  
Oral Route ◽  
Solid Organ ◽  
Immunocompromised Patients ◽  
In Vivo Models ◽  
Transplant Patients

Hepatitis E virus is an important emerging pathogen producing a lethal impact on the pregnant population and immunocompromised patients. Starting in 1983, it has been described as the cause for acute hepatitis transmitted via the fecal–oral route. However, zoonotic and blood transfusion transmission of HEV have been reported in the past few decades, leading to the detailed research of HEV pathogenesis. The reason behind HEV being highly virulent to the pregnant population particularly during the third trimester, leading to maternal and fetal death, remains unknown. Various host factors (immunological, nutritional, hormonal) and viral factors have been studied to define the key determinants assisting HEV to be virulent in pregnant and immunocompromised patients. Similarly, chronic hepatitis is seen particularly in solid organ transplant patients, resulting in fatal conditions. This review describes recent advances in the immunopathophysiology of HEV infections in general, pregnant, and immunocompromised populations, and further elucidates the in vitro and in vivo models utilized to understand HEV pathogenesis.

scholarly journals Melanin Externalization in Candida albicans Depends on Cell Wall Chitin Structures

2010 ◽  
Vol 9 (9) ◽  
pp. 1329-1342 ◽  
Author(s):  
Claire A. Walker ◽  
Beatriz L. Gómez ◽  
Héctor M. Mora-Montes ◽  
Kevin S. Mackenzie ◽  
Carol A. Munro ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Fungal Pathogen ◽  
Cell Walls ◽  
Chitin Synthesis ◽  
Melanin Production ◽  
Content Type ◽  
Encoding Gene ◽  
Chitinase Genes

ABSTRACT The fungal pathogen Candida albicans produces dark-pigmented melanin after 3 to 4 days of incubation in medium containing l-3,4-dihydroxyphenylalanine (l-DOPA) as a substrate. Expression profiling of C. albicans revealed very few genes significantly up- or downregulated by growth in l-DOPA. We were unable to determine a possible role for melanin in the virulence of C. albicans. However, we showed that melanin was externalized from the fungal cells in the form of electron-dense melanosomes that were free or often loosely bound to the cell wall exterior. Melanin production was boosted by the addition of N-acetylglucosamine to the medium, indicating a possible association between melanin production and chitin synthesis. Melanin externalization was blocked in a mutant specifically disrupted in the chitin synthase-encoding gene CHS2. Melanosomes remained within the outermost cell wall layers in chs3Δ and chs2Δ chs3Δ mutants but were fully externalized in chs8Δ and chs2Δ chs8Δ mutants. All the CHS mutants synthesized dark pigment at equivalent rates from mixed membrane fractions in vitro, suggesting it was the form of chitin structure produced by the enzymes, not the enzymes themselves, that was involved in the melanin externalization process. Mutants with single and double disruptions of the chitinase genes CHT2 and CHT3 and the chitin pathway regulator ECM33 also showed impaired melanin externalization. We hypothesize that the chitin product of Chs3 forms a scaffold essential for normal externalization of melanosomes, while the Chs8 chitin product, probably produced in cell walls in greater quantity in the absence of CHS2, impedes externalization.

scholarly journals In Vitro Effect of Local Anesthetics onCandida albicansGerm Tube Formation

1994 ◽  
Vol 1 (4) ◽  
pp. 193-197 ◽  
Author(s):  
Acácio Rodrigues ◽  
Cidália Pina Vaz ◽  
A. Freitas Fonseca ◽  
J. Martinez de Oliveira ◽  
Henrique Barros
Keyword(s):  
Germ Tube ◽  
Inhibitory Effect ◽  
Tube Formation ◽  
Vaginal Candidiasis ◽  
Sabouraud Agar ◽  
Colony Forming Units ◽  
Vitro Effect ◽  
Phosphate Buffered Saline ◽  
Dose Dependent

Objective:This study was planned to clarify the in vitro effect of lidocaine and bupivacaine on germ tube formation byCandida albicansisolates from cases of clinical vaginal candidiasis.Methods:FourteenC. albicansstrains (clinical vaginal isolates) were grown on Sabouraud agar for 24 h at 37℃ and tested as follows: 100 μl of a yeast suspension [105colony forming units (CFU)/ml of phosphate buffered saline (PBS)] was added to 500 μl of fresh human serum with lidocaine or bupivacaine (pure salts) in serial concentrations. The test was run in duplicate. Controls were prepared for each strain. After 4 h of incubation at 37℃, samples were taken from each vial and 200 yeasts were counted in a counting chamber. The pH of each suspension was measured.Results:The results are given as the mean of the 2 readings and are expressed as the percentage of blastoconidia with germ tubes/total blastoconidia.Conclusions:Our experiments show that both lidocaine and bupivacaine have a dose-dependent inhibitory effect, pH-independent, on germ tube formation byC. albicansand that both drugs seem to be promising in the treatment of genital candidiasis due to the combination of anesthetic and antifungal properties.

scholarly journals Fungicidal Activity of Fluconazole against Candida albicans in a Synthetic Vagina-Simulative Medium

2004 ◽  
Vol 48 (1) ◽  
pp. 161-167 ◽  
Author(s):  
Mahomed-Yunus S. Moosa ◽  
Jack D. Sobel ◽  
Hussain Elhalis ◽  
Wenjin Du ◽  
Robert A. Akins
Keyword(s):  
Acetic Acid ◽  
Candida Albicans ◽  
Drug Development ◽  
Carboxylic Acids ◽  
Fungicidal Activity ◽  
Vaginal Candidiasis ◽  
Ph Range ◽  
Cure Rates ◽  
Systemic Infections

ABSTRACT Fluconazole (FLZ) has emerged as a highly successful agent in the management of systemic infections of Candida. Cure rates for symptomatic candidiasis following single 150-mg FLZ dose therapy exceed 90%. In vitro, however, FLZ is fungistatic only in a narrow pH range and is not effective at vaginal pH, 4.2. This study evaluated the effect of FLZ on Candida albicans under in vitro conditions resembling the vaginal microenvironment, using vagina-simulative medium (VS). We found that FLZ was fungicidal for C. albicans in VS, but not in other media at the same pH, 4.2. In VS, FLZ was fungicidal at concentrations of ≥8 μg/ml and reduced viability by greater than 99.9%. Analysis of the components of VS indicated that 17 mM acetic acid, a concentration achieved in the vagina, was responsible for the synergistic, fungicidal effect. This effect was not seen at neutral pH. Other substrates were not effective substitutes for acetic acid; however, short-chained carboxylic acids, glyoxylate and malonate, were effective. Most strains of C. albicans that were resistant to FLZ under standard conditions were killed by FLZ plus acetate. Other species of Candida were also killed, except C. krusei and C. glabrata. This study shows that FLZ has fungicidal activity for Candida species under in vitro conditions that mimic the vaginal microenvironment. This raises the possibility that FLZ may also have fungicidal effects during treatment of vaginal candidiasis. Elucidating the mechanism by which FLZ and acetate interact may disclose vulnerable pathways that could be exploited in drug development.

Increase in the in vitro susceptibility of Staphylococcus aureus to antimicrobial agents in the presence of Candida albicans

1979 ◽  
Vol 25 (4) ◽  
pp. 429-435 ◽  
Author(s):  
J. deRepentigny ◽  
R. Lévesque ◽  
L. G. Mathieu
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Candida Albicans ◽  
Inhibitory Activity ◽  
Antimicrobial Agents ◽  
Mixed Cultures ◽  
Alpha Toxin ◽  
In Vitro Susceptibility ◽  
Pure Cultures

In experiments with mixed cultures of Staphylococcus aureus and Candida albicans both in the absence and in the presence of 5-fluorocytosine (5-FC), we have observed that (1) there is an inhibition of S. aureus growth in mixed cultures with C. albicans in media supplemented with 1 μg/mL of 5-FC and that 5-FC has no effect on staphylococci in pure cultures; (2) this inhibition occurred with clinically isolated and laboratory strains and could be reversed by specific metabolites; (3) Staphylococcus aureus was inhibited by filtrates of C. albicans cultures treated with 5-FC and this seemed to be favored by some C. albicans filterable product which can affect the cell wall and the permeability of the staphylococcal cells since they become sensitive to 5-FC; (4) nine other commonly used antimicrobials showed an increased inhibitory activity against S. aureus in mixed cultures with C. albicans; and (5) there is a decrease in the number of precipitating antigens of S. aureus and of the activity of alpha toxin when this species was grown with both C. albicans and 5-FC. Our results indicate that the susceptibility of some species to antimicrobials could be significantly modified in the presence of other species. One cannot exclude that a similar phenomenon could happen in hosts under treatment with antibiotics against infection.

scholarly journals SSD1 Is Integral to Host Defense Peptide Resistance in Candida albicans

2008 ◽  
Vol 7 (8) ◽  
pp. 1318-1327 ◽  
Author(s):  
Kimberly D. Gank ◽  
Michael R. Yeaman ◽  
Satoshi Kojima ◽  
Nannette Y. Yount ◽  
Hyunsook Park ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Host Defense ◽  
Genomic Library ◽  
Inflammatory Responses ◽  
Host Defense Peptides ◽  
Antimicrobial Peptide Resistance ◽  
Null Mutants

ABSTRACT Candida albicans is usually a harmless human commensal. Because inflammatory responses are not normally induced by colonization, antimicrobial peptides are likely integral to first-line host defense against invasive candidiasis. Thus, C. albicans must have mechanisms to tolerate or circumvent molecular effectors of innate immunity and thereby colonize human tissues. Prior studies demonstrated that an antimicrobial peptide-resistant strain of C. albicans, 36082R, is hypervirulent in animal models versus its susceptible counterpart (36082S). The current study aimed to identify a genetic basis for antimicrobial peptide resistance in C. albicans. Screening of a C. albicans genomic library identified SSD1 as capable of conferring peptide resistance to a susceptible surrogate, Saccharomyces cerevisiae. Sequencing confirmed that the predicted translation products of 36082S and 36082R SSD1 genes were identical. However, Northern analyses corroborated that SSD1 is expressed at higher levels in 36082R than in 36082S. In isogenic backgrounds, ssd1Δ/ssd1Δ null mutants were significantly more susceptible to antimicrobial peptides than parental strains but had equivalent susceptibilities to nonpeptide stressors. Moreover, SSD1 complementation of ssd1Δ/ssd1Δ mutants restored parental antimicrobial peptide resistance phenotypes, and overexpression of SSD1 conferred enhanced peptide resistance. Consistent with these in vitro findings, ssd1 null mutants were significantly less virulent in a murine model of disseminated candidiasis than were their parental or complemented strains. Collectively, these results indicate that SSD1 is integral to C. albicans resistance to host defense peptides, a phenotype that appears to enhance the virulence of this organism in vivo.

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