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1.
Microb Pathog ; 188: 106550, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38262494

RESUMEN

Cytokines of the interleukin (IL)-1 superfamily including the different IL-36 isoforms, have been reported as mediators of acute and chronic inflammation in human skin diseases, such as psoriasis. Here, we demonstrated for the first time that Sporothrix schenckii and S. brasiliensis, the fungi that cause subcutaneous infection sporotrichosis, can induce the expression of IL-36α, IL-36γ and IL-36Ra in human keratinocytes and primary peripheral blood mononuclear cells (PBMCs). Specifically, IL-36γ was differentially expressed by keratinocytes stimulated with Sporothrix yeasts when compared to the commensal microorganism Staphylococcus epidermidis. The exposure of keratinocytes to 24 h or 7-days culture supernatant of PBMCs stimulated with Sporothrix induced higher IL-36γ production compared to direct stimulation of keratinocytes with the live fungus. We identified that IL-36γ mRNA expression in keratinocytes is increased in the presence of IL-17, TNF, IL-1ß and IL-1α and these cytokines may act synergistically to maintain IL-36γ production. Lastly, using a cohort of 164 healthy individuals, we showed that individuals carrying variants of the IL36G gene (rs11690399 and rs11683399) exhibit increased IL-36γ production as well as increased innate cytokine production after Sporothrix exposure. Importantly, stimulation of PBMCs with recombinant IL-36γ increased the production of IL-1ß and IL-6, while IL-36Ra were able to decrease the concentration of these cytokines. Our findings contribute to the understanding of the pathogenesis of sporotrichosis and suggest that IL-36γ may be involved in maintaining the cytokine loop that leads to tissue destruction by exacerbating the immune response in sporotrichosis. Of high interest, we present the IL-36 signalling pathway as a potential new therapeutic target.


Asunto(s)
Sporothrix , Esporotricosis , Humanos , Citocinas/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Interleucinas/genética , Interleucinas/metabolismo , Queratinocitos , Leucocitos Mononucleares , Sporothrix/genética
2.
Mycoses ; 67(1)2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38282360

RESUMEN

Fungal skin infections are distributed worldwide and can be associated with economic and social traits. The immune response related to skin cells is complex and its understanding is essential to the comprehension of each cell's role and the discovery of treatment alternatives. The first studies of trained immunity (TI) described the ability of monocytes, macrophages and natural killer (NK) cells to develop a memory-like response. However, the duration of TI does not reflect the shorter lifespan of these cells. These conclusions supported later studies showing that TI can be observed in stem and haematopoietic cells and, more recently, also in non-immune skin cells such as fibroblasts, highlighting the importance of resident cells in response to skin disorders. Besides, the participation of less studied proinflammatory cytokines in the skin immune response, such as IL-36γ, shed light into a new possibility of inflammatory pathway blockade by drugs. In this review, we will discuss the skin immune response associated with fungal infections, the role of TI in skin and clinical evidence supporting opportunities and challenges of TI and other inflammatory responses in the pathogenesis of fungal skin infections.


Asunto(s)
Micosis , Inmunidad Entrenada , Humanos , Inmunidad Innata , Macrófagos , Monocitos
3.
Cell Immunol ; 378: 104555, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35696852

RESUMEN

Sporotrichosis is a deep mycosis caused by dimorphic species of the genus Sporothrix, with differences in pathogenicity between S. schenckii and S. brasiliensis species. Recently, it was discovered that the cell wall peptidorhamnomannan (PRM) from S. brasiliensis has additional unknown rhamnose residues. We hypothesize that the structural differences of Sporothrix spp PRMs impact the host's immune response and may explain the severity of sporotrichosis caused by S. brasiliensis. We demonstrate that S. brasiliensis yeasts and its PRM (S.b PRM) induced a strong inflammatory response in human PBMCs, with high production of TNF-α, IL-6 and IL-1ß and induction of T-helper cytokines IFN-γ, IL-17 and IL-22. In contrast, S. schenckii yeasts and its PRM induced higher concentrations of interleukin-1 receptor antagonist (IL-1Ra), which resulted in low production of T-helper cytokines such as IL-17 and IL-22. CR3 and dectin-1 were required for cytokine induction by both PRMs, while TLR2 and TLR4 were required for the response of S.s PRM and S.b PRM, respectively. IL-1ß and IL-1α production induced by S. brasiliensis yeasts and S.b PRM were dependent on inflammasome and caspase-1 activation. S. schenckii and S.s PRM were able to induce IL-1ß independent of ROS. In conclusion, these findings improve our understanding of the pathogenesis of Sporothrix spp. by reporting differences of immunological responses induced by S. schenckii and S. brasiliensis. The study also opens the gateway for novel treatment strategies targeting local inflammation and tissue destruction induced by S. brasiliensis infection through IL-1 inhibition.


Asunto(s)
Sporothrix , Esporotricosis , Citocinas , Glicoproteínas , Humanos , Interleucina-17 , Esporotricosis/patología
4.
Vet Dermatol ; 33(2): 113-e32, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34734438

RESUMEN

BACKGROUND: Fungal culture is widely used as a diagnostic tool for detecting dermatophytosis. However, the presence of fungal contaminants can influence the culture's performance and compromise the diagnosis. OBJECTIVE: To verify whether the sample processing time can affect the performance of fungal culture for the diagnosis of Microsporum canis infection in cats. ANIMALS: Forty Persian cats. METHODS AND MATERIALS: Hair and scale samples were collected by combing the coat using a 5 × 5 cm sterile polyester carpet. The carpets were assigned randomly to four groups based on time point of processing samples after collection (i.e. used for culture on a selective agar medium for dermatophytes): Group 1: 8 h (n = 10); Group 2: 24 h (n = 10); Group 3: 48 h (n = 10); and Group 4: 72 h (n = 10). Cultures were compared regarding the degree of fungal invasion by either M. canis or nondermatophytic contaminant moulds (NDM). RESULTS: Processing samples after 24 h of storage resulted in increased isolation rates of NDM and decreased isolation rates of M. canis. Samples processed after 48 h and 72 h presented more than half of the plates with a high degree of fungal contamination (i.e. NDM occupying ≥50% of the total fungal mass). However, samples processed after 8 h and 24 h presented a lower degree (P < 0.05) of NDM plate invasion and higher recovery rates of M. canis when compared to samples processed after 48 h and 72 h. CONCLUSIONS AND CLINICAL IMPORTANCE: Delayed processing time is closely associated with the overgrowth of contaminants and with lower recovery rates of M. canis.


Asunto(s)
Enfermedades de los Gatos , Dermatomicosis , Animales , Enfermedades de los Gatos/diagnóstico , Gatos , Dermatomicosis/diagnóstico , Dermatomicosis/microbiología , Dermatomicosis/veterinaria , Cabello/microbiología , Microsporum , Manejo de Especímenes/veterinaria
5.
Mem Inst Oswaldo Cruz ; 115: e200401, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33146242

RESUMEN

BACKGROUND: Candida glabrata yeast is the second cause of candidiasis worldwide. Differs from other yeasts since assimilates only glucose and trehalose (a characteristic used in rapid identification tests for this pathogen) by secreting into the medium a highly active acid trehalase encoded by the CgATH1 gene. OBJECTIVE: This study aimed to characterise the function of the acid trehalase in the physiopathology of C. glabrata. METHODS: Gene deletion was performed to obtain a mutant ath1Δ strain, and the ability of the ath1Δ strain to grow in trehalase, or the presence of trehalase activity in the ath1Δ yeast cells, was verified. We also tested the virulence of the ath1Δ strain in a murine model of infection. FINDINGS: The ath1Δ mutant strain grows normally in the presence of glucose, but loses its ability to grow in trehalose. Due to the high acid trehalase activity present in wild-type cells, the cytoplasmic neutral trehalase activity is only detected in the ath1Δ strain. We also observed a significantly lower virulence of the ath1Δ strain in a murine model of infection with either normal or immunocompromised mice. MAIN CONCLUSIONS: The acid trehalase is involved in the hydrolysis of external trehalose by C. glabrata, and the enzyme also plays a major virulence role during infectivity.


Asunto(s)
Candida glabrata/genética , Trehalasa/metabolismo , Virulencia/genética , Animales , Candida glabrata/metabolismo , Candida glabrata/patogenicidad , Candida glabrata/fisiología , Candidiasis , Eliminación de Gen , Genes Fúngicos , Hidrolasas , Ratones , Trehalasa/genética , Trehalasa/fisiología , Trehalosa/análisis , Virulencia/fisiología
6.
Med Mycol ; 54(8): 846-55, 2016 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-27343286

RESUMEN

In this study, we analyzed the impact of immunization with the peptidorhamnomannan (PRM) from the cell wall of the fungus Scedosporium (Lomentospora) prolificans in a murine model of invasive scedosporiosis. Immunization with PRM decreased the survival of mice infected with S. prolificans. Immunization of mice with PRM led to decreased secretion of pro-inflammatory cytokines and chemokines but did not affect the secretion of IL-10. Mice immunized with PRM showed an increase in IgG1 secretion, which is an immunoglobulin linked to a nonprotective response. Splenocytes isolated from mice infected with S. prolificans and immunized with PRM showed no differences in the percentages of Th17 cells and no increase in the frequency of the CD4(+)CD62L(Low) T cell population. PRM-immunized mice showed a significant increase in the percentage of Treg cells. In summary, our results indicated that immunization with PRM did not assist or improve the immunological response against S. prolificans infection. PRM exacerbated the infection process by reducing the inflammatory response, thereby facilitating colonization, virulence and dissemination by the fungus.


Asunto(s)
Glicoproteínas/metabolismo , Inmunosupresores/metabolismo , Micosis/microbiología , Micosis/patología , Scedosporium/crecimiento & desarrollo , Scedosporium/inmunología , Animales , Modelos Animales de Enfermedad , Femenino , Vacunas Fúngicas/administración & dosificación , Vacunas Fúngicas/inmunología , Inmunoglobulina G/sangre , Ratones Endogámicos BALB C , Linfocitos T Reguladores/inmunología
7.
Med Mycol ; 52(5): 546-51, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24934802

RESUMEN

Paracoccidioidomycosis (PCM) is a chronic granulomatous disease that is caused by the thermally dimorphic fungus Paracoccidioides brasiliensis. It is endemic in some countries of Latin America and can cause a high-burden fungal infection with significant morbidity and mortality. The peptide P10, which demonstrates immune protection against experimental PCM, was radiolabeled with a radioisotope and evaluated in vivo. The radiolabeling was conducted to trace the pharmacokinetics of the molecule in principal organs and tissues. This was achieved with high radiochemical purity. Biodistribution and scintigraphic imaging showed fast blood clearance that was mainly renal; however, hepatobiliar excretion was also, with marked uptake in cervical lymph nodes. This profile may be useful for the development of a prophylactic drug or vaccine for patients exposed to PCM.


Asunto(s)
Antifúngicos/farmacocinética , Paracoccidioides/inmunología , Paracoccidioidomicosis/microbiología , Péptidos/farmacocinética , Animales , Quelantes/química , Ratones , Ratones Endogámicos BALB C , Paracoccidioidomicosis/prevención & control
8.
Mycopathologia ; 178(3-4): 177-88, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25135302

RESUMEN

Paracoccidioidomycosis is a systemic granulomatous disease caused by Paracoccidioides spp. A peptide from the major diagnostic antigen gp43, named P10, induces a T-CD4(+) helper-1 immune response in mice and protects against intratracheal challenge with virulent P. brasiliensis. Previously, we evaluated the efficacy of the P10 peptide alone or combined with antifungal drugs in mice immunosuppressed and infected with virulent isolate of P. brasiliensis. In the present work, our data suggest that P10 immunization leads to an effective cellular immune response associated with an enhanced T cell proliferative response. P10-stimulated splenocytes increased nitric oxide (NO) production and induced high levels of IFN-γ, IL-1ß and IL-12. Furthermore, significantly increased concentrations of pro-inflammatory cytokines were also observed in lung homogenates of immunized mice. P10 immunization was followed by minimal fibrosis in response to infection. Combined with antifungal drugs, P10 immunization most significantly improved survival of anergic infected mice. Administration of either itraconazole or sulfamethoxazole/trimethoprim together with P10 immunization resulted in 100 % survival up to 200 days post-infection, whereas untreated mice died within 80 days. Hence, our data show that P10 immunization promotes a strong specific immune response even in immunocompromised hosts and thus P10 treatment represents a powerful adjuvant therapy to chemotherapy.


Asunto(s)
Antígenos Fúngicos/inmunología , Vacunas Fúngicas/inmunología , Glicoproteínas/inmunología , Paracoccidioides/inmunología , Paracoccidioidomicosis/prevención & control , Fragmentos de Péptidos/inmunología , Animales , Antígenos Fúngicos/administración & dosificación , Antígenos Fúngicos/genética , Proliferación Celular , Citocinas/metabolismo , Modelos Animales de Enfermedad , Vacunas Fúngicas/administración & dosificación , Vacunas Fúngicas/genética , Glicoproteínas/administración & dosificación , Glicoproteínas/genética , Huésped Inmunocomprometido , Leucocitos Mononucleares/inmunología , Masculino , Ratones Endogámicos BALB C , Óxido Nítrico/metabolismo , Fragmentos de Péptidos/administración & dosificación , Fragmentos de Péptidos/genética , Bazo/inmunología , Análisis de Supervivencia , Vacunación/métodos
9.
Fungal Genet Biol ; 60: 64-73, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23608320

RESUMEN

The principal capsular component of Cryptococcus neoformans, glucuronoxylomannan (GXM), interacts with surface glycans, including chitin-like oligomers. Although the role of GXM in cryptococcal infection has been well explored, there is no information on how chitooligomers affect fungal pathogenesis. In this study, surface chitooligomers of C. neoformans were blocked through the use of the wheat germ lectin (WGA) and the effects on animal pathogenesis, interaction with host cells, fungal growth and capsule formation were analyzed. Treatment of C. neoformans cells with WGA followed by infection of mice delayed mortality relative to animals infected with untreated fungal cells. This observation was associated with reduced brain colonization by lectin-treated cryptococci. Blocking chitooligomers also rendered yeast cells less efficient in their ability to associate with phagocytes. WGA did not affect fungal viability, but inhibited GXM release to the extracellular space and capsule formation. In WGA-treated yeast cells, genes that are involved in capsule formation and GXM traffic had their transcription levels decreased in comparison with untreated cells. Our results suggest that cellular pathways required for capsule formation and pathogenic mechanisms are affected by blocking chitin-derived structures at the cell surface of C. neoformans. Targeting chitooligomers with specific ligands may reveal new therapeutic alternatives to control cryptococcosis.


Asunto(s)
Cryptococcus neoformans/patogenicidad , Cápsulas Fúngicas/metabolismo , Fagocitosis/efectos de los fármacos , Polisacáridos/metabolismo , Aglutininas del Germen de Trigo/farmacología , Animales , Encéfalo/microbiología , Quitina/metabolismo , Criptococosis/tratamiento farmacológico , Criptococosis/patología , Cryptococcus neoformans/crecimiento & desarrollo , Cryptococcus neoformans/metabolismo , Cápsulas Fúngicas/efectos de los fármacos , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Ratones , Ratones Endogámicos C57BL , Aglutininas del Germen de Trigo/metabolismo
10.
J Fungi (Basel) ; 9(5)2023 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-37233259

RESUMEN

Paracoccidioidomycosis (PCM) is a systemic mycosis caused by Paracoccidioides brasiliensis, a thermally dimorphic fungus, which is the most frequent endemic systemic mycosis in many Latin American countries, where ~10 million people are believed to be infected. In Brazil, it is ranked as the tenth most common cause of death among chronic infectious diseases. Hence, vaccines are in development to combat this insidious pathogen. It is likely that effective vaccines will need to elicit strong T cell-mediated immune responses composed of IFNγ secreting CD4+ helper and CD8+ cytolytic T lymphocytes. To induce such responses, it would be valuable to harness the dendritic cell (DC) system of antigen-presenting cells. To assess the potential of targeting P10, which is a peptide derived from gp43 secreted by the fungus, directly to DCs, we cloned the P10 sequence in fusion with a monoclonal antibody to the DEC205 receptor, an endocytic receptor that is abundant on DCs in lymphoid tissues. We verified that a single injection of the αDEC/P10 antibody caused DCs to produce a large amount of IFNγ. Administration of the chimeric antibody to mice resulted in a significant increase in the levels of IFN-γ and IL-4 in lung tissue relative to control animals. In therapeutic assays, mice pretreated with αDEC/P10 had significantly lower fungal burdens compared to control infected mice, and the architecture of the pulmonary tissues of αDEC/P10 chimera-treated mice was largely normal. Altogether, the results obtained so far indicate that targeting P10 through a αDEC/P10 chimeric antibody in the presence of polyriboinosinic: polyribocytidylic acid is a promising strategy in vaccination and therapeutic protocols to combat PCM.

11.
Expert Rev Vaccines ; 22(1): 1136-1153, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37936254

RESUMEN

INTRODUCTION: Fungal infections are caused by a broad range of pathogenic fungi that are found worldwide with different geographic distributions, incidences, and mortality rates. Considering that there are relatively few approved medications available for combating fungal diseases and no vaccine formulation commercially available, multiple groups are searching for new antifungal drugs, examining drugs for repurposing and developing antifungal vaccines, in order to control deaths, sequels, and the spread of these complex infections. AREAS COVERED: This review provides a summary of advances in fungal vaccine studies and the different approaches under development, such as subunit vaccines, whole organism vaccines, and DNA vaccines, as well as studies that optimize the use of adjuvants. We conducted a literature search of the PubMed with terms: fungal vaccines and genus of fungal pathogens (Cryptococcus spp. Candida spp. Coccidioides spp. Aspergillus spp. Sporothrix spp. Histoplasma spp. Paracoccidioides spp. Pneumocystis spp. and the Mucorales order), a total of 177 articles were collected from database. EXPERT OPINION: Problems regarding the immune response development in an immunocompromised organism, the similarity between fungal and mammalian cells, and the lack of attention by health organizations to fungal infections are closely related to the fact that, at present, there are no fungal vaccines available for clinical use.


Asunto(s)
Micosis , Vacunas , Animales , Humanos , Antifúngicos/uso terapéutico , Hongos , Micosis/prevención & control , Micosis/tratamiento farmacológico , Micosis/epidemiología , Vacunas/uso terapéutico , Desarrollo de Vacunas , Mamíferos
12.
BMC Microbiol ; 12: 28, 2012 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-22394555

RESUMEN

BACKGROUND: Antimicrobial peptides are present in animals, plants and microorganisms and play a fundamental role in the innate immune response. Gomesin is a cationic antimicrobial peptide purified from haemocytes of the spider Acanthoscurria gomesiana. It has a broad-spectrum of activity against bacteria, fungi, protozoa and tumour cells. Candida albicans is a commensal yeast that is part of the human microbiota. However, in immunocompromised patients, this fungus may cause skin, mucosal or systemic infections. The typical treatment for this mycosis comprises three major categories of antifungal drugs: polyenes, azoles and echinocandins; however cases of resistance to these drugs are frequently reported. With the emergence of microorganisms that are resistant to conventional antibiotics, the development of alternative treatments for candidiasis is important. In this study, we evaluate the efficacy of gomesin treatment on disseminated and vaginal candidiasis as well as its toxicity and biodistribution. RESULTS: Treatment with gomesin effectively reduced Candida albicans in the kidneys, spleen, liver and vagina of infected mice. The biodistribution of gomesin labelled with technetium-99 m showed that the peptide is captured in the kidneys, spleen and liver. Enhanced production of TNF-α, IFN-γ and IL-6 was detected in infected mice treated with gomesin, suggesting an immunomodulatory activity. Moreover, immunosuppressed and C. albicans-infected mice showed an increase in survival after treatment with gomesin and fluconazole. Systemic administration of gomesin was also not toxic to the mice. CONCLUSIONS: Gomesin proved to be effective against experimental Candida albicans infection. It can be used as an alternative therapy for candidiasis, either alone or in combination with fluconazole. Gomesin's mechanism is not fully understood, but we hypothesise that the peptide acts through the permeabilisation of the yeast membrane leading to death and/or releasing the yeast antigens that trigger the host immune response against infection. Therefore, data presented in this study reinforces the potential of gomesin as a therapeutic antifungal agent in both humans and animals.


Asunto(s)
Antifúngicos/uso terapéutico , Péptidos Catiónicos Antimicrobianos/uso terapéutico , Candidiasis Vulvovaginal/tratamiento farmacológico , Candidiasis/tratamiento farmacológico , Arañas/química , Animales , Péptidos Catiónicos Antimicrobianos/farmacocinética , Candida albicans/efectos de los fármacos , Femenino , Fluconazol/uso terapéutico , Interferón gamma/metabolismo , Interleucina-6/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Pruebas de Sensibilidad Microbiana , Factor de Necrosis Tumoral alfa/metabolismo
13.
Front Immunol ; 12: 670992, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34046037

RESUMEN

Paracoccidioidomycosis (PCM) is an endemic mycosis in Latin America caused by the thermodimorphic fungi of the genus Paracoccidioides spp. Paracoccidioides lutzii (PL) is one of the 5 species that constitute the Paracoccidioides genus. PL expresses low amounts of glycoprotein (Gp) 43 (PLGp43) and PLGp43 displays few epitopes in common with the P. brasiliensis (PB) immunodominant antigen PBGp43, which is commonly used for serological diagnosis of PCM. This difference in structure between the glycoproteins markedly reduces the efficiency of serological diagnosis in patients infected with PL. We previously demonstrated that peptide 10 (P10) from the PBGp43 induces protective immune responses in in vitro and in vivo models of PB PCM. Since, P10 has proven to be a promising therapeutic to combat PB, we sought to identify peptides in PL that could similarly be applied for the treatment of PCM. PL yeast cell proteins were isolated from PL: dendritic cell co-cultures and subjected to immunoproteomics. This approach identified 18 PL peptides that demonstrated in silico predictions for immunogenicity. Eight of the most promising peptides were synthesized and applied to lymphocytes obtained from peptide-immunized or PL-infected mice as well as to in vitro cultures with peptides or dendritic cells pulsed the peptides. The peptides LBR5, LBR6 and LBR8 efficiently promoted CD4+ and CD8+ T cell proliferation and dendritic cells pulsed with LBR1, LBR3, LBR7 or LBR8 stimulated CD4+ T cell proliferation. We observed increases of IFN-γ in the supernatants from primed T cells for the conditions with peptides without or with dendritic cells, although IL-2 levels only increased in response to LBR8. These novel immunogenic peptides derived from PL will be employed to develop new peptide vaccine approaches and the proteins from which they are derived can be used to develop new diagnostic assays for PL and possibly other Paracoccidioides spp. These findings identify and characterize new peptides with a promising therapeutic profile for future against this important neglected systemic mycosis.


Asunto(s)
Antígenos Fúngicos/metabolismo , Linfocitos T CD4-Positivos/inmunología , Células Dendríticas/inmunología , Proteínas Fúngicas/metabolismo , Inmunoterapia/métodos , Macrófagos/inmunología , Paracoccidioides/fisiología , Paracoccidioidomicosis/inmunología , Animales , Antígenos Fúngicos/genética , Proliferación Celular , Células Cultivadas , Resistencia a la Enfermedad , Proteínas Fúngicas/genética , Humanos , Activación de Linfocitos , Activación de Macrófagos , Masculino , Ratones , Ratones Endogámicos BALB C , Paracoccidioidomicosis/terapia , Péptidos/genética , Péptidos/metabolismo
14.
J Fungi (Basel) ; 7(6)2021 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-34071195

RESUMEN

The repurposing strategy was applied herein to evaluate the effects of lopinavir, an aspartic protease inhibitor currently used in the treatment of HIV-infected individuals, on the globally widespread opportunistic human fungal pathogen Candida albicans by using in silico, in vitro and in vivo approaches in order to decipher its targets on fungal cells and its antifungal mechanisms of action. Secreted aspartic proteases (Saps) are the obviously main target of lopinavir. To confirm this hypothesis, molecular docking assays revealed that lopinavir bound to the Sap2 catalytic site of C. albicans as well as inhibited the Sap hydrolytic activity in a typically dose-dependent manner. The inhibition of Saps culminated in the inability of C. albicans yeasts to assimilate the unique nitrogen source (albumin) available in the culture medium, culminating with fungal growth inhibition (IC50 = 39.8 µM). The antifungal action of lopinavir was corroborated by distinct microscopy analyses, which evidenced drastic and irreversible changes in the morphology that justified the fungal death. Furthermore, our results revealed that lopinavir was able to (i) arrest the yeasts-into-hyphae transformation, (ii) disturb the synthesis of neutral lipids, including ergosterol, (iii) modulate the surface-located molecules, such as Saps and mannose-, sialic acid- and N-acetylglucosamine-containing glycoconjugates, (iv) diminish the secretion of hydrolytic enzymes, such as Saps and esterase, (v) negatively influence the biofilm formation on polystyrene surface, (vi) block the in vitro adhesion to epithelial cells, (vii) contain the in vivo infection in both immunocompetent and immunosuppressed mice and (viii) reduce the Sap production by yeasts recovered from kidneys of infected animals. Conclusively, the exposed results highlight that lopinavir may be used as a promising repurposing drug against C. albicans infection as well as may be used as a lead compound for the development of novel antifungal drugs.

15.
Artículo en Inglés | MEDLINE | ID: mdl-33014889

RESUMEN

Treatment modalities for systemic mycoses are still limited. Currently, the main antifungal therapeutics include polyenes, azoles, and echinocandins. However, even in the setting of appropriate administration of antifungals, mortality rates remain unacceptably high. Moreover, antifungal therapy is expensive, treatment periods can range from weeks to years, and toxicity is also a serious concern. In recent years, the increased number of immunocompromised individuals has contributed to the high global incidence of systemic fungal infections. Given the high morbidity and mortality rates, the complexity of treatment strategies, drug toxicity, and the worldwide burden of disease, there is a need for new and efficient therapeutic means to combat invasive mycoses. One promising avenue that is actively being pursued is nanotechnology, to develop new antifungal therapies and efficient vaccines, since it allows for a targeted delivery of drugs and antigens, which can reduce toxicity and treatment costs. The goal of this review is to discuss studies using nanoparticles to develop new therapeutic options, including vaccination methods, to combat systemic mycoses caused by Candida sp., Cryptococcus sp., Paracoccidioides sp., Histoplasma sp., Coccidioides sp., and Aspergillus sp., in addition to providing important information on the use of different types of nanoparticles, nanocarriers and their corresponding mechanisms of action.


Asunto(s)
Micosis , Nanopartículas , Vacunas , Antifúngicos/uso terapéutico , Equinocandinas , Humanos , Micosis/tratamiento farmacológico , Micosis/prevención & control
16.
Front Microbiol ; 11: 582107, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33240236

RESUMEN

Pseudomonas aeruginosa is an opportunistic pathogen associated with life-threatening nosocomial and community-acquired infections. Antibiotic resistance is an immediate threat to public health and demands an urgent action to discovering new antimicrobial agents. One of the best alternatives for pre-clinical tests with animal models is the greater wax moth Galleria mellonella. Here, we evaluated the antipseudomonal activity of silver nanoparticles (AgNPs) against P. aeruginosa strain UCBPP-PA14 using G. mellonella larvae. The AgNPs were synthesized through a non-toxic biogenic process involving microorganism fermentation. The effect of AgNPs was assessed through characterization and quantification of the hemocytic response, nodulation and phenoloxidase cascade. On average, 80% of the larvae infected with P. aeruginosa and prophylactically treated with nanoparticles survived. Both the specific and total larvae hemocyte counts were restored in the treated group. In addition, the nodulation process and the phenoloxidase cascade were less exacerbated when the larvae were exposed to the silver nanoparticles. AgNPs protect the larvae from P. aeruginosa infection by directly killing the bacteria and indirectly by preventing an exacerbated immunological response against the pathogen. Our results suggest that the prophylactic use of AgNPs has a strong protective activity against P. aeruginosa infection.

17.
J Feline Med Surg ; 22(8): 805-808, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-31592711

RESUMEN

OBJECTIVES: The aim of this study was to evaluate the diagnostic concordance between the toothbrush and carpet techniques for the detection of Microsporum canis in cats in a field study. METHODS: Thirty-nine Persian cats from a cattery were used. Fungal culture samples from the haircoat of each cat were collected by stroking the coat with a sterile toothbrush and a 5 × 5 cm-sized sterile carpet square (n = 78 total samples). Specimens were inoculated onto Mycosel Agar and incubated at 25°C for 21 days. Both techniques were compared using the following parameters: number of plates without fungal growth, number of plates with contaminant growth and number of plates positive for dermatophytes. RESULTS: The feline population in the study cattery was 39. Thirty (77%) were symptomatic and nine (23%) asymptomatic. The diagnosis was made via carpet and toothbrush methods and 78 cultures were performed. On day 21, M canis was detected in all culture plates. No contaminant molds were observed. CONCLUSIONS AND RELEVANCE: The concordance rate between the carpet and toothbrush techniques among the 78 evaluable culture plates was 100%. Both methods are equally effective for collecting material for Mcanis culture. Additionally, both techniques are inexpensive and easy to perform in feline clinical practice.


Asunto(s)
Enfermedades de los Gatos/diagnóstico , Técnicas de Cultivo/veterinaria , Dermatomicosis/veterinaria , Microsporum/aislamiento & purificación , Animales , Enfermedades de los Gatos/microbiología , Gatos , Técnicas de Cultivo/métodos , Dermatomicosis/diagnóstico , Dermatomicosis/microbiología
18.
J Fungi (Basel) ; 6(3)2020 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-32664191

RESUMEN

Candida auris and Candida haemulonii complex (C. haemulonii, C. haemulonii var. vulnera and C. duobushaemulonii) are phylogenetically related species that share some physiological features and habits. In the present study, we compared the virulence of these yeast species using two different experimental models: (i) Galleria mellonella larvae to evaluate the survival rate, fungal burden, histopathology and phagocytosis index and (ii) BALB/c mice to evaluate the survival. In addition, the fungal capacity to form biofilm over an inert surface was analyzed. Our results showed that in both experimental models, the animal survival rate was lower when infected with C. auris strains than the C. haemulonii species complex. The hemocytes of G. mellonella showed a significantly reduced ability to phagocytize the most virulent strains forming the C. haemulonii species complex. Interestingly, for C. auris, it was impossible to measure the phagocytosis index due to a general lysis of the hemocytes. Moreover, it was observed a greater capability of biofilm formation by C. auris compared to C. haemulonii species complex. In conclusion, we observed that C. auris and C. haemulonii complex have different levels of pathogenicity in the experimental models employed in the present study.

19.
Infect Immun ; 77(4): 1700-7, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19204092

RESUMEN

Paracoccidioidomycosis (PCM) is a systemic granulomatous disease caused by the dimorphic fungus Paracoccidioides brasiliensis. Anti-PCM vaccine formulations based on the secreted fungal cell wall protein (gp43) or the derived P10 sequence containing a CD4(+) T-cell-specific epitope have shown promising results. In the present study, we evaluated new anti-PCM vaccine formulations based on the intranasal administration of P. brasiliensis gp43 or the P10 peptide in combination with the Salmonella enterica FliC flagellin, an innate immunity agonist binding specifically to the Toll-like receptor 5, in a murine model. BALB/c mice immunized with gp43 developed high-specific-serum immunoglobulin G1 responses and enhanced interleukin-4 (IL-4) and IL-10 levels. On the other hand, mice immunized with recombinant purified flagellins genetically fused with P10 at the central hypervariable domain, either flanked or not by two lysine residues, or the synthetic P10 peptide admixed with purified FliC elicited a prevailing Th1-type immune response based on lung cell-secreted type 1 cytokines. Mice immunized with gp43 and FliC and intratracheally challenged with P. brasiliensis yeast cells had increased fungal proliferation and lung tissue damage. In contrast, mice immunized with the chimeric flagellins and particularly those immunized with P10 admixed with FliC reduced P. brasiliensis growth and lung damage. Altogether, these results indicate that S. enterica FliC flagellin modulates the immune response to P. brasiliensis P10 antigen and represents a promising alternative for the generation of anti-PCM vaccines.


Asunto(s)
Antígenos Fúngicos , Flagelina , Proteínas Fúngicas , Vacunas Fúngicas , Glicoproteínas , Paracoccidioides/inmunología , Paracoccidioidomicosis/prevención & control , Péptidos , Animales , Anticuerpos Antibacterianos/sangre , Especificidad de Anticuerpos , Antígenos Fúngicos/química , Antígenos Fúngicos/genética , Antígenos Fúngicos/inmunología , Citocinas/metabolismo , Modelos Animales de Enfermedad , Flagelina/genética , Flagelina/inmunología , Flagelina/metabolismo , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/inmunología , Vacunas Fúngicas/administración & dosificación , Vacunas Fúngicas/genética , Vacunas Fúngicas/inmunología , Glicoproteínas/química , Glicoproteínas/genética , Glicoproteínas/inmunología , Humanos , Inmunización , Pulmón/inmunología , Pulmón/microbiología , Masculino , Ratones , Ratones Endogámicos BALB C , Paracoccidioides/patogenicidad , Paracoccidioidomicosis/inmunología , Paracoccidioidomicosis/microbiología , Péptidos/síntesis química , Péptidos/genética , Péptidos/inmunología , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Proteínas Recombinantes de Fusión/metabolismo , Salmonella enterica/genética , Salmonella enterica/inmunología , Salmonella enterica/metabolismo
20.
Mem Inst Oswaldo Cruz ; 104(3): 513-21, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19547881

RESUMEN

Deaths caused by systemic mycoses such as paracoccidioidomycosis, cryptococcosis, histoplasmosis, candidiasis, aspergillosis, coccidioidomycosis and zygomycosis amounted to 3,583 between 1996-2006 in Brazil. When analysed as the underlying cause of death, paracoccidioidomycosis represented the most important cause of deaths among systemic mycoses (approximately 51.2%). When considering AIDS as the underlying cause of death and the systemic mycoses as associated conditions, cryptococcosis (50.9%) appeared at the top of the list, followed by candidiasis (30.2%), histoplasmosis (10.1%) and others. This mortality analysis is useful in understanding the real situation of systemic mycoses in Brazil, since there is no mandatory notification of patients diagnosed with systemic mycoses in the official health system.


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/mortalidad , Causas de Muerte , Micosis/mortalidad , Infecciones Oportunistas Relacionadas con el SIDA/clasificación , Adolescente , Adulto , Brasil/epidemiología , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Micosis/clasificación , Paracoccidioidomicosis/mortalidad , Adulto Joven
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