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1.
PLoS Pathog ; 16(2): e1008240, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32106253

RESUMO

Cryptococcus neoformans is an opportunistic human pathogen, which causes serious disease in immunocompromised hosts. Infection with this pathogen is particularly relevant in HIV+ patients, where it leads to around 200,000 deaths per annum. A key feature of cryptococcal pathogenesis is the ability of the fungus to survive and replicate within the phagosome of macrophages, as well as its ability to be expelled from host cells via a novel non-lytic mechanism known as vomocytosis. Here we show that cryptococcal vomocytosis from macrophages is strongly enhanced by viral coinfection, without altering phagocytosis or intracellular proliferation of the fungus. This effect occurs with distinct, unrelated human viral pathogens and is recapitulated when macrophages are stimulated with the anti-viral cytokines interferon alpha or beta (IFNα or IFNß). Importantly, the effect is abrogated when type-I interferon signalling is blocked, thus underscoring the importance of type-I interferons in this phenomenon. Lastly, our data help resolve previous, contradictory animal studies on the impact of type I interferons on cryptococcal pathogenesis and suggest that secondary viral stimuli may alter patterns of cryptococcal dissemination in the host.


Assuntos
Coinfecção , Criptococose , Cryptococcus neoformans , Infecções por HIV , HIV-1 , Macrófagos , Coinfecção/imunologia , Coinfecção/microbiologia , Coinfecção/patologia , Coinfecção/virologia , Criptococose/imunologia , Criptococose/microbiologia , Criptococose/patologia , Criptococose/virologia , Cryptococcus neoformans/imunologia , Cryptococcus neoformans/patogenicidade , Células HEK293 , Infecções por HIV/imunologia , Infecções por HIV/microbiologia , Infecções por HIV/patologia , Infecções por HIV/virologia , HIV-1/imunologia , HIV-1/patogenicidade , Humanos , Interferon-alfa/imunologia , Interferon beta/imunologia , Macrófagos/imunologia , Macrófagos/patologia , Macrófagos/virologia , Transdução de Sinais/imunologia
2.
Nat Chem Biol ; 16(3): 337-344, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31932719

RESUMO

Infection by the fungal pathogen Cryptococcus neoformans causes lethal meningitis, primarily in immune-compromised individuals. Colonization of the brain by C. neoformans is dependent on copper (Cu) acquisition from the host, which drives critical virulence mechanisms. While C. neoformans Cu+ import and virulence are dependent on the Ctr1 and Ctr4 proteins, little is known concerning extracellular Cu ligands that participate in this process. We identified a C. neoformans gene, BIM1, that is strongly induced during Cu limitation and which encodes a protein related to lytic polysaccharide monooxygenases (LPMOs). Surprisingly, bim1 mutants are Cu deficient, and Bim1 function in Cu accumulation depends on Cu2+ coordination and cell-surface association via a glycophosphatidyl inositol anchor. Bim1 participates in Cu uptake in concert with Ctr1 and expression of this pathway drives brain colonization in mouse infection models. These studies demonstrate a role for LPMO-like proteins as a critical factor for Cu acquisition in fungal meningitis.


Assuntos
Cobre/metabolismo , Cryptococcus neoformans/metabolismo , Oxigenases de Função Mista/metabolismo , Animais , Criptococose/metabolismo , Cryptococcus neoformans/patogenicidade , Modelos Animais de Doenças , Feminino , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Meningite/metabolismo , Meningite/fisiopatologia , Camundongos , Camundongos Endogâmicos A , Polissacarídeos/metabolismo , Virulência
3.
Infect Immun ; 88(3)2020 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-31871099

RESUMO

Cryptococcosis is an infectious disease caused by two fungal species, Cryptococcus neoformans and Cryptococcus gattii While C. neoformans affects mainly immunocompromised patients, C. gattii infects both immunocompetent and immunocompromised individuals. Laccase is an important virulence factor that contributes to the virulence of C. neoformans by promoting pulmonary growth and dissemination to the brain. The presence of laccase in C. neoformans can shift the host immune response toward a nonprotective Th2-type response. However, the role of laccase in the immune response against C. gattii remains unclear. In this study, we characterized laccase activity in C. neoformans and C. gattii isolates from Thailand and investigated whether C. gattii that is deficient in laccase might modulate immune responses during infection. C. gattii was found to have higher laccase activity than C. neoformans, indicating the importance of laccase in the pathogenesis of C. gattii infection. The expression of laccase promoted intracellular proliferation in macrophages and inhibited in vitro fungal clearance. Mice infected with a lac1Δ mutant strain of C. gattii had reduced lung burdens at the early but not the late stage of infection. Without affecting type-1 and type-2 responses, the deficiency of laccase in C. gattii induced cryptococcus-specific interleukin-17 (IL-17) cytokine, neutrophil accumulation, and expression of the neutrophil-associated cytokine gene Csf3 and chemokine genes Cxcl1, Cxcl2, and Cxcl5 in vivo, as well as enhanced neutrophil-mediated phagocytosis and killing in vitro Thus, our data suggest that laccase constitutes an important virulence factor of C. gattii that plays roles in attenuating Th17-type immunity, neutrophil recruitment, and function during the early stage of infection.


Assuntos
Criptococose , Cryptococcus gattii/imunologia , Cryptococcus neoformans/imunologia , Lacase/metabolismo , Animais , Proliferação de Células , Quimiocinas/metabolismo , Criptococose/imunologia , Criptococose/metabolismo , Cryptococcus gattii/patogenicidade , Cryptococcus neoformans/patogenicidade , Citocinas/metabolismo , Macrófagos/imunologia , Camundongos , Neutrófilos/metabolismo , Virulência/imunologia , Fatores de Virulência/metabolismo
4.
Nat Commun ; 10(1): 4566, 2019 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-31594939

RESUMO

Fungal dissemination into the bloodstream is a critical step leading to invasive fungal infections. Here, using intravital imaging, we show that Kupffer cells (KCs) in the liver have a prominent function in the capture of circulating Cryptococcus neoformans and Candida albicans, thereby reducing fungal dissemination to target organs. Complement C3 but not C5, and complement receptor CRIg but not CR3, are involved in capture of C. neoformans. Internalization of C. neoformans by KCs is subsequently mediated by multiple receptors, including CR3, CRIg, and scavenger receptors, which work synergistically along with C5aR signaling. Following phagocytosis, the growth of C. neoformans is inhibited by KCs in an IFN-γ independent manner. Thus, the liver filters disseminating fungi from circulation via KCs, providing a mechanistic explanation for the enhanced risk of cryptococcosis among individuals with liver diseases, and suggesting a therapeutic strategy to prevent fungal dissemination through enhancing KC functions.


Assuntos
Infecções Fúngicas Invasivas/imunologia , Macrófagos do Fígado/imunologia , Fígado/imunologia , Fagocitose , Animais , Candida albicans/imunologia , Candida albicans/isolamento & purificação , Candida albicans/patogenicidade , Complemento C3/genética , Complemento C3/imunologia , Complemento C3/metabolismo , Cryptococcus neoformans/imunologia , Cryptococcus neoformans/isolamento & purificação , Cryptococcus neoformans/patogenicidade , Modelos Animais de Doenças , Feminino , Humanos , Microscopia Intravital , Infecções Fúngicas Invasivas/sangue , Infecções Fúngicas Invasivas/microbiologia , Macrófagos do Fígado/metabolismo , Macrófagos do Fígado/microbiologia , Fígado/citologia , Fígado/diagnóstico por imagem , Masculino , Camundongos , Camundongos Knockout , Microscopia Confocal , Receptores de Complemento/genética , Receptores de Complemento/imunologia , Receptores de Complemento/metabolismo
5.
mSphere ; 4(5)2019 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-31578250

RESUMO

Felipe Santiago-Tirado studies the cell biology of cryptococcal infections. In this mSphere of Influence article, he reflects on how the papers "Systematic Genetic Analysis of Virulence in the Human Fungal Pathogen Cryptococcus neoformans" (https://doi.org/10.1016/j.cell.2008.07.046) and "Unraveling the Biology of a Fungal Meningitis Pathogen Using Chemical Genetics" (https://doi.org/10.1016/j.cell.2014.10.044) by the Noble and Madhani groups influenced his thinking by showcasing the various modern applications of yeast genetics in an organism where genetic manipulation was difficult.


Assuntos
Cryptococcus neoformans/genética , Cryptococcus neoformans/patogenicidade , Fatores de Virulência/genética , Proteínas Fúngicas/genética , Deleção de Genes , Humanos , Virulência
6.
PLoS Genet ; 15(9): e1008394, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31536509

RESUMO

Courtship is pivotal for successful mating. However, courtship is challenging for the Cryptococcus neoformans species complex, comprised of opportunistic fungal pathogens, as the majority of isolates are α mating type. In the absence of mating partners of the opposite mating type, C. deneoformans can undergo unisexual reproduction, during which a yeast-to-hyphal morphological transition occurs. Hyphal growth during unisexual reproduction is a quantitative trait, which reflects a strain's ability to undergo unisexual reproduction. In this study, we determined whether unisexual reproduction confers an ecological benefit by promoting foraging for mating partners. Through competitive mating assays using strains with different abilities to produce hyphae, we showed that unisexual reproduction potential did not enhance competition for mating partners of the same mating type, but when cells of the opposite mating type were present, cells with enhanced hyphal growth were more competitive for mating partners of either the same or opposite mating type. Enhanced mating competition was also observed in a strain with increased hyphal production that lacks the mating repressor gene GPA3, which contributes to the pheromone response. Hyphal growth in unisexual strains also enables contact between adjacent colonies and enhances mating efficiency during mating confrontation assays. The pheromone response pathway activation positively correlated with unisexual reproduction hyphal growth during bisexual mating and exogenous pheromone promoted bisexual cell fusion. Despite the benefit in competing for mating partners, unisexual reproduction conferred a fitness cost. Taken together, these findings suggest C. deneoformans employs hyphal growth to facilitate contact between colonies at long distances and utilizes pheromone sensing to enhance mating competition.


Assuntos
Cryptococcus neoformans/genética , Genes Fúngicos Tipo Acasalamento/genética , Reprodução Assexuada/fisiologia , Comunicação Celular , Fusão Celular , Cryptococcus/genética , Cryptococcus/patogenicidade , Cryptococcus neoformans/patogenicidade , Proteínas Fúngicas/genética , Genes Fúngicos Tipo Acasalamento/fisiologia , Hifas/genética , Feromônios , Reprodução/genética , Reprodução Assexuada/genética
7.
Drug Discov Ther ; 13(4): 177-182, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31534068

RESUMO

Cryptococcus neoformans, a human pathogenic fungus, infects immunocompromised humans and causes serious diseases such as cerebral meningitis. C. neoformans controls the expression of virulence factors in response to the host environment via various signal transduction pathways. Understanding the molecular mechanisms involved in C. neoformans infection will contribute to the development of methods to prevent and treat C. neoformans-related diseases. C. neoformans produces virulence factors, such as a polysaccharide capsule and melanin, to escape host immunity. Several proteins of C. neoformans are reported to regulate production of the virulence factors. In this review, on the basis of studies using gene-deficient mutants of C. neoformans and animal infection models, we outline the signal transduction pathways involved in the regulation of virulence factors.


Assuntos
Criptococose/microbiologia , Cryptococcus neoformans/patogenicidade , Fatores de Virulência/metabolismo , Animais , Criptococose/metabolismo , Cryptococcus neoformans/genética , Modelos Animais de Doenças , Regulação Fúngica da Expressão Gênica , Humanos , Evasão da Resposta Imune , Mutação , Transdução de Sinais , Fatores de Virulência/genética
8.
mSphere ; 4(4)2019 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-31391283

RESUMO

Cryptococcus neoformans is an important fungal pathogen, causing life-threatening pneumonia and meningoencephalitis. Brain dissemination of C. neoformans is thought to be a consequence of an active infection in the lung which then extravasates to other sites. Brain invasion results from dissemination via either transport by free yeast cells in the bloodstream or Trojan horse transport within mononuclear phagocytes. We assessed brain dissemination in three mouse models of infection: intravenous, intratracheal, and intranasal models. All three modes of infection resulted in dissemination of C. neoformans to the brain in less than 3 h. Further, C. neoformans was detected in the entirety of the upper respiratory tract and the ear canals of mice. In recent years, intranasal infection has become a popular mechanism to induce pulmonary infection because it avoids surgery, but our findings show that instillation of C. neoformans produces cryptococcal nasal infection. These findings imply that immunological studies using intranasal infection should assume that the initial sites of infection of infection are brain, lung, and upper respiratory tract, including the nasal airways.IMPORTANCE Cryptococcus neoformans causes an estimated 181, 000 deaths each year, mostly associated with untreated HIV/AIDS. C. neoformans has a ubiquitous worldwide distribution. Humans become infected from exposure to environmental sources, after which the fungus lays dormant within the human body. Upon AIDS-induced immunosuppression or therapy-induced immunosuppression (required for organ transplant recipients or those suffering from autoimmune disorders), cryptococcal disease reactivates and causes life-threatening meningitis and pneumonia. This study showed that upon contact with the host, C. neoformans can quickly (a few hours) reach the host brain and also colonizes the nose of infected animals. Therefore, this work paves the way to better knowledge of how C. neoformans travels through the host body. Understanding how C. neoformans infects, disseminates, and survives within the host is critically required so that we can prevent infections and the disease caused by this deadly fungus.


Assuntos
Administração Intranasal , Encéfalo/microbiologia , Criptococose/microbiologia , Cryptococcus neoformans/patogenicidade , Nariz/microbiologia , Administração Intravenosa , Animais , Modelos Animais de Doenças , Pulmão/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Traqueia/microbiologia
9.
Gene ; 717: 144043, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31400407

RESUMO

Genes involved in the repair of DNA damage are emerging as playing important roles during the disease processes caused by pathogenic fungi. However, there are potentially hundreds of genes involved in DNA repair in a fungus and some of those genes can play additional roles within the cell. One such gene is RAD23, required for virulence of the human pathogenic fungus Cryptococcus neoformans, that encodes a protein involved in the nucleotide excision repair (NER) pathway. However, Rad23 is a dual function protein, with a role in either repair of damaged DNA or protein turn over by directing proteins to the proteasome. Here, these two functions of Rad23 were tested by the creation of a series of domain deletion alleles of RAD23 and the assessment of the strains for DNA repair, proteasome functions, and virulence properties. Deletion of the different domains was able to uncouple the two functions of Rad23, and the phenotypes of strains carrying such forms indicated that the role of RAD23 in virulence is due to its function in proteasomal-mediated protein degradation rather than NER.


Assuntos
Cryptococcus neoformans/genética , Cryptococcus neoformans/patogenicidade , Reparo do DNA/fisiologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Animais , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Larva/microbiologia , Mariposas/microbiologia , Mutação , Complexo de Endopeptidases do Proteassoma/metabolismo , Domínios Proteicos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Estresse Fisiológico/genética , Virulência
10.
BMC Infect Dis ; 19(1): 710, 2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31405376

RESUMO

BACKGROUND: Pulmonary Cryptococcosis (PC) is diagnosed with increasing incidence in recent years, but it does not commonly involve the pleural space. Here, we report a HIV-negative case with advanced stage IIIB non-small cell lung cancer (NSCLC) treated with radiation therapy presented with dyspnea, a new PET-positive lung mass and bilateral pleural effusion suspecting progressive cancer. However, the patient has been diagnosed as pulmonary cryptococcal infection and successfully treated with oral fluconazole therapy. CASE PRESENTATION: A 77-year-old male with advanced stage non-small cell lung cancer treated with combined chemo-radiation therapy who presented with progressive dyspnea, a new PET-positive left lower lobe lung mass and bilateral pleural effusions. Initial diagnostic thoracentesis and bronchoscopy yielded no cancer, but instead found yeast forms consistent with cryptococcal organisms in the transbronchial biopsies of the left lower lobe lung mass. Subsequent to this, the previously collected pleural fluid culture showed growth of Cryptococcus neoformans. The same sample of pleural effusion was tested and was found to be positive for crytococcal antigen (CrAg) by a lateral flow assay (LFA). The patient has been treated with oral fluconazole therapy resulting in gradual resolution of the nodular infiltrates. CONCLUSION: PC should be considered in immunosuppressed cancer patients. Additionally, concomitant pleural involvement in pulmonary cryptococcal infections may occur. The incidence of false positive 18FDG-PET scans in granulomatous infections and the use of CrAg testing in pleural fluid to aid in diagnosis are reviewed.


Assuntos
Criptococose/diagnóstico por imagem , Criptococose/microbiologia , Pneumopatias Fúngicas/diagnóstico por imagem , Pneumopatias Fúngicas/microbiologia , Derrame Pleural/microbiologia , Administração Oral , Idoso , Antifúngicos/administração & dosagem , Antifúngicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/complicações , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Criptococose/tratamento farmacológico , Cryptococcus neoformans/patogenicidade , Fluconazol/administração & dosagem , Fluconazol/uso terapêutico , Humanos , Hospedeiro Imunocomprometido , Pneumopatias Fúngicas/tratamento farmacológico , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/radioterapia , Masculino , Derrame Pleural/diagnóstico por imagem , Derrame Pleural/etiologia , Tomografia por Emissão de Pósitrons
11.
J Mycol Med ; 29(3): 273-277, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31409527

RESUMO

Following a fatal case of Cryptococcus neoformans meningitis in a child with X-linked hyper-immunoglobulin M syndrome (XHIGM), we evaluated the fungal isolate in an experimental infection in a mouse model with respect to microbiology, epidemiology, virulence and response to therapy. The minimum inhibitory concentrations for antifungals in the susceptibility test were 0.5mg/L for amphotericin B, 4.0mg/L for fluconazole and 0.12mg/L for voriconazole. Evaluation of pathogenicity by means of an experimental infection in BALB/c mice showed that fungus isolated from the blood and cerebrospinal fluid of the child was able to disseminate, reaching the spleen, lungs and brain, where it caused significant macroscopic alterations in the size and texture of each organ. Treatment of infected mice with amphotericin B reduced the fungal load in the spleen and lungs, but not in the brain.


Assuntos
Cryptococcus neoformans/isolamento & purificação , Cryptococcus neoformans/patogenicidade , Síndrome de Imunodeficiência com Hiper-IgM Tipo 1/complicações , Síndrome de Imunodeficiência com Hiper-IgM Tipo 1/microbiologia , Meningite Criptocócica/diagnóstico por imagem , Meningite Criptocócica/microbiologia , Anfotericina B/farmacologia , Animais , Antifúngicos/farmacologia , Pré-Escolar , Cryptococcus neoformans/efeitos dos fármacos , Modelos Animais de Doenças , Evolução Fatal , Humanos , Síndrome de Imunodeficiência com Hiper-IgM Tipo 1/diagnóstico , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Tomografia Computadorizada por Raios X
12.
PLoS Pathog ; 15(7): e1007945, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31356623

RESUMO

Metabolically quiescent pathogens can persist in a viable non-replicating state for months or even years. For certain infectious diseases, such as tuberculosis, cryptococcosis, histoplasmosis, latent infection is a corollary of this dormant state, which has the risk for reactivation and clinical disease. During murine cryptococcosis and macrophage uptake, stress and host immunity induce Cryptococcus neoformans heterogeneity with the generation of a sub-population of yeasts that manifests a phenotype compatible with dormancy (low stress response, latency of growth). In this subpopulation, mitochondrial transcriptional activity is regulated and this phenotype has been considered as a hallmark of quiescence in stem cells. Based on these findings, we worked to reproduce this phenotype in vitro and then standardize the experimental conditions to consistently generate this dormancy in C. neoformans. We found that incubation of stationary phase yeasts (STAT) in nutriment limited conditions and hypoxia for 8 days (8D-HYPOx) was able to produced cells that mimic the phenotype obtained in vivo. In these conditions, mortality and/or apoptosis occurred in less than 5% of the yeasts compared to 30-40% of apoptotic or dead yeasts upon incubation in normoxia (8D-NORMOx). Yeasts in 8D-HYPOx harbored a lower stress response, delayed growth and less that 1% of culturability on agar plates, suggesting that these yeasts are viable but non culturable cells (VBNC). These VBNC were able to reactivate in the presence of pantothenic acid, a vitamin that is known to be involved in quorum sensing and a precursor of acetyl-CoA. Global metabolism of 8D-HYPOx cells showed some specific requirements and was globally shut down compared to 8D-NORMOx and STAT conditions. Mitochondrial analyses showed that the mitochondrial mass increased with mitochondria mostly depolarized in 8D-HYPOx compared to 8D-NORMox, with increased expression of mitochondrial genes. Proteomic and transcriptomic analyses of 8D-HYPOx revealed that the number of secreted proteins and transcripts detected also decreased compared to 8D-NORMOx and STAT, and the proteome, secretome and transcriptome harbored specific profiles that are engaged as soon as four days of incubation. Importantly, acetyl-CoA and the fatty acid pathway involving mitochondria are required for the generation and viability maintenance of VBNC. Altogether, these data show that we were able to generate for the first time VBNC phenotype in C. neoformans. This VBNC state is associated with a specific metabolism that should be further studied to understand dormancy/quiescence in this yeast.


Assuntos
Cryptococcus neoformans/fisiologia , Cryptococcus neoformans/patogenicidade , Animais , Criptococose/microbiologia , Cryptococcus neoformans/genética , Meios de Cultura , Ácidos Graxos/metabolismo , Proteínas Fúngicas/metabolismo , Humanos , Camundongos , Viabilidade Microbiana , Mitocôndrias/genética , Mitocôndrias/metabolismo , Oxigênio/metabolismo , Ácido Pantotênico/farmacologia , Fenótipo , Transcriptoma
13.
PLoS Negl Trop Dis ; 13(7): e0007566, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31329596

RESUMO

Pathogens and hosts require rapid modulation of virulence and defense mechanisms at the infection axis, but monitoring such modulations is challenging. In studying the human fungal pathogen Cryptococcus neoformans, mouse and rabbit infection models are often employed to shed light on the disease mechanisms but that may not be clinically relevant. In this study, we developed an animal infection model using the non-human primate cynomolgus monkey Macaca fascicularis. In addition, we systematically profiled and compared transcriptional responses between the infected mice and the cynomolgus monkey, using simultaneous or dual RNA next-generation sequencing. We demonstrated that there are shared but distinct transcriptional profiles between the two models following C. neoformans infection. Specifically, genes involved in immune and inflammatory responses are all upregulated. Osteoclastogenesis and insulin signaling are also significantly co-regulated in both models and disrupting an osteoclastogenesis-associated gene (OC-STAMP) or the insulin-signaling process significantly altered the host tolerance to C. neoformans. Moreover, C. neoformans was shown to activate metal sequestration, dampen the sugar metabolism, and control cell morphology during infection. Taking together, we described the development of a non-human primate model of cryptococcosis that allowed us to perform an in-depth analysis and comparison of transcriptome profiles during infections of two animal models and conceptually identify host genes important in disease responses. This study provides new insights in understanding fungal pathogenesis mechanisms that potentially facilitate the identification of novel drug targets for the treatment of cryptococcal infection.


Assuntos
Criptococose/genética , Cryptococcus neoformans , Perfilação da Expressão Gênica , Pneumopatias Fúngicas/genética , Animais , Criptococose/imunologia , Criptococose/microbiologia , Cryptococcus neoformans/genética , Cryptococcus neoformans/imunologia , Cryptococcus neoformans/patogenicidade , Modelos Animais de Doenças , Insulina/metabolismo , Pneumopatias Fúngicas/imunologia , Pneumopatias Fúngicas/microbiologia , Macaca fascicularis , Masculino , Proteínas de Membrana/metabolismo , Metais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Osteogênese , Análise de Sequência de RNA , Transdução de Sinais , Virulência/genética
14.
J Mycol Med ; 29(3): 239-244, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31221506

RESUMO

BACKGROUND: Evaluation of the pathogenesis of clinical and environmental cryptococcal isolates to the central nervous system is necessary for understanding the risk. This study was designed to determine the in vitro expression of six important virulent genes of Cryptococcus neoformans/gattii in Human Brain Microvascular Endothelial cells (hBMEC). METHODS: The hBMEC were infected with Cryptococcus to determine invasion and survival rate at 3, 12 and 24hours by subsequent colony count of internalized yeasts. The whole RNA of the intracellular Cryptococcus was extracted to quantify the expression of CAP10, PLB1, ENA1, URE1, LAC1, and MATα genes by real-time quantitative PCR for 3 and 12hours of infection. RESULTS: Invasion and survival rates were higher in clinical and standard strains of C. neoformans. A significant difference was observed among the clinical and environmental isolates for the expression of CAP10, ENA1, LAC1, MATα and URE1 at 3hours, and ENA1, LAC1, MATα, PLB1 and URE1 at 12hours. Clinical isolates showed significant upregulation of all the genes except PLB1, which was higher in environmental isolates. Relative expressions at the two time-points showed statistically significant (P=0.043) changes for the clinical isolates and no significance (P=0.063) for environmental isolates. CONCLUSION: The C. gattii (VGI) isolates showed significantly lower invasion and survival than C. neoformans (VNI, and VNII) irrespective of their sources. Clinical isolates exhibited higher expression for the majority of the virulent genes until 12hours of infection, probably due to their better adaptation in the host system and enhanced pathogenicity than the environmental counterparts.


Assuntos
Barreira Hematoencefálica/microbiologia , Cryptococcus gattii/genética , Cryptococcus gattii/patogenicidade , Cryptococcus neoformans/genética , Cryptococcus neoformans/patogenicidade , Células Endoteliais/virologia , Fatores de Virulência/genética , Barreira Hematoencefálica/citologia , Linhagem Celular , Criptococose/microbiologia , Microbiologia Ambiental , Proteínas Fúngicas/genética , Expressão Gênica , Genótipo , Interações entre Hospedeiro e Microrganismos/genética , Humanos
15.
J Infect Chemother ; 25(11): 901-905, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31182330

RESUMO

INTRODUCTION: Cryptococcus neoformans is known to be a cause of meningitis. However, as cryptococcal endocarditis is rare, it is not well understood. Here, we describe a case with Implantable Cardioverter Defibrillator associated endocarditis and meningitis caused by Cryptococcus neoformans and we review the literature associated cryptococcal endocarditis. CASE PRESENTATION: A 72 years old Japanese male presented in emergency department with non-productive cough and respiratory discomfort. His past medical history was ischemic heart disease four years ago and ICD was implanted. Physical examination was unremarkable. Chest computer tomography revealed ground glass opacity in the right lung. He received a diagnosis of amiodarone-induced interstitial pneumonitis and high dose steroid pulse therapy. Septic shock and acute respiratory failure occurred after steroid therapy. Cryptococcus neoformans was identified by blood culture and cerebral spinal fluid. Intravenous liposomal Amphotericin B and oral flucytosine were initiated. Transesophageal echocardiography revealed vegetation on the lead of the ICD. Diagnosis of cryptococcal endocarditis was made. The patient died despite antifungal therapy was continued. DISCUSSION: We analyzed our case and 8 cases of cryptococcal endocarditis in the literature for 40 years. Almost all of the patients had previous valve replacement surgery or immunocompromised state. Three cases had meningitis. Surgery performed in 3 cases. The overall mortality rate were 44.4%. CONCLUSIONS: Cryptococcal endocarditis is rare and carries a high mortality. Almost all of the patients had underlying diseases. Diagnosis needs repeating blood culture and echocardiogram, sometimes. Cryptococcal endocarditis needs lumber puncture for rule out meningitis.


Assuntos
Criptococose/diagnóstico , Cryptococcus neoformans/patogenicidade , Idoso , Antifúngicos/uso terapêutico , Criptococose/tratamento farmacológico , Criptococose/microbiologia , Criptococose/mortalidade , Cryptococcus neoformans/efeitos dos fármacos , Humanos , Masculino , Meningite Criptocócica/diagnóstico , Meningite Criptocócica/tratamento farmacológico , Meningite Criptocócica/microbiologia , Meningite Criptocócica/mortalidade
16.
Prensa méd. argent ; 105(5): 302-308, jun 2019. fig, tab
Artigo em Inglês | LILACS, BINACIS | ID: biblio-1024638

RESUMO

Aim: The current venture, were made to evaluate the inhibitory effect of Trigonella foenum seed Extract and ZiO2 Nanoparticles on some selected species of Fungi and Bacteria. Materials and Methods: two bacterial species included Pseudomonas aeruginosa and Staphylococcus aureus and three fungal species which is Cryptococcus neoformans, Candidda albicans and Chaetomium were used to evaluate the antibacterial activity of Trigonella foenum Extract and ZiO2 Nanoparticles. Results: This study showed that the Zirconium Oxide (ZiO2) nanoparticles have antifungal and antibacterial activities on the isolates of Cryptococcus neoformans, Candida alicans and Staphylococcus aureus, respectively. While the antimicrobial activity of Zirconium Oxide nanoparticles on the Chaetomium and Pseudomonas aeruginosa was negative. All tested fungi and bacterial isolates were found to be sensitive to Trigonella foenum seed extract, the results of the compination of the ZiO2 Nanoparticle and the Trigonella foenum seed extract were poisitive for all tested fungi isolates and bacterial isolates. The XRD analysis was done for Zirconium Oxide nanoparticles and the result showed that the biocrystallization on the surface of the Zirconium Oxide manoparticles. The average partides size was about (29.8) nm. Conclusions: This investigation conclude that the use of Trigonella foenum seed Extract has the effect of killing all bacteria and fungi under study, result indicate the Trigonella foenun seed Extract best antibacterial efficacy than the ZiO2 together (AU)


Assuntos
Humanos , Pseudomonas aeruginosa/patogenicidade , Staphylococcus aureus/patogenicidade , Candida albicans/patogenicidade , Chaetomium/patogenicidade , Cryptococcus neoformans/patogenicidade , Trigonella/microbiologia , Nanopartículas/efeitos adversos , Fabaceae/efeitos adversos , Anti-Infecciosos/uso terapêutico , Antibacterianos/uso terapêutico , Antifúngicos/uso terapêutico
17.
Am J Med ; 132(8): 977-983.e1, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31077652

RESUMO

BACKGROUND: Cryptococcal epidemiology is changing in the modern antiretroviral era, and immune status informs outcomes. We describe the differences in clinical presentation and mortality of cryptococcosis by immune status in the antiretroviral therapy era. METHODS: We conducted a single-center retrospective cohort study of patients diagnosed with cryptococcosis from 2002 through 2017. Data included demographics, clinical features, diagnostics, and mortality. RESULTS: We identified 304 patients with Cryptococcus neoformans infections: 105 (35%) were people living with human immunodeficiency virus (HIV), 41 (13%) had a history of transplantation, and 158 (52%) were non-HIV nontransplant (NHNT). Age analysis showed that people living with HIV were younger (40 years) than transplant (53 years) and NHNT (61 years) (P < .001). Fevers and headache were more common in people living with HIV (70% and 57%) than in transplant (49% and 29%) and NHNT (49% and 38%) (P = .003 and P = .001), respectively. Meningitis was more common in people living with HIV (68%) than in transplant recipients (32%) or NHNT (39%, P < .001). Disseminated cryptococcosis was more common in people living with HIV (97%) as compared with transplant (66%) or NHNT (73%) (P < .001). Time to diagnosis from hospitalization was longer for transplant (median 2 days, interquartile range [IQR] ± 9 days) and NHNT patients (median 2 days, IQR ± 7 days) as compared with people living with HIV (median 1 day, IQR ± 2 days) (P = .003). NHNT patients had a higher risk of 90-day mortality (hazard ratio 3.3; 95% confidence interval, 1.9-5.8) as compared with people living with HIV. CONCLUSIONS: The majority of cryptococcosis occurs in NHNT patients. NHNT patients had more localized pulmonary cryptococcosis and significantly higher 90-day mortality. Cryptococcosis in NHNT patients appears to be a distinct entity that needs further study and requires a higher level of clinical suspicion than it currently receives.


Assuntos
Criptococose/mortalidade , Adulto , Estudos de Coortes , Criptococose/etiologia , Cryptococcus neoformans/efeitos dos fármacos , Cryptococcus neoformans/patogenicidade , Feminino , Infecções por HIV/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Transplante de Órgãos/efeitos adversos , Transplante de Órgãos/métodos , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Estatísticas não Paramétricas
18.
Nat Commun ; 10(1): 2035, 2019 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-31048698

RESUMO

Cryptococcus neoformans (C. neoformans var. grubii) is an environmentally acquired pathogen causing 181,000 HIV-associated deaths each year. We sequenced 699 isolates, primarily C. neoformans from HIV-infected patients, from 5 countries in Asia and Africa. The phylogeny of C. neoformans reveals a recent exponential population expansion, consistent with the increase in the number of susceptible hosts. In our study population, this expansion has been driven by three sub-clades of the C. neoformans VNIa lineage; VNIa-4, VNIa-5 and VNIa-93. These three sub-clades account for 91% of clinical isolates sequenced in our study. Combining the genome data with clinical information, we find that the VNIa-93 sub-clade, the most common sub-clade in Uganda and Malawi, was associated with better outcomes than VNIa-4 and VNIa-5, which predominate in Southeast Asia. This study lays the foundation for further work investigating the dominance of VNIa-4, VNIa-5 and VNIa-93 and the association between lineage and clinical phenotype.


Assuntos
Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Criptococose/microbiologia , Cryptococcus neoformans/genética , Genoma Fúngico/genética , Filogenia , Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Antifúngicos/uso terapêutico , Ensaios Clínicos como Assunto , Criptococose/epidemiologia , Cryptococcus neoformans/isolamento & purificação , Cryptococcus neoformans/patogenicidade , Humanos , Incidência , Laos/epidemiologia , Malaui/epidemiologia , Tailândia/epidemiologia , Resultado do Tratamento , Uganda/epidemiologia , Vietnã/epidemiologia , Sequenciamento Completo do Genoma
19.
Biopolymers ; 110(6): e23276, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30938841

RESUMO

Cryptococcus neoformans is a fungal pathogen that causes cryptococcal meningitis in immunocompromised individuals. Existing antifungal treatment plans have high mammalian toxicity and increasing drug resistance, demonstrating the dire need for new, nontoxic therapeutics. Antimicrobial peptoids are one alternative to combat this issue. Our lab has recently identified a tripeptoid, AEC5, with promising efficacy and selectivity against C. neoformans. Here, we report studies into the broad-spectrum efficacy, killing kinetics, mechanism of action, in vivo half-life, and subchronic toxicity of this compound. Most notably, these studies have demonstrated that AEC5 rapidly reduces fungal burden, killing all viable fungi within 3 hours. Additionally, AEC5 has an in vivo half-life of 20+ hours and no observable in vivo toxicity following 28 days of daily injections. This research represents an important step in the characterization of AEC5 as a practical treatment option against C. neoformans infections.


Assuntos
Antifúngicos/química , Peptoides/química , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Linhagem Celular , Cryptococcus neoformans/efeitos dos fármacos , Cryptococcus neoformans/patogenicidade , Sinergismo Farmacológico , Flucitosina/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Meia-Vida , Humanos , Rim/efeitos dos fármacos , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/patologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/microbiologia , Meningite Criptocócica/tratamento farmacológico , Meningite Criptocócica/patologia , Testes de Sensibilidade Microbiana , Peptoides/metabolismo , Peptoides/farmacologia , Peptoides/uso terapêutico , Sorbitol/química
20.
PLoS Pathog ; 15(3): e1007627, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30897162

RESUMO

Cryptococcus neoformans is a leading cause of invasive fungal infections among immunocompromised patients. However, the cellular constituents of the innate immune response that promote clearance versus progression of infection upon respiratory acquisition of C. neoformans remain poorly defined. In this study, we found that during acute C. neoformans infection, CCR2+ Ly6Chi inflammatory monocytes (IM) rapidly infiltrate the lungs and mediate fungal trafficking to lung-draining lymph nodes. Interestingly, this influx of IM is detrimental to the host, since ablating IM or impairing their recruitment to the lungs improves murine survival and reduces fungal proliferation and dissemination. Using a novel conditional gene deletion strategy, we determined that MHC class II expression by IM did not mediate their deleterious impact on the host. Furthermore, although ablation of IM reduced the number of lymphocytes, innate lymphoid cells, and eosinophils in the lungs, the effects of IM were not dependent on these cells. We ascertained that IM in the lungs upregulated transcripts associated with alternatively activated (M2) macrophages in response to C. neoformans, consistent with the model that IM assume a cellular phenotype that is permissive for fungal growth. We also determined that conditional knockout of the prototypical M2 marker arginase 1 in IM and deletion of the M2-associated transcription factor STAT6 were not sufficient to reverse the harmful effects of IM. Overall, our findings indicate that C. neoformans can subvert the fungicidal potential of IM to enable the progression of infection through a mechanism that is not dependent on lymphocyte priming, eosinophil recruitment, or downstream M2 macrophage polarization pathways. These results give us new insight into the plasticity of IM function during fungal infections and the level of control that C. neoformans can exert on host immune responses.


Assuntos
Criptococose/imunologia , Monócitos/fisiologia , Receptores CCR2/metabolismo , Animais , Criptococose/patologia , Cryptococcus neoformans/metabolismo , Cryptococcus neoformans/patogenicidade , Modelos Animais de Doenças , Interações Hospedeiro-Patógeno/imunologia , Imunidade Inata/imunologia , Imunidade Inata/fisiologia , Inflamação/imunologia , Inflamação/microbiologia , Pulmão/patologia , Pneumopatias Fúngicas/fisiopatologia , Macrófagos , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/imunologia , Monócitos/microbiologia , Receptores CCR2/genética
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