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1.
Microbiol Spectr ; 11(3): e0431122, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37140398

RESUMO

Nelfinavir, an orally administered inhibitor of human immunodeficiency virus protease, inhibits the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro. We conducted a randomized controlled trial to evaluate the clinical efficacy and safety of nelfinavir in patients with SARS-CoV-2 infection. We included unvaccinated asymptomatic or mildly symptomatic adult patients who tested positive for SARS-CoV-2 infection within 3 days before enrollment. The patients were randomly assigned (1:1) to receive oral nelfinavir (750 mg; thrice daily for 14 days) combined with standard-of-care or standard-of-care alone. The primary endpoint was the time to viral clearance, confirmed using quantitative reverse-transcription PCR by assessors blinded to the assigned treatment. A total of 123 patients (63 in the nelfinavir group and 60 in the control group) were included. The median time to viral clearance was 8.0 (95% confidence interval [CI], 7.0 to 12.0) days in the nelfinavir group and 8.0 (95% CI, 7.0 to 10.0) days in the control group, with no significant difference between the treatment groups (hazard ratio, 0.815; 95% CI, 0.563 to 1.182; P = 0.1870). Adverse events were reported in 47 (74.6%) and 20 (33.3%) patients in the nelfinavir and control groups, respectively. The most common adverse event in the nelfinavir group was diarrhea (49.2%). Nelfinavir did not reduce the time to viral clearance in this setting. Our findings indicate that nelfinavir should not be recommended in asymptomatic or mildly symptomatic patients infected with SARS-CoV-2. The study is registered with the Japan Registry of Clinical Trials (jRCT2071200023). IMPORTANCE The anti-HIV drug nelfinavir suppresses the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro. However, its efficacy in patients with COVID-19 has not been studied. We conducted a multicenter, randomized controlled trial to evaluate the efficacy and safety of orally administered nelfinavir in patients with asymptomatic or mildly symptomatic COVID-19. Compared to standard-of-care alone, nelfinavir (750 mg, thrice daily) did not reduce the time to viral clearance, viral load, or the time to resolution of symptoms. More patients had adverse events in the nelfinavir group than in the control group (74.6% [47/63 patients] versus 33.3% [20/60 patients]). Our clinical study provides evidence that nelfinavir, despite its antiviral effects on SARS-CoV-2 in vitro, should not be recommended for the treatment of patients with COVID-19 having no or mild symptoms.


Assuntos
Fármacos Anti-HIV , COVID-19 , Adulto , Humanos , SARS-CoV-2 , Nelfinavir/efeitos adversos , Fatores de Tempo , Resultado do Tratamento
3.
Nat Commun ; 13(1): 3176, 2022 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-35676290

RESUMO

Retinoic acid-inducible gene (RIG)-I is an essential innate immune sensor that recognises pathogen RNAs and induces interferon (IFN) production. However, little is known about how host proteins regulate RIG-I activation. Here, we show that leukocyte cell-derived chemotaxin 2 (LECT2), a hepatokine and ligand of the MET receptor tyrosine kinase is an antiviral regulator that promotes the RIG-I-mediated innate immune response. Upon binding to MET, LECT2 induces the recruitment of the phosphatase PTP4A1 to MET and facilitates the dissociation and dephosphorylation of phosphorylated SHP2 from MET, thereby protecting RIG-I from SHP2/c-Cbl-mediated degradation. In vivo, LECT2 overexpression enhances RIG-I-dependent IFN production and inhibits lymphocytic choriomeningitis virus (LCMV) replication in the liver, whereas these changes are reversed in LECT2 knockout mice. Forced suppression of MET abolishes IFN production and antiviral activity in vitro and in vivo. Interestingly, hepatocyte growth factor (HGF), an original MET ligand, inhibits LECT2-mediated anti-viral signalling; conversely, LECT2-MET signalling competes with HGF-MET signalling. Our findings reveal previously unrecognized crosstalk between MET-mediated proliferation and innate immunity and suggest that targeting LECT2 may have therapeutic value in infectious diseases and cancer.


Assuntos
Fatores de Restrição Antivirais , Peptídeos e Proteínas de Sinalização Intercelular , Proteínas Proto-Oncogênicas c-met , Animais , Fatores de Restrição Antivirais/imunologia , Imunidade Inata , Peptídeos e Proteínas de Sinalização Intercelular/imunologia , Leucócitos/metabolismo , Ligantes , Camundongos , Proteínas Proto-Oncogênicas c-met/metabolismo
4.
BMC Infect Dis ; 22(1): 335, 2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-35382751

RESUMO

BACKGROUND: Aureobasidium melanigenum is a ubiquitous dematiaceous fungus that rarely causes invasive human infections. Here, we present a case of Aureobasidium melanigenum bloodstream infection in a 20-year-old man with long-term catheter use. CASE PRESENTATION: A 20-year-old man receiving home care with severe disabilities due to cerebral palsy and short bowel syndrome, resulting in long-term central venous catheter use, was referred to our hospital with a fever. After the detection of yeast-like cells in blood cultures on day 3, antifungal therapy was initiated. Two identification tests performed at a clinical microbiological laboratory showed different identification results: Aureobasidium pullulans from matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and Cryptococcus albidus from a VITEK2 system. Therefore, we changed the antifungal drug to liposomal amphotericin B. The fungus was identified as A. melanigenum by DNA sequence-based analysis. The patient recovered with antifungal therapy and long-term catheter removal. CONCLUSION: It is difficult to correctly identify A. melanigenum by routine microbiological testing. Clinicians must pay attention to the process of identification of yeast-like cells and retain A. melanigenum in cases of refractory fungal infection.


Assuntos
Cateteres Venosos Centrais , Micoses , Sepse , Adulto , Antifúngicos/uso terapêutico , Aureobasidium , Humanos , Masculino , Micoses/tratamento farmacológico , Sepse/tratamento farmacológico , Adulto Jovem
5.
JAC Antimicrob Resist ; 4(1): dlac018, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35265841

RESUMO

Background: Candida glabrata is an emerging fungal pathogen in immune-compromised hosts. Previously undetected C. glabrata isolates were successfully recovered from clinical specimens by adding sterols to the growth medium. The clinical isolates are unable to synthesize ergosterol but can take up exogenous sterols under aerobic conditions. Objectives: This study characterizes the sterol-auxotrophic C. glabrata strains, examines the mutation(s) in sterol synthesis genes, characterizes the drug susceptibility and evaluates the virulence in a mouse infection model. Methods: Drug susceptibility of the C. glabrata strains was evaluated in a sterol-supplemented medium. The coding sequences of the sterol synthesis genes were analysed in six sterol-auxotrophic strains of C. glabrata. The fungal burden of mice infected with C. glabrata strain was determined. Results: The sterol-auxotrophic strains showed high-level resistance to both azoles and amphotericin B when sterols were supplied in the test medium. Additionally, the strains harbour missense mutations in either ERG1 or ERG7. Significant differences in fungal burden were not observed between the sterol-auxotrophic strain and the sterol-competent strain with the mice infection models. Conclusions: The sterol-auxotrophic C. glabrata strain investigated in this study seemed to maintain intact virulence, probably due to the supply of exogenous sterols from host organ(s). This suggests that exogenous sterol uptake develops antifungal resistance during infection.

6.
Med Mycol J ; 63(2): 27-35, 2022 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-35173102

RESUMO

Aspergillus lentulus was first reported in 2005 as a cryptic species of Aspergillus fumigatus, and since then, its resistance to azole drugs and the high mortality rate of infected individuals have emerged as problems. Although it has been reported that P450 14-α sterol demethylase (Cyp51) is involved in azole resistance in A. lentulus, the specific resistance mechanism has not been elucidated. In this study, we successfully introduced the entire A. fumigatus cyp51A gene into the cyp51A locus in A. lentulus using the CRISPR/Cas9 genome-editing system. The A. lentulus strains harboring A. fumigatus cyp51A showed reduced minimum inhibitory concentrations for itraconazole and voriconazole compared with those of the parent strain. This finding suggests that Cyp51A is involved in azole resistance in A. lentulus and may contribute to the elucidation of the mechanism of resistance to azole drugs via Cyp51A and to the development of new antifungal drugs. In addition, our successful application of the CRISPR/Cas9 system to A. lentulus opens the door to examination of other gene functions in this fungus.


Assuntos
Azóis , Farmacorresistência Fúngica , Antifúngicos/farmacologia , Aspergillus , Aspergillus fumigatus/genética , Azóis/farmacologia , Sistemas CRISPR-Cas , Farmacorresistência Fúngica/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Edição de Genes , Humanos , Testes de Sensibilidade Microbiana
7.
Antimicrob Agents Chemother ; 66(3): e0208121, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35041512

RESUMO

Limited data are available on breakthrough fungemia, defined as fungemia that develops on administration of antifungal agents, in patients with hematological disorders. We reviewed the medical and microbiological records of adult patients with hematological diseases who had breakthrough fungemia between January 2008 and July 2019 at Toranomon Hospital and Toranomon Hospital Kajigaya in Japan. A total of 121 cases of breakthrough fungemia were identified. Of the 121 involved patients, 83, 11, 5, and 22 were receiving micafungin, voriconazole, itraconazole, and liposomal amphotericin B, respectively, when the breakthrough occurred. Of the 121 causative breakthrough fungal strains, 96 were Candida species, and the rest were 13 cases of Trichosporon species, 7 of Fusarium species, 2 of Rhodotorula mucilaginosa, and 1 each of Cryptococcus neoformans, Exophiala dermatitidis, and Magnusiomyces capitatus. The crude 14-day mortality rate of breakthrough fungemia was 36%. Significant independent factors associated with the crude 14-day mortality rate were age of ≥60 years (P = 0.011), chronic renal failure (P = 0.0087), septic shock (P < 0.0001), steroid administration (P = 0.0085), and liposomal amphotericin B breakthrough fungemia (P = 0.0011). An absolute neutrophil count of >500/µL was significantly more common in candidemia in the multivariate analysis (P = 0.0065), neutropenia and nonallogeneic hematopoietic stem cell transplants were significantly more common in Trichosporon fungemia (P = 0.036 and P = 0.033, respectively), and voriconazole breakthrough fungemia and neutropenia were significantly more common in Fusarium fungemia (P = 0.016 and P = 0.016, respectively). The epidemiological and clinical characteristics of breakthrough fungemia of patients with hematological disorders were demonstrated. Some useful factors to predict candidemia, Trichosporon fungemia, and Fusarium fungemia were identified.


Assuntos
Candidemia , Cryptococcus neoformans , Fungemia , Fusarium , Doenças Hematológicas , Trichosporon , Adulto , Antifúngicos/uso terapêutico , Candida , Candidemia/tratamento farmacológico , Fungemia/tratamento farmacológico , Fungemia/microbiologia , Doenças Hematológicas/complicações , Doenças Hematológicas/tratamento farmacológico , Humanos , Pessoa de Meia-Idade
8.
Antimicrob Agents Chemother ; 66(1): e0163021, 2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-34780271

RESUMO

There are few reports on the clinical course of proven invasive aspergillosis (IA) due to rare/cryptic species in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients. We retrospectively reviewed the electronic medical records of patients who underwent allo-HSCT between January 2012 and December 2018. Of 934 allo-HSCT recipients, 10 were diagnosed with proven IA and 61 were diagnosed with probable IA. DNA sequencing was performed in cases of proven IA, and Aspergillus could be identified to the species level in 8 of the 10 cases. Three were due to A. fumigatus, and 5 were due to rare/cryptic Aspergillus species, namely, A. turcosus, A. felis, A. viridinutans, A. nidulans, and A. calidoustus. In these 8 patients, no patients with IA due to A. fumigatus died, whereas 3 of the 5 with IA due to rare/cryptic species died within 12 weeks. The 2 surviving cases of IA due to rare/cryptic species were treated with surgical resection and antifungal treatment. Susceptibility testing for cryptic species in 4 cases showed an amphotericin B MIC > 1 mg/L in 3 cases, itraconazole MIC > 1 mg/L in 2 cases, and voriconazole MIC > 1 mg/L in 2 cases. In conclusion, more than half of the causative pathogens of proven IA were rare/cryptic species, so it is important to accurately identify the Aspergillus species. In addition, surgical treatment might be an important option in cases of proven IA, given the possibility that the causative organisms are azole-resistant A. fumigatus or rare/cryptic species.


Assuntos
Aspergilose , Transplante de Células-Tronco Hematopoéticas , Infecções Fúngicas Invasivas , Antifúngicos/uso terapêutico , Aspergilose/tratamento farmacológico , Aspergillus/genética , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Infecções Fúngicas Invasivas/tratamento farmacológico , Estudos Retrospectivos
9.
Trials ; 22(1): 309, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33910617

RESUMO

OBJECTIVES: The aim of this trial is to evaluate the antiviral efficacy, clinical efficacy, and safety of nelfinavir in patients with asymptomatic and mild COVID-19. TRIAL DESIGN: The study is designed as a multicenter, open-label, blinded outcome assessment, parallel group, investigator-initiated, exploratory, randomized (1:1 ratio) controlled clinical trial. PARTICIPANTS: Asymptomatic and mild COVID-19 patients will be enrolled in 10 university and teaching hospitals in Japan. The inclusion and exclusion criteria are as follows: Inclusion criteria: (1) Japanese male or female patients aged ≥ 20 years (2) SARS-CoV-2 detected from a respiratory tract specimen (e.g., nasopharyngeal swab or saliva) using PCR, LAMP, or an antigen test within 3 days before obtaining the informed consent (3) Provide informed consent Exclusion criteria: (1) Symptoms developed ≥ 8 days prior to enrolment (2) SpO2 < 96 % (room air) (3) Any of the following screening criteria: a) ALT or AST ≥ 5 × upper limit of the reference range b) Child-Pugh class B or C c) Serum creatinine ≥ 2 × upper limit of the reference range and creatinine clearance < 30 mL/min (4) Poorly controlled diabetes (random blood glucose ≥ 200 mg/dL or HbA1c ≥ 7.0%, despite treatment) (5) Unsuitable serious complications based on the assessment of either the principal investigator or the sub-investigator (6) Hemophiliac or patients with a marked hemorrhagic tendency (7) Severe diarrhea (8) Hypersensitivity to the investigational drug (9) Breastfeeding or pregnancy (10) With childbearing potential and rejecting contraceptive methods during the study period from the initial administration of the investigational drug (11) Receiving rifampicin within the previous 2 weeks (12) Participated in other clinical trials and received drugs within the previous 12 weeks (13) Undergoing treatment for HIV infection (14) History of SARS-CoV-2 vaccination or wishes to be vaccinated against SARS-CoV-2 (15) Deemed inappropriate (for miscellaneous reasons) based on the assessment of either the principal investigator or the sub-investigator INTERVENTION AND COMPARATOR: Patients who meet the inclusion criteria and do not meet any of the exclusion criteria will be randomized to either the nelfinavir group or the symptomatic treatment group. The nelfinavir group will be administered 750 mg of nelfinavir orally, three times daily for 14 days (treatment period). However, if a participant tests negative on two consecutive PCR tests of saliva samples, administration of the investigational drug for that participant can be discontinued at the discretion of the investigators. The symptomatic treatment group will not be administered the investigational drug, but all other study procedures and conditions will be the same for both groups for the duration of the treatment period. After the treatment period of 14 days, each group will be followed up for 14 days (observational period). MAIN OUTCOMES: The primary endpoint is the time to negative conversion of SARS-CoV-2. During the study period from Day 1 to Day 28, two consecutive negative PCR results of saliva samples will be considered as the negative conversion of the virus. The secondary efficacy endpoints are as follows: For patients with both asymptomatic and mild disease: area under the curve of viral load, half decay period of viral load, body temperature at each time point, all-cause mortality, incidence rate of pneumonia, percentage of patients with newly developed pneumonia, rate of oxygen administration, and the percentage of patients who require oxygen administration. For asymptomatic patients: incidence of symptomatic COVID-19, incidence of fever (≥ 37.0 °C for two consecutive days), incidence of cough For patients with mild disease: incidence of defervescence (< 37.0 °C), incidence of recovery from clinical symptoms, incidence of improvement of each symptom The secondary safety endpoints are adverse events and clinical examinations. RANDOMIZATION: Patients will be randomized to either the nelfinavir group or the symptomatic treatment group using the electric data capture system (1:1 ratio, dynamic allocation based on severity [asymptomatic], and age [< 60 years]). BLINDING (MASKING): Only the assessors of the primary outcome will be blinded (blinded outcome assessment). NUMBERS TO BE RANDOMIZED (SAMPLE SIZE): The sample size was determined based on our power analysis to reject the null hypothesis, S (t | z =1) = S (t | z = 0) where S is a survival function, t is time to negative conversion, and z denotes randomization group, by the log-rank test with a two-sided p value of 0.05. We estimated viral dynamic parameters by fitting a nonlinear mixed-effects model to reported viral load data, and simulated our primary endpoint from viral-load time-courses that were realized from sets of viral dynamics parameters sampled from the estimated probability distribution of the parameters (sample size: 2000; 1000 each for randomization group). From this estimation of the hazard ratio between the randomization groups for the event of negative conversion using this simulation dataset, the required number of events for rejecting our null hypothesis with a power of 0.80 felled 97.345 by plugging the estimated hazard ratio, 1.79, in Freedman's equation. Therefore, we decided the required number of randomizations to be 120 after consideration of the frequency of censoring and the anticipated rate of withdrawal caused by factors such as withdrawal of consent. TRIAL STATUS: Protocol version 6.0 of February 12, 2021. Recruitment started on July 22, 2020 and is anticipated to be completed by March 31, 2022. TRIAL REGISTRATION: This trial was registered in Japan Registry of Clinical Trials (jRCT) ( jRCT2071200023 ) on 21 July 21, 2020. FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol. The study protocol has been reported in accordance with the Standard Protocol Items: Recommendations for Clinical Interventional Trials (SPIRIT) guidelines (Additional file 2).


Assuntos
Tratamento Farmacológico da COVID-19 , Infecções por HIV , Vacinas contra COVID-19 , Feminino , Infecções por HIV/diagnóstico , Infecções por HIV/tratamento farmacológico , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Nelfinavir/efeitos adversos , Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto , SARS-CoV-2 , Resultado do Tratamento
10.
Sci Rep ; 11(1): 555, 2021 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-33436955

RESUMO

It remains unclear how hepatic steatosis links to inflammation. Leukocyte cell-derived chemotaxin 2 (LECT2) is a hepatokine that senses fat in the liver and is upregulated prior to weight gain. The aim of this study was to investigate the significance of LECT2 in the development of nonalcoholic steatohepatitis (NASH). In human liver biopsy samples, elevated LECT2 mRNA levels were positively correlated with body mass index (BMI) and increased in patients who have steatosis and inflammation in the liver. LECT2 mRNA levels were also positively correlated with the mRNA levels of the inflammatory genes CCR2 and TLR4. In C57BL/6J mice fed with a high-fat diet, mRNA levels of the inflammatory cytokines Tnfa and Nos2 were significantly lower in Lect2 KO mice. In flow cytometry analyses, the number of M1-like macrophages and M1/M2 ratio were significantly lower in Lect2 KO mice than in WT mice. In KUP5, mouse kupffer cell line, LECT2 selectively enhanced the LPS-induced phosphorylation of JNK, but not that of ERK and p38. Consistently, LECT2 enhanced the LPS-induced phosphorylation of MKK4 and TAB2, upstream activators of JNK. Hepatic expression of LECT2 is upregulated in association with the inflammatory signature in human liver tissues. The elevation of LECT2 shifts liver residual macrophage to the M1-like phenotype, and contributes to the development of liver inflammation. These findings shed light on the hepatokine LECT2 as a potential therapeutic target that can dissociate liver steatosis from inflammation.


Assuntos
Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Ativação de Macrófagos/genética , Hepatopatia Gordurosa não Alcoólica/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Linhagem Celular , Dieta Hiperlipídica/efeitos adversos , Expressão Gênica/genética , Inflamação/genética , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Células de Kupffer/metabolismo , Fígado/citologia , Camundongos Endogâmicos C57BL , Terapia de Alvo Molecular , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/terapia , Fosforilação/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Regulação para Cima
11.
J Virol ; 94(2)2020 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-31645450

RESUMO

A number of positive-strand RNA viruses, such as hepatitis C virus (HCV) and poliovirus, use double-membrane vesicles (DMVs) as replication sites. However, the role of cellular proteins in DMV formation during virus replication is poorly understood. HCV NS4B protein induces the formation of a "membranous web" structure that provides a platform for the assembly of viral replication complexes. Our previous screen of NS4B-associated host membrane proteins by dual-affinity purification, liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), and small interfering RNA (siRNA) methods revealed that the Surfeit 4 (Surf4) gene, which encodes an integral membrane protein, is involved in the replication of the JFH1 subgenomic replicon. Here, we investigated in detail the effect of Surf4 on HCV replication. Surf4 affects HCV replication in a genotype-independent manner, whereas HCV replication does not alter Surf4 expression. The influence of Surf4 on HCV replication indicates that while Surf4 regulates replication, it has no effect on entry, translation, assembly, or release. Analysis of the underlying mechanism showed that Surf4 is recruited into HCV RNA replication complexes by NS4B and is involved in the formation of DMVs and the structural integrity of RNA replication complexes. Surf4 also participates in the replication of poliovirus, which uses DMVs as replication sites, but it has no effect on the replication of dengue virus, which uses invaginated/sphere-type vesicles as replication sites. These findings clearly show that Surf4 is a novel cofactor that is involved in the replication of positive-strand RNA viruses using DMVs as RNA replication sites, which provides valuable clues for DMV formation during positive-strand RNA virus replication.IMPORTANCE Hepatitis C virus (HCV) NS4B protein induces the formation of a membranous web (MW) structure that provides a platform for the assembly of viral replication complexes. The main constituents of the MW are double-membrane vesicles (DMVs). Here, we found that the cellular protein Surf4, which maintains endoplasmic reticulum (ER)-Golgi intermediate compartments and the Golgi compartment, is recruited into HCV RNA replication complexes by NS4B and is involved in the formation of DMVs. Moreover, Surf4 participates in the replication of poliovirus, which uses DMVs as replication sites, but has no effect on the replication of dengue virus, which uses invaginated vesicles as replication sites. These results indicate that the cellular protein Surf4 is involved in the replication of positive-strand RNA viruses that use DMVs as RNA replication sites, providing new insights into DMV formation during virus replication and potential targets for the diagnosis and treatment of positive-strand RNA viruses.


Assuntos
Estruturas da Membrana Celular/metabolismo , Hepacivirus/fisiologia , Proteínas de Membrana/metabolismo , RNA Viral/biossíntese , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/fisiologia , Linhagem Celular Tumoral , Estruturas da Membrana Celular/genética , Estruturas da Membrana Celular/virologia , Genótipo , Humanos , Proteínas de Membrana/genética , RNA Viral/genética , Proteínas não Estruturais Virais/genética
12.
PLoS One ; 14(8): e0220989, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31398236

RESUMO

Cryptococcus gattii is a capsular fungal pathogen, which causes life-threatening cryptococcosis in immunocompetent individuals. This emerging pathogen is less likely to be recognized by innate immunity compared to traditional Cryptococcus neoformans strains. Previous studies indicate that C-type lectin receptors (CLRs), including dectin-1 and dectin-2, play a role in recognizing cryptococcal cells; however, it remains to be elucidated whether the receptors physically associate with C. gattii yeast cell surfaces. Based on the previous findings, we hypothesized that culture conditions influence the expression or exposure of CLR ligands on C. gattii. Therefore, in the present study, we first investigated the culture conditions that induce exposure of CLR ligands on C. gattii yeast cells via the binding assay using recombinant fusion proteins of mouse CLR and IgG Fc, Fc dectin-1 and Fc dectin-2. Common fungal culture media, such as yeast extract-peptone-dextrose (YPD) broth, Sabouraud broth, and potato dextrose agar, did not induce the exposure of dectin-1 ligands, including ß-1,3-glucan, on both capsular and acapsular C. gattii strains, in contrast to Fc dectin-1 and Fc dectin-2 bound to C. gattii cells growing in the conventional synthetic dextrose (SD) medium [may also be referred to as a yeast nitrogen base with glucose medium]. The medium also induced the exposure of dectin-1 ligands on C. neoformans, whereas all tested media induced dectin-1 and dectin-2 ligands in a control fungus Candida albicans. Notably, C. gattii did not expose dectin-1 ligands in SD medium supplemented with yeast extract or neutral buffer. In addition, compared to YPD medium-induced C. gattii, SD medium-induced C. gattii more efficiently induced the phosphorylation of Syk, Akt, and Erk1/2 in murine dendritic cells (DCs). Afterwards, the cells were considerably engulfed by DCs and remarkably induced DCs to secrete the inflammatory cytokines. Overall, the findings suggest that C. gattii alters its immunostimulatory potential in response to the environment.


Assuntos
Cryptococcus gattii/imunologia , Meio Ambiente , Imunomodulação , Animais , Células da Medula Óssea/metabolismo , Membrana Celular/metabolismo , Cryptococcus gattii/crescimento & desenvolvimento , Células Dendríticas/metabolismo , Lectinas Tipo C/metabolismo , Ligantes , Camundongos Endogâmicos C57BL , Ligação Proteica , Solubilidade
13.
Med Mycol J ; 60(1): 11-16, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30814465

RESUMO

Aspergillus fumigatus is a critical human fungal pathogen that infects the host via inhalation of airborne conidia. These conidia then germinate to form filamentous hyphae, which secrete various elements to survive in the host lung.Elements such as proteins secreted by A. fumigatus can act as virulence factors in host tissues. Among secreted proteins, we were interested in the thaumatin-like proteins of A. fumigatus. In our analysis of the function of thaumatin-like proteins, we found that, like CalA and CalB, CalC has a secreted form. Originally, CalC was predicted to be a GPI-anchored protein, as documented in the Aspergillus Genome Database. Here, we report on a novel secreted form of CalC. Furthermore, we established two novel hybridomas, C103 and C306, which recognized CalC. Monoclonal antibodies produced by these hybridomas responded to recombinant CalC produced by the mammalian cell line HEK293T and to the supernatant of cultured A. fumigatus.Taken together, our data suggest that calC can be spliced to give rise to a novel secretory form of CalC, which is present in the supernatant of cultured A. fumigatus. The hybridomas that we established will be helpful in understanding the biological role of A. fumigatus CalC.


Assuntos
Anticorpos Monoclonais , Aspergillus fumigatus/genética , Aspergillus fumigatus/imunologia , Proteínas Fúngicas , Aspergillus fumigatus/patogenicidade , Aspergillus fumigatus/fisiologia , Proteínas Fúngicas/metabolismo , Células HEK293/metabolismo , Humanos , Hifas/metabolismo , Pulmão/microbiologia , Virulência
14.
Hepatology ; 69(1): 160-178, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30070727

RESUMO

Leukocyte cell-derived chemotaxin-2 (LECT2) was originally identified as a hepatocyte-secreted chemokine-like factor and a positive target of ß-catenin signaling. Here, we dissected out the mechanisms by which LECT2 modulates hepatocellular carcinoma (HCC) development using both HCC mouse models and human HCC samples. We have demonstrated that LECT2 exhibits dual abilities as it has profound repercussions on the tumor phenotype itself and the immune microenvironment. Its absence confers Ctnnb-1-mutated tumor hepatocytes a stronger ability to undergo epithelial to mesenchymal transition and fosters the accumulation of pejorative inflammatory monocytes harboring immunosuppressive properties and strong tumor-promoting potential. Consistent with our HCC mouse model, a low level of LECT2 in human HCC is strongly associated with high tumor grade and the presence of inflammatory infiltrates, emphasizing the clinical value of LECT2 in human liver tumorigenesis. Conclusion: Our findings have demonstrated that LECT2 is a key player in liver tumorigenesis because its absence reshapes the tumor microenvironment and the tumor phenotype, revealing LECT2 as a promising immunotherapeutic option for HCC.


Assuntos
Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Monócitos/fisiologia , Receptores Acoplados a Proteínas G/fisiologia , Receptores de Peptídeos/fisiologia , Animais , Carcinoma Hepatocelular/etiologia , Modelos Animais de Doenças , Progressão da Doença , Humanos , Inflamação/complicações , Neoplasias Hepáticas/etiologia , Camundongos , Células Tumorais Cultivadas
15.
Artigo em Inglês | MEDLINE | ID: mdl-29914956

RESUMO

A pan-azole-resistant Aspergillus fumigatus strain with the cyp51A mutations Gly138Ser and Asn248Lys was isolated from a patient receiving long-term voriconazole treatment. PCR fragments containing cyp51A with the mutations were introduced along with the Cas9 protein and single guide RNA into the azole-resistant/susceptible strains. Recombinant strains showed increased susceptibility via the replacement of Ser138 by glycine. Genetic recombination, which has been hampered thus far in clinical isolates, can now be achieved using CRISPR/Cas9 genome editing.


Assuntos
Antifúngicos/uso terapêutico , Aspergilose/tratamento farmacológico , Aspergillus fumigatus/efeitos dos fármacos , Aspergillus fumigatus/genética , Sistema Enzimático do Citocromo P-450/genética , Farmacorresistência Fúngica/genética , Proteínas Fúngicas/genética , Edição de Genes/métodos , Voriconazol/uso terapêutico , Idoso , Aspergillus fumigatus/isolamento & purificação , Sistemas CRISPR-Cas/genética , Humanos , Masculino
16.
Artigo em Inglês | MEDLINE | ID: mdl-29530846

RESUMO

Limited data are available on micafungin breakthrough fungemia (MBF), fungemia that develops on administration of micafungin, in patients with hematological disorders. We reviewed medical and microbiological records of patients with hematological disorders who developed MBF between January 2008 and June 2015. A total of 39 patients with MBF were identified, and Candida (30 strains) and non-Candida (9 strains) fungal species were recognized as causative strains. Among 35 stored strains, Candida parapsilosis (14 strains), Trichosporon asahii (7 strains), Candida glabrata (5 strains), and other fungal species (9 strains) were identified by sequencing. Neutropenia was identified as an independent predictor of non-Candida fungemia (P = 0.023). T. asahii was the most common causative strain (7/19) during neutropenia. The 14-day crude mortality rate of patients treated with early micafungin change (EMC) to other antifungal agents was lower than that of the patients not treated with EMC (14% versus 43%, P = 0.044). Most of the stored causative Candida strains were susceptible (80%) or showed wild-type susceptibility (72%) to micafungin. The MICs of voriconazole for T. asahii were low (range, 0.015 to 0.12 µg/ml), whereas the MICs of amphotericin B for T. asahii were high (range, 2 to 4 µg/ml). MBF caused by non-Candida fungus should be considered, especially in patients with neutropenia. EMC could improve early mortality. Based on epidemiology and drug susceptibility profiling, empirical voriconazole-containing therapy might be suitable for treating MBF during neutropenia to cover for T. asahii.


Assuntos
Antifúngicos/farmacologia , Fungemia/microbiologia , Micafungina/farmacologia , Antifúngicos/uso terapêutico , Candida/efeitos dos fármacos , Candida/patogenicidade , Farmacorresistência Fúngica/genética , Equinocandinas/farmacologia , Equinocandinas/uso terapêutico , Fungemia/tratamento farmacológico , Humanos , Micafungina/uso terapêutico , Testes de Sensibilidade Microbiana , Trichosporon/efeitos dos fármacos , Trichosporon/patogenicidade , Voriconazol/farmacologia , Voriconazol/uso terapêutico
17.
Med Mycol ; 56(3): 382-386, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-28992282

RESUMO

The efficacy of recombinant interferon γ (rIFN-γ) for cryptococcal meningoencephalitis has been poorly understood. Compared to Cryptococcus gattii, rIFN-γ significantly improved the survival in experimental meningoencephalitis due to Cryptococcus neoformans. The number of phagocytic macrophages and the levels of inflammatory cytokines production for ex vivo co-incubation with C. neoformans were increased after rIFN-γ stimulation but not C. gattii. Intraspecies differences of phagocytosis by the rIFN-γ-activated macrophages might be associated to the severity of cryptococcal infection.


Assuntos
Interferon gama/uso terapêutico , Macrófagos/efeitos dos fármacos , Meningoencefalite/tratamento farmacológico , Animais , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Linhagem Celular , Contagem de Colônia Microbiana , Cryptococcus gattii/efeitos dos fármacos , Cryptococcus gattii/patogenicidade , Cryptococcus neoformans/efeitos dos fármacos , Cryptococcus neoformans/patogenicidade , Modelos Animais de Doenças , Feminino , Interferon gama/farmacologia , Macrófagos/citologia , Macrófagos/metabolismo , Meningoencefalite/microbiologia , Meningoencefalite/mortalidade , Meningoencefalite/patologia , Camundongos , Camundongos Endogâmicos C57BL , Fagocitose/efeitos dos fármacos , Especificidade da Espécie , Taxa de Sobrevida , Virulência
18.
J Biol Chem ; 293(2): 662-676, 2018 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-29184003

RESUMO

Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpesvirus-8 (HHV-8) causes a persistent infection, presenting latent and lytic replication phases during its life cycle. KSHV-related diseases are associated with deregulated expression of inflammatory cytokines, including IL-6 and IL-10, but the mechanisms underlying this dysregulation are unclear. Herein, we report a molecular mechanism for KSHV-induced IL-10 gene expression. KSHV replication and transcription activator (K-RTA) is a molecular switch for the initiation of expression of viral lytic genes, and we describe, for the first time, that K-RTA significantly activates the promoter of the human IL-10 gene. Of note, mutations involving a basic region of K-RTA reduced the association of K-RTA with the IL-10 promoter. Moreover, the host-cell transcription factors, specificity proteins (SP) 1 and 3, play a pivotal cooperative role in K-RTA-mediated transactivation of the IL-10 promoter. K-RTA can interact with SP1 and SP3 directly in vitro, and electrophoresis mobility shift assays (EMSAs) revealed co-operative interaction involving K-RTA, SP1, and SP3 in binding to the IL-10 promoter. As DNase I footprinting assays indicated that K-RTA did not affect SP3 binding to the IL-10 promoter, SP3 can function to recruit K-RTA to the IL-10 promoter. These findings indicate that K-RTA can directly contribute to IL-10 up-regulation via a functional interplay with the cellular transcription factors SP1 and SP3.


Assuntos
Interleucina-10/genética , Interleucina-10/metabolismo , Proteínas Virais/metabolismo , Sítios de Ligação/genética , Sítios de Ligação/fisiologia , Regulação Viral da Expressão Gênica/genética , Regulação Viral da Expressão Gênica/fisiologia , Humanos , Regiões Promotoras Genéticas/genética , Fator de Transcrição Sp1/genética , Fator de Transcrição Sp1/metabolismo , Fator de Transcrição Sp3/genética , Fator de Transcrição Sp3/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ativação Transcricional/genética , Ativação Transcricional/fisiologia , Proteínas Virais/genética , Replicação Viral/genética , Replicação Viral/fisiologia
19.
Biochem Biophys Rep ; 12: 166-171, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29090278

RESUMO

Leukocyte cell-derived chemotaxin 2 (LECT2) is a secreted pleiotropic protein that is mainly produced by the liver. We have previously shown that LECT2 plays an important role in the pathogenesis of inflammatory liver diseases. Lipopolysaccharide/d-galactosamine (LPS/d-GalN)-induced acute liver injury is a known animal model of fulminant hepatic failure. Here we found that this hepatic injury was alleviated in LECT2-deficient mice. The levels of TNF-α and IFN-γ, which mediate this hepatitis, had significantly decreased in these mice, with the decrease in IFN-γ production notably greater than that in TNF-α. We therefore analyzed IFN-γ-producing cells in liver mononuclear cells. Flow cytometric analysis showed significantly reduced IFN-γ production in hepatic NK and NKT cells in LECT2-deficient mice compared with in wild-type mice. We also demonstrated a decrease in IFN-γ production in LECT2-deficient mice after systemic administration of recombinant IL-12, which is known to induce IFN-γ in NK and NKT cells. These results indicate that a decrease of IFN-γ production in NK and NKT cells was involved in the alleviation of LPS/d-GalN-induced liver injury in LECT2-deficient mice.

20.
Med Mycol ; 55(7): 713-719, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28199672

RESUMO

Mucormycosis is the second most common mould infection, often indistinguishable from other invasive mould infections such as aspergillosis. Although an appropriate antifungal therapy is effective at an early stage of the infection, there is no reliable diagnostic method for decision making. Thus, it is necessary to develop an efficient method that can detect mucormycosis rapidly and accurately. We searched for secreted or membrane-bound proteins of Rhizopus oryzae, which is the most common pathogen of mucormycosis, using the method of a signal sequence trap by retrovirus-mediated expression (SST-REX). Among the identified proteins, a Rhizopus-specific antigen was selected as a candidate, and efficacy of this specific antigen was evaluated using R. oryzae-infected mice. Of 302 clones obtained from the SST-REX library, a hypothetical protein (23 kDa, named "protein RSA") was selected as a candidate because of its highest prevalence of clones. Protein RSA was detected at significantly higher concentrations in serum and in lung homogenates of the infected mice as compared to those of uninfected mice. Our study indicates that protein RSA may be a promising biomarker of R. oryzae infection. SST-REX may be useful for comprehensive screening of prospective eukaryotic biomarkers of intractable mould infections.


Assuntos
Antígenos de Fungos/análise , Antígenos de Fungos/sangue , Mucormicose/diagnóstico , Rhizopus/isolamento & purificação , Animais , Sangue/microbiologia , Feminino , Pulmão/microbiologia , Camundongos Endogâmicos ICR , Mucormicose/microbiologia , Sinais Direcionadores de Proteínas
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