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1.
Antimicrob Agents Chemother ; : e0042024, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38780261

RESUMO

Capsid assembly mediated by hepatitis B virus (HBV) core protein (HBc) is an essential part of the HBV replication cycle, which is the target for different classes of capsid assembly modulators (CAMs). While both CAM-A ("aberrant") and CAM-E ("empty") disrupt nucleocapsid assembly and reduce extracellular HBV DNA, CAM-As can also reduce extracellular HBV surface antigen (HBsAg) by triggering apoptosis of HBV-infected cells in preclinical mouse models. However, there have not been substantial HBsAg declines in chronic hepatitis B (CHB) patients treated with CAM-As to date. To investigate this disconnect, we characterized the antiviral activity of tool CAM compounds in HBV-infected primary human hepatocytes (PHHs), as well as in HBV-infected human liver chimeric mice and mice transduced with adeno-associated virus-HBV. Mechanistic studies in HBV-infected PHH revealed that CAM-A, but not CAM-E, induced a dose-dependent aggregation of HBc in the nucleus which is negatively regulated by the ubiquitin-binding protein p62. We confirmed that CAM-A, but not CAM-E, induced HBc-positive cell death in both mouse models via induction of apoptotic and inflammatory pathways and demonstrated that the degree of HBV-positive cell loss was positively correlated with intrahepatic HBc levels. Importantly, we determined that there is a significantly lower level of HBc per hepatocyte in CHB patient liver biopsies than in either of the HBV mouse models. Taken together, these data confirm that CAM-As have a unique secondary mechanism with the potential to kill HBc-positive hepatocytes. However, this secondary mechanism appears to require higher intrahepatic HBc levels than is typically observed in CHB patients, thereby limiting the therapeutic potential.

2.
Appl Environ Microbiol ; 90(2): e0149223, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38299813

RESUMO

The rumen houses a diverse community that plays a major role in the digestion process in ruminants. Anaerobic gut fungi (AGF) are key contributors to plant digestion in the rumen. Here, we present a global amplicon-based survey of the rumen AGF mycobiome by examining 206 samples from 15 animal species, 15 countries, and 6 continents. The rumen AGF mycobiome was highly diverse, with 81 out of 88 currently recognized AGF genera or candidate genera identified. However, only six genera (Neocallimastix, Orpinomyces, Caecomyces, Cyllamyces, NY9, and Piromyces) were present at >4% relative abundance. AGF diversity was higher in members of the families Antilocapridae and Cervidae compared to Bovidae. Community structure analysis identified a pattern of phylosymbiosis, where host family (10% of total variance) and species (13.5%) partially explained the rumen mycobiome composition. As well, diet composition (9%-19%), domestication (11.14%), and biogeography (14.1%) also partially explained AGF community structure; although sampling limitation, geographic range restrictions, and direct association between different factors hindered accurate elucidation of the relative contribution of each factor. Pairwise comparison of rumen and fecal samples obtained from the same subject (n = 13) demonstrated greater diversity and inter-sample variability in rumen versus fecal samples. The genera Neocallimastix and Orpinomyces were present in higher abundance in rumen samples, while Cyllamyces and Caecomyces were enriched in fecal samples. Comparative analysis of global rumen and feces data sets revealed a similar pattern. Our results provide a global view of AGF community in the rumen and identify patterns of AGF variability between rumen and feces in herbivores Gastrointestinal (GI) tract.IMPORTANCERuminants are highly successful and economically important mammalian suborder. Ruminants are herbivores that digest plant material with the aid of microorganisms residing in their GI tract. In ruminants, the rumen compartment represents the most important location where microbially mediated plant digestion occurs, and is known to house a bewildering array of microbial diversity. An important component of the rumen microbiome is the anaerobic gut fungi (AGF), members of the phylum Neocallimastigomycota. So far, studies examining AGF diversity have mostly employed fecal samples, and little is currently known regarding the identity of AGF residing in the rumen compartment, factors that impact the observed patterns of diversity and community structure of AGF in the rumen, and how AGF communities in the rumen compare to AGF communities in feces. Here, we examined the rumen AGF diversity using an amplicon-based survey targeting a wide range of wild and domesticated ruminants (n = 206, 15 different animal species) obtained from 15 different countries. Our results demonstrate that while highly diverse, no new AGF genera were identified in the rumen mycobiome samples examined. Our analysis also indicate that animal host phylogeny, diet, biogeography, and domestication status could play a role in shaping AGF community structure. Finally, we demonstrate that a greater level of diversity and higher inter-sample variability was observed in rumen compared to fecal samples, with two genera (Neocallimastix and Orpinomyces) present in higher abundance in rumen samples, and two others (Cyllamyces and Caecomyces) enriched in fecal samples. Our results provide a global view of the identity, diversity, and community structure of AGF in ruminants, elucidate factors impacting diversity and community structure of the rumen mycobiome, and identify patterns of AGF community variability between the rumen and feces in the herbivorous GI tract.


Assuntos
Cervos , Rúmen , Humanos , Animais , Anaerobiose , Rúmen/microbiologia , Herbivoria , Fungos/genética , Ruminantes
3.
Artigo em Inglês | MEDLINE | ID: mdl-37170869

RESUMO

Two strains of Gram-negative, anaerobic, rod-shaped bacteria, from an abundant but uncharacterized rumen bacterial group of the order 'Christensenellales', were phylogenetically and phenotypically characterized. These strains, designated R-7T and WTE2008T, shared 98.6-99.0 % sequence identity between their 16S rRNA gene sequences. R-7T and WTE2008T clustered together on a distinct branch from other Christensenellaceae strains and had <88.1 % sequence identity to the closest type-strain sequence from Luoshenia tenuis NSJ-44T. The genome sequences of R-7T and WTE2008T had 83.6 % average nucleotide identity to each other, and taxonomic assignment using the Genome Taxonomy Database indicates these are separate species within a novel family of the order 'Christensenellales'. Cells of R-7T and WTE2008T lacked any obvious appendages and their cell wall ultra-structures were characteristic of Gram-negative bacteria. The five most abundant cellular fatty acids of both strains were C16 : 0, C16 : 0 iso, C17 : 0 anteiso, C18 : 0 and C15 : 0 anteiso. The strains used a wide range of the 23 soluble carbon sources tested, and grew best on cellobiose, but not on sugar-alcohols. Xylan and pectin were fermented by both strains, but not cellulose. Acetate, hydrogen, ethanol and lactate were the major fermentation end products. R-7T produced considerably more hydrogen than WTE2008T, which produced more lactate. Based on these analyses, Aristaeellaceae fam. nov. and Aristaeella gen. nov., with type species Aristaeella hokkaidonensis sp. nov., are proposed. Strains R-7T (=DSM 112795T=JCM 34733T) and WTE2008T (=DSM 112788T=JCM 34734T) are the proposed type strains for Aristaeella hokkaidonensis sp. nov. and Aristaeella lactis sp. nov., respectively.


Assuntos
Ácidos Graxos , Rúmen , Animais , Ácidos Graxos/química , RNA Ribossômico 16S/genética , Filogenia , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Composição de Bases , Análise de Sequência de DNA , Bactérias Gram-Negativas , Hidrogênio
4.
J Hepatol ; 77(2): 332-343, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35218813

RESUMO

BACKGROUND & AIMS: Chronic HBV is clinically categorized into 4 phases by a combination of serum HBV DNA levels, HBeAg status and alanine aminotransferase (ALT): immunotolerant (IT), immune-active (IA), inactive carrier (IC) and HBeAg-negative hepatitis (ENEG). Immune and virological measurements in the blood have proven useful but are insufficient to explain the interrelation between the immune system and the virus since immune dynamics differ in the blood and liver. Furthermore, the inflammatory response in the liver and parenchymal cells cannot be fully captured in blood. METHODS: Immunological composition and transcriptional profiles of core needle liver-biopsies in chronic HBV phases were compared to those of healthy controls by multiplex immunofluorescence and RNA-sequencing (n = 37 and 78, respectively) analyses. RESULTS: Irrespective of the phase-specific serological profiles, increased immune-gene expression and frequency was observed in chronic HBV compared to healthy livers. Greater transcriptomic deregulation was seen in IA and ENEG (172 vs. 243 DEGs) than in IT and IC (13 vs. 35 DEGs) livers. Interferon-stimulated genes, immune-activation and exhaustion genes (ICOS, CTLA4, PDCD1) together with chemokine genes (CXCL10, CXCL9) were significantly induced in IA and ENEG livers. Moreover, distinct immune profiles associated with ALT elevation and a more accentuated immune-exhaustion profile (CTLA4, TOX, SLAMF6, FOXP3) were observed in ENEG, which set it apart from the IA phase (LGALS9, PDCD1). Interestingly, all HBV phases showed downregulation of metabolic pathways vs. healthy livers (fatty and bile acid metabolism). Finally, increased leukocyte infiltrate correlated with serum ALT, but not with HBV DNA or viral proteins. CONCLUSION: Our comprehensive multi-parametric analysis of human livers revealed distinct inflammatory profiles and pronounced differences in intrahepatic gene profiles across all chronic HBV phases in comparison to healthy liver. LAY SUMMARY: Immunological studies on chronic HBV remain largely restricted to assessment of peripheral responses due to the limited access to the site of infection, the liver. In this study, we comprehensively analyzed livers from a well-defined cohort of patients with chronic HBV and uninfected controls with state-of-the-art techniques, and evaluated the differences in gene expression profiles and inflammation characteristics across distinct disease phases in patients with chronic HBV.


Assuntos
Hepatite B Crônica , Hepatite B , Antígeno CTLA-4 , DNA Viral/genética , Antígenos E da Hepatite B , Vírus da Hepatite B/genética , Humanos , Inflamação/genética
5.
PLoS Genet ; 13(1): e1006570, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28103245

RESUMO

Oxidative stress is a major cause of mutation but little is known about how growth in the absence of oxygen impacts the rate and spectrum of mutations. We employed long-term mutation accumulation experiments to directly measure the rates and spectra of spontaneous mutation events in Escherichia coli populations propagated under aerobic and anaerobic conditions. To detect mutations, whole genome sequencing was coupled with methods of analysis sufficient to identify a broad range of mutational classes, including structural variants (SVs) generated by movement of repetitive elements. The anaerobically grown populations displayed a mutation rate nearly twice that of the aerobic populations, showed distinct asymmetric mutational strand biases, and greater insertion element activity. Consistent with mutation rate and spectra observations, genes for transposition and recombination repair associated with SVs were up-regulated during anaerobic growth. Together, these results define differences in mutational spectra affecting the evolution of facultative anaerobes.


Assuntos
Escherichia coli/genética , Frequência do Gene , Taxa de Mutação , Oxigênio/metabolismo , Anaerobiose , Reparo do DNA , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Sequências Repetitivas de Ácido Nucleico/genética
6.
Artigo em Inglês | MEDLINE | ID: mdl-31481448

RESUMO

The global spread of multidrug-resistant enterobacteria warrants new strategies to combat these pathogens. One possible approach is the reconsideration of "old" antimicrobials, which remain effective after decades of use. Synthetic 5-nitrofurans such as furazolidone, nitrofurantoin, and nitrofurazone are such a class of antimicrobial drugs. Recent epidemiological data showed a very low prevalence of resistance to this antimicrobial class among clinical Escherichia coli isolates in various parts of the world, forecasting the increasing importance of its uses to battle antibiotic-resistant enterobacteria. However, although they have had a long history of clinical use, a detailed understanding of the 5-nitrofurans' mechanisms of action remains limited. Nitrofurans are known as prodrugs that are activated in E. coli by reduction catalyzed by two redundant nitroreductases, NfsA and NfsB. Furazolidone, nevertheless, retains relatively significant antibacterial activity in the nitroreductase-deficient ΔnfsA ΔnfsBE. coli strain, indicating the presence of additional activating enzymes and/or antibacterial activity of the unreduced form. Using genome sequencing, genetic, biochemical, and bioinformatic approaches, we discovered a novel 5-nitrofuran-activating enzyme, AhpF, in E. coli The discovery of a new nitrofuran-reducing enzyme opens new avenues for overcoming 5-nitrofuran resistance, such as designing nitrofuran analogues with higher affinity for AhpF or screening for adjuvants that enhance AhpF expression.


Assuntos
Escherichia coli/enzimologia , Nitrorredutases/metabolismo , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Furazolidona/química , Furazolidona/farmacologia , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Nitrofuranos/metabolismo , Nitrofuranos/farmacologia , Nitrofurantoína/química , Nitrofurantoína/farmacologia , Nitrofurazona/química , Nitrofurazona/farmacologia , Nitrorredutases/genética , Peroxirredoxinas/genética , Peroxirredoxinas/metabolismo
7.
Genome Res ; 24(9): 1517-25, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24907284

RESUMO

Ruminant livestock represent the single largest anthropogenic source of the potent greenhouse gas methane, which is generated by methanogenic archaea residing in ruminant digestive tracts. While differences between individual animals of the same breed in the amount of methane produced have been observed, the basis for this variation remains to be elucidated. To explore the mechanistic basis of this methane production, we measured methane yields from 22 sheep, which revealed that methane yields are a reproducible, quantitative trait. Deep metagenomic and metatranscriptomic sequencing demonstrated a similar abundance of methanogens and methanogenesis pathway genes in high and low methane emitters. However, transcription of methanogenesis pathway genes was substantially increased in sheep with high methane yields. These results identify a discrete set of rumen methanogens whose methanogenesis pathway transcription profiles correlate with methane yields and provide new targets for CH4 mitigation at the levels of microbiota composition and transcriptional regulation.


Assuntos
Proteínas Arqueais/genética , Metagenoma , Metano/biossíntese , Microbiota , Rúmen/microbiologia , Ovinos/microbiologia , Animais , Archaea/genética , Archaea/metabolismo , Proteínas Arqueais/metabolismo , Sequência de Bases , Dados de Sequência Molecular , Fenótipo , Característica Quantitativa Herdável , Rúmen/metabolismo , Ovinos/metabolismo , Transcriptoma
8.
Ophthalmology ; 123(3): 497-504, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26686965

RESUMO

PURPOSE: The objective of this study was to compare the cost associated with surgical versus interferon-alpha 2b (IFNα2b) treatment for ocular surface squamous neoplasia (OSSN). DESIGN: A matched, case-control study. PARTICIPANTS: A total of 98 patients with OSSN, 49 of whom were treated surgically and 49 of whom were treated medically. METHODS: Patients with OSSN treated with IFNα2b were matched to patients treated with surgery on the basis of age and date of treatment initiation. Financial cost to the patient was calculated using 2 different methods (hospital billing and Medicare allowable charges) and compared between the 2 groups. These fees included physician fees (clinic, pathology, anesthesia, and surgery), facility fees (clinic, pathology, and operating room), and medication costs. Time invested by patients was calculated in terms of number of visits to the hospital and compared between the 2 groups. Parking costs, transportation, caregiver wages, and lost wages were not considered in our analysis. MAIN OUTCOME MEASURES: Number of clinic visits and cost of therapy as represented by both hospital charges and Medicare allowable charges. RESULTS: When considering cost in terms of time, the medical group had an average of 2 more visits over 1 year compared with the surgical group. Cost as represented by hospital charges was higher in the surgical group (mean, $17 598; standard deviation [SD], $7624) when compared with the IFNα2b group (mean, $4986; SD, $2040). However, cost between the 2 groups was comparable when calculated on the basis of Medicare allowable charges (surgical group: mean, $3528; SD, $1610; medical group: mean, $2831; SD, $1082; P = 1.00). The highest cost in the surgical group was the excisional biopsy (hospital billing $17 598; Medicare allowable $3528), and the highest cost in the medical group was interferon ($1172 for drops, average 8.0 bottles; $370 for injections, average 5.4 injections). CONCLUSIONS: Our data in this group of patients previously demonstrated equal efficacy of surgical versus medical treatment. In this article, we consider costs of therapy and found that medical treatment involved two more office visits, whereas surgical treatment could be more or equally costly depending on insurance coverage.


Assuntos
Carcinoma in Situ/economia , Carcinoma de Células Escamosas/economia , Neoplasias da Túnica Conjuntiva/economia , Doenças da Córnea/economia , Fatores Imunológicos/economia , Interferon-alfa/economia , Procedimentos Cirúrgicos Oftalmológicos/economia , Administração Tópica , Idoso , Idoso de 80 Anos ou mais , Carcinoma in Situ/terapia , Carcinoma de Células Escamosas/terapia , Estudos de Casos e Controles , Neoplasias da Túnica Conjuntiva/tratamento farmacológico , Neoplasias da Túnica Conjuntiva/cirurgia , Neoplasias da Túnica Conjuntiva/terapia , Doenças da Córnea/tratamento farmacológico , Doenças da Córnea/cirurgia , Doenças da Córnea/terapia , Efeitos Psicossociais da Doença , Neoplasias Oculares/tratamento farmacológico , Neoplasias Oculares/economia , Neoplasias Oculares/cirurgia , Neoplasias Oculares/terapia , Feminino , Custos Hospitalares , Humanos , Interferon alfa-2 , Masculino , Medicare/economia , Pessoa de Meia-Idade , Soluções Oftálmicas , Proteínas Recombinantes/economia , Estudos Retrospectivos , Estados Unidos
9.
BMC Genomics ; 15: 356, 2014 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-24886150

RESUMO

BACKGROUND: In silico, secretome proteins can be predicted from completely sequenced genomes using various available algorithms that identify membrane-targeting sequences. For metasecretome (collection of surface, secreted and transmembrane proteins from environmental microbial communities) this approach is impractical, considering that the metasecretome open reading frames (ORFs) comprise only 10% to 30% of total metagenome, and are poorly represented in the dataset due to overall low coverage of metagenomic gene pool, even in large-scale projects. RESULTS: By combining secretome-selective phage display and next-generation sequencing, we focused the sequence analysis of complex rumen microbial community on the metasecretome component of the metagenome. This approach achieved high enrichment (29 fold) of secreted fibrolytic enzymes from the plant-adherent microbial community of the bovine rumen. In particular, we identified hundreds of heretofore rare modules belonging to cellulosomes, cell-surface complexes specialised for recognition and degradation of the plant fibre. CONCLUSIONS: As a method, metasecretome phage display combined with next-generation sequencing has a power to sample the diversity of low-abundance surface and secreted proteins that would otherwise require exceptionally large metagenomic sequencing projects. As a resource, metasecretome display library backed by the dataset obtained by next-generation sequencing is ready for i) affinity selection by standard phage display methodology and ii) easy purification of displayed proteins as part of the virion for individual functional analysis.


Assuntos
Bacteriófagos/metabolismo , Técnicas de Visualização da Superfície Celular , Metagenoma/genética , Metagenômica/métodos , Rúmen/microbiologia , Animais , Bovinos , Celulossomas/metabolismo , Bases de Dados de Proteínas , Sequenciamento de Nucleotídeos em Larga Escala , Fases de Leitura Aberta , Análise de Sequência de DNA
10.
Ophthalmology ; 121(5): 994-1000, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24411578

RESUMO

PURPOSE: Treatment for ocular surface squamous neoplasia (OSSN) has historically been surgery, but nonsurgical interventions are increasingly used. Treatment with interferon is efficacious, but evidence is needed regarding recurrence and complication rates in comparison with surgery. The objective of this study is to compare the recurrence and complication rates of surgical treatment and interferon treatment for OSSN. DESIGN: A matched, case-control study. PARTICIPANTS: Ninety-eight patients with OSSN, 49 of whom were treated with interferon (IFN) α2b therapy and 49 of whom were treated with surgical intervention. METHODS: Patients with OSSN were treated with surgery versus IFNα2b therapy, either in topical or injection form. Median follow-up after lesion resolution was 21 months (range, 0-173 months) for the IFNα2b group and 24 months (range, 0.9-108 months) for the surgery group. MAIN OUTCOME MEASURES: The primary outcome measure for the study was the rate of recurrence of OSSN in each of the treatment groups. Recurrence rates were evaluated using Kaplan-Meier survival analysis. RESULTS: Mean patient age and sex were similar between the groups. There was a trend toward higher clinical American Joint Committee on Cancer tumor grade in the IFNα2b group. Despite this, the number of recurrences was equal at 3 per group. The 1-year recurrence rate was 5% in the surgery group versus 3% in the IFNα2b group (P = 0.80). There was no statistically significant difference in the recurrence rate between the surgically and medically treated groups. Nonlimbal location was a risk factor for recurrence (hazard ratio, 8.96) in the entire study population. In patients who were treated successfully, the side effects of the 2 treatments were similar, with mild discomfort seen in the majority of patients in both groups. There was no limbal stem cell deficiency, symblepharon, or diplopia noted in either group. Two patients were excluded from the IFNα2b group because of intolerance to the medication. CONCLUSIONS: No difference in the recurrence rate of OSSN was found between surgical versus IFNα2b therapy.


Assuntos
Carcinoma in Situ/terapia , Carcinoma de Células Escamosas/terapia , Neoplasias da Túnica Conjuntiva/terapia , Doenças da Córnea/terapia , Interferon-alfa/uso terapêutico , Recidiva Local de Neoplasia/diagnóstico , Procedimentos Cirúrgicos Oftalmológicos , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/uso terapêutico , Carcinoma in Situ/tratamento farmacológico , Carcinoma in Situ/patologia , Carcinoma in Situ/cirurgia , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Estudos de Casos e Controles , Neoplasias da Túnica Conjuntiva/tratamento farmacológico , Neoplasias da Túnica Conjuntiva/patologia , Neoplasias da Túnica Conjuntiva/cirurgia , Doenças da Córnea/tratamento farmacológico , Doenças da Córnea/patologia , Doenças da Córnea/cirurgia , Crioterapia , Neoplasias Oculares/tratamento farmacológico , Neoplasias Oculares/patologia , Neoplasias Oculares/cirurgia , Neoplasias Oculares/terapia , Feminino , Humanos , Interferon alfa-2 , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Soluções Oftálmicas , Complicações Pós-Operatórias , Proteínas Recombinantes/uso terapêutico , Fatores de Risco , Resultado do Tratamento , Acuidade Visual/fisiologia
11.
Proteins ; 81(5): 911-7, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23345031

RESUMO

Butyrivibrio proteoclasticus is a significant component of the microbial population of the rumen of dairy cattle. It is a xylan-degrading organism whose genome encodes a large number of open reading frames annotated as fiber-degrading enzymes. We have determined the three-dimensional structure of Est2A, an acetyl xylan esterase from B. proteoclasticus, at 2.1 Å resolution, along with the structure of an inactive mutant (H351A) at 2.0 Å resolution. The structure reveals two domains-a C-terminal SGNH domain and an N-terminal jelly-roll domain typical of CE2 family structures. The structures are accompanied by experimentally determined enzymatic parameters against two model substrates, para-nitrophenyl acetate and para-nitrophenyl butyrate. The suite of fiber-degrading enzymes produced by B. proteoclasticus provides a rich source of new enzymes of potential use in industrial settings.


Assuntos
Acetilesterase/química , Acetilesterase/metabolismo , Butyrivibrio/enzimologia , Bovinos/microbiologia , Acetilesterase/genética , Animais , Butyrivibrio/genética , Butyrivibrio/metabolismo , Celulose/metabolismo , Cristalografia por Raios X , Modelos Moleculares , Mutagênese Sítio-Dirigida , Mutação , Conformação Proteica
12.
JHEP Rep ; 5(4): 100664, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36908748

RESUMO

Background & Aims: Patterns of liver HBV antigen expression have been described but not quantified at single-cell resolution. We applied quantitative techniques to liver biopsies from individuals with chronic hepatitis B and evaluated sampling heterogeneity, effects of disease stage, and nucleos(t)ide (NUC) treatment, and correlations between liver and peripheral viral biomarkers. Methods: Hepatocytes positive for HBV core and HBsAg were quantified using a novel four-plex immunofluorescence assay and image analysis. Biopsies were analysed from HBeAg-positive (n = 39) and HBeAg-negative (n = 75) participants before and after NUC treatment. To evaluate sampling effects, duplicate biopsies collected at the same time point were compared. Serum or plasma samples were evaluated for levels of HBV DNA, HBsAg, hepatitis B core-related antigen (HBcrAg), and HBV RNA. Results: Diffusely distributed individual HBV core+ cells and foci of HBsAg+ cells were the most common staining patterns. Hepatocytes positive for both HBV core and HBsAg were rare. Paired biopsies revealed large local variation in HBV staining within participants, which was confirmed in a large liver resection. NUC treatment was associated with a >100-fold lower median frequency of HBV core+ cells in HBeAg-positive and HBeAg-negative participants, whereas reductions in HBsAg+ cells were not statistically significant. The frequency of HBV core+ hepatocytes was lower in HBeAg-negative participants than in HBeAg-positive participants at all time points evaluated. Total HBV+ hepatocyte burden correlated with HBcrAg, HBV DNA, and HBV RNA only in baseline HBeAg-positive samples. Conclusions: Reductions in HBV core+ hepatocytes were associated with HBeAg-negative status and NUC treatment. Variation in HBV positivity within individual livers was extensive. Correlations between the liver and the periphery were found only between biomarkers likely indicative of cccDNA (HBV core+ and HBcrAg, HBV DNA, and RNA). Impact and Implications: HBV infects liver hepatocyte cells, and its genome can exist in two forms that express different sets of viral proteins: a circular genome called cccDNA that can express all viral proteins, including the HBV core and HBsAg proteins, or a linear fragment that inserts into the host genome typically to express HBsAg, but not HBV core. We used new techniques to determine the percentage of hepatocytes expressing the HBV core and HBsAg proteins in a large set of liver biopsies. We find that abundance and patterns of expression differ across patient groups and even within a single liver and that NUC treatment greatly reduces the number of core-expressing hepatocytes.

13.
Nat Commun ; 14(1): 3798, 2023 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-37365172

RESUMO

Despite their role in host nutrition, the anaerobic gut fungal (AGF) component of the herbivorous gut microbiome remains poorly characterized. Here, to examine global patterns and determinants of AGF diversity, we generate and analyze an amplicon dataset from 661 fecal samples from 34 mammalian species, 9 families, and 6 continents. We identify 56 novel genera, greatly expanding AGF diversity beyond current estimates (31 genera and candidate genera). Community structure analysis indicates that host phylogenetic affiliation, not domestication status and biogeography, shapes the community rather than. Fungal-host associations are stronger and more specific in hindgut fermenters than in foregut fermenters. Transcriptomics-enabled phylogenomic and molecular clock analyses of 52 strains from 14 genera indicate that most genera with preferences for hindgut hosts evolved earlier (44-58 Mya) than those with preferences for foregut hosts (22-32 Mya). Our results greatly expand the documented scope of AGF diversity and provide an ecologically and evolutionary-grounded model to explain the observed patterns of AGF diversity in extant animal hosts.


Assuntos
Micobioma , Animais , Micobioma/genética , Filogenia , Fezes/microbiologia , Sistema Digestório , Evolução Biológica , Mamíferos
14.
J Biol Chem ; 286(2): 942-51, 2011 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-21036901

RESUMO

Cross-talk between Gα(i)- and Gα(q)-linked G-protein-coupled receptors yields synergistic Ca(2+) responses in a variety of cell types. Prior studies have shown that synergistic Ca(2+) responses from macrophage G-protein-coupled receptors are primarily dependent on phospholipase Cß3 (PLCß3), with a possible contribution of PLCß2, whereas signaling through PLCß4 interferes with synergy. We here show that synergy can be induced by the combination of Gßγ and Gα(q) activation of a single PLCß isoform. Synergy was absent in macrophages lacking both PLCß2 and PLCß3, but it was fully reconstituted following transduction with PLCß3 alone. Mechanisms of PLCß-mediated synergy were further explored in NIH-3T3 cells, which express little if any PLCß2. RNAi-mediated knockdown of endogenous PLCßs demonstrated that synergy in these cells was dependent on PLCß3, but PLCß1 and PLCß4 did not contribute, and overexpression of either isoform inhibited Ca(2+) synergy. When synergy was blocked by RNAi of endogenous PLCß3, it could be reconstituted by expression of either human PLCß3 or mouse PLCß2. In contrast, it could not be reconstituted by human PLCß3 with a mutation of the Y box, which disrupted activation by Gßγ, and it was only partially restored by human PLCß3 with a mutation of the C terminus, which partly disrupted activation by Gα(q). Thus, both Gßγ and Gα(q) contribute to activation of PLCß3 in cells for Ca(2+) synergy. We conclude that Ca(2+) synergy between Gα(i)-coupled and Gα(q)-coupled receptors requires the direct action of both Gßγ and Gα(q) on PLCß and is mediated primarily by PLCß3, although PLCß2 is also competent.


Assuntos
Sinalização do Cálcio/fisiologia , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Subunidades beta da Proteína de Ligação ao GTP/metabolismo , Subunidades gama da Proteína de Ligação ao GTP/metabolismo , Fosfolipase C beta/metabolismo , Animais , Complemento C5a/metabolismo , Humanos , Macrófagos/metabolismo , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Mutagênese , Células NIH 3T3 , Fosfolipase C beta/genética , RNA Interferente Pequeno , Receptores Purinérgicos P2/metabolismo , Difosfato de Uridina/metabolismo
15.
Int Immunol ; 23(5): 307-15, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21422152

RESUMO

IL-33 is an IL-1-related cytokine which has been implicated in T(h)2-associated biology and allergic diseases in humans and mice. IL-33 stimulates T(h)2 cells, mast cells, eosinophils, basophils, iNKT cells and circulating CD34(+) stem cells to proliferate and produce pro-allergic cytokines such as IL-5 and IL-13. IL-33 mediates its cytokine effects through a receptor consisting of ST2 and IL-1RAcP. Whereas IL-1RAcP is ubiquitously expressed, ST2 expression is cell-type restricted and determines responsiveness to IL-33. Studies employing ST2-deficient mice have reported variable results on the role of this receptor, and consequently IL-33, with regards to allergic lung inflammation. In this study, we demonstrate that IL-33 is important for allergic lung inflammation. Intra-nasal administration of IL-33 triggered an immediate allergic response in the airways, and more importantly, we show that endogenous IL-33 contributes to airway inflammation and peripheral antigen-specific responses in ovalbumin-induced acute allergic lung inflammation using IL-33-deficient mice. Our results suggest that IL-33 is sufficient and required for severe allergic inflammation in the lung and support the concept of IL-33 as a therapeutic target in allergic lung inflammation.


Assuntos
Citocinas/biossíntese , Interleucinas/imunologia , Hipersensibilidade Respiratória/imunologia , Hipersensibilidade Respiratória/patologia , Linfócitos T/imunologia , Células Th2/metabolismo , Animais , Citocinas/imunologia , Inflamação/imunologia , Interleucina-33 , Interleucinas/deficiência , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Linfócitos T/metabolismo , Células Th2/imunologia
16.
J Interprof Educ Pract ; 29: 100524, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35935734

RESUMO

Telemedicine may provide equitable, accessible, and affordable healthcare to individuals globally. Recently tele-medicine has emerged as a vital resource for interdisciplinary healthcare professionals to provide critical medical care on the frontlines during the combined COVID-19 pandemic and the drug and opioid crisis. With the recent 2020 expansion of insurance coverage of telemedicine services by the United States Centers for Medicare & Medicaid Services, there has been an uptick in the need to understand how to comprehensively train physicians and health care professionals on telemedicine during a public health crisis. This study gathered 98 survey responses from interdisciplinary healthcare professionals regarding their telemedicine experience, focusing on trends of use with the drug and opioid crisis during the COVID-19 pandemic. The results demonstrate that during the COVID-19 pandemic, telemedicine provided a novel, innovative way to address an unmet need in healthcare and may aid to improve safe medication stewardship (SaMS) practice guidelines. Further expanded population-based research and randomized clinical trials are necessary to confirm these preliminary recommendations and form best practices for use in digital health and telemedicine. In addition, further studies will confirm the benefits of interdisciplinary healthcare professionals' engagement in harm reduction strategies via telemedicine to address improving safe medication use.

17.
Microbiome ; 10(1): 76, 2022 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-35546409

RESUMO

Although there is now an extensive understanding of the diversity of microbial life on earth through culture-independent metagenomic DNA sequence analyses, the isolation and cultivation of microbes remains critical to directly study them and confirm their metabolic and physiological functions, and their ecological roles. The majority of environmental microbes are as yet uncultured however; therefore, bringing these rare or poorly characterized groups into culture is a priority to further understand microbiome functions. Moreover, cultivated isolates may find utility in a range of applications, such as new probiotics, biocontrol agents, and agents for industrial processes. The growing abundance of metagenomic and meta-transcriptomic sequence information from a wide range of environments provides more opportunities to guide the isolation and cultivation of microbes of interest. In this paper, we discuss a range of successful methodologies and applications that have underpinned recent metagenome-guided isolation and cultivation of microbe efforts. These approaches include determining specific culture conditions to enrich for taxa of interest, to more complex strategies that specifically target the capture of microbial species through antibody engineering and genome editing strategies. With the greater degree of genomic information now available from uncultivated members, such as via metagenome-assembled genomes, the theoretical understanding of their cultivation requirements will enable greater possibilities to capture these and ultimately gain a more comprehensive understanding of the microbiomes. Video Abstract.


Assuntos
Metagenoma , Microbiota , Bactérias/genética , Genômica , Metagenoma/genética , Metagenômica/métodos , Microbiota/genética
18.
Front Plant Sci ; 13: 1025698, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36340377

RESUMO

Asexual Epichloë are endophytic fungi that form mutualistic symbioses with cool-season grasses, conferring to their hosts protection against biotic and abiotic stresses. Symbioses are maintained between grass generations as hyphae are vertically transmitted from parent to progeny plants through seed. However, endophyte transmission to the seed is an imperfect process where not all seeds become infected. The mechanisms underpinning the varying efficiencies of seed transmission are poorly understood. Host gene expression in response to Epichloë sp. LpTG-3 strain AR37 was examined within inflorescence primordia and ovaries of high and low endophyte transmission genotypes within a single population of perennial ryegrass. A genome-wide association study was conducted to identify population-level single nucleotide polymorphisms (SNPs) and associated genes correlated with vertical transmission efficiency. For low transmitters of AR37, upregulation of perennial ryegrass receptor-like kinases and resistance genes, typically associated with phytopathogen detection, comprised the largest group of differentially expressed genes (DEGs) in both inflorescence primordia and ovaries. DEGs involved in signaling and plant defense responses, such as cell wall modification, secondary metabolism, and reactive oxygen activities were also abundant. Transmission-associated SNPs were associated with genes for which gene ontology analysis identified "response to fungus" as the most significantly enriched term. Moreover, endophyte biomass as measured by quantitative PCR of Epichloë non-ribosomal peptide synthetase genes, was significantly lower in reproductive tissues of low-transmission hosts compared to high-transmission hosts. Endophyte seed-transmission efficiency appears to be influenced primarily by plant defense responses which reduce endophyte colonization of host reproductive tissues.

19.
Microorganisms ; 10(9)2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36144352

RESUMO

Anaerobic fungi from the herbivore digestive tract (Neocallimastigomycetes) are primary lignocellulose modifiers and hold promise for biotechnological applications. Their molecular detection is currently difficult due to the non-specificity of published primer pairs, which impairs evolutionary and ecological research with environmental samples. We developed and validated a Neocallimastigomycetes-specific PCR primer pair targeting the D2 region of the ribosomal large subunit suitable for screening, quantifying, and sequencing. We evaluated this primer pair in silico on sequences from all known genera, in vitro with pure cultures covering 16 of the 20 known genera, and on environmental samples with highly diverse microbiomes. The amplified region allowed phylogenetic differentiation of all known genera and most species. The amplicon is about 350 bp long, suitable for short-read high-throughput sequencing as well as qPCR assays. Sequencing of herbivore fecal samples verified the specificity of the primer pair and recovered highly diverse and so far unknown anaerobic gut fungal taxa. As the chosen barcoding region can be easily aligned and is taxonomically informative, the sequences can be used for classification and phylogenetic inferences. Several new Neocallimastigomycetes clades were obtained, some of which represent putative novel lineages such as a clade from feces of the rodent Dolichotis patagonum (mara).

20.
JHEP Rep ; 4(1): 100388, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34950863

RESUMO

BACKGROUND & AIMS: We aim to describe the liver immune microenvironment by analyzing liver biopsies from patients with chronic HBV infection (CHB). Host immune cell signatures and their corresponding localization were characterized by analyzing the intrahepatic transcriptome in combination with a custom multiplex immunofluorescence panel. METHOD: Matching FFPE and fresh frozen liver biopsies were collected from immune active patients within the open-label phase IV study GS-US-174-0149. RNA-Seq was conducted on 53 CHB liver biopsies from 46 patients. Twenty-eight of the 53 samples had matched FFPE biopsies and were stained with a 12-plex panel including cell segmentation, immune and viral biomarkers. Corresponding serum samples were screened using the MSD Human V-plex Screen Service to identify peripheral correlates for the immune microenvironment. RESULTS: Using unsupervised clustering of the transcriptome, we reveal two unique liver immune signatures classified as immune high and immune low based on the quantification of the liver infiltrate gene signatures. Multiplex immunofluorescence analysis demonstrated large periportal lymphoid aggregates in immune high samples consisting of CD4 and CD8 T cells, B cells and macrophages. Differentiation of the high and low immune microenvironments was independent of HBeAg status and peripheral viral antigen levels. In addition, longitudinal analysis indicates that treatment and normalization of ALT correlates with a decrease in liver immune infiltrate and inflammation. Finally, we screened a panel of peripheral biomarkers and identified ICAM-1 and CXCL10 as biomarkers that strongly correlate with these unique immune microenvironments. CONCLUSION: These data provide a description of immune phenotypes in patients with CHB and show that immune responses are downregulated in the liver following nucleotide analogue treatment. This may have important implications for both the safety and efficacy of immune modulator programs aimed at HBV cure. LAY SUMMARY: Liver biopsies from patients with chronic hepatitis B were submitted to RNA-Seq and multiplex immunofluorescence and identified two different liver immune microenvironments: immune high and immune low. Immune high patients showed elevated immune pathways, including interferon signaling pathways, and increase presence of immune cells. Longitudinal analysis of biopsies from treatment experienced patients showed that treatment correlates with a marked decrease in inflammation and these findings may have important implications for both safety and efficacy of immune modulator programs for HBV cure.

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