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1.
PLoS Pathog ; 17(2): e1009304, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33544760

RESUMEN

S. epidermidis is a substantial component of the human skin microbiota, but also one of the major causes of nosocomial infection in the context of implanted medical devices. We here aimed to advance the understanding of S. epidermidis genotypes and phenotypes conducive to infection establishment. Furthermore, we investigate the adaptation of individual clonal lines to the infection lifestyle based on the detailed analysis of individual S. epidermidis populations of 23 patients suffering from prosthetic joint infection. Analysis of invasive and colonizing S. epidermidis provided evidence that invasive S. epidermidis are characterized by infection-supporting phenotypes (e.g. increased biofilm formation, growth in nutrient poor media and antibiotic resistance), as well as specific genetic traits. The discriminating gene loci were almost exclusively assigned to the mobilome. Here, in addition to IS256 and SCCmec, chromosomally integrated phages was identified for the first time. These phenotypic and genotypic features were more likely present in isolates belonging to sequence type (ST) 2. By comparing seven patient-matched nasal and invasive S. epidermidis isolates belonging to identical genetic lineages, infection-associated phenotypic and genotypic changes were documented. Besides increased biofilm production, the invasive isolates were characterized by better growth in nutrient-poor media and reduced hemolysis. By examining several colonies grown in parallel from each infection, evidence for genetic within-host population heterogeneity was obtained. Importantly, subpopulations carrying IS insertions in agrC, mutations in the acetate kinase (AckA) and deletions in the SCCmec element emerged in several infections. In summary, these results shed light on the multifactorial processes of infection adaptation and demonstrate how S. epidermidis is able to flexibly repurpose and edit factors important for colonization to facilitate survival in hostile infection environments.

2.
PLoS Pathog ; 16(8): e1008562, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32833988

RESUMEN

Merkel Cell Polyomavirus (MCPyV) is the etiological agent of the majority of Merkel Cell Carcinomas (MCC). MCPyV positive MCCs harbor integrated, defective viral genomes that constitutively express viral oncogenes. Which molecular mechanisms promote viral integration, if distinct integration patterns exist, and if integration occurs preferentially at loci with specific chromatin states is unknown. We here combined short and long-read (nanopore) next-generation sequencing and present the first high-resolution analysis of integration site structure in MCC cell lines as well as primary tumor material. We find two main types of integration site structure: Linear patterns with chromosomal breakpoints that map closely together, and complex integration loci that exhibit local amplification of genomic sequences flanking the viral DNA. Sequence analysis suggests that linear patterns are produced during viral replication by integration of defective/linear genomes into host DNA double strand breaks via non-homologous end joining, NHEJ. In contrast, our data strongly suggest that complex integration patterns are mediated by microhomology-mediated break-induced replication, MMBIR. Furthermore, we show by ChIP-Seq and RNA-Seq analysis that MCPyV preferably integrates in open chromatin and provide evidence that viral oncogene expression is driven by the viral promoter region, rather than transcription from juxtaposed host promoters. Taken together, our data explain the characteristics of MCPyV integration and may also provide a model for integration of other oncogenic DNA viruses such as papillomaviruses.


Asunto(s)
Carcinoma de Células de Merkel/patología , Reparación del ADN por Unión de Extremidades , Poliomavirus de Células de Merkel/genética , Infecciones por Polyomavirus/complicaciones , Infecciones Tumorales por Virus/complicaciones , Integración Viral , Replicación Viral , Antígenos Virales de Tumores , Neoplasias Óseas/genética , Neoplasias Óseas/secundario , Neoplasias Óseas/virología , Carcinoma de Células de Merkel/genética , Carcinoma de Células de Merkel/virología , Humanos , Infecciones por Polyomavirus/genética , Infecciones por Polyomavirus/virología , Recombinación Genética , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/virología , Infecciones Tumorales por Virus/genética , Infecciones Tumorales por Virus/virología , Proteínas Virales/genética
3.
Oncol Rep ; 34(2): 755-62, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26062728

RESUMEN

Multidrug resistance (MDR) remains a formidable challenge in the use of chemotherapy and represents a powerful obstacle to the treatment of leukemia. ATP-binding cassette subfamily B member 1 (ABCB1) is a recognized factor which causes MDR and is closely related to poor outcome and relapse in leukemia. Ongoing research concerning the strategy for inhibiting the abnormally high activity of the ABCB1 transporter is critically needed. In the present study, we sought to elucidate the interaction between ABCB1 transporter and butorphanol. Our results showed that butorphanol significantly antagonized ABCB1-mediated drug efflux and increased the intracellular drug concentration by inhibiting the transport activity of ABCB1 in leukemia cells. Mechanistic investigations demonstrated that butorphanol did not alter the protein expression or localization of ABCB1 in HL60/VCR and K562/ADR cells. Furthermore, homology modeling indicated that butorphanol could fit into the large drug-binding cavity of ABCB1 and form a binding conformation. In conclusion, butorphanol reversed the ABCB1-mediated MDR in leukemia cells by directly suppressing the efflux activity of ABCB1.


Asunto(s)
Butorfanol/administración & dosificación , Resistencia a Antineoplásicos/efectos de los fármacos , Leucemia/tratamiento farmacológico , Subfamilia B de Transportador de Casetes de Unión a ATP/antagonistas & inhibidores , Subfamilia B de Transportador de Casetes de Unión a ATP/genética , Antineoplásicos/administración & dosificación , Línea Celular Tumoral , Doxorrubicina/administración & dosificación , Resistencia a Múltiples Medicamentos/genética , Humanos , Leucemia/genética , Leucemia/patología , Proteínas de Neoplasias/biosíntesis , Paclitaxel/administración & dosificación
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