Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
iScience ; 27(7): 110283, 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-39040063

RESUMEN

The emergence of novel Omicron subvariants has raised concerns regarding the efficacy of immunity induced by prior Omicron subvariants breakthrough infection (BTI) or reinfection against current circulating Omicron subvariants. Here, we prospectively investigated the durability of antibody and T cell responses in individuals post Omicron BA.2.2 BTI, with or without subsequent Omicron BA.5 reinfection. Our findings reveal that the emerging Omicron subvariants, including CH.1.1, XBB, and JN.1, exhibit extensive immune evasion induced by previous infections. Notably, the level of IgG and neutralizing antibodies were found to correlate with subsequent Omicron BA.5 reinfection. Fortunately, T cell responses recognizing both Omicron BA.2 and CH.1.1 peptides were observed. Furthermore, Omicron BA.5 reinfection may alleviate immune imprinting induced by WT-vaccination, bolster virus-specific ICS+ T cell responses, and promote the phenotypic differentiation of virus-specific memory CD8+ T cells. Antigen-updated or T cell-conserved vaccines are needed to control the transmission of diverse emerging SARS-CoV-2 variants.

3.
J Infect Dis ; 224(4): 586-594, 2021 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-33978754

RESUMEN

BACKGROUND: The duration of humoral and T and B cell response after the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains unclear. METHODS: We performed a cross-sectional study to assess the virus-specific antibody and memory T and B cell responses in coronavirus disease 2019 (COVID-19) patients up to 343 days after infection. Neutralizing antibodies and antibodies against the receptor-binding domain, spike, and nucleoprotein of SARS-CoV-2 were measured. Virus-specific memory T and B cell responses were analyzed. RESULTS: We enrolled 59 patients with COVID-19, including 38 moderate, 16 mild, and 5 asymptomatic patients; 31 (52.5%) were men and 28 (47.5%) were women. The median age was 41 years (interquartile range, 30-55). The median day from symptom onset to enrollment was 317 days (range 257 to 343 days). We found that approximately 90% of patients still have detectable immunoglobulin (Ig)G antibodies against spike and nucleocapsid proteins and neutralizing antibodies against pseudovirus, whereas ~60% of patients had detectable IgG antibodies against receptor-binding domain and surrogate virus-neutralizing antibodies. The SARS-CoV-2-specific IgG+ memory B cell and interferon-γ-secreting T cell responses were detectable in more than 70% of patients. CONCLUSIONS: Severe acute respiratory syndrome coronavirus 2-specific immune memory response persists in most patients approximately 1 year after infection, which provides a promising sign for prevention from reinfection and vaccination strategy.


Asunto(s)
Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , COVID-19/inmunología , Inmunidad Celular/inmunología , Adulto , Linfocitos B/inmunología , Estudios Transversales , Femenino , Humanos , Inmunoglobulina G/inmunología , Memoria Inmunológica/inmunología , Masculino , Persona de Mediana Edad , Proteínas de la Nucleocápside/inmunología , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Linfocitos T/inmunología
5.
Arch Virol ; 165(6): 1489-1494, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32266550

RESUMEN

We detected a novel bovine hepacivirus N (HNV) subtype, IME_BovHep_01, in the serum of cattle in Tengchong, Yunnan, China, by high-throughput sequencing. The complete genome of IME_BovHep_01, was sequenced using an Illumina MiSeq sequencer and found to be 8850 nt in length, encoding one hypothetical protein. BLASTn analysis showed that the genome sequence shared similarity with the bovine hepacivirus isolate BovHepV_209/Ger/2014, with 88% query coverage and 70.8% identity. However, the highest similarity was to bovine hepacivirus N strain BRBovHep_RS963, for which only a partial genome sequence is available, with 68% query coverage and 81.5% identity. Sequence comparisons and phylogenetic analysis suggested that IME_BovHep_01 is a novel HNV subtype. Importantly, IME_BovHep_01 is the first member of this new genotype for which the complete genome sequence was determined.


Asunto(s)
Bovinos/virología , Genoma Viral , Hepacivirus/genética , Hepacivirus/aislamiento & purificación , Animales , Secuencia de Bases , China , Variación Genética , Genotipo , Hepacivirus/clasificación , Filogenia , Análisis de Secuencia de ADN , Secuenciación Completa del Genoma
6.
Arch Virol ; 164(3): 907-911, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30656464

RESUMEN

A novel negevirus, tentatively named Manglie virus (MaV), was isolated from Culex tritaeniorhynchus from the village of Manglie, Yunnan, China, in August 2011. It was identified by high-throughput sequencing of cell culture supernatants, and the complete genome was sequenced using an Illumina MiSeq sequencer. The complete MaV genome comprised 9,218 nt encoding three hypothetical proteins and had a poly(A) tail. BLASTn analysis showed that the genome had the greatest similarity to Ngewotan virus strain Nepal22, with query coverage of 100% and 79% identity. Genomic and phylogenetic analyses demonstrated that MaV should be considered a novel negevirus.


Asunto(s)
Culex/virología , Genoma Viral , Virus de Insectos/genética , Virus de Insectos/aislamiento & purificación , Virus ARN/genética , Virus ARN/aislamiento & purificación , Animales , Secuencia de Bases , China , Virus de Insectos/clasificación , Filogenia , Virus ARN/clasificación , Proteínas Virales/genética , Secuenciación Completa del Genoma
7.
IEEE Trans Image Process ; 23(1): 264-73, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24184727

RESUMEN

Vector bilateral filtering has been shown to provide good tradeoff between noise removal and edge degradation when applied to multispectral/hyperspectral image denoising. It has also been demonstrated to provide dynamic range enhancement of bands that have impaired signal to noise ratios (SNRs). Typical vector bilateral filtering described in the literature does not use parameters satisfying optimality criteria. We introduce an approach for selection of the parameters of a vector bilateral filter through an optimization procedure rather than by ad hoc means. The approach is based on posing the filtering problem as one of nonlinear estimation and minimization of the Stein's unbiased risk estimate of this nonlinear estimator. Along the way, we provide a plausibility argument through an analytical example as to why vector bilateral filtering outperforms bandwise 2D bilateral filtering in enhancing SNR. Experimental results show that the optimized vector bilateral filter provides improved denoising performance on multispectral images when compared with several other approaches.


Asunto(s)
Algoritmos , Color , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Procesamiento de Señales Asistido por Computador , Sensibilidad y Especificidad , Relación Señal-Ruido
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...