clone

克隆
  • 文章类型: Journal Article
    结核分枝杆菌(Mtb)是引起结核病的病原体,并对许多现有药物产生耐药性。唯一获得许可的结核病疫苗,BCG,无法提供全面的防御。所以,维持免疫反应对消除结核病至关重要。我们先前的计算机模拟研究报道了五种未表征的蛋白质作为潜在的疫苗抗原。在这篇文章中,我们认为未表征的MtbH37Rv差异区(RD-2)Rv1987蛋白是有希望的疫苗候选物。使用反向疫苗学和基于免疫信息学的质量检查参数,然后进行离体初步研究,分析了蛋白质的疫苗质量。Rv1987蛋白的计算机模拟分析预测它是表面定位的,分泌,单螺旋,抗原性,非过敏性,并且与宿主蛋白非同源。通过CD4+和CD8+T细胞通过MHC-I和MHC-II结合亲和力和B细胞表位的存在对Rv1987进行的免疫信息学分析预测了其免疫原性。蛋白质与免疫细胞受体TLR-4的3D模型结构的对接复合物分析揭示了蛋白质潜在相互作用的能力。此外,克隆了靶蛋白编码基因Rv1987,过度表达,纯化,并通过质谱(MS)分析以报告目标肽。qRT-PCR基因表达分析表明,它能够激活巨噬细胞并显着增加许多关键细胞因子(TNF-α,IL-1β,和IL-10)。我们的计算机内分析和离体初步研究揭示了靶蛋白的免疫原性潜力。这些发现表明Rv1987被用作有效的亚单位疫苗抗原,并且进一步的动物模型免疫调节研究将促进新的TB疫苗发现和/或BCG疫苗补充管道。
    Mycobacterium tuberculosis (Mtb) is the pathogen that causes tuberculosis and develops resistance to many of the existing drugs. The sole licensed TB vaccine, BCG, is unable to provide a comprehensive defense. So, it is crucial to maintain the immunological response to eliminate tuberculosis. Our previous in silico study reported five uncharacterized proteins as potential vaccine antigens. In this article, we considered the uncharacterized Mtb H37Rv regions of difference (RD-2) Rv1987 protein as a promising vaccine candidate. The vaccine quality of the protein was analyzed using reverse vaccinology and immunoinformatics-based quality-checking parameters followed by an ex vivo preliminary investigation. In silico analysis of Rv1987 protein predicted it as surface localized, secretory, single helix, antigenic, non-allergenic, and non-homologous to the host protein. Immunoinformatics analysis of Rv1987 by CD4 + and CD8 + T-cells via MHC-I and MHC-II binding affinity and presence of B-cell epitope predicted its immunogenicity. The docked complex analysis of the 3D model structure of the protein with immune cell receptor TLR-4 revealed the protein\'s capability for potential interaction. Furthermore, the target protein-encoded gene Rv1987 was cloned, over-expressed, purified, and analyzed by mass spectrometry (MS) to report the target peptides. The qRT-PCR gene expression analysis shows that it is capable of activating macrophages and significantly increasing the production of a number of key cytokines (TNF-α, IL-1β, and IL-10). Our in-silico analysis and ex vivo preliminary investigations revealed the immunogenic potential of the target protein. These findings suggest that the Rv1987 be undertaken as a potent subunit vaccine antigen and that further animal model immuno-modulation studies would boost the novel TB vaccine discovery and/or BCG vaccine supplement pipeline.
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  • 文章类型: Journal Article
    免疫组织化学BCL2阳性有助于滤泡性淋巴瘤(FL)的诊断;然而,少数FL病例为BCL2阴性,因此,诊断具有挑战性。我们回顾性分析了发病率,形态学,免疫表型,和BCL21+的遗传状态(克隆124弱/局灶性阳性),BCL20(阴性),和BCL2有争议的FL与BCL22+(强阳性)FL进行比较,以阐明诊断线索。在1068例FL中,103(10%)合并BCL21(37例,4%),BCL20(61例,6%),或BCL2有争议(5例,0.5%)包括在最终分析中。BCL21+和BCL20FL往往有有限的阶段疾病,结节性疾病,和3A/3B级组织学,显示出比BCL22+FL更高的完全应答率。在103个BCL20、BCL21+、或BCL2有争议的FL案件,34(33%)的弥漫性区域由CD20阳性的小至中等大小的淋巴样细胞组成,低度B细胞淋巴瘤的特征。59%和37%的病例观察到滤泡间致密CD20阳性细胞和滤泡间CD10阳性细胞簇,分别。在其余13/40例(33%)中,BCL2被其它克隆E17/SP66转化为BCL22+。CD23和MUM1在10/40(25%)和1/40(3%)病例中呈阳性,分别。6/37(16%)和31/34(91%)例检测到IGH/BCL2融合和克隆性,分别。总之,在大多数情况下,对CD20和/或CD10阳性细胞的分布以及弥漫性区域的存在进行形态学检查可用于诊断FL。大多数剩余的FL病例可以使用其他BCL2克隆和克隆性分析来诊断。
    BCL2 positivity by immunohistochemistry is helpful for the diagnosis of follicular lymphoma (FL); however, a minority of FL cases are BCL2-negative, and the diagnosis is thus challenging. We retrospectively analyzed the incidence, morphology, immunophenotype, and genetic status of BCL21+ (weakly/focally positive by clone 124), BCL20 (negative), and BCL2controversial FLs compared with BCL22+ (strongly positive) FLs to clarify diagnostic clues. In 1068 FL cases, 103 (10%) with BCL21+ (37 cases, 4%), BCL20 (61 cases, 6%), or BCL2controversial (5 cases, 0.5%) were included in the final analysis. BCL21+ and BCL20 FLs tended to have limited stage disease, nodal disease, and grades 3A/3B histology and showed a higher complete response rate than BCL22+ FLs. Among 103 BCL20, BCL21+, or BCL2controversial FL cases, 34 (33%) had a diffuse area composed of CD20-positive small-to medium-sized lymphoid cells, a feature of low-grade B-cell lymphoma. Interfollicular dense CD20-positive cells and interfollicular clusters of CD10-positive cells were observed in 59% and 37% of cases, respectively. In remaining 13/40 cases (33%), BCL2 was converted to BCL22+ by other clones E17/SP66. CD23 and MUM1 were positive in 10/40 (25%) and 1/40 (3%) cases, respectively. IGH/BCL2 fusion and clonality were detected in 6/37 (16%) and 31/34 (91%) cases, respectively. In conclusion, morphological examination of the distribution of CD20-and/or CD10-positive cells and the presence of diffuse area could be used to diagnose FL in most cases. The majority of the remaining FL cases could be diagnosed using other BCL2 clones and clonality analyses.
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  • 文章类型: Journal Article
    背景:这项工作报告了西班牙侵袭性化脓性链球菌的抗菌素耐药性数据,由“侵袭性A组链球菌监测计划”收集,2007-2020年。
    方法:通过测序确定emm分型。对青霉素的易感性,四环素,红霉素,和克林霉素通过E检验测定。tetM,tetO,msrD,mefa,ermB,ermTR,和ermT通过PCR寻找。大环内酯抗性表型(M,cMLSB,和iMLSB)使用红霉素-克林霉素双盘试验检测。抗性克隆通过它们的emm类型鉴定,多位点序列类型(ST),抗性基因型,和大环内酯耐药表型。
    结果:青霉素敏感性普遍。237/1983分离株对四环素的耐药性(12.0%)(152只携带tetM,48只携带tetO,和33携带两者)。在172/1983分离株中检测到红霉素耐药性(8.7%);ermB在83中存在,mefA在58中存在,msrD在51中存在,ermTR在46中存在,ermT在36中存在。在78/1983分离株中存在克林霉素抗性(甲基化酶介导的)(3.9%)。确定了八个主要的抗性克隆:两个仅对四环素具有抗性(emm22/ST46/tetM和emm77/ST63/tetO),三种仅对红霉素耐药(emm4/ST39/mefA-msrD/M,emm12/ST36/mefA-msrD/M,和emm28/ST52/ermB/cMLSB),和三个四环素-红霉素共耐药(emm11/ST403/tetM-ermB/cMLSB,emm77/ST63/tetO-ermTR/iMLSB,和emm77/ST63/tetM-tetO-ermTR/iMLSB)。
    结论:四环素,红霉素,2007年至2020年间,克林霉素耐药率下降。抗性克隆比例的时间变化决定了抗性率的变化。
    BACKGROUND: This work reports on antimicrobial resistance data for invasive Streptococcus pyogenes in Spain, collected by the \'Surveillance Program for Invasive Group A Streptococcus\', in 2007-2020.
    METHODS: emm typing was determined by sequencing. Susceptibility to penicillin, tetracycline, erythromycin, and clindamycin was determined via the E-test. tetM, tetO, msrD, mefA, ermB, ermTR, and ermT were sought by PCR. Macrolide-resistant phenotypes (M, cMLSB, and iMLSB) were detected using the erythromycin-clindamycin double-disk test. Resistant clones were identified via their emm type, multilocus sequence type (ST), resistance genotype, and macrolide resistance phenotype.
    RESULTS: Penicillin susceptibility was universal. Tetracycline resistance was recorded for 237/1983 isolates (12.0%) (152 carried only tetM, 48 carried only tetO, and 33 carried both). Erythromycin resistance was detected in 172/1983 isolates (8.7%); ermB was present in 83, mefA in 58, msrD in 51, ermTR in 46, and ermT in 36. Clindamycin resistance (methylase-mediated) was present in 78/1983 isolates (3.9%). Eight main resistant clones were identified: two that were tetracycline-resistant only (emm22/ST46/tetM and emm77/ST63/tetO), three that were erythromycin-resistant only (emm4/ST39/mefA-msrD/M, emm12/ST36/mefA-msrD/M, and emm28/ST52/ermB/cMLSB), and three that were tetracycline-erythromycin co-resistant (emm11/ST403/tetM-ermB/cMLSB, emm77/ST63/tetO-ermTR/iMLSB, and emm77/ST63/tetM-tetO-ermTR/iMLSB).
    CONCLUSIONS: Tetracycline, erythromycin, and clindamycin resistance rates declined between 2007 and 2020. Temporal variations in the proportion of resistant clones determined the change in resistance rates.
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  • 文章类型: Journal Article
    Intestinal carriage of extended spectrum β-lactamase (ESBL)-producing Escherichia coli is a frequent, increasing, and worrying phenomenon, but little is known about the molecular scenario and the evolutionary forces at play. We screened 45 veal calves, known to have high prevalence of carriage, for ESBL-producing E. coli on 514 rectal swabs (one randomly selected colony per sample) collected over 6 months. We characterized the bacterial clones and plasmids carrying blaESBL genes with a combination of genotyping methods, whole genome sequencing, and conjugation assays. One hundred and seventy-three ESBL-producing E. coli isolates [blaCTX-M-1 (64.7%), blaCTX-M-14 (33.5%), or blaCTX-M-15 (1.8%)] were detected, belonging to 32 bacterial clones, mostly of phylogroup A. Calves were colonized successively by different clones with a trend in decreasing carriage. The persistence of a clone in a farm was significantly associated with the number of calves colonized. Despite a high diversity of E. coli clones and blaCTX-M-carrying plasmids, few blaCTX-M gene/plasmid/chromosomal background combinations dominated, due to (i) efficient colonization of bacterial clones and/or (ii) successful plasmid spread in various bacterial clones. The scenario \"clone versus plasmid spread\" depended on the farm. Thus, epistatic interactions between resistance genes, plasmids, and bacterial clones contribute to optimize fitness in specific environments. IMPORTANCE The gut microbiota is the epicenter of the emergence of resistance. Considerable amount of knowledge on the molecular mechanisms of resistance has been accumulated, but the ecological and evolutionary forces at play in nature are less studied. In this context, we performed a field work on temporal intestinal carriage of extended spectrum β-lactamase (ESBL)-producing Escherichia coli in veal farms. Veal calves are animals with one of the highest levels of ESBL producing E. coli fecal carriage, due to early high antibiotic exposure. We were able to show that calves were colonized successively by different ESBL-producing E. coli clones, and that two main scenarios were at play in the spread of blaCTX-M genes among calves: efficient colonization of several calves by a few bacterial clones and successful plasmid spread in various bacterial clones. Such knowledge should help develop new strategies to fight the emergence of antibiotic-resistance.
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  • 文章类型: Journal Article
    Due to the misuse of chemical pesticides, small green leafhoppers (Empoasca onukii Matsuda) have developed resistance to pesticides, thereby posing a serious problem to the tea industry. Glutathione S-transferases (GSTs) are an important family of enzymes that are involved in pesticide resistance in Empoasca onukii Matsuda. Empoasca onukii GST sigma 1 (EoGSTs1, GenBank: MK443501) is a member of the GST family. In this study, the full-length cDNA of EoGSTs1 was cloned by reverse transcription polymerase chain reaction (qPCR), and its taxonomic identity was examined. Furthermore, we performed bioinformatics and phylogenetic analyses of the gene and structural and functional domain prediction of the protein. The results demonstrate that EoGSTS1 belongs to the Sigma family of GSTs; the full-length EoGSTs1 cDNA is 841 bp with a 624-bp coding region that encodes a 23.68932-kDa protein containing 207 amino acids. The theoretical isoelectric point (IEP) was calculated to be 6.00. Phylogenetic analysis indicates that EoGSTS1 is closely related to the Sub psaltriayangi subfamily of the Cicadoidea superfamily in order Hemiptera, whereas it is distantly related to Periplaneta americana of order Blattodea. Amino acid sequence alignment of EoGSTS1 and GSTs from four other insects of order Hemiptera revealed protein sequence conservation. Tertiary structure analysis and structural domain functional predictions of the protein revealed that EoGSTS1 contains nine α helices and two β sheets with one conserved GST domain. The results of enzyme activity assay showed that recombinant EoGSTs1 (rEoGSTs1) protein had catalytic activity for substrate 1-chloro-2,4-dinitrobenzene (CDNB) and exhibited the highest activity at pH 7 and 25 °C. The Michaelis constant Km of rEoGSTs1 protein was 0.07782 ± 0.01990 mmol/L, and the maximum reaction rate Vmax was 12.15 ± 1.673 µmol/min⋅mg. Our study clarified the taxonomic identity of small green leafhopper EoGSTs1 and revealed some properties of the gene and its encoded protein sequence. According to the catalytic activity of the rEoGSTs1 enzyme on the model substrate CDNB, we infer that it functions in the degradation of exogenous substances.
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  • 文章类型: Journal Article
    BACKGROUND: From around the year 2000, Northern Europe experienced a rise in impetigo caused by Staphylococcus aureus resistant to fusidic acid. A single clone of S. aureus was found to be the bacterial pathogen involved in the impetigo outbreak in Norway, Sweden, the UK and Ireland, termed \'the epidemic European fusidic acid-resistant impetigo clone\' (EEFIC). We have followed the incidence of impetigo during the years 2001-2012 based on all patients in general practice in the island community of Austevoll, Western Norway. We previously reported a marked decline of impetigo incidence in Austevoll, from 0.0260 cases per person-year in 2002 to 0.0038 in 2009. This article explores indications of an end to the impetigo epidemic caused by the EEFIC clone.
    METHODS: All four general practitioners (GPs) in the community (mean population = 4400) were asked to diagnose impetigo in a uniform way and to take bacterial specimens from all impetigo cases. Phenotypic characteristics of specimen bacteria were determined for the whole period and molecular analyses were performed on isolates in the period 2008-2012.
    RESULTS: We observed a further decline in incidence of impetigo in Austevoll in the study period. The proportion of fusidic acid-resistant S. aureus isolates decreased during the period 2002-2012, with a mean of 80% in the epidemic years of 2002-2004, 55% in 2005-2009, and 6% in 2010-2012. In total, 44 S. aureus isolates from impetigo were subject to molecular analyses in the period 2008-2012, and 11 were found to be related to the EEFIC. All EEFIC isolates were found in 2008-2009, with no new isolates in 2010-2012.
    CONCLUSIONS: There is an apparent end to the impetigo epidemic related to the EEFIC in this population in Western Norway.
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