Virus-like particle vaccine with B-cell epitope from porcine epidemic diarrhea virus (PEDV) incorporated into hepatitis B virus core capsid provides clinical alleviation against PEDV in neonatal piglets through lactogenic immunity

Porcine epidemic diarrhea virus (PEDV) has had a negative economic impact on the global swine industry for decades since its first emergence in the 1970s in Europe. In 2013, PEDV emerged for the first time in the United States, causing immense economic losses to the swine industry. Efforts to protect U.S. swine herds from PEDV infection and limit PEDV transmission through vaccination had only limited success so far. Following the previous success in our virus-like particle (VLP) based vaccine in mouse model, in this study we determined the immunogenicity and protective efficacy of a VLP-based vaccine containing B-cell epitope ⁷⁴⁸YSNIGVCK⁷⁵⁵ from the spike protein of PEDV incorporated into the hepatitis B virus core capsid (HBcAg), in a comprehensive pregnant gilt vaccination and piglet challenge model. The results showed that the vaccine was able to induce significantly higher virus neutralization response in gilt milk, and provide alleviation of clinical signs for piglets experimentally infected with PEDV. Piglets from pregnant gilt that was vaccinated with the VLP vaccine had faster recovery from the clinical disease, less small intestinal lesions, and higher survival rate at 10 days post-challenge (DPC).     

A method to avoid errors associated with the analysis of hypermutated viral sequences by alignment-based methods

The human genome encodes for a family of editing enzymes known as APOBEC3 (apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like3). They induce context dependent G-to-A changes, referred to as “hypermutation”, in the genome of viruses such as HIV, SIV, HBV and endogenous retroviruses. Hypermutation is characterized by aligning affected sequences to a reference sequence. We show that indels (insertions/deletions) in the sequences lead to an incorrect assignment of APOBEC3 targeted and non-target sites. This can result in an incorrect identification of hypermutated sequences and erroneous biological inferences made based on hypermutation analysis.     

Systemic diseases and biotherapies: Understanding,evaluating, and preventing the risk of hepatitis B reactivation

Hepatitis B virus (HBV) reactivation can occur in chronic carriers of the HBV surface antigen (HBsAg) and constitutes a well-known complication of immunosuppressive therapy. HBV reactivation has also been reported after contact with the HBV. The increasing use of biological agents (TNFα antagonists, rituximab, abatacept, and tocilizumab) to treat systemic diseases has resulted in numerous publications about the risk of HBV reactivation. The relevant scientific societies have issued recommendations designed to prevent HBV reactivation. The main measures consist of screening for markers indicating chronic HBV infection (HBsAg) or HBV infection in the distant past (antibodies to the HBV core antigen) before initiating biological therapies, vaccinating marker-negative patients, and considering close follow-up or antiviral treatment before immunosuppressive treatment initiation or in the event of HBV reactivation. Here, we discuss the pathophysiological mechanisms underlying HBV reactivation during biological treatments, most notably in patients with occult HBV infection or markers for remote HBV infection, whose hepatocyte nuclei may contain a resistance form of HBV DNA known as covalently closed circular DNA (cccDNA). Assessment of the risk of reactivation relies on the HBV status, drugs used, and data from the literature. Finally, we discuss the various recommendations and modalities for HBV vaccination, preemptive treatment, and patient management, according to the level of risk and to the circumstances in which reactivation occurs.     

大骨节病病毒病因研究补遗

有关大骨节病(Kaschin-Beck disease,KBD)的病因问题至今仍有争论,本文对以往发表的文章添加必要的补充。以KBD病儿外周血白细胞的病变与KBD剖检病例软骨细胞和骨髓血细胞的病变对照比较。结果清晰地显示该3类细胞呈现完全相同的病变过程:胞核内出现由少到多、由小到大的嗜酸性包涵体,伴随以染色质被溶解破坏反比例地减少耗尽,最终细胞坏死、整个核形成一个嗜酸性包涵体的红色大团块。本文认为:隶属KBD的3类细胞的同一模式坏死,应是两次电镜所见的同一病毒所引起;KBD的本质应是该病毒引起的全身性传染病,软骨病变仅是其全身病变的一部分。     

大剂量维生素C辅助免疫球蛋白治疗感染病毒性心肌炎的临床疗效

目的探讨大剂量维生素C辅助免疫球蛋白治疗感染病毒性心肌炎(VMC)的临床疗效。方法 58例感染病毒性心肌炎患儿,采用抽签法分为对照组及观察组,每组29例。两组均予以常规对症治疗,对照组采用免疫球蛋白治疗,观察组在对照组基础上加用大剂量维生素C治疗。对比两组临床疗效,治疗前、治疗2周后的心肌酶谱指标[肌酸激酶同工酶(CK-MB)、肌酸激酶(CK)、乳酸脱氢酶(LDH)]及炎症因子[白细胞介素-17(IL-17)、细胞间粘附分子-1(ICAM-1)、肿瘤坏死因子-α(TNF-α)]水平。结果观察组治疗总有效率93.10%高于对照组的72.41%,差异有统计学意义(P<0.05)。治疗2周后,两组CK-MB、LDH、CK均较治疗前降低,且观察组CK-MB(23.47±4.38)U/L、LDH(156.51±6.87)U/L、CK(153.87±67.20)U/L低于对照组的(33.56±5.20)、(188.04±9.27)、(251.33±82.46)U/L,差异有统计学意义(P<0.05)。治疗2周后,两组IL-17、ICAM-1、TNF-α水平均较治疗前降低,且观察组低于对照组,差异有统计学意义(P<0.05)。结论大剂量维生素C辅助免疫球蛋白治疗感染病毒性心肌炎患儿疗效显著,能够显著改善患儿心肌酶谱水平,降低炎症因子水平,值得临床推广。     

Exome sequencing and case–control analyses identify RCC1 as a candidate breast cancer susceptibility gene

Breast cancer is a genetic disease but the known genes explain a minority of cases. To elucidate the molecular basis of breast cancer in the Tunisian population, we performed exome sequencing on six BRCA1/BRCA2 mutation‐negative patients with familial breast cancer and identified a novel frameshift mutation in RCC1, encoding the Regulator of Chromosome Condensation 1. Subsequent genotyping detected the 19‐bp deletion in additional 5 out of 153 (3%) breast cancer patients but in none of 400 female controls (p = 0.0015). The deletion was enriched in patients with a positive family history (5%, p = 0.0009) and co‐segregated with breast cancer in the initial pedigree. The mutant allele was lost in 4/6 breast tumors from mutation carriers which may be consistent with the hypothesis that RCC1 dysfunction provides a selective disadvantage at the stage of tumor progression. In summary, we propose RCC1 as a likely breast cancer susceptibility gene in the Tunisian population.     

The linear plasmid pMC3-2 from Morchella conica is structurally related to adenoviruses

Summary pMC3-2, one of two linear plasmids localised in the mitochondria of the ascomycete Morchella conica, was completely sequenced. It is 6044 bp in size, contains terminal inverted repeats of 713 and 710 bp length and two open reading frames, ORF1 and ORF2, spanning 2706 bp and 918 bp, respectively. ORF1 probably encodes a viral B-type DNA-polymerase. Concerning ORF2, no homology to any other published protein-or DNA-sequence could be detected. According to the structure of DNA-polymerases, linear plasmids can be grouped into two classes reflecting their localisation either in the cytoplasm or within the mitochondria. In general, the structure of plasmid pMC3-2, as well as of other linear plasmids from filamentous fungi, indicates a close relationship of these genetic elements to adenoviruses.     

A precore-defective mutant of hepatitis B virus associated with e antigen-negative chronic liver disease

The pathogenesis of chronic liver disease (CLD) due to persistent hepatitis B virus (HBV) infection has not been defined, but the disease activity is believed to correlate with the presence of hepatitis B e-antigen (HBeAg) antigenemia and high viremia. The molecular characterization of an HBV mutant isolated from an HBeAg-negative patient with severe CLD required amplification of the circulating HBV DNA (2 pg/ml) by the polymerase chain reaction (PCR). Direct sequencing of the nucleotides from five independent amplifications of the conserved precore region consistently revealed a G to A mutation in each of the two terminal codons of the precore region. Codon 28 was mutated from tryptophan-encoding TGG to a translational stop codon, TAG; codon 29 preceding the core initiation codon was changed from GGC to GAC. For biologic evaluation of these mutations on HBV replication and expression of HBeAg in vitro, HepG2 cells were transfected with cloned, recircularized mutant HBV DNA. The transfected cells contained subviral core particles in the cytoplasm and secreted mature HBV, without HBeAg, into the medium. The findings present the first evidence that complete HBV genomes can be amplified by PCR and are replication-competent in vitro. The data also indicate that HBeAg is not necessary for replication of HBV and furthermore suggest that HBeAg is not required for the progression of HBV-induced CLD.     

肾综合征出血热病毒结构蛋白在患者尿中融合细胞上的表达及其意义

为了探讨汉坦病毒（ＨＶ）结构蛋白与患者尿融合细胞的关系，采用抗ＨＶ包膜结构蛋白Ｇ２的单克隆抗体ＭｃＡｂ－ＬＶ４８Ａ，抗ＨＶ血凝素的ＭｃＡｂ－３Ｄ８，抗ＨＶ核衣壳蛋白的ＭｃＡｂ－Ａ３５等，分别对３０例肾综合征出血热患者尿液中的融合细胞进行免疫酶染色。结果ＭｃＡｂ－ＬＶ４８Ａ阳性率为７０％（２１／３０）；ＭｃＡｂ－３Ｄ８阳性率为７３％（２２／３０）；ＭｃＡｂ－Ａ３５阳性率为７％（２／３０）。该结果提示，患者尿液中的融合细胞的形成与ＨＶ膜结构蛋白在泌尿系统上皮细胞上的表达有密切关系。