ELISA for detection of group-common and virus-specific antibodies in human and simian sera induced by herpes simplex and related simian viruses

A rapid (3.5 h) enzyme-linked immunosorbent assay (ELISA) was developed for the detection of serum antibodies to herpes simplex virus type 1 (HSV-1) and to two antigenically related monkey viruses, simian agent 8 (SA8) and Herpesvirus simiae (B virus). Crude preparations of detergent solubilized infected cells and similarly treated control mock-infected cells served as antigens for coating wells in microplates. Biotinylated protein A and avidin-conjugated alkaline phosphatase were used to detect antibodies in sera from different species (humans, monkeys and rabbits). Three prototype assays are described with three degrees of specificity. Common or specific determinants on the viral antigens could be assayed in simple competition tests using similar antigen preparations to those coating the wells. The specific assays permitted rapid differential serodiagnosis of antibodies to human and simian herpesviruses.     

Improve immunogenicity of DNA vaccine against foot-and-mouth disease virus: Role of intron and probably viral 3C protease as biological adjuvants

Foot-and-mouth disease (FMD) is one of the most important diseases with heavy economic losses. The causative agent of the disease is a virus, named as FMD virus, belonging to the picornavirus family. There is no treatment for the disease and vaccination is the main control strategy. Several vaccination methods have been introduced against FMD including DNA vaccines. In this study, two genetic constructs, which were defined by absence and presence of an intron, were tested for their ability to induce the anti-FMD virus responses in mouse. Both constructs encoded a fusion protein consisting of viral (P12A and 3C) and EGFP proteins under the control of CMV promoter. The protein expression was studied in the COS-7 cells transfected with the plasmids by detecting EGFP protein. Cell death was induced in the cells expressing the P12A3C-EGFP, but not the EGFP, protein. This might be explained by the protease activity of the 3C protein which cleaved critical proteins of the host cells. Mice injected with the intron-containing plasmid induced 16-fold higher antibody level than the intronless plasmid. In addition, serum neutralization antibodies were only induced in the mice injected with intron-containing plasmid. In conclusion, the use of intron might be a useful strategy for enhancing antibody responses by DNA vaccines. Moreover, cell death inducing activity of the 3C protein might suggest applying it along with DNA vaccines to improve immunogenicity.     

A Novel Wide-Range Freshwater Cyanophage MinS1 Infecting the Harmful Cyanobacterium Microcystis aeruginosa

Microcystis aeruginosa, as one of the major players in algal bloom, produces microcystins, which are strongly hepatotoxic, endangering human health and damaging the ecological environment. Biological control of the overgrowth of Microcystis with cyanophage has been proposed to be a promising solution for algal bloom. In this study, a novel strain of Microcystis cyanophage, MinS1, was isolated. MinS1 contains an icosahedral head approximately 54 nm in diameter and a 260 nm-long non-contractile tail. The phage genome consists of a linear, double-stranded 49,966 bp DNA molecule, which shares very low homology with known phages in the NCBI database (only 1% of the genome showed weak homology with known phages when analyzed by megablast). The phage contains 75 ORFs, of which 23 ORFs were predicted to code for proteins of known function, 39 ORFs were predicted to code for proteins of unknown function, and 13 ORFs showed no similarity to any protein sequences. Transmission electron microscopy and phylogenetic analysis showed that MinS1 belongs to the family Siphoviridae. Various experiments confirmed that the phage could infect several different orders of cyanobacteria, including Chroococcales, Nostocales, Oscillatoriales, Hormogonales, and Synechococcales, indicating that it has a very broad host range. In addition, MinS1 has no known antibiotic tolerance genes, virulence genes, and tRNAs, and it is tolerant to temperature, pH, UV, and salinity, suggesting that MinS1 has good potential for application as a biological control agent against cyanobacterial blooms. This study expands the diversity and knowledge of cyanophages, and it provides useful information for the development of novel prevention and control measures against cyanobacterial blooms.     

Mercury as a possible link between maternal obesity and autism spectrum disorder

The incidence of both obesity and autism spectrum disorders (ASD) has dramatically increased during the last decades. Moreover, the most recent studies have revealed increased risk of ASD in offspring of overweight and obese women. However, the mechanisms of association between ASD and maternal obesity are unknown. Taking into account the existing data indicating the association between mercury (Hg) exposure and development of obesity and ASD, we hypothesize that Hg may serve as an additional link between maternal obesity and ASD. In particular, it is supposed that obesity is associated with excessive accumulation of Hg in the maternal organism. After conception, the fetus is developing in the conditions of Hg overload within the body of obese women thus predisposing to the development of ASD. The proposed hypothesis may be confirmed by the existing data. In particular, previous studies demonstrated that overweight and obese persons are characterized by a significantly higher level of Hg in hair, blood and urine than the lean ones. Therefore, an obese organism is characterized by elevated Hg burden that may be transferred to the fetus during pregnancy. Moreover, multiple studies have demonstrated a tight association between maternal and children Hg status being indicative of placental transfer of metal from maternal organism to offspring. Finally, a growing body of data indicates the influence of Hg exposure and Hg status on the risk of ASD in children. However, additional experimental and clinical studies are required to prove the hypothesis and provide novel data on the role of Hg in maternal obesity-associated ASD development. In particular, the contribution of Hg to ASD development in children from obese mothers should be determined. If a significant role of Hg in maternal obesity ASD risk will be confirmed, this will open additional perspectives of risk modification. Taking into account the universal mechanisms of Hg toxicity, transport, and accumulation, further preventive actions may be undertaken to reduce the risk of Hg toxicity and Hg-associated ASD development. In particular, it is supposed that the use of Hg chelators (like N,N′bis-(2-mercaptoethyl)isophthalamide, NMBI), antioxidants, and anti-inflammatory compounds prior or during pregnancy may have a beneficial effect. However, the safety of such actions should repeatedly be tested to avoid adverse health effects in a developing fetus.     

Natural mannosylation of HIV-1 gp120 imposes no immunoregulatory effects in primary human plasmacytoid dendritic cells

Plasmacytoid dendritic cells (pDCs) play a vital role in activation of anti-HIV-1 immunity, and suppression of pDCs might mitigate immune responses against HIV-1. HIV-1 gp120 high-mannose has been attributed immunosuppressive roles in human myeloid DCs, but no receptors for high-mannose have so far been reported on human pDCs. Here we show that upon activation with HIV-1 or by a synthetic compound triggering the same receptor in human pDCs as single-stranded RNA, human pDCs upregulate the mannose receptor (MR, CD206). To examine the functional outcome of this upregulation, inactivated intact or viable HIV-1 particles with various degrees of mannosylation were cultured with pDCs. Activation of pDCs was determined by assaying secretion of IFN-alpha, viability, and upregulation of several pDC-activation markers: CD40, CD86, HLA-DR, CCR7, and PD-L1. The level of activation negatively correlated with degree of mannosylation, however, subsequent reduction in the original mannosylation level had no effect on the pDC phenotype. Furthermore, two of the infectious HIV-1 strains induced profound necrosis in pDCs, also in a mannose-independent manner. We therefore conclude that natural mannosylation of HIV-1 is not involved in HIV-1-mediated immune suppression of pDCs.     

Expression of NY-ESO-1, MAGE-A3, PRAME and WT1 in different subgroups of breast cancer: An indication to immunotherapy?

ObjectivesCancer Testis Antigens are immunogenic tumor-specific proteins. We investigated NY-ESO-1, MAGE-A3 and PRAME, in addition to WT1 expression in different Breast Cancer (BC) subtypes. We then evaluated the expression rate of NY-ESO-1 in early Triple Negative breast cancer (TNBC), and investigated whether its expression would be maintained or lost in the metastatic setting to explore possible immunotherapy indication.Materials and methodsThree subgroups of BC patients were selected by the expression of ER, PgR and Her2. Tissue microarray was performed on a total of 92 Invasive BC. Sections were stained for NY-ESO-1, MAGE-A3, PRAME and WT1. The second cohort was composed by 26 metastatic TNBC patients from whom both the primary and secondary lesion tissues were available. Sections were stained for NY-ESO-1.ResultsNY-ESO-1 was the only differentially expressed antigen and was absent in ER+ and ER-PgR + tumors, as for an exclusive expression of either NY-ESO-1 or at least one hormonal receptor (HR+). NY-ESO-1 was particularly represented in TNBC. No correlation has been found between MAGE-A3 and PRAME expression and subtype WT1 had low expression, except in the Her2+ group. In the second cohort, NY-ESO-1 was expressed in 12 and 24% of primary and metastatic lesions respectively.ConclusionsThis study defines a distinction between HR+ and HR-tumors through NY-ESO-1 expression.TNBC subgroup has the highest frequency of NY-ESO-1+ cases, and it could be the candidate population for the development of anti-NY-ESO-1 vaccine, both in the adjuvant or metastatic setting, and for the selection of cases suitable for immunotherapy.     

昆虫杆状病毒表达载体系统的发展

近年来随着关键技术的不断改进,昆虫杆状病毒表达载体系统更趋于完善。适合规模化生产的昆虫细胞系与衍生和改造细胞系的建立,提高了系统的糖基化能力及蛋白表达量。BaculoGold、Bac-to-Bac、flashBAC、BaculoDirect、MultiBac等重组杆状病毒构建技术的应用,简化了构建过程,提高了重组效率。通过删除部分杆状病毒基因、改造启动子以及引入调控序列等途径优化,昆虫杆状病毒表达载体系统的蛋白表达量获得进一步提高。此文对昆虫细胞、杆状病毒及重组杆状病毒的构建技术的发展进行综述。     

BCG vaccine: WHO position paper,February 2018 – Recommendations

This article presented the World Health Organization’s (WHO) recommendations on the use of on Bacille Calmette-Guérin (BCG) vaccine excerpted from the BCG vaccines: WHO position paper – February 2018 published in the Weekly Epidemiological Record [1]. This position paper replaces the 2004 WHO position paper on Bacille Calmette-Guérin (BCG) vaccine [2] and the 2007 WHO revised BCG vaccination guidelines for infants at risk for human immunodeficiency virus (HIV) infection [3]. It incorporates recent developments in the tuberculosis (TB) field, provides revised guidance on the immunization of children infected with HIV, and re-emphasizes the importance of the birth dose. This position paper also includes recommendations for the prevention of leprosy.Footnotes to this paper provide a number of core references including references to grading tables that assess the quality of the scientific evidence, and to the evidence-to-recommendation tables. In accordance with its mandate to provide guidance to Member States on health policy matters, WHO issues a series of regularly updated position papers on vaccines and combinations of vaccines against diseases that have an international public health impact. These papers are concerned primarily with the use of vaccines in large-scale immunization programmes; they summarize essential background information on diseases and vaccines, and conclude with WHO’s current position on the use of vaccines in the global context. Recommendations on the use of cholera vaccines were discussed by the Strategic Advisory Group of Experts (SAGE) in October 2017; evidence presented at these meetings can be accessed at: http://www.who.int/immunization/sage/meetings/2017/october/presentations_background_docs/en/     

Development of a high-growth enterovirus 71 vaccine candidate inducing cross-reactive neutralizing antibody responses

Although Enterovirus 71 (EV71) has only one serotype based on serum neutralization tests using hyperimmune animal antisera, three major genogroups (A, B and C) including eleven genotypes (A, B1-B2, and C1-C5) can be well classified based on phylogenetic analysis. Since 1997, large-scale EV71 epidemics occurred cyclically with different genotypes in the Asia-Pacific region. Therefore, development of EV71 vaccines is a national priority in several Asian countries. Currently, five vaccine candidates have been evaluated in clinical trials in China (three C4 candidates), Singapore (one B2 candidate), and Taiwan (one B4 candidate). Overall, the peak viral titers of these 5 vaccine candidates could only reach about 10⁷ TCID₅₀/mL. Moreover, genotypes of these 5 candidates are different from the current predominant genotype B5 in Taiwan and South-Eastern Asia. We adapted a high-growth EV71 genotype B5 (HG-B5) virus after multiple passages and plaque selections in Vero cells and the HG-B5 virus could reach high titers (>10⁸ TCID₅₀/mL) in a microcarrier-based cell culture system. The viral particles were further purified and formulated with alum adjuvant. After two doses of intramuscular immunization in rabbits, the HG-B5 vaccine candidate could induce cross-reactive neutralizing antibodies against the three major EV71 genogroups. In conclusion, a high-growth EV71 virus was successfully adapted in Vero cells and could induce broad spectrum neutralizing antibody titers against three (A, B5, and C4) genotypes in rabbits.