Competent Cell Research Articles

Abstract 933: Surface-tethered IL-12 improves tumor-specific T-cell therapy and enhances inflammatory activity in tumors without inducing systemic toxicities

Abstract Introduction Interleukin-12 (IL-12) is a potent cytokine that augments anti-tumor immune responses by promoting CD4 T cell Th1 differentiation, increasing CD8 T cell and NK cell cytotoxicity, inducing MHC expression on antigen presenting cells, and reprogramming myeloid-derived suppressor cells. However, the clinical utility of IL-12 administered systemically or produced by genetically engineered tumor-specific T cells has been limited by toxicities. DeepTM IL-12 is a fusion protein between IL-12 and a Fab antibody against CD45, an abundant surface receptor on T cells. This tethers IL-12 onto tumor-specific T cells prior to adoptive cell transfer (ACT) with the aim of reducing systemic exposure and focusing IL-12 function on the tumor microenvironment. Here, we describe the superior safety and efficacy profiles of Deep IL-12 tethered T cells in an immune competent adoptive cell therapy model for solid tumors. Methods The safety and efficacy of Deep IL-12 Primed T cells were evaluated in the PMEL/B16-F10 cancer model. CD8 PMEL T cells contain a TCR that recognizes the gp100 antigen expressed in B16-F10 melanoma cells. Deep IL-12 was loaded onto PMEL CD8 T cells to generate Deep IL-12 Primed PMEL T cells which were then adoptively transferred into mice bearing B16-F10 tumors. We compared tumor size, body weight change, cytokine release, circulating toxicity biomarkers, immune cell activity and histopathology in mice treated with Deep IL-12 Primed T cells and PMEL T cells alone or co-administered with recombinant IL-12. Results Deep IL-12 Primed PMEL T cells significantly improved tumor growth inhibition and overall survival in mice bearing established B16-F10 tumors as compared with PMEL T cell therapy alone or combined with systemic co-administration of IL-12. Deep IL-12 Primed PMEL T cells were well-tolerated, as administration of at least 40 million Deep IL-12 Primed PMEL T cells did not cause overt toxicities in non-tumor bearing mice. Deep IL-12 Primed PMEL T cells, but not PMEL T cells combined with systemic IL-12, resulted in elevated and sustained induction of IFNγ in the tumor microenvironment. In contrast, IFNγ induction in serum was transient and returned to baseline levels within four days of ACT. Interestingly, Deep IL-12 Priming increased both accumulation and activity of the adoptively transferred PMEL T cells in the tumor microenvironment but not in off-target healthy tissues such as the spleen. Further toxicological analysis of Deep IL-12 Primed tumor-reactive T cells will be discussed. Conclusions Deep IL-12 Priming enables tethering of IL-12 to the surface of tumor-specific T cells prior to ACT. This improves anti-tumor efficacy by promoting T cell function selectively in the tumor microenvironment and avoids toxicity by limiting systemic IL-12 exposure, resulting in a highly favorable benefit-risk profile for Deep IL-12 Primed T cells. Citation Format: De-Kuan Chang, Gulzar Ahmad, Jonathan Nardozzi, Katharine Sackton, Jesse Lyons, Karsten Sauer, Thomas Andresen, Douglas Jones. Surface-tethered IL-12 improves tumor-specific T-cell therapy and enhances inflammatory activity in tumors without inducing systemic toxicities [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 933.

Optimization of electrospray fabrication of stem cell–embedded alginate–gelatin microspheres and their assembly in 3D-printed poly(ε-caprolactone) scaffold for cartilage tissue engineering

ObjectiveOur study reports the optimization of electrospray human bone marrow stromal cell (hBMSCs)–embedded alginate–gelatin (Alg-Gel, same as following) microspheres for the purpose of their assembly in 3D-printed poly(ε-caprolactone) (PCL) scaffold for the fabrication of a mechanically stable and biological supportive tissue engineering cartilage construct. MethodsThe fabrication of the Alg-Gel microspheres using an electrospray technique was optimized in terms of polydispersity, yield of microspheres and circularity and varying fabrication conditions. PCL scaffolds were designed and printed by melt extrusion. Then, four groups were set: Alg-hBMSC microspheres cultured in the 2D well plate (Alg-hBMSCs+2D) group, Alg-Gel-hBMSC microspheres cultured in the 2D well plate (Alg-Gel-hBMSCs+2D) group, Alg-Gel-hBMSC microspheres embedded in PCL scaffold cultured in the 2D well plate (Alg-Gel-hBMSCs+2D) group and Alg-Gel-hBMSCs microspheres cultured in the 3D bioreactor (Alg-Gel-hBMSCs+3D) group. Cell viability, proliferation and chondrogenic differentiation were evaluated, and mechanical test was performed. ResultsNonaggregated, low polydispersity and almost spherical microspheres of average diameter of 200–300 μm were produced with alginate 1.5 w: v%, gelatin (Type B) concentration of 0.5 w: v % and CaCl2 coagulating bath concentration of 3.0 w: v %, using 30G needle size and 8 kV and 0.6 bar voltage and air pressure, respectively. Alginate with gelatin hydrogel improved viability and promoted hBMSC proliferation better than alginate microspheres. Interestingly, hBMSCs embedded in microspheres assembled in 3D-printed PCL scaffold and cultured in a 3D bioreactor were more proliferative in comparison to the previous two groups (p < 0.05). Similarly, the GAG content, GAG/DNA ratio as well as Coll 2 and Aggr gene expression were increased in the last two groups. ConclusionOptimization of hBMSC-embedded Alg-Gel microspheres produced by electrospray has been performed. The Alg-Gel composition selected allows conservation of hBMSC viability and supports proliferation and matrix deposition. The possibility to seed and assemble microspheres in designed 3D-printed PCL scaffolds for the fabrication of a mechanically stable and biological supportive tissue engineering cartilage construct was demonstrated. Translational potential of this articleWe optimize and demonstrate that electrospray microsphere fabrication is a cytocompatible and facile process to produce the hBMSC-embedded microsize tissue-like particles that can easily be assembled into a stable construct. This finding could have application in the development of mechanically competent stem cell–based tissue engineering of cartilage regeneration.

Proteins from male and female reproductive tracts involved in sperm function regulation.

SummarySpermatogenesis is a dynamic process that culminates in the production of mature spermatozoa in the seminiferous tubules of sexually mature animals. Although sperm leaving the testis are fully differentiated, they must further undergo two additional maturation steps before acquiring the capability to fertilize the egg. Such processes take place during the epididymal residency and transport in the seminal fluid during ejaculation and, after delivery into the female reproductive tract, during the journey aiming the encountering the egg in the oviduct. Throughout this trip, spermatozoa are exposed to different reproductive fluids whose molecular compositions regulate the progress towards obtaining a fertilized competent cell. This review summarizes the evidence obtained so far supporting the participation of male and female reproductive tract-derived proteins in the modulation of sperm fertilizing ability and discusses the mechanisms by which such regulation may be accomplished.

Delivering "Chromatic Bacteria" Fluorescent Protein Tags to Proteobacteria Using Conjugation.

Recently, we published a large and versatile set of plasmids, the chromatic bacteria toolbox, to deliver eight different fluorescent protein genes and four combinations of antibiotic resistance genes to Gram-negative bacteria. Fluorescent tags are important tools for single-cell microbiology, synthetic community studies, biofilm, and host-microbe interaction studies. Using conjugation helper strain E. coli S17-1 as a donor, we show how plasmid conjugation can be used to deliver broad host range plasmids, Tn5 transposons delivery plasmids, and Tn7 transposon delivery plasmids into species belonging to the Proteobacteria. To that end, donor and recipient bacteria are grown under standard growth conditions before they are mixed and incubated under non-selective conditions. Then, transconjugants or exconjugant recipients are selected on selective media. Mutant colonies are screened using a combination of tools to ensure that the desired plasmids or transposons are present and that the colonies are not containing any surviving donors. Through conjugation, a wide range of Gram-negative bacteria can be modified without prior, often time-consuming, establishment of competent cell and electroporation procedures that need to be adjusted for every individual strain. The here presented protocol is not exclusive for the delivery of Chromatic bacteria plasmids and transposons, but can also be used to deliver other mobilizable plasmids to bacterial recipients.

The potential and prospects of the quantitative phase imaging (QPI) diagnostic technology in obstetrics and gynecology

Rationale:An important role of immunological factors in the endometriosis pathophysiology allows for their consideration as diagnostic and prognostic disease markers. A promising approach to the diagnosis of immunological abnormalities is based on the non-invasive cell diagnostic technology of quantitative phase imaging (QPI), with underlying principles of laser interferometry and holography.Aim:To assess the QPI potential to identify diagnostic criteria for cell immunity abnormalities in female patients with external endometriosis.Materials and methods:We performed a quantitative assessment of the cytotoxic potential of peripheral blood lymphocytes from 22 patients with endometrioid ovarian cysts (mean age, 27.1 ± 3.4 years), 20 patients with uterine leiomyoma (mean age, 29.3 ± 4.1 years) and 20 health non-pregnant women of child-bearing age (mean age, 28.7 ± 3.6 years). We used the non-invasive QPI technique with the module for phase interference microscopy of the Russian hardand software complex Bioni (Westtrade Ltd., Russia).Results:We studied phase interference pictures of native lymphocytes to identify morphological and densitometry characteristics for CD4+ и CD8+ cells. Two groups of cells were identified in the cytotoxic lymphocyte population, which differed in their values of the phase thickness (Hcyt) and the area of cytoplasm adjacent to the membrane and containing the perforin granules (Scyt). It was found, that in the healthy controls the proportion of perforin-positive cytotoxic CD8+ lymphocytes was 37.1 ± 5.15%, in the patients with endometriosis 29.8 ± 6.34%, and in those with uterine leiomyoma 42.6 ± 5.89%.Discussion:Assessment of the lymphocyte cytotoxic potential by quantitative determination of cells containing perforin granules may be an important diagnostic and prognostic criterion of the disease course.Conclusion:Studies of the intracellular structures of lymphocytes by non-invasive and non-reagent technology QPI allows not only for a detailed evaluation of pathophysiological mechanisms of immune competent cell transformation in the course of a pathological process, but also gives future directions for development of new approaches to functional assessment of the immune system based on the results obtained.

In vitro characterization of hepatic toxicity of Alternaria toxins.

Alternaria mycotoxins are secondary fungal metabolites which can contaminate food and feed. They are produced by Alternaria species with alternariol (AOH), alternariol monomethyl ether (AME), tenuazonic acid (TeA), and tentoxin (TEN) as the main representatives for Alternaria mycotoxins in food. Once passing the intestinal barrier, Alternaria toxins can reach the liver to exert yet uncharacterized molecular effects. Therefore, hepatic in vitro systems were used to examine selected Alternaria mycotoxins for their induction of metabolism-dependent cytotoxicity, phosphorylation of the histone H2AX as a surrogate marker for DNA double-strand breaks, and relevant marker genes for hepatotoxicity. Analysis of cell viability as well as the induction of H2AX phosphorylation in the hepatocarcinoma cell line HepG2 revealed a detoxification of 100μmol/l AME and AOH by pre-treatment with S9 liver homogenate as shown by a decrease in cytotoxicity and H2AX histone phosphorylation to levels observed in control cells. Concentrations up to 100μmol/l TeA and TEN did not induce H2AX phosphorylation whether metabolized or not. In the metabolically competent human hepatoma cell line HepaRG, no cytotoxicity of Alternaria toxins occurred even at high concentrations up to 100μmol/l, which indicates a low cytotoxic potential. Induction of gene expression associated with liver toxicity was analyzed by quantitative real-time PCR using a specific hepatotoxicity PCR array in HepaRG cells: here, an evidence was found that 50μmol/l of AOH, AME, TeA, and TEN might be associated with hepatotoxic effects, necrosis, and the development of diseases like cholestasis and phospholipidosis.

Assessing soil extracellular DNA decomposition dynamics through plasmid amendment coupled with real-time PCR

Determining soil extracellular DNA decomposition dynamics is essential to assessing lateral gene transfer possibility, nutrient-cycling efficiency, and the reliability of DNA-based methods for examining microbes in soils. The existing methods based on competent cell transformation and stable isotope probes are generally inefficient and not strictly quantitative. Therefore, this study aimed to establish a rigorously quantitative and efficient approach to monitor the decomposition dynamics of the soil extracellular DNA. A soil was collected from a Tibetan alpine meadow. Extracellular DNA was simulated by modified exogenous plasmids. The plasmid solution was sprayed onto the fresh soil and thoroughly homogenized. Then, the soil was incubated for 4 weeks, during which they were sampled and immediately stored at − 20 °C on days 0, 0.5, 1, 2, 4, 8, 16, and 28 of the incubation. Finally, the total soil DNA was extracted, and the exogenous plasmid copies remained in the soils were determined using real-time PCR. Additionally, another similar experiment was conducted with a sterilized soil to assess the abiotic influences on the changes in the exogenous plasmid copies. In the fresh soil, the exogenous plasmid DNA copies decreased quickly in the first 12 h of the incubation, remained stable in the following 36 h, and gradually dropped to 1.10–5.20% of the initial plasmid copies at sampling time 0 after being incubated for 4 weeks. The variations in the soil plasmid DNA copies fitted well with the modified exponential decay model. As for the sterilized soil, the exogenous plasmid copies remained stable during the 16 day’s incubation. However, they dramatically dropped after being incubated for 28 days, which was probably elicited by the recolonization of microbes in the soil. Collectively, the decrease in the exogenous plasmid DNA copies could be mainly attributed to biological activities. Extracellular DNA can persist in soil for more than 4 weeks. Exogenous plasmid amendment coupled with real-time PCR provides a convenient and rigorously quantitative approach for monitoring extracellular DNA degradation in soils.

Impedimetric analysis on the mass transfer properties of intact and competent E. coli cells

Competent Escherichia coli cells are commonly used in bacterial transformation owing to its high permeability for bioorganic macromolecules like plasmid DNA. However, the mass transfer property of competent E. coli cell has not fully investigated. In the present study, mass transfer coefficients of competent and intact E. coli cells in deionized water were evaluated by impedimetric analysis of the release of cytoplasmic compounds. Because competent cells have a higher permeability after chemical treatment, the lumped mass transfer coefficient of a competent cell was approximately 6.5 times larger than that of an intact cell at room temperature. Release of cytoplasmic components was accelerated at an elevated temperature of 42 °C, which is the heat shock temperature used during bacterial transformation. At this elevated temperature, assessed lumped mass transfer coefficients of intact and competent E. coli cells were 9.28 × 10−4 min−1 and 97.10 × 10−4 min−1, respectively. Significant increase in the mass transfer coefficient of the competent cell is caused by cytolysis of cells. The double layer capacitances were also assessed from the electrochemical spectra confirming the enhanced ion release from E. coli cells and rupture of the competent cell under prolonged exposure at the elevated temperature. Impedimetric detection of the ion release with analyses using an equivalent circuit model provides a method to evaluate mass transfer properties of biomolecules.

Using a gene expression biomarker to identify DNA damage-inducing agents in microarray profiles.

High-throughput transcriptomic technologies are increasingly being used to screen environmental chemicals in vitro to provide mechanistic context for regulatory testing. The TGx-DDI biomarker is a 64-gene expression profile generated from testing 28 model chemicals or treatments (13 that cause DNA damage and 15 that do not) in human TK6 cells. While the biomarker is very accurate at predicting DNA damage inducing (DDI) potential using the nearest shrunken centroid method, the broad utility of the biomarker using other computational methods is not fully known. Here, we determined the accuracy of the biomarker used with the Running Fisher test, a nonparametric correlation test. In TK6 cells, the methods could readily differentiate DDI and non-DDI compounds with balanced accuracies of 87-97%, depending on the threshold for determining DDI positives. The methods identified DDI agents in the metabolically competent hepatocyte cell line HepaRG (accuracy = 90%) but not in HepG2 cells or hepatocytes derived from embryonic stem cells (60 and 80%, respectively). DDI was also accurately classified when the gene expression changes were derived using the nCounter technology (accuracy = 89%). In addition, we found: (1) not all genes contributed equally to the correlations; (2) the minimal overlap in genes between the biomarker and the individual comparisons required for significant positive correlation was 10 genes, but usually was much higher; and (3) different sets of genes in the biomarker can by themselves contribute to the significant correlations. Overall, these results demonstrate the utility of the biomarker to accurately classify DDI agents. Environ. Mol. Mutagen. 59:772-784, 2018. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

High-efficiency transformation of Yarrowia lipolytica using electroporation.

Yarrowia lipolytica is an industrial host organism with incredible potential for metabolic engineering. However, the genetic tools and capacities in this host lag behind those of conventional counterparts. In this study, we sought to increase the transformation efficiency of Y. lipolytica by creating a simple protocol using electroporation. Efficiency was increased by optimizing wash buffers, pre-culture growth time, OD600 of competent cells, voltage, competent cell volume, DNA concentration, and recovery time. The outcome of these optimizations led to a simple protocol with maximum linear fragment transformation efficiency of 1.6×104 transformants per μg DNA and 2.8×104 transformants per μg DNA for episomal plasmid transformation. The protocol presented here is superior to other Y. lipolytica transformation protocols as it requires no lengthy pretreatment and no required carrier DNA to achieve efficiencies on par with, or exceeding, previously reported methods.

Abstract 4313: Methylated BAF155 promotes cancer metastasis by cooperating with BRD4 to potentiate genes addicted to super-enhancers

Abstract Triple-negative breast cancers (TNBC) lack the expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). TNBC is the most aggressive breast cancer subtype and is often associated with distant metastasis, poor prognosis, and lack of targeted treatment options. The failure to identify a few genes driving metastasis through sequencing of paired tumors at primary and metastatic sites implies that epigenetic mechanisms may play important roles in TNBC metastasis. Recently, we found that an epigenetic enzyme coactivator associated arginine methyltransferase 1 (CARM1) is highly expressed in TNBC and its high expression correlates with poor prognosis. Subsequently we identified BRG1-Associated Factor 155 (BAF155), a component of SWI/SNF chromatin remodeling complex, as a novel CARM1 substrate. Transcriptome analyses of BAF155 methylation competent and defective cell lines identified many genes involved in regulating cancer metastasis are methyl-BAF155 targets. Methylation of BAF155 was found to promote metastasis in the TNBC xenografted mouse models. We generated a methyl-BAF155 antibody that could specifically detect methylated BAF155 (me-BAF155) by IHC and chromatin immunoprecipitation followed by sequencing (ChIP-seq). We mapped global me-BAF155 genomic association sites using ChIP-seq and discovered that me-BAF155 was highly enriched in super-enhancers (SEs), regulatory elements on chromatin that are known to drive high transcription of many oncogenes. SEs are known to recruit BRD4, a BET family bromodomain protein. Indeed, global me-BAF155 binding peaks greatly overlap with those of BRD4 binding sites. Treatment of TNBC cells with either BRD4 inhibitor JQ1 or CARM1 inhibitor TP-064 significantly reduced the expression of me-BAF155 target genes. Together our data suggest that me-BAF155 is an important epigenetic target for treatment of cancer metastasis in TNBC cells. Citation Format: Eui-Jun Kim, Yidan Wang, Li Lu, Lixin Rui, Xuehua Zhong, Kari B. Wisinski, Wei Xu. Methylated BAF155 promotes cancer metastasis by cooperating with BRD4 to potentiate genes addicted to super-enhancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4313.

Enhancing biocompatibility of Co-Cr alloy implants via electrical discharge process

ABSTRACTWith increasing popularity of Electrical Discharge Machining (EDM) method upon part manufacturing precision with tailorable surface properties; the assessment of EDM process was therefore carried out concerning the surface alteration of medical grade Co-Cr alloy biomaterials. The samples surface were EDMed at different spark energy levels by varying current and On-time to investigate the surface characteristics, and it's biological responses. MTT assay and cytocompatibility test were conducted to examine the in-vitro biocompatibility confirming the higher competent cell viability and proficient RBC lysis for the surface treated with spark energy ranging from 960J–1500J. Here the experimental results revealed that application of low-current (5 A) and high On-time (200 µs) favors the synthesis of high-quality biocompatible substrates. Thus, surface modification of Co-Cr implants using EDM can be considered as a promising method for improving surface properties essential for biomedical applications.

Kloning dan Analisis Bioinformatika Gen MSP1 Plasmodium falciparum Isolat Kota Jayapura

Cloning gene involves the construction of a recombinant plasmid that inserted in a competent cell. On the other hand, genetic engineering requires bioinformatic analysis to be converted into tabulation and data interpretation. The study, titled "cloning block 2 MSP1 gene of Plasmodium falciparum isolate Jayapura city and bioinformatics analysis" is aimed to improve the technique of cloning the MSP1 gene of P. falciparum, initiated the creation of DH5α competent cells, ligations and transformations, plasmid isolation, confirmation the recombinant plasmid and able to perform bioinformatics analysis and construct phylogenetic tree. This study began with the manufacture of E. coli DH5α competent cells, MSP1 gene ligation in pJET1.2/blunt vector and transformation by using the heat shock transformation method, plasmid isolation of alkali lysis method, then plasmid confirmed by PCR and sequencing method, further sequence analysis and phylogenetic tree construction. The results showed that confirmation of MSP1 gene presence in pJET1.2/blunt with PCR was successful. From a total of 4 positive colonies grown in liquid culture, then isolated plasmid and confirmed with PCR obtained electroferogram bands with a size about 1049 bp indicates the presence of MSP1 gene in plasmid. Based on the results, cloning of MSP1 gene using pJET1.2/blunt cloning vector and competent cell E. coli DH5α has been successfully performed. Bioinformatics analysis of sequencing result and phylogenetic tree were constructed successfully with 2 clusters isolate of malaria patients from Jayapura city. Key words: Bioinformatics, cloning gene, heat shock transformation, MSP1, P. falciparum.

Expression and Characterization of Calcium- and Zinc-Tolerant Xylose Isomerase from Anoxybacillus kamchatkensis G10.

The enzyme xylose isomerase (E.C. 5.3.1.5, XI) is responsible for the conversion of an aldose to ketose, especially xylose to xylulose. Owing to the ability of XI to isomerize glucose to fructose, this enzyme is used in the food industry to prepare high-fructose corn syrup. Therefore, we studied the characteristics of XI from Anoxybacillus kamchatkensis G10, a thermophilic bacterium. First, the gene coding for XI (xylA) was inserted into the pET-21a(+) expression vector and the construct was transformed into the Escherichia coli competent cell BL21 (DE3). The expression of recombinant XI was induced in the absence of isopropyl-thio-β-galactopyranoside and purified using Ni-NTA affinity chromatography. The optimum temperature of recombinant XI was 80°C and measurement of the heat stability indicated that 55% of residual activity was maintained after 2 h incubation at 60°C. The optimum pH was found to be 7.5 in sodium phosphate buffer. Magnesium, manganese, and cobalt ions were found to increase the enzyme activity; manganese was the most effective. Additionally, recombinant XI was resistant to the presence of Ca²⁺ and Zn²⁺ ions. The kinetic properties, Km and Vmax, were calculated as 81.44 mM and 2.237 μmol/min/mg, respectively. Through redundancy analysis, XI of A. kamchatkensis G10 was classified into a family containing type II XIs produced by the genera Geobacillus, Bacillus, and Thermotoga. These results suggested that the thermostable nature of XI of A. kamchatkensis G10 may be advantageous in industrial applications and food processing.

Modulation of mRNA Translation and Cell Viability by Influenza A Virus Derived Nonstructural Protein 1.

Translation of in vitro transcribed messenger RNA (mRNA) is known to be compromised by cell's innate immune responses. Herein we show that when mRNA encoding nonstructural protein 1 (NS1), an immune evasion gene derived from influenza A virus, is co-delivered with mRNA encoding green fluorescent protein (GFP), higher GFP expression can be observed in four different interferon competent cell types within 6 h, indicating NS1's wide host range property and rapid counter response to the cells' innate immune response. Enhanced mRNA translation correlates with reduced interferon production in all tested cell types and substituting a small portion of luciferase mRNA with NS1 mRNA enhances luciferase production compared to the same dose composing of only luciferase mRNA although in a cell type specific manner. Toxicity caused by transfection of unmodified mRNA is mitigated with the delivery of NS1 mRNA and is observed only in NS1 without cleavage and polyadenylation specificity factor 30 kda (CPSF30) inhibition function. Conversely, delivery of mRNA encoding NS1 with CPSF30 inhibition function aggravated toxicity. Overall, we demonstrate that NS1 enhanced mRNA transfection through active evasion of innate immune responses and modulated cellular viability during mRNA transfection.

Hepatitis D virus replication is sensed by MDA5 and induces IFN-β/λ responses in hepatocytes

Hepatitis B virus (HBV) and D virus (HDV) co-infections cause the most severe form of viral hepatitis. HDV induces an innate immune response, but it is unknown how the host cell senses HDV and if this defense affects HDV replication. We aim to characterize interferon (IFN) activation by HDV, identify the responsible sensor and evaluate the effect of IFN on HDV replication. HDV and HBV susceptible hepatoma cell lines and primary human hepatocytes (PHH) were used for infection studies. Viral markers and cellular gene expression were analyzed at different time points after infection. Pattern recognition receptors (PRRs) required for HDV-mediated IFN activation and the impact on HDV replication were studied using stable knock-down or overexpression of the PRRs. Microarray analysis revealed that HDV but not HBV infection activated a broad range of interferon stimulated genes (ISGs) in HepG2NTCP cells. HDV strongly activated IFN-β and IFN-λ in cell lines and PHH. HDV induced IFN levels remained unaltered upon RIG-I (DDX58) or TLR3 knock-down, but were almost completely abolished upon MDA5 (IFIH1) depletion. Conversely, overexpression of MDA5 but not RIG-I and TLR3 in HuH7.5NTCP cells partially restored ISG induction. During long-term infection, IFN levels gradually diminished in both HepG2NTCP and HepaRGNTCP cell lines. MDA5 depletion had little effect on HDV replication despite dampening HDV-induced IFN response. Moreover, treatment with type I or type III IFNs did not abolish HDV replication. Active replication of HDV induces an IFN-β/λ response, which is predominantly mediated by MDA5. This IFN response and exogenous IFN treatment have only a moderate effect on HDV replication in vitro indicating the adaption of HDV replication to an IFN-activated state. In contrast to hepatitis B virus, infection with hepatitis D virus induces a strong IFN-β/λ response in innate immune competent cell lines. MDA5 is the key sensor for the recognition of hepatitis D virus replicative intermediates. An IFN-activated state did not prevent hepatitis D virus replication in vitro, indicating that hepatitis D virus is resistant to self-induced innate immune responses and therapeutic IFN treatment.

Genome-wide tracking of dCas9-methyltransferase footprints

In normal mammalian development cytosine methylation is essential and is directed to specific regions of the genome. Despite notable advances through mapping its genome-wide distribution, studying the direct contribution of DNA methylation to gene and genome regulation has been limited by the lack of tools for its precise manipulation. Thus, combining the targeting capability of the CRISPR–Cas9 system with an epigenetic modifier has attracted interest in the scientific community. In contrast to profiling the genome-wide cleavage of a nuclease competent Cas9, tracing the global activity of a dead Cas9 (dCas9) methyltransferase fusion protein is challenging within a highly methylated genome. Here, we report the generation and use of an engineered, methylation depleted but maintenance competent mouse ES cell line and find surprisingly ubiquitous nuclear activity of dCas9-methyltransferases. Subsequent experiments in human somatic cells refine these observations and point to an important difference between genetic and epigenetic editing tools that require unique experimental considerations.

A novel genotoxin-specific qPCR array based on the metabolically competent human HepaRG™ cell line as a rapid and reliable tool for improved in vitro hazard assessment.

Although the value of the regulatory accepted batteries for in vitro genotoxicity testing is recognized, they result in a high number of false positives. This has a major impact on society and industries developing novel compounds for pharmaceutical, chemical, and consumer products, as afflicted compounds have to be (prematurely) abandoned or further tested on animals. Using the metabolically competent human HepaRG™ cell line and toxicogenomics approaches, we have developed an upgraded, innovative, and proprietary gene classifier. This gene classifier is based on transcriptomic changes induced by 12 genotoxic and 12 non-genotoxic reference compounds tested at sub-cytotoxic concentrations, i.e., IC10 concentrations as determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The resulting gene classifier was translated into an easy-to-handle qPCR array that, as shown by pathway analysis, covers several different cellular processes related to genotoxicity. To further assess the predictivity of the tool, a set of 5 known positive and 5 known negative test compounds for genotoxicity was evaluated. In addition, 2 compounds with debatable genotoxicity data were tested to explore how the qPCR array would classify these. With an accuracy of 100%, when equivocal results were considered positive, the results showed that combining HepaRG™ cells with a genotoxin-specific qPCR array can improve (geno)toxicological hazard assessment. In addition, the developed qPCR array was able to provide additional information on compounds for which so far debatable genotoxicity data are available. The results indicate that the new in vitro tool can improve human safety assessment of chemicals in general by basing predictions on mechanistic toxicogenomics information.

Construction of Overexpression Vector of CONSTANS Gene Plant in &lt;i&gt;Brassica napus&lt;/i&gt; and Production of Transgenic Plants

The CONSTANS target gene from Brassica napus was cloned, and the full length amplified primer of it was designed and amplified on the sequence released on NCBI. The target gene fragments were sequenced and the restriction loci were analyzed. The enzyme primers (BamHⅠ, SacⅠ) were designed, and the target gene fragments were connected to the eukaryotic expression vector pBI121 through BamHⅠ and SacⅠ double enzyme digestion. PCR identification result indicated that PBI121+CONSTANS overexpression vector was successfully constructed. The overexpression vector was transformed into the competent EHA105 cell, and the seeds of T0 were infected by Arabidopsis thaliana . The positive plants were screened by MS solid medium containing Cara (50 mg/L). PCR identification showed that PBI121+CONSTANS overexpression vector was successfully introduced into Arabidopsis thaliana and 12 transgenic positive seedlings were obtained, which did the preparation for the gene function analysis.

Design and development of metabolically competent cell lines for high throughput, chemical compound, toxicity testing

Design and development of metabolically competent cell lines for high throughput, chemical compound, toxicity testing