Optimized protocol for the large scale production of HIV pseudovirions by transient transfection of HEK293T cells with linear fully deacylated polyethylenimine

MLK3 Regulates Inflammatory Response via Activation of AP-1 Pathway in HEK293 and RAW264.7 Cells

Inflammation is a critically important barrier found in innate immunity. However, severe and sustained inflammatory conditions are regarded as causes of many different serious diseases, such as cancer, atherosclerosis, and diabetes. Although numerous studies have addressed how inflammatory responses proceed and what kinds of proteins and cells are involved, the exact mechanism and protein components regulating inflammatory reactions are not fully understood. In this paper, to determine the regulatory role of mixed lineage kinase 3 (MLK3), which functions as mitogen-activated protein kinase kinase kinase (MAP3K) in cancer cells in inflammatory response to macrophages, we employed an overexpression strategy with MLK3 in HEK293 cells and used its inhibitor URMC-099 in lipopolysaccharide (LPS)-treated RAW264.7 cells. It was found that overexpressed MLK3 increased the mRNA expression of inflammatory genes (COX-2, IL-6, and TNF-α) via the activation of AP-1, according to a luciferase assay carried out with AP-1-Luc. Overexpression of MLK3 also induced phosphorylation of MAPKK (MEK1/2, MKK3/6, and MKK4/7), MAPK (ERK, p38, and JNK), and AP-1 subunits (c-Jun, c-Fos, and FRA-1). Phosphorylation of MLK3 was also observed in RAW264.7 cells stimulated by LPS, Pam3CSK, and poly(I:C). Finally, inhibition of MLK3 by URMC-099 reduced the expression of COX-2 and CCL-12, phosphorylation of c-Jun, luciferase activity mediated by AP-1, and phosphorylation of MAPK in LPS-treated RAW264.7 cells. Taken together, our findings strongly suggest that MLK3 plays a central role in controlling AP-1-mediated inflammatory responses in macrophages and that this enzyme can serve as a target molecule for treating AP-1-mediated inflammatory diseases.

Peroxidase from foxtail millet bran exerts anti-colorectal cancer activity via targeting cell-surface GRP78 to inactivate STAT3 pathway

Molecular targeted therapy has become an emerging promising strategy in cancer treatment, and screening the agents targeting at cancer cell specific targets is very desirable for cancer treatment. Our previous study firstly found that a secretory peroxidase of class III derived from foxtail millet bran (FMBP) exhibited excellent targeting anti-colorectal cancer (CRC) activity in vivo and in vitro, whereas its underlying target remains unclear. The highlight of present study focuses on the finding that cell surface glucose-regulated protein 78 (csGRP78) abnormally located on CRC is positively correlated with the anti-CRC effects of FMBP, indicating it serves as a potential target of FMBP against CRC. Further, we demonstrated that the combination of FMBP with the nucleotide binding domain (NBD) of csGRP78 interfered with the downstream activation of signal transducer and activator of transcription 3 (STAT3) in CRC cells, thus promoting the intracellular accumulation of reactive oxygen species (ROS) and cell grown inhibition. These phenomena were further confirmed in nude mice tumor model. Collectively, our study highlights csGRP78 acts as an underlying target of FMBP against CRC, uncovering the clinical potential of FMBP as a targeted agent for CRC in the future.

Anti-Inflammatory, Antioxidant, Moisturizing, and Antimelanogenesis Effects of Quercetin 3-O-β-D-Glucuronide in Human Keratinocytes and Melanoma Cells via Activation of NF-κB and AP-1 Pathways

Quercetin 3-O-β-D-glucuronide (Q-3-G), the glucuronide conjugate of quercetin, has been reported as having anti-inflammatory properties in the lipopolysaccharide-stimulated macrophages, as well as anticancer and antioxidant properties. Unlike quercetin, which has been extensively described to possess a wide range of pharmacological activities including skin protective effects, the pharmacological benefits and mechanisms Q-3-G in the skin remained to be elucidated. This study focused on characterizing the skin protective properties, including anti-inflammatory and antioxidant properties, of Q-3-G against UVB-induced or H₂O₂-induced oxidative stress, the hydration effects, and antimelanogenesis activities using human keratinocytes (HaCaT) and melanoma (B16F10) cells. Q-3-G down-regulated the expression of the pro-inflammatory gene and cytokine such as cyclooxygenase-2 (COX-2) and tumor necrosis factor (TNF)-α in H₂O₂ or UVB-irradiated HaCaT cells. We also showed that Q-3-G exhibits an antioxidant effect using free radical scavenging assays, flow cytometry, and an increased expression of nuclear factor erythroid 2- related factor 2 (Nrf2). Q-3-G reduced melanin production in α-melanocyte-stimulating hormone (α-MSH)-induced B16F10 cells. The hydration effects and mechanisms of Q-3-G were examined by evaluating the moisturizing factor-related genes, such as transglutaminase-1 (TGM-1), filaggrin (FLG), and hyaluronic acid synthase (HAS)-1. In addition, Q-3-G increased the phosphorylation of c-Jun, Jun N-terminal kinase (JNK), Mitogen-activated protein kinase (MAPK) kinase 4 (MKK4), and TAK1, involved in the MAPKs/AP-1 pathway, and the phosphorylation of IκBα, IκB kinase (IKK)-α, Akt, and Src, involved in the NF-κB pathway. Taken together, we have demonstrated that Q-3-G exerts anti-inflammatory, antioxidant, moisturizing, and antimelanogenesis properties in human keratinocytes and melanoma cells through NF-κB and AP-1 pathways.

HIV-1 inhibits haematopoiesis via microRNA secreted by virus-infected CD4+ T cells

INTRODUCTION

HIV-1-infected patients develop haematological disorders such as cytopenias. One possible explanation is the inhibition of haematopoiesis at the level of differentiation of CD34+ haematopoietic progenitor stem cells. Based on our previous studies, we hypothesised that there may be viral encoded, or host cellular factors which participate in the process of inhibition of haematopoiesis.

MATERIALS AND METHODS

Virus-depleted media from infected CD4+ T cells was prepared by filtration and added to CD34+ cell differentiation semisolid medium. We have also used the virus-depleted media to isolate host/viral factors including miRNA. Isolated miRNAs were screened for their haematopoietic inhibitory function using the miRNA mining approach.

RESULTS

Addition of virus-depleted media caused a 40% inhibition of differentiation of CD34+ cells into myeloid and erythroid colony formation. Real-time RT-PCR showed miR-15a and miR-24 from both pIndie-C1 and pNL4.3 HIV-1-infected cells showed a significant differential expression when compared to control media.

CONCLUSION

In this study, we have identified two miRNAs, miR-15a and miR-24 secreted from purified HIV-1-infected CD4+ T cells that inhibited CD34+ haematopoietic progenitor stem cell differentiation into myeloid and erythroid colonies in vitro.

Ginsenoside Rc from Korean Red Ginseng (Panax ginseng C.A. Meyer) Attenuates Inflammatory Symptoms of Gastritis, Hepatitis and Arthritis

Korean Red Ginseng (KRG) is an herbal medicine prescribed worldwide that is prepared from Panax ginseng C.A. Meyer (Araliaceae). Out of ginseng’s various components, ginsenosides are regarded as the major ingredients, exhibiting anticancer and anti-inflammatory activities. Although recent studies have focused on understanding the anti-inflammatory activities of KRG, compounds that are major anti-inflammatory components, precisely how these can suppress various inflammatory processes has not been fully elucidated yet. In this study, we aimed to identify inhibitory saponins, to evaluate the in vivo efficacy of the saponins, and to understand the inhibitory mechanisms. To do this, we employed in vitro lipopolysaccharide-treated macrophages and in vivo inflammatory mouse conditions, such as collagen (type II)-induced arthritis (CIA), EtOH/HCl-induced gastritis, and lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-triggered hepatitis. Molecular mechanisms were also verified by real-time PCR, immunoblotting analysis, and reporter gene assays. Out of all the ginsenosides, ginsenoside Rc (G-Rc) showed the highest inhibitory activity against the expression of tumor necrosis factor (TNF)-[Formula: see text], interleukin (IL)-1[Formula: see text], and interferons (IFNs). Similarly, this compound attenuated inflammatory symptoms in CIA, EtOH/HCl-mediated gastritis, and LPS/D-galactosamine (D-GalN)-triggered hepatitis without altering toxicological parameters, and without inducing gastric irritation. These anti-inflammatory effects were accompanied by the suppression of TNF-[Formula: see text] and IL-6 production and the induction of anti-inflammatory cytokine IL-10 in mice with CIA. G-Rc also attenuated the increased levels of luciferase activity by IRF-3 and AP-1 but not NF-[Formula: see text]B. In support of this phenomenon, G-Rc reduced TBK1, IRF-3, and ATF2 phosphorylation in the joint and liver tissues of mice with hepatitis. Therefore, our results strongly suggest that G-Rc may be a major component of KRG with useful anti-inflammatory properties due to its suppression of IRF-3 and AP-1 pathways.

Ginsenoside Rc from Panax ginseng exerts anti-inflammatory activity by targeting TANK-binding kinase 1/interferon regulatory factor-3 and p38/ATF-2

Background

Ginsenoside Rc (G-Rc) is one of the major protopanaxadiol-type saponins isolated from Panax ginseng, a well-known medicinal herb with many beneficial properties including anticancer, anti-inflammatory, antiobesity, and antidiabetic effects. In this study, we investigated the effects of G-Rc on inflammatory responses in vitro and examined the mechanisms of these effects.

Methods

The in vitro inflammation system used lipopolysaccharide-treated macrophages, tumor necrosis factor-α/interferon-γ-treated synovial cells, and HEK293 cells transfected with various inducers of inflammation.

Results

G-Rc significantly inhibited the expression of macrophage-derived cytokines, such as tumor necrosis factor-α and interleukin-1β. G-Rc also markedly suppressed the activation of TANK-binding kinase 1/IκB kinase ε/interferon regulatory factor-3 and p38/ATF-2 signaling in activated RAW264.7 macrophages, human synovial cells, and HEK293 cells.

Conclusion

G-Rc exerts its anti-inflammatory actions by suppressing TANK-binding kinase 1/IκB kinase ε/interferon regulatory factor-3 and p38/ATF-2 signaling.

Anti-Inflammatory and Antinociceptive Activities of Anthraquinone-2-Carboxylic Acid

Anthraquinone compounds are one of the abundant polyphenols found in fruits, vegetables, and herbs. However, the in vivo anti-inflammatory activity and molecular mechanisms of anthraquinones have not been fully elucidated. We investigated the activity of anthraquinones using acute inflammatory and nociceptive experimental conditions. Anthraquinone-2-carboxylic acid (9,10-dihydro-9,10-dioxo-2-anthracenecarboxylic acid, AQCA), one of the major anthraquinones identified from Brazilian taheebo, ameliorated various inflammatory and algesic symptoms in EtOH/HCl- and acetylsalicylic acid- (ASA-) induced gastritis, arachidonic acid-induced edema, and acetic acid-induced abdominal writhing without displaying toxic profiles in body and organ weight, gastric irritation, or serum parameters. In addition, AQCA suppressed the expression of inflammatory genes such as cyclooxygenase- (COX-) 2 in stomach tissues and lipopolysaccharide- (LPS-) treated RAW264.7 cells. According to reporter gene assay and immunoblotting analyses, AQCA inhibited activation of the nuclear factor- (NF-) κB and activator protein- (AP-) 1 pathways by suppression of upstream signaling involving interleukin-1 receptor-associated kinase 4 (IRAK1), p38, Src, and spleen tyrosine kinase (Syk). Our data strongly suggest that anthraquinones such as AQCA act as potent anti-inflammatory and antinociceptive components in vivo, thus contributing to the immune regulatory role of fruits and herbs.

Bioreactor concepts for cell culture-based viral vaccine production

Vaccine manufacturing processes are designed to meet present and upcoming challenges associated with a growing vaccine market and to include multi-use facilities offering a broad portfolio and faster reaction times in case of pandemics and emerging diseases. The final products, from whole viruses to recombinant viral proteins, are very diverse, making standard process strategies hardly universally applicable. Numerous factors such as cell substrate, virus strain or expression system, medium, cultivation system, cultivation method, and scale need consideration. Reviewing options for efficient and economical production of human vaccines, this paper discusses basic factors relevant for viral antigen production in mammalian cells, avian cells and insect cells. In addition, bioreactor concepts, including static systems, single-use systems, stirred tanks and packed-beds are addressed. On this basis, methods towards process intensification, in particular operational strategies, the use of perfusion systems for high product yields, and steps to establish continuous processes are introduced.

AP-1/IRF-3 Targeted Anti-Inflammatory Activity of Andrographolide Isolated from Andrographis paniculata

Andrographolide (AG) is an abundant component of plants of the genus Andrographis and has a number of beneficial properties including neuroprotective, anticancer, anti-inflammatory, and antidiabetic effects. Despite numerous pharmacological studies, the precise mechanism of AG is still ambiguous. Thus, in the present study, we investigated the molecular mechanisms of AG and its target proteins as they pertain to anti-inflammatory responses. AG suppressed the production of nitric oxide (NO) and prostaglandin E₂ (PGE₂), as well as the mRNA abundance of inducible NO synthase (iNOS), tumor necrosis factor-alpha (TNF-α), cyclooxygenase (COX)-2, and interferon-beta (IFN-β) in a dose-dependent manner in both lipopolysaccharide- (LPS-) activated RAW264.7 cells and peritoneal macrophages. AG also substantially ameliorated the symptoms of LPS-induced hepatitis and EtOH/HCl-induced gastritis in mice. Based on the results of luciferase reporter gene assays, kinase assays, and measurement of nuclear levels of transcription factors, the anti-inflammatory effects of AG were found to be clearly mediated by inhibition of both (1) extracellular signal-regulated kinase (ERK)/activator protein (AP)-1 and (2) IκB kinase ε (IKKε)/interferon regulatory factor (IRF)-3 pathways. In conclusion, we detected a novel molecular signaling pathway by which AG can suppress inflammatory responses. Thus, AG is a promising anti-inflammatory drug with two pharmacological targets.

Generation of a genome scale lentiviral vector library for EF1α promoter-driven expression of human ORFs and identification of human genes affecting viral titer

The bottleneck in elucidating gene function through high-throughput gain-of-function genome screening is the limited availability of comprehensive libraries for gene overexpression. Lentiviral vectors are the most versatile and widely used vehicles for gene expression in mammalian cells. Lentiviral supernatant libraries for genome screening are commonly generated in the HEK293T cell line, yet very little is known about the effect of introduced sequences on the produced viral titer, which we have shown to be gene dependent. We have generated an arrayed lentiviral vector library for the expression of 17,030 human proteins by using the GATEWAY® cloning system to transfer ORFs from the Mammalian Gene Collection into an EF1alpha promoter-dependent lentiviral expression vector. This promoter was chosen instead of the more potent and widely used CMV promoter, because it is less prone to silencing and provides more stable long term expression. The arrayed lentiviral clones were used to generate viral supernatant by packaging in the HEK293T cell line. The efficiency of transfection and virus production was estimated by measuring the fluorescence of IRES driven GFP, co-expressed with the ORFs. More than 90% of cloned ORFs produced sufficient virus for downstream screening applications. We identified genes which consistently produced very high or very low viral titer. Supernatants from select clones that were either high or low virus producers were tested on a range of cell lines. Some of the low virus producers, including two previously uncharacterized proteins were cytotoxic to HEK293T cells. The library we have constructed presents a powerful resource for high-throughput gain-of-function screening of the human genome and drug-target discovery. Identification of human genes that affect lentivirus production may lead to improved technology for gene expression using lentiviral vectors.

BAY 11-7082 is a broad-spectrum inhibitor with anti-inflammatory activity against multiple targets

BAY 11-7082 (BAY) is an inhibitor of κB kinase (IKK) that has pharmacological activities that include anticancer, neuroprotective, and anti-inflammatory effects. In this study, BAY-pharmacological target pathways were further characterized to determine how this compound simultaneously suppresses various responses. Primary and cancerous (RAW264.7 cells) macrophages were activated by lipopolysaccharide, a ligand of toll-like receptor 4. As reported previously, BAY strongly suppressed the production of nitric oxide, prostaglandin E₂, and tumor necrosis factor-α and reduced the translocation of p65, major subunit of nuclear factor-κB, and its upstream signaling events such as phosphorylation of IκBα, IKK, and Akt. In addition, BAY also suppressed the translocation and activation of activator protein-1, interferon regulatory factor-3, and signal transducer and activator of transcription-1 by inhibiting the phosphorylation or activation of extracellular signal-related kinase, p38, TANK-binding protein, and Janus kinase-2. These data strongly suggest that BAY is an inhibitor with multiple targets and could serve as a lead compound in developing strong anti-inflammatory drugs with multiple targets in inflammatory responses.

3-(4-(tert-Octyl)phenoxy)propane-1,2-diol suppresses inflammatory responses via inhibition of multiple kinases

Novel anti-inflammatory compounds were synthesised by derivatization of militarin, a compound isolated from Cordyceps militaris that is an ethnopharmacologically well-known herbal medicine with multiple benefits such as anti-cancer, anti-inflammatory, anti-obesity, and anti-diabetic properties. In this study, we explored the in vitro and in vivo anti-inflammatory potencies of these compounds during inflammatory responses, their inhibitory mechanisms, and acute toxicity profiles. To do this, we studied inflammatory conditions using in vitro lipopolysaccharide-treated macrophages and several in vivo inflammatory models such as dextran sodium sulphate (DSS)-induced colitis, EtOH/HCl-induced gastritis, and arachidonic acid-induced ear oedema. Methods used included real-time PCR, immunoblotting analysis, immunoprecipitation, reporter gene assays, and direct kinase assays. Of the tested compounds, compound III showed the highest nitric oxide (NO) inhibitory activity. This compound also inhibited the production of prostaglandin (PG)E(2) at the transcriptional level by suppression of Syk/NF-κB, IKKɛ/IRF-3, and p38/AP-1 pathways in lipopolysaccharide (LPS)-activated RAW264.7 cells and peritoneal macrophages. Consistent with these findings, compound III strongly ameliorated inflammatory symptoms in colitis, gastritis, and ear oedema models. In acute toxicity tests, there were no significant differences in body and organ weights, serum parameters, and stomach lesions between the untreated and compound III-treated mice. Therefore, this compound has the potential to be served as a lead chemical for developing a promising anti-inflammatory drug candidate with multiple kinase targets.

COS-1 cells as packaging host for production of lentiviruses

We present a protocol for in vitro production of recombinant lentiviruses using COS-1 African green monkey kidney epithelial cells and HEK293T human embryonic kidney epithelial cells as packaging cells. COS-1 and HEK293T express SV40 large T antigen, amplifying transfected circular plasmids harboring SV40 replication origin. Support protocols for evaluation of transfection efficiency by in situ β-galactosidase enzyme activity assay and titer of infection-capable virions are also provided. Advantages of using COS-1 packaging cells over the standard HEK293T cells for contamination-sensitive applications or automated processing are discussed.

Large-scale manufacture and characterization of a lentiviral vector produced for clinical ex vivo gene therapy application

From the perspective of a pilot clinical gene therapy trial for Wiskott-Aldrich syndrome (WAS), we implemented a process to produce a lentiviral vector under good manufacturing practices (GMP). The process is based on the transient transfection of 293T cells in Cell Factory stacks, scaled up to harvest 50 liters of viral stock per batch, followed by purification of the vesicular stomatitis virus glycoprotein-pseudotyped particles through several membrane-based and chromatographic steps. The process leads to a 200-fold volume concentration and an approximately 3-log reduction in protein and DNA contaminants. An average yield of 13% of infectious particles was obtained in six full-scale preparations. The final product contained low levels of contaminants such as simian virus 40 large T antigen or E1A sequences originating from producer cells. Titers as high as 2 × 10(9) infectious particles per milliliter were obtained, generating up to 6 × 10(11) infectious particles per batch. The purified WAS vector was biologically active, efficiently expressing the genetic insert in WAS protein-deficient B cell lines and transducing CD34(+) cells. The vector introduced 0.3-1 vector copy per cell on average in CD34(+) cells when used at the concentration of 10(8) infectious particles per milliliter, which is comparable to preclinical preparations. There was no evidence of cellular toxicity. These results show the implementation of large-scale GMP production, purification, and control of advanced HIV-1-derived lentiviral technology. Results obtained with the WAS vector provide the initial manufacturing and quality control benchmarking that should be helpful to further development and clinical applications.

Identification of the cellular prohibitin 1/prohibitin 2 heterodimer as an interaction partner of the C-terminal cytoplasmic domain of the HIV-1 glycoprotein

Our studies aim to elucidate the functions carried out by the very long, and in its length highly conserved, C-terminal cytoplasmic domain (Env-CT) of the HIV-1 glycoprotein. Mass spectrometric analysis of cellular proteins bound to a tagged version of the HIV Env-CT led to the identification of the prohibitin 1 and 2 proteins (Phb1 and Phb2). These ubiquitously expressed proteins, which exist as stable heterodimers, have been shown to have multiple functions within cells and to localize to multiple cellular and extracellular compartments. The specificity of binding of the Phb1/Phb2 complex to the Env-CT was confirmed in various manners, including coimmunoprecipitation with authentic provirally encoded, full-length Env. Strong binding was dependent on Env residues 790 to 800 and could be severely inhibited by the double mutation L799R/L800Q but not by mutation of these amino acids individually. Analysis of the respective mutant virions revealed that their different abilities to bind Phb1/Phb2 correlated with their replicative properties. Thus, mutated virions with single mutations [HIV-Env-(L799R) and HIV-Env-(L800Q)] replicated similarly to wild-type HIV, but HIV-Env-(L799R/L800Q) virions, which cannot bind Phb1/Phb2, exhibited a cell-dependent replicative phenotype similar to that of HIV-Env-Tr712, lacking the entire Env-CT domain. Thus, replicative spread was achieved, although somewhat delayed, in "permissive" MT-4 cells but failed to occur in "nonpermissive" H9 T cells. These results point to binding of the Phb1/Phb2 complex to the Env-CT as being of importance for replicative spread in nonpermissive cells, possibly by modulating critical Phb-dependent cellular process(es).

HIV pseudovirion vaccine exposing Env "fusion intermediates"-response to immunisation in human CD4/CCR5-transgenic rats

Immune responses to a pseudovirion-based HIV vaccine enriched in Env conformations, which have been induced to an authentic intermediate fusion stage by interaction with the cellular HIV receptor complex, have been analysed in human CD4/CCR5-transgenic rats. High titre Env-binding antibodies were elicited. However, these immune sera failed to neutralise HIV-1, but rather led to an enhancement of infection in vitro. This enhancing activity appeared to be directed towards contaminating cellular proteins in the vaccine and was able to mask neutralisation of potent, mixed-in neutralising antibodies. The induced Env-specific antibodies, purified on the basis of binding to monomeric Env, retained high-binding activity, but failed to be neutralising. Thus, it remains unclear whether vaccines based on induced HIV Env fusion intermediates can elicit broadly neutralising responses.

Advantages of COS-1 monkey kidney epithelial cells as packaging host for small-volume production of high-quality recombinant lentiviruses

The HEK293T human embryonic kidney cells have been used widely as a packaging host for transfection-based production of recombinant lentiviruses. The present study describes advantages of using COS-1 African green monkey kidney cells versus HEK293T cells as a packaging host for small-volume production of high-quality recombinant lentiviruses. The particle performance index, defined as the ratio of infection-competent viral particles to the total number of particles, was three- to four-fold greater in transfection supernatants generated using COS-1 cells than that generated using HEK293T cells. Adhesion of HEK293T cells to the cell culture-treated plastic surface was weak, causing significant HEK293T cell contamination in the transfection supernatants produced by laboratory automation using the 96-well cell culture plates. In contrast, COS-1 cells adhered strongly to the plastic surface, and cell contamination was not detected in the transfection supernatants. These results suggest that COS-1 cells may be a useful alternative packaging host for use for automated generation of large numbers of high-quality lentivirus reagents, particularly because they eliminate the need for additional purification steps to remove viral particles from cell culture supernatant.