Overexpression of miR-32 in Chinese hamster ovary cells increases production of Fc-fusion protein.

The demand for industrial genetically modified host cells were increased with the growth of the biopharmaceutical market. Numerous studies on improving host cell productivity have shown that altering host cell growth and viability through genetic engineering can increase recombinant protein production. During the last decades, it was demonstrated that overexpression or downregulation of some microRNAs in Chinese Hamster Ovary (CHO) cells as the host cell in biopharmaceutical manufacturing, can improve their productivity.

Computational and Experimental Evaluation of Linker Peptides and Thioredoxin Fusion Tag in CD20-rituximab Specific Interactions.

Background: Overexpression of CD20 protein on the surface of B cells in lymphoma can be targeted by several anti-CD20 molecules. The development of accessible interactive epitopes is more favorable than the full-length transmembrane CD20 in the affinity assessment of anti-CD20 monoclonal antibodies (mAbs).

Methods: The sequence of these epitopes was extracted, and the effects of different linker peptides and the location of histidine (His)-tag were computationally analyzed.

Multiple myeloma cell-derived exosomes promote favorable tumor functional performance by polarizing macrophages toward M2-like cells.

It has long been hypothesized that leukemic cells are able to modulate the fate of resident cells in the tumor microenvironment (TME) toward either supporting or immunosuppressive cells for the development of tumors. Exosomes can be a potential culprit in imposing tumor desire. There is evidence about the impact of tumor-derived exosomes on different immune cells in different malignancies.

Development and characterization of single domain monoclonal antibody against programmed cell death ligand-1; as a cancer inhibitor candidate.

Objectives: One of the important interactions in controlling the human immune system is the reaction between checkpoint proteins such as programmed cell death-1 (PD-1) and its ligand, PD-L1. These are negative immunoregulatory molecules that promote immune evasion of tumor cells. PD-L1 expression is an immune-mediated mechanism used by various malignant cells in order to down-regulate the immune system.

Optimization of culture conditions for high-level expression of soluble and active tumor necrosis factor-α in E. coli.

Anti-TNF inhibitors exert their therapeutic effect by inhibition of the excessive amounts of TNF-α within the body. Recombinant TNF-α should be produced in a soluble refolded form to investigate the effectiveness and efficiency of anti-TNF-α compounds. In this research, the designed cassette was subcloned in the pET28a expression vector and expressed in E.

Enhancement of Expression Level of Modified t-PA (TNKase) in Leishmania tarentolae by Induction System.

Background: The expression of bio-therapeutic proteins in mammalian cells, such as CHO, attains high homogeneity related to post-translational modifications. Although CHO remains the most popular cell line for bestselling biotherapeutic proteins on the market, there are still drawbacks such as expensive culture media, long time line, and high drug cost. Recently, researches on a novel Leishmania protozoan system have confirmed that this low-level eukaryote could represent a competitive alternative to the mammalian cell lines.

Development of Genetically Modified Chinese Hamster Ovary Host Cells for the Enhancement of Recombinant Tissue Plasminogen Activator Expression.

Background: Chinese hamster ovary (CHO) cells are the most commonly used host system for the expression of high quality recombinant proteins. However, the development of stable, high-yielding CHO cell lines is a major bottleneck in the industrial manufacturing of therapeutic proteins. Therefore, different strategies such as the generation of more efficient expression vectors and establishment of genetically engineered host cells have been employed to increase the efficiency of cell line development.

Enhanced truncated-t-PA (CT-b) expression in high-cell-density fed-batch cultures of Pichia pastoris through optimization of a mixed feeding strategy by response surface methodology.

Recently, Pichia pastoris has been the focal point of interest as an expression system for production of many recombinant proteins. The study and optimization of feeding strategy are of major importance to achieve maximum volumetric productivity in fed-batch cultivations. Among different feeding strategies used in P.

Design of a novel chimeric tissue plasminogen activator with favorable Vampire bat plasminogen activator properties.

Fibrinolytic agents are widely used in treatment of the thromboembolic disorders. The new generations like recombinant tissue plasminogen activator (t-PA, alteplase) are not showing promising results in clinical practice in spite of displaying specific binding to fibrin in vitro. Vampire bat plasminogen activator (b-PA) is a plasminogen activator with higher fibrin affinity and specificity in comparison to t-PA resulting in reduced probability of hemorrhage.

Expression of a novel chimeric-truncated tPA in Pichia pastoris with improved biochemical properties.

Thrombolytic therapy by plasminogen activators (PAs) has been a main goal in the treatment of acute myocardial infarction. Despite improved outcomes of currently available thrombolytic therapies, all these agents have different drawbacks that may result in less than optimal outcomes. In order to make tissue plasminogen activator (tPA) more potent, while being more resistant to plasminogen activator inhibitor-1 (PAI-1) and having a higher affinity to fibrin, a new chimeric-truncated form of tPA (CT tPA) was designed and expressed in Pichia pastoris.

Engineering the cellular protein secretory pathway for enhancement of recombinant tissue plasminogen activator expression in Chinese hamster ovary cells: effects of CERT and XBP1s genes.

Cell line development is the most critical and also the most time-consuming step in the production of recombinant therapeutic proteins. In this regard, a variety of vector and cell engineering strategies have been developed for generating high-producing mammalian cells; however, the cell line engineering approach seems to show various results on different recombinant protein producer cells. In order to improve the secretory capacity of a recombinant tissue plasminogen activator (t-PA)-producing Chinese hamster ovary (CHO) cell line, we developed cell line engineering approaches based on the ceramide transfer protein (CERT) and X-box binding protein 1 (XBP1) genes.

Immune responses against a new HIV-1 p24-gp41/pCAGGS-IL-12 DNA vaccine in Balb/c mice.

Background: Development of an effective vaccine is highly needed in order to restrict the AIDS pandemic. DNA vaccines initiate both arms of immunity without the potential of causing disease. HIV-1 p24 and gp41 (gag and env) proteins play important roles in viral pathogenesis and are effective candidates for immune induction and vaccine design.

Combined TGE-SGE expression of novel PAI-1-resistant t-PA in CHO DG44 cells using orbitally shaking disposable bioreactors.

An important modification of thrombolytic agents is resistance to plasminogen activator inhibitor-1 (PAI-1). In previous studies, a new truncated PAI-1-resistant variant was developed based on deletion of the first three domains in t-PA and the substitution of KHRR 128-131 amino acids with AAAA in the truncated t-PA. The novel variant expressed in a static culture system of Chinese Hamster Ovary (CHO) DG44 cells exhibited a higher resistance to PAI-1 when compared with the full-length commercial drug; Actylase.

A novel variant of t-PA resistant to plasminogen activator inhibitor-1; expression in CHO cells based on in silico experiments.

Resistance to PAI-1 is a factor which confers clinical benefits in thrombolytic therapy. The only US FDA approved PAI-1 resistant drug is Tenecteplase®. Deletion variants of t-PA have the advantage of fewer disulfide bonds in addition to higher plasma half lives.

Increased expression of recombinant human tissue plasminogen activator in Leishmania tarentolae.

Recombinant tissue plasminogen activator (rt-PA) is one of the most important thrombolytic agents for treating cardiovascular obstructions such as stroke. Glycoprotein rt-PA is a serine protease, consisting of 527 amino acids of which 35 are cysteine residues. A variety of recombinant protein expression systems have been developed for heterologous gene expression in prokaryotic and eukaryotic hosts.

Expression of a novel chimeric truncated t-PA in CHO cells based on in silico experiments.

Tissue plasminogen activator (t-PA) is one of the fibrin-specific serine proteases that play a crucial role in the fibrinolytic system. The rapid clearance of the drug from the circulation, caused by its active uptake in the liver, has lead to complicated clinical applications. Different forms of plasminogen activators have been developed to treat thrombotic disease.

Human Tissue Plasminogen Activator Expression in Escherichia coli using Cytoplasmic and Periplasmic Cumulative Power.

Tissue plasminogen activator (tPA) is a serine protease, which is composed of five distinct structural domains with 17 disulfide bonds, representing a model of high-disulfide proteins in human body. One of the most important limitations for high yield heterologous protein production in Escherichia coli (E. coli) is the expression of complex proteins with multiple disulfide bridges.

Cloning and expression of functional full-length human tissue plasminogen activator in Pichia pastoris.

Human tissue plasminogen activator (t-PA) plays a pivotal role in the treatment of acute myocardial infarction, ischemic stroke, and deep vein thrombosis. It has the benefit of generating no adverse effects such as fibrinogen depletion, systemic hemorrhage, and immunologic reactions. Human t-PA is a serine-protease enzyme containing 527 amino acid residues in five structural domains.

Molecular cloning of cDNA of mammalian and chicken II gonadotropin-releasing hormones (mGnRHs and cGnRH-II) in the beluga (Huso huso) and the disruptive effect of methylmercury on gene expression.

Two gonadotropin-releasing hormone (GnRH) isoforms were identified in the beluga (Huso huso) brain by cDNA sequencing: prepro-mammalian GnRH (mGnRH) and prepro-chicken GnRH-II (cGnRH-II). The nucleotide sequences of the beluga mGnRH and cGnRH-II precursors are 273 and 258 base pairs (bp) long, encoding peptides of 91 and 86 amino acids, respectively. To investigate the effect of methylmercury (MeHg) on GnRH gene expression, animals were fed with four diets containing increasing levels of MeHg (0 mg kg(-1) [control]; 0.

Cloning and expression of Leishmania major superoxide dismutase B1: A potential target antigen for serodiagnosis of Leishmaniasis.

Background: Leishmaniasis- a neglected public health problem- is a group of diseases affecting an estimated 12 million people worldwide.

Objective: In the present study, recombinant Leishmania major superoxide dismutase B1 (rLmSODB1) has been utilized as a potential antigen for the serodiagnosis of human cutaneous (CL) and visceral leishmaniasis (VL) in the endemic regions of southern part of Iran. Additionally, the sensitivity and specificity of ELISA-based serodiagnosis using rLmSODB1 and the soluble Leishmania antigen (SLA) were compared.

Prevalence of viral hepatitis and molecular analysis of HBV among voluntary blood donors in west Iran.

To determine the prevalence of viral hepatitis infection and hepatitis B virus (HBV) molecular characterization, 11,200 blood donors from citizens of Shahrekord (a city located in west of Iran) were investigated. Results showed HBsAg-positive in 1.78% of persons (n=200), anti-HDV-positive in 3% of HBsAg-positive cases (n=6) and anti-HCV-positive in 0.

Clinical, virologic and phylogenetic features of hepatitis B infection in Iranian patients.

Aim: To characterize the clinical, serologic and virologic features of hepatitis B virus (HBV) infection in Iranian patients with different stages of liver disease.

Methods: Sixty two patients comprising of 12 inactive carriers, 30 chronic hepatitis patients, 13 patients with liver cirrhosis and 7 patients with hepatocellular carcinoma (HCC) were enrolled in the study. The HBV S, C and basal core promoter (BCP) regions were amplified and sequenced, and the clinical, serologic, phylogenetic and virologic characteristics were investigated.

Expression of human tissue plasminogen activator in the trypanosomatid protozoan Leishmania tarentolae.

A variety of recombinant protein expression systems have been developed for heterologous genes in both prokaryotic and eukaryotic systems such as bacteria, yeast, mammals, insects, transgenic animals and transgenic plants. Also, it has been reported that Leishmania tarentolae, a trypanosomatid protozoan parasite of the white-spotted wall gecko (Tarentola annularis), has the capability of expressing heterologous genes. Trypanosomatidae are rich in glycoproteins, which can account for more than 10% of total protein.

Molecular analysis and phylogenetic characterization of HIV in Iran.

The rate of human immunodeficiency virus type 1 (HIV-1) infection in Iran has increased dramatically in the last few years. While the earliest cases were found in hemophiliacs, intravenous drug users are now fueling the outbreak. In this study, both the 122 clones of HIV-1 gag p17 and the 131 clones of env V1-V5 region were obtained from 61 HIV-1 seropositives belonging to these two groups in Iran.