Advances in the treatment of human T-cell lymphotropic virus type-I associated myelopathy.

INTRODUCTION: Nearly 2-3% of those 10 to 20 million individuals infected with the Human T-cell lymphotropic virus type-1 (HTLV-1); are predisposed to developing HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). It is a neuro-inflammatory disease; differentiated from multiple sclerosis based on the presence of typical neurologic symptoms, confirmation of HTLV-1 infection, and other molecular biomarkers. AREAS COVERED: A brief review of the epidemiology, host immune responses, and molecular pathogenesis of HAM/TSP is followed by detailed discussions about the host-related risk factors for developing HAM/TSP and success/failure stories of the attempted management strategies. EXPERT OPINION: Currently, there is no effective treatment for HAM/TSP. Anti-retroviral therapy, peculiar cytokines (IFN-α), some anti-oxidants, and allograft bone marrow transplantation have been used for treating these patients with limited success. Under current conditions, asymptomatic carriers should be examined periodically by a neurologist for early signs of spinal cord injury. Then it is crucial to determine the progress rate to adapt the best management plan for each patient. Corticosteroid therapy is most beneficial in those with acute myelitis. However, slow-progressing patients are best managed using a combination of symptomatic and physical therapy. Additionally, preventive measures should be taken to decrease further spread of HTLV-1 infection.

Fenugreek Seed Extract Regulates Human Umbilical Vein Endothelial Cell Angiogenesis and Proliferation via the PI3K/Akt/Cyclin D1 Pathway.

The significance of angiogenesis in tumour progression has been widely documented. Hence, the identification of anti-angiogenic agents with fewer common side effects would be valuable in cancer therapy. In this study, we evaluated the anti-angiogenic and anti-proliferative effects of a hydro-alcoholic extract of fenugreek seed (HAEF) on human umbilical vein endothelial cells (HUVECs). Human umbilical vein endothelial cells were treated with various concentrations of HAEF and the half-maximal inhibitory concentration (IC50) value was estimated by using the MTT assay. Vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and matrix metalloproteinase enzyme (MMP-2 and MMP-9) gene expression profiles were evaluated by using quantitative RT-PCR (qRT-PCR). Moreover, MMP activities and PI3K, Akt and cyclin D1 protein expression levels were evaluated by gel zymography and Western blotting, respectively. HAEF reduced HUVEC viability, with an IC50 value of 200 µg/ml. The qRT-PCR results demonstrated that treatment with HAEF markedly reduced MMP-2/MMP-9, VEGF and bFGF gene expression, as compared to the control group. We also found that MMP-2/MMP-9 enzyme activity and PI3K/Akt/cyclin D1 protein expression were notably decreased in cells treated with HAEF. Our results suggest that HAEF can potentially inhibit angiogenesis, and also affect cellular proliferation by targeting the PI3K/Akt/cyclin D1 pathway. Thus, fenugreek seed extract merits further investigation as a source of compounds with anti-cancer properties.

Rigosertib is more potent than wortmannin and rapamycin against adult T-cell leukemia-lymphoma.

Human T lymphotropic virus type 1 (HTLV-1) infection can cause adult T-cell lymphoblastic leukemia (ATLL), an incurable, chemotherapy-resistant malignancy. In a quest for new therapeutic targets, our study sought to determine the levels of AKT, mTOR, and PI3K in ATLL MT-2 cells, HTLV-1 infected NIH/3T3 cells (Inf-3T3), and HTLV-1 infected patients (Carrier, HAM/TSP, and ATLL). Furthermore, the effects of rigosertib, wortmannin, and rapamycin on the PI3K/Akt/mTOR pathway to inhibit the proliferation of ATLL cells were examined. The results showed that mRNA expression of Akt/PI3K/mTOR was down-regulated in carrier, HAM/TSP, and ATLL patients, as well as MT-2, and Inf-3T3 cells, compared to the healthy individuals and untreated MT-2 and Inf-3T3 as controls. However, western blotting revealed an increase in the phosphorylated and activated forms of AKT and mTOR. Treating the cells with rapamycin, wortmannin, and rigosertib decreased the phosphorylated forms of Akt and mTOR and restored their mRNA expression levels. Using these inhibitors also significantly boosted the expression of the pro-apoptotic genes, Bax/Bcl-2 ratio as well as the expression of the tumor suppressor gene p53 in the MT-2 and Inf-3T3cells. Rigosertib was more potent than wortmannin and rapamycin in inducing sub-G1 and G2-M cell cycle arrest, as well as late apoptosis in the Inf-3T3 and MT-2 cells. It also synergized the cytotoxic effects of vincristine. These findings demonstrate that HTLV-1 downregulation of the mRNA level may occur as a negative feedback response to increased PI3K-Akt-mTOR phosphorylation by HTLV-1. Therefore, using rigosertib alone or in combination with common chemotherapy drugs may be beneficial in ATLL patients.

The In Vitro Pro-inflammatory Functions of the SP/NK1R System in Prostate Cancer: a Focus on Nuclear Factor-Kappa B (NF-κB) and Its Pro-inflammatory Target Genes.

Prostate cancer is one of the main global health threats for men which is in close association with chronic inflammation. Neuropeptide substance P (SP), acting through neurokinin receptor (NK-1R), induces various pro-inflammatory responses which are strongly involved in the pathogenesis of several diseases as well as cancer. Therefore, we aimed to investigate the pro-inflammatory functions of the SP/NK1R complex in prostate cancer and the therapeutic effects of its inhibition by NK-1R antagonist, aprepitant, in vitro. MTT assay was conducted for the cytotoxicity assessment of aprepitant in prostate cancer cells. The protein expression levels were evaluated by Western blot assay. Quantitative real-time PCR (qRT-PCR) was applied to measure mRNA expression levels of pro-inflammatory cytokines. Concurrently, the protein concentrations of pro-inflammatory cytokines were also analyzed by enzyme-linked immunosorbent assay. We observed that SP increased the levels of pro-inflammatory cytokines (IL-1ß, IL-6, and TNF-α), while treatment with aprepitant reduced the effects of SP. We also indicated that SP increased the protein levels of nuclear factor-kappa B (NF-κB), as the main regulator of inflammatory processes, and also an NF-κB target gene, cyclooxygenase 2 (COX-2) in prostate cancer cells, while treatment with aprepitant reversed these effects. Taken together, our findings highlight the importance of the SP/NK1R system in the modulation of pro-inflammatory responses in prostate cancer cells and suggest that aprepitant may be developed as a novel anti-inflammatory agent for the management of cancer-associated inflammation.

Molecular insight into the study of adult T-cell leukemia/lymphoma (ATLL): Ten-year studies on HTLV-1 associated diseases in an endemic region.

The outcome of successful infection, including human T-cell leukemia virus type 1 (HTLV-1), is determined by the interactions between the host and the infectious agent. Ten years of work on HTLV-1-associated diseases in an endemic region of Iran have been critically compared in the present study. The outstanding findings of RNA-seq, system biology analysis, and gene expression measurements on adult T-cell leukemia/lymphoma (ATLL) and enzootic bovine leukosis(EBL) in our lab encouraged us to investigate the significant role of oncogenes in the ATLL malignancy. Most studies assessed such interactions by the proviral load (PVL), Tax, and HBZ regulatory proteins in HTLV-1 and the host's immunological and cell cycle factors. The current study is a comprehensive comparing view of our previously published and unpublished results investigating the HTLV-1-host interactions leading to the transformation of the infected cell. The main focus has been on the essential proteins implicated in the virus dissemination, cell survival, and proliferation of infected cells toward leukemia development and progression. Similar to its homolog BLV-AS-1-2 in EBL, the HTLV-1-HBZ is a pivotal factor in the maintenance and progression of the ATLL. In addition, the inappropriate activities of the PI3K/Akt pathway, BRCAs, and RAD51 in the DNA repair system, which are orchestrating many other immortalization pathways, might be the central factors in the manifestation of ATLL. HTLV-1-HBZ and the host PI3K/Akt pathway, BCAs, and RAD51 could be suggested as influential targets for the prognosis and proper therapy of ATLL.

Glutathione reductase system changes in HTLV-1 infected patients.

During chronic HTLV-1 infections oxidative stress occurs and contributes in viral pathogenesis. Glutaredoxin (Grx) system is one of the most effective antioxidant components. The system maintains the cellular redox and scavenges reactive oxygen species through the function of glutathione reductase (GR) enzyme, NADPH and reduced glutathione (GSH). This study was performed to investigate potential changes in GR gene expression and activity as well as GSH level, and their association with the viral load in HTLV-1 infection. Forty HTLV-1 seropositive patients divided into two groups: asymptomatic carriers (N = 20) and HAM/TSP (N = 20) with the same number of age and sex-matched healthy controls were recruited in this study. GR cellular gene expression and viral load in PBMCs were determined using Real-time PCR Technique. Enzyme activity and GSH level in sera were measured by commercial kits based on manufacturer's provided protocols. GR gene expression and GR enzyme activity, as well as GSH level, were significantly lower in HTLV-1 patients. A negative correlation between viral load and GR gene expression/enzyme activity was observed in HAM/TSP group. Similarly, a negative relationship between viral load and GSH levels was observed in both carrier and HAM/TSP groups. We also found that in profound complicated condition of HTLV-1 infection, HAM/TSP, Grx system components activity was significantly decreased compared to the controls. Such observation was not the case in clinically healthy HTLV-1 carriers. These findings may shed a light on the conditions contributing in pathogenesis of the complications and exacerbation of the disease in the HAM/TSP cases. Supplementary Information: The online version contains supplementary material available at 10.1007/s13337-022-00758-y.

Challenges of expressing recombinant human tissue factor as a secreted protein in Pichia pastoris.

Tissue factor (TF) is the core reagent in the prothrombin time (PT) assay. In this study, expression and α-factor mediated secretion of three forms of tissue factor (full-length TF (Full-TF), extracellular plus transmembrane domain (TED-TF), and only extracellular domain (ED-TF) were investigated in Pichia pastoris. The amino acid sequence of TF was obtained from the UniProt database, back-translated and codon-optimized for expression in Pichia pastoris. The Full-TF sequence was synthesized but the ED-TF, TED-TF coding fragments were extracted from the Full-TF by PCR. All the coding sequences were cloned into pPICZαA vector in-frame with the α-factor; and electroporated into KM71H. The culture supernatants and the cell lysates were analyzed using SDS-PAGE, dot-blotting, and Western-blotting for expression of TF. The Full-TF and TED-TF expression vector pPICZαA were successfully inserted into the KM71H, but the product was not detected in the SDS-PAGE analysis of the culture supernatant. However, ED-TF expression and secretion was verified by SDS-PAGE, dot blotting, and Western blotting. It seems that the TM domain in the Full-TF and TED-TF have an important role in impairing α-factor-mediated secretion of TF. Therefore, further investigation is necessary to overcome challenges of expressing Full-TF as a heterologous protein in P. pastoris.

The Level of Mesenchymal-Epithelial Transition Autophosphorylation is Correlated with Esophageal Squamous Cell Carcinoma Migration.

Background: The MET receptor is a critical member of cancer-associated receptor tyrosine kinases and plays an important role in different biological activities, including differentiation, migration, and cell proliferation. Methods: In this study, novel MET inhibitors were introduced and applied on esophageal squamous carcinoma cell line KYSE-30, and the level of proliferation and migration, as well as the activated form of MET receptor protein were assessed in the examined cells. The human KYSE-30 cell line was cultured according to ATCC recommendations. The mRNA level of the MET gene was measured in the examined cell line using the quantitative RT-PCR assay. Cytotoxicity evaluation test was performed at different concentrations of heterocyclic anti-MET compounds (i.e. D1, D2, D5, D6, D7, and D8). Finally, the capability of these compounds in MET receptor inhibition was evaluated using the migration assay and Western blot. All experiments were performed in triplicate and repeated three times with similar results. Results: Cell growth and proliferation were significantly inhibited (p ≤ 0.05) by all the above-mentioned compounds. Moreover, the majority of compounds significantly prevented the cell migration (p ≤ 0.05) and inhibited MET autophosphorylation. Interestingly, the level of phosphorylated MET was significantly correlated with KYSE-30 cell migration. Conclusion: The obtained data introduced and confirmed the biological activities of the mentioned novel compounds in KYSE-30 cells and proposed that the therapeutic inhibition of MET with these compounds may be a powerful approach for inhibiting cancer cell migration and proliferation although some structural optimizations are needed to improve their inhibitory functions.

Interleukin-6 as A Prognostic Biomarker in Perinatal Asphyxia.

OBJECTIVE: Early diagnosis is has a crucial role in both prevention and treatment of asphyxia-related complications. The current study aimed to evaluate the prognostic value of interleukin-6 (IL-6) and hypoxic-ischemic encephalopathy grade in the prediction of mortality and the developmental status of neonates affected by prenatal asphyxia. MATERIALS & METHODS: This cohort study was conducted on 38 term asphyxiated infants at Ghaem hospital, Mashhad, Iran, from 2013 to 2017. The HIE grade and serum IL-6 levels were determined at the time of birth. The developmental status was evaluated using the Denver II test at the end of the two-year follow-up. RESULTS: HIE grade 3 resulted in 83% mortality rate and developmental delay among all survivors. The mean IL-6 level was 2.7 ng/ml in the control group (not affected HIE), which increased up to 29, 175, and 136 ng/ml in those with HIE grades of 1, 2, and 3, respectively. According to the ROC curve analysis, the cut-off level of 24 pg/ml could predict the developmental delay with sensitivity and specificity of 96 and 92%, respectively. CONCLUSION: The IL-6 level and HIE grade are potential prognostic biomarkers for the determination of mortality and morbidity in asphyxiated neonates.

PD-1 and PD-L1 inhibitors foster the progression of adult T-cell Leukemia/Lymphoma.

Immunotherapy through immune checkpoints blockade and its subsequent clinical application has revolutionized the treatment of a spectrum of solid tumors. Blockade of Programmed cell death protein-1 and its ligand has shown promising results in clinical studies. The clinical trials that enrolled patients with different hematopoietic malignancies including non-Hodgkin lymphoma, Hodgkin lymphoma, and acute myeloid leukemia (AML) showed that anti-PD-1 agents could have potential therapeutic effects in the patients. Adult T-cell leukemia/lymphoma (ATLL) is a non-Hodgkin T-cell Lymphoma that is developed in a minority of HTLV-1-infected individuals after a long latency period. The inhibition of PD-1 as a treatment option is currently being investigated in ATLL patients. In this review, we present a summary of the biology of the PD-1/PD-L1 pathway, the evidence in the literature to support anti-PD-1/PDL-1 application in the treatment of different lymphoid, myeloid, and virus-related hematological malignancies, and controversies related to PD-1/PD-L1 blocking in the management of ATLL patients.

Application of Molecular Docking for the Development of Improved HIV-1 Reverse Transcriptase Inhibitors.

INTRODUCTION: Inhibition of the reverse transcriptase (RT) enzyme of the human immunodeficiency virus (HIV) by low molecular weight inhibitors is still an active area of research. Here, protein-ligand interactions and possible binding modes of novel compounds with the HIV-1 RT binding pocket (the wild-type as well as Y181C and K103N mutants) were obtained and discussed. METHODS: A molecular fragment-based approach using FDA-approved drugs were followed to design novel chemical derivatives using delavirdine, efavirenz, etravirine and rilpivirine as the scaffolds. The drug-likeliness of the derivatives was evaluated using Swiss-ADME. The parent molecule and derivatives were then docked into the binding pocket of related crystal structures (PDB ID: 4G1Q, 1IKW, 1KLM and 3MEC). Genetic Optimization for Ligand Docking (GOLD) Suite 5.2.2 software was used for docking and the results analyzed in the Discovery Studio Visualizer 4. A derivative was chosen for further analysis, if it passed drug-likeliness and the docked energy was more favorable than that of its parent molecule. Out of the fifty-seven derivatives, forty-eight failed in drug-likeness screening by Swiss-ADME or at the docking stage. RESULTS: The final results showed that the selected compounds had higher predicted binding affinities than their parent scaffolds in both wild-type and the mutants. Binding energy improvement was higher for the structures designed based on second-generation NNRTIs (etravirine and rilpivirine) than the first-generation NNRTIs (delavirdine and efavirenz). For example, while the docked energy for rilpivirine was -51 KJ/mol, it was improved for its derivatives RPV01 and RPV15 up to - 58.3 and -54.5 KJ/mol, respectively. CONCLUSION: In this study, we have identified and proposed some novel molecules with improved binding capacity for HIV RT using a fragment-based approach.

Protective effects of BiP inducer X (BIX) against diabetic cardiomyopathy in rats.

Diabetic cardiomyopathy (DC) is associated with impaired endoplasmic reticulum (ER) function, development of ER stress, and induction of cardiac cell apoptosis. Preventive effects of BiP inducer X (BIX) were investigated against DC characteristic changes in a type 2 diabetes rat model. To establish diabetes, a high-fat diet and a single dose of streptozotocin were administered. Then, animals were assigned into the following groups: control, BIX, diabetic animals monitored for one, two, and three weeks. Diabetic rats were treated with BIX for one, two, and three weeks. Expressions of various ER stress and apoptotic markers were assessed by immunoblotting method. CHOP gene expression was assessed by Real-time PCR. Tissue expression of BiP was evaluated by immunohistochemistry method. Hematoxylin and eosin and Masson's trichrome staining were performed to assess histological changes in the left ventricle. Cardiac cell apoptosis was examined using TUNEL assay. BIX administration suppressed the activation of the ER stress markers and cleavage of procaspase-3 in the diabetic rats. Likewise, tissue expression of BiP protein was increased, while CHOP mRNA levels were decreased. These results were accompanied by reducing cardiac fibrosis and myocardial cell apoptosis suggesting protective effects of BIX against the development of DC by decreasing cardiomyocyte apoptosis and fibrosis.

Substance P accelerates the progression of human esophageal squamous cell carcinoma via MMP-2, MMP-9, VEGF-A, and VEGFR1 overexpression.

Tachykinins such as Substance P (SP) are a group of neuropeptides that are involved in cancer development. Neurokinin-1 receptor (NK-1R) is the main tachykinin receptor mediating the effects of SP, which is overexpressed in human esophageal squamous cell carcinoma (ESCC) and other malignant tissues. However, the effects of SP/NK-1R system on the migration of esophageal cancer cells and angiogenesis is not clear yet. This study seeks to obtain data to address these research gaps. In order to assess the effects of the FDA-approved aprepitant drug, a commercially available NK-1R antagonist, on the viability of KYSE-30 ESCC cells, resazurin assay was performed. The influence of SP/NK-1R system on the migration potential of these cells was examined using scratch assay. The effects of this system on the expression levels of metastatic factors were also examined by RT-PCR and western blot analyses. The half-maximal inhibitory concentration (IC50) value for KYSE-30 cells treated with aprepitant found to be 29.88 µM. Treatment with SP significantly promoted KYSE-30 esophageal cancer cell migration, and aprepitant blocked this effect. In addition, SP significantly induced the expression of matrix metalloproteinase-2 (MMP-2), MMP-9, vascular endothelial growth factor-A (VEGF-A), and VEGF receptor1 (VEGFR1) in the cells, whereas aprepitant inhibited the up-regulation effects caused by SP. SP plays important roles in the development of human esophageal squamous cell carcinoma by promoting cancer cell invasion and enhancing the expression of factors involved in cellular migration and angiogenesis, which can be blocked by the NK-1R antagonist, aprepitant.

Bacterial staphylokinase as a promising third-generation drug in the treatment for vascular occlusion.

Vascular occlusion is one of the major causes of mortality and morbidity. Blood vessel blockage can lead to thrombotic complications such as myocardial infarction, stroke, deep venous thrombosis, peripheral occlusive disease, and pulmonary embolism. Thrombolytic therapy currently aims to rectify this through the administration of recombinant tissue plasminogen activator. Research is underway to design an ideal thrombolytic drug with the lowest risk. Despite the potent clot lysis achievable using approved thrombolytic drugs such as alteplase, reteplase, streptokinase, tenecteplase, and some other fibrinolytic agents, there are some drawbacks, such as high production cost, systemic bleeding, intracranial hemorrhage, vessel re-occlusion by platelet-rich and retracted secondary clots, and non-fibrin specificity. In comparison, bacterial staphylokinase, is a new, small-size plasminogen activator, unlike bacterial streptokinase, it hinders the systemic degradation of fibrinogen and reduces the risk of severe hemorrhage. A fibrin-bound plasmin-staphylokinase complex shows high resistance to a2-antiplasmin-related inhibition. Staphylokinase has the potential to be considered as a promising thrombolytic agent with properties of cost-effective production and the least side effects.

Designing a multifunctional staphylokinase variant (SAK-2RGD-TTI) with appropriate thrombolytic activity in vitro.

OBJECTIVE: Thrombin, platelets, and plasmin are three key factors involved in hemostasis and thrombolysis. Thrombolytic therapy with clinically approved drugs is often followed by recurrent thrombosis caused by thrombin-induced platelet aggregation from the clot debris. In order to minimize these problems, new constructs were designed for the expression of recombinant staphylokinase (rSAK) and also a fusion protein composed of staphylokinase, 20 amino acids containing 2 RGD followed by tsetse thrombin Inhibitor (SAK-2RGD-TTI) in Pichia pastoris. RESULT: Modeling the tertiary structure of SAK-2RGD-TTI showed that the linker containing RGD and TTI did not interfere with proper folding of SAK. In laboratory testing, the purified SAK-2RGD-TTI (420 µg/mL) dissolved an average of 45% of the blood clot. The activity of the SAK-2RGD-TTI was also confirmed in various tests including human plasminogen activation assay, fibrin clot lysis assay, well diffusion method, activated partial thromboplastin time and platelet rich clot lysis assay. CONCLUSION: Our findings suggest that SAK-2RGD-TTI has improved therapeutic properties preventing reocclussion. It further confirms that it is practicable to assemble and produce a hybrid multifunctional protein that targets hemostatic process at various stages.

Construction of Epstein-Bar virus cocktail peptide fused with Fcγ of IgG: as a potential delivery system for vaccine development.

Epstein-Barr virus (EBV) associated with several diseases such as contagious mononucleosis chronic active EBV infection, and diverse sorts of malignant tumors. Therefore, using applicable vaccines could be advantageous for public health. Yet, the vaccine has been unavailable to protect from EBV so far. In the current study, to develop a multi-peptide vaccine for EBV and assess its expression in Pichia pastoris yeast system, three immunodominant sequences in glycoprotein (gp) 85, gp350 and latent membrane protein 1 (LMP1) were chosen. To construct fusion peptide, -GGGGS- liker was applied. After cloning the fusion peptide in the pPICZαA expression vector, this recombinant vector processed and transfected into Pichia pastoris host cells. The expression of high level of EBV fusion peptide was confirmed by dot blot and SDS-PAGE procedures. The Pichia pastoris is capable of supporting EBV fusion peptide expression. The application of this fusion peptide as a peptide vaccine to fight EBV is suggested.

Complete sequence of human T cell leukemia virus type 1 in ATLL patients from Northeast Iran, Mashhad revealed a prematurely terminated protease and an elongated pX open reading frame III.

To gain insight into the origin, evolution, dissemination and viral factors affecting HTLV-1-associated diseases, knowing the complete viral genome sequences is important. So far, no full-length HTLV-1 genome sequence has been reported from Iran. Here we report the complete nucleotide sequence of HTLV-1 viruses isolated from adult T cell leukemia/lymphoma (ATLL) patients from this region. The genome size of HTLV-1-MhD (Mashhad) was found to be 9036 bp and sequence analysis of the LTR region showed that it belongs to cosmopolitan subtype A. Comparing the sequences with isolates from another endemic area (HTLV-1ATK) revealed variations in the U3 region (~3.4%), while there was 99.1% and 97.0% similarity in R and U5 regions, respectively. The nucleotide sequences of HTLV-1 gag, pro and pol genes had a difference of 1.1% compared with HTLV-1 ATK with 16 nucleotides replaced in the gag and 27 in the pol regions. There was no variability in the amino acid sequences in the p24gag, however three residues were different in the p19gag and one in the p15gag. The nucleotide sequence of env showed a divergence of 1.5% compared to ATK with 22-nucleotide variation. The HTLV-1-MhD Tax, p13, p30, and p12 had 99.1, 100, 98.8, and 98%, respectively similarity with the prototype strain. Four amino acid changes were detected in ORF1 and ORF2 products p12 and p30, respectively, while the p13 region showed 100% conservation. The nucleotide identity between the isolates of Mashhad and those isolated from France, Germany, China, Canada and Brazil was 99.1%, 99.2%, 97.9%, 99% and 99.3%, respectively. Four amino acid changes compared with HTLV-1ATK from Japan were detected in ORF1 and ORF2 products p12 and p30, respectively, while the p13 region showed 100% conservation. This data could provide information regarding the evolutionary history, phylogeny, origin of the virus and vaccine design.

Comparison of expression optimization of new derivative of staphylokinase (SAK-2RGD-TTI) with the rSAK.

Staphylokinase (SAK) is a promising thrombolytic agent for the treatment of patients suffering from blood-clotting disorders. To increase the potency of SAK and to minimize vessel reocclusion, a new construct bearing SAK motif fused to tsetse thrombin inhibitor (TTI) via a 20-amino acid linker with 2 RGD (2 × arginine-glycine-aspartic acid inhibiting platelet aggregation via attachment to integrin receptors of platelet) was codon optimized and expressed comparatively in Pichia pastoris GS115 as a Mut+ strain and KM71H as a Muts strain. Fusion protein was optimized in terms of best expression condition and fibrinolytic activity and compared with the rSAK. Expression level of the designed construct reached up to 175 mg/L of the culture medium after 72-hr stimulation with 2.5% methanol and remained steady for 3-4 days. The highest expression was obtained at the range of 2-3% methanol. The SAK-2RGD-TT (relative activity >82%) was more active at 25-37 °C than rSAK (relative activity of 93%). Further, it showed relative activity >80% at pH ranges of 7-9. Western blot analysis showed two bands of nearly 27 and 24 kDa at ratio of 5 to 3, respectively. The specific fibrinolytic activity of the SAK-2RGD-TTI was measured as 8,269 U/mg, and 19,616 U/mg for the nonpurified and purified proteins, respectively. Deglycosylation by using tunicamycin in culture medium resulted in higher fibrinolytic activity of SAK-2RGD-TTI (2.2 fold). Consequently, compared to the rSAK, at the same equimolar proportion, addition of RGD and TTI fragments could increase fibrinolytic activity. Also, P. pastoris can be considered as an efficient host for overexpression of the soluble SAK-2RGD-TTI with high activity without requiring a complicated purification procedure.

Production of Universal Group O Red Blood Cells by Alpha-N-Acetylgalactosaminidase Enzyme Expressed in Pichia pastoris.

Enzymatic removal of blood groups antigens A and B is an efficient method for production of universal red blood cells. In this research, an α-N-acetylgalactosaminidase (NAGA) enzyme was expressed in Pichia pastoris for digestion of the A blood antigen. DNA sequence of the gene NAGA, originally expressed in Elizabethkingia meningosepticum (NAGA-EM), was ordered for optimization and synthesis. It was then expressed in P. pastoris (KM71H and GS115 strains). Expression of the recombinant NAGA was evaluated by dot blot, SDS-PAGE, and Western blotting. The activity of the enzyme was measured using a synthetic substrate in addition to the conversion of group A red blood cells to the O cells. Expression of NAGA-EM with an apparent molecular mass of 55 kDa was verified by dot blot, SDS-PAGE and Western blot analysis. The maximum enzyme activity in the supernatant of KM71H was higher than that in the GS115 (250 vs. 200 U/ml). Treated group A RBCs did not react with the anti-A antiserum or with the sera from individuals with blood groups B and O. The results of this study indicated that NAGA-EM is an efficient enzyme for production of universal O blood cells.

Molecular targeting for treatment of human T-lymphotropic virus type 1 infection.

Human T-cell lymphotropic virus type 1 (HTLV-1) infection is linked to adult T-cell leukemia-lymphoma (ATLL) and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and several other disorders. ATLL occurs in approximately 5% of the 15-20 million people infected by HTLV-1 in the world. In general, ATLL is resistant to chemotherapy, which underlines the need for new and effective therapeutic strategies. Previous studies highlighted the role of viral enzymes, responsible for viral replication, and regulatory proteins such as Tax and HBZ in the progression of HTLV-1-associated diseases. There are conflicting reports on the efficacy of current enzyme inhibitors, mainly developed against human immunodeficiency virus (HIV), for treatment of HTLV-1 infection. New treatment approaches including monoclonal antibodies show promising results and exert significant cytotoxic effects on ATLL cells. This manuscript reviews the recent developments in molecular targeting for treatment of HTLV-1 infection.