scholarly journals Pre-Clinical Evaluation of the Nanoliposomal antiPCSK9 Vaccine in Healthy Non-Human Primates

Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 749
Author(s):  
Amir Abbas Momtazi-Borojeni ◽  
Mahmoud R. Jaafari ◽  
Maciej Banach ◽  
Armita Mahdavi Gorabi ◽  
Hedayat Sahraei ◽  
...  
Keyword(s):  
Plasma Levels ◽  
Plasma Lipid ◽  
Inflammatory Biomarkers ◽  
Organ Injury ◽  
Therapeutic Effects ◽  
Humoral Immune ◽  
Resultant Data ◽  
Vitro Binding ◽  
Organ Performance

Background: Our previous studies showed the safe preventive and therapeutic effects of immunization using the nanoliposomal antiPCSK9 vaccine called “Liposomal Immunogenic Fused PCSK9-Tetanus plus Alum adjuvant” (L-IFPTA), in mouse models of atherosclerosis. Here we aimed to ascertain the immunogenicity and safety of the L-IFPTA vaccine in a pre-clinical study in healthy non-human primates. Methods: Five male rhesus macaque monkeys were subcutaneously immunized with the L-IFPTA vaccine, four times with bi-weekly intervals. To evaluate immunogenicity, the plasma antiPCSK9 antibody in immunized monkeys was detected and quantified using the ELISA method. The functionality of the induced antiPCSK9 antibodies was determined by the PCSK9/LDLR in vitro binding assay kit. The safety of the vaccine was tested using the evaluation of several major circulating indicators including plasma lipid alterations, inflammatory biomarkers and organ injury biomarkers. Results: The resultant data indicated that the L-IFPTA vaccine significantly and highly induced the generation of functional and safe antiPCSK9 antibodies in immunized monkeys. Plasma levels of specific biomarkers indicating organ performance including creatinine, urea, uric acid, bilirubin, ALP, AS, ALT and TSH were not significantly altered. After immunization in healthy monkeys, non-prespecified endpoints (plasma levels of TC, LDL-C, VLDL-C and TG) were non-significantly reduced by 11.6 ± 36%; 16 ± 28%; 22 ± 53% and 24 ± 51%, respectively, while HDL-C was slightly increased by 2 ± 64%. There were also no significant changes in plasma levels of pro- and anti-inflammatory biomarkers. Conclusion: The L-IFPTA vaccine could efficiently stimulate the host humoral immune response to produce active antibodies that inhibit plasma PCSK9 while not provoking systemic inflammation and not adversely affecting organ performance.

scholarly journals Fabrication and Characterization of a Biomaterial Based on Extracellular-Vesicle Functionalized Graphene Oxide

2021 ◽  
Vol 9 ◽  
Author(s):  
Julia Driscoll ◽  
Anuradha Moirangthem ◽  
Irene K. Yan ◽  
Tushar Patel
Keyword(s):  
Graphene Oxide ◽  
Stem Cell ◽  
Biological Effects ◽  
Organ Injury ◽  
Hepatocyte Proliferation ◽  
Therapeutic Effects ◽  
Solid Organ ◽  
Functionalized Graphene ◽  
Functionalized Graphene Oxide

Mesenchymal stem cell (MSC) derived extracellular vesicles (EV) are emerging as acellular therapeutics for solid organ injury and as carriers for drug delivery. Graphene-based materials are novel two-dimensional crystal structure-based materials with unique characteristics of stiffness, strength and elasticity that are being explored for various structural and biological applications. We fabricated a biomaterial that would capture desirable properties of both graphene and stem cell derived EV. Metabolically engineered EV that express azide groups were cross-linked with alkyne-functionalized graphene oxide (GO) via a copper catalyzed alkyne-azide cycloaddition (CuAAC) reaction. The crosslinking between EV and GO was accomplished without the need for ligand expression on the metal. Scanning electron and fluorescence microscopy demonstrated excellent cross-linking between EV and GO. Biological effects were assessed by phagocytosis studies and cell viability studies. The uptake of GO or sonicated GO (sGO) resulted in a durable pro-inflammatory immune response. Cell studies further showed that crosslinked GO-EV scaffolds exhibited cell-type dependent cytotoxicity on liver cancer cells whereas there was minimal impact on healthy hepatocyte proliferation. In vitro, neither GO-EV nor sGO-EV induced DNA strand breaks. In vivo studies in zebrafish revealed gross developmental malformations but treatment-induced mortality was only seen with the highest doses of GO-EV and sGO-EV. With these advantages, this engineered biomaterial combining the versatility of graphene with the therapeutic effects of MSC-EV has potential for applications in tissue engineering and regenerative medicine.

In Vitro and in Vivo Comparison of Binding of 99m-Tc-Iabeled Anti-CEA MAb F33-104 with 99m-Tc-labeled Anti-CEA MAb BW431/26

1999 ◽  
Vol 38 (04) ◽  
pp. 115-119
Author(s):  
N. Oriuchi ◽  
S. Sugiyama ◽  
M. Kuroki ◽  
Y. Matsuoka ◽  
S. Tanada ◽  
...  
Keyword(s):  
Nude Mice ◽  
Binding Capacity ◽  
Colon Adenocarcinoma ◽  
Human Colon ◽  
Cell Binding ◽  
Vitro Binding ◽  
Labeling Method ◽  
Human Colon Adenocarcinoma

Summary Aim: The purpose of this study was to assess the potential for radioimmunodetection (RAID) of murine anti-carcinoembryonic antigen (CEA) monoclonal antibody (MAb) F33-104 labeled with technetium-99m (99m-Tc) by a reduction-mediated labeling method. Methods: The binding capacity of 99m-Tc-labeled anti-CEA MAb F33-104 with CEA by means of in vitro procedures such as immunoradiometric assay and cell binding assay and the biodistribution of 99m-Tc-labeled anti-CEA MAb F33-104 in normal nude mice and nude mice bearing human colon adenocarcinoma LS180 tumor were investigated and compared with 99m-Tc-labeled anti-CEA MAb BW431/26. Results: The in vitro binding rate of 99m-Tc-labeled anti-CEA MAb F33-104 with CEA in solution and attached to the cell membrane was significantly higher than 99m-Tclabeled anti-CEA MAb BW431/261 (31.4 ± 0.95% vs. 11.9 ± 0.55% at 100 ng/mL of soluble CEA, 83.5 ± 2.84% vs. 54.0 ± 2.54% at 107 of LS 180 cells). In vivo, accumulation of 99m-Tc-labeled anti-CEA MAb F33-104 was higher at 18 h postinjection than 99m-Tc-labeled anti-CEA MAb BW431/26 (20.1 ± 3.50% ID/g vs. 14.4 ± 3.30% ID/g). 99m-Tcactivity in the kidneys of nude mice bearing tumor was higher at 18 h postinjection than at 3 h (12.8 ± 2.10% ID/g vs. 8.01 ± 2.40% ID/g of 99m-Tc-labeled anti-CEA MAb F33-104, 10.7 ± 1.70% ID/g vs. 8.10 ± 1.75% ID/g of 99m-Tc-labeled anti-CEA MAb BW431/26). Conclusion: 99m-Tc-labeled anti-CEA MAb F33-104 is a potential novel agent for RAID of recurrent colorectal cancer.

Clinical Trials in Thrombosis: Secondary Prevention of Myocardial Infarction

1976 ◽  
Vol 35 (01) ◽  
pp. 049-056 ◽  
Author(s):  
Christian R Klimt ◽  
P. H Doub ◽  
Nancy H Doub
Keyword(s):  
Myocardial Infarction ◽  
Secondary Prevention ◽  
Case Control ◽  
Therapeutic Effects ◽  
Case Control Studies ◽  
Definitive Answer ◽  
Inhibition Of Platelet Aggregation ◽  
Prospective Trials

SummaryNumerous in vivo and in vitro experiments, investigating the inhibition of platelet aggregation and the prevention of experimentally-induced thrombosis, suggest that anti-platelet drugs, such as aspirin or the combination of aspirin and dipyridamole or sulfinpyrazone, may be effective anti-thrombotic agents in man. Since 1971, seven randomized prospective trials and two case-control studies have been referenced in the literature or are currently being conducted, which evaluate the effects of aspirin, sulfinpyrazone, or dipyridamole in combination with aspirin in the secondary prevention of myocardial infarction. A critical review of these trials indicates a range of evidence from no difference to a favorable trend that antiplatelet drugs may serve as anti-thrombotic agents in man. To date, a definitive answer concerning the therapeutic effects of these drugs in the secondary prevention of coronary heart disease is not available.

The d-Enantiomer Form of Indobufen Totally Accounts for the Anti-Cyclooxygenase and Antiplatelet Activity Ex Vivo and for the Increase in Bleeding Time by Indobufen in Man

1992 ◽  
Vol 67 (02) ◽  
pp. 258-263 ◽  
Author(s):  
Raffaele De Caterina ◽  
Rosa Sicari ◽  
An Yan ◽  
Walter Bernini ◽  
Daniela Giannessi ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Platelet Aggregation ◽  
Plasma Levels ◽  
Bleeding Time ◽  
Ex Vivo ◽  
Random Sequence ◽  
Antiplatelet Agent ◽  
Antiplatelet Drug ◽  
Double Blind

SummaryIndobufen is an antiplatelet drug able to inhibit thromboxane production and cyclooxygenase-dependent platelet aggregation by a reversible inhibition of cyclooxygenase. Indobufen exists in two enantiomeric forms, of which only d-indobufen is active in vitro in inhibiting cyclooxygenase. In order to verify that also inhibition of platelet function is totally accounted for by d-indobufen, ten patients with proven coronary artery disease (8 male, 2 female, age, mean ± S.D., 58.7 ± 7.5 years) were given, in random sequence, both 100 mg d-indobufen and 200 mg dl-indobufen as single administrations in a double-blind crossover design study with a washout period between treatments of 72 h. In all patients thromboxane (TX) B2 generation after spontaneous clotting (at 0, 1, 2, 4, 6, 8, 12, 24 h), drug plasma levels (at the same times), platelet aggregation in response to ADP, adrenaline, arachidonic acid, collagen, PAF, and bleeding time (at 0, 2, 12 h) were evaluated after each treatment. Both treatments determined peak inhibition of TXB2 production at 2 h from administration, with no statistical difference between the two treatments (97 ±3% for both treatments). At 12 h inhibition was 87 ± 6% for d-indobufen and 88 ± 6% for dl-indobufen (p = NS). Inhibition of TXB2 production correlated significantly with plasma levels of the drugs. Maximum inhibitory effect on aggregation was seen in response to collagen 1.5 pg/ml (63 ± 44% for d-indobufen and 81 ± 22% for dl-indobufen) and arachidonic acid 0.5-2 mM (78 ± 34% for d-indobufen and 88 ± 24% for dl-indobufen) at 2 h after each administration. An effect of both treatments on platelet aggregation after 12 h was present only for adrenaline 2 μM (55 ± 41% for d-indobufen and 37 ± 54% for dl-indobufen), collagen 1.5 pg/ml (69 ± 30% for d-indobufen and 51 ± 61% for dl-indobufen), arachidonic acid 0.5-2 mM (56 ± 48% for d-indobufen and 35 ± 49% for dl-indobufen). The extent of inhibition of TX production and the extent of residual platelet aggregation were never significantly different between treatments. Bleeding time prolongation was similar in the two treatment groups without showing a pronounced and long lasting effect (from 7.0 ± 2.0 min to 10.0 ± 3.0 min at 2 h and 8.0 ± 2.0 min at 12 h for d-indobufen; from 6.0 ±1.0 min to 8.5 ± 2.0 min at 2 h and 8.0 ± 1.0 min at 12 h for dl-indobufen). These results demonstrate that the biological activity of dl-indobufen as an antiplatelet agent in vivo is totally accounted for by d-indobufen.

Effects of Ticlopidine of Platelet Function in Men with Stable Angina Pectoris

1985 ◽  
Vol 54 (04) ◽  
pp. 808-812 ◽  
Author(s):  
Ulf Berglund ◽  
Henning von Schenck ◽  
Lars Wallentin
Keyword(s):  
Platelet Aggregation ◽  
Angina Pectoris ◽  
Platelet Function ◽  
Plasma Levels ◽  
Platelet Reactivity ◽  
Inhibitory Effect ◽  
Controlled Study ◽  
Double Blind ◽  
Platelet Factor

SummaryThe effects of ticlopidine (T) (500 mg daily) on platelet function were investigated in a double-blind placebo-controlled study in 38 middle-aged men with stable incapacitating angina pectoris. The in vitro platelet reactivity to aggregating agents, the platelet sensitivity to prostacyclin and the plasma levels of platelet specific proteins and fibrinogen were determined before and after 4 and 8 weeks of treatment. T exerted a potent inhibitory effect on ADP- and collagen-induced platelet aggregation. The effect of T was proportional to the pretreatment reactivity to ADP and collagen. The inhibitory effect of T on the epinephrine response was less pronounced. The plasma levels of beta-thromboglobulin, platelet factor 4 and fibrinogen were not influenced by T. The platelet inhibition of prostacyclin was potentiated by T, and it was demonstrated that T and prostacyclin had synergistic inhibitory effects on platelet aggregation.

The Involvement of Platelets and the Coronary Vasculature in Collagen-Induced Sudden Death in Rabbits

1985 ◽  
Vol 53 (01) ◽  
pp. 070-074 ◽  
Author(s):  
G Mallarkey ◽  
G M Smith
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Platelet Count ◽  
Sudden Death ◽  
Myocardial Ischaemia ◽  
Plasma Levels ◽  
Sodium Citrate ◽  
Plasma Samples ◽  
Calcium Entry Blockers

SummaryThe mechanism of collagen-induced sudden death in rabbits was studied by measuring blood pressure (BP), heart rate, ECG, the continuous platelet count and the plasma levels of thromboxane B2 (TxB2) and 6-keto prostaglandin Fia (6-keto PGF1α). Death was preceded by myocardial ischaemia and a sharp fall in BP which occurred before any fall in platelet count was observed. The calcium entry blockers (CEBs), verapamil, nifedipine and PY 108-068 protected the rabbits from sudden death without any significant effect on the decrease in the platelet count or increase in plasma TxB2 levels. 6-keto PGF1α could not be detected in any plasma samples. Indomethacin and tri-sodium citrate also protected the rabbits but significantly reduced the fall in platelet count and plasma TxB2. In vitro studies on isolated aortae indicated that verapamil non-specifically inhibited vasoconstriction induced by KC1, adrenaline and U46619 (a thromboxane agonist). It is concluded that CEBs physiologically antagonize the vasoconstricting actions of platelet-derived substances and that it is coronary vasoconstriction that is primarily the cause of death.

Discovery of New AKT1 Inhibitors by Combination of In silico Structure Based Virtual Screening Approaches and Biological Evaluations

2019 ◽  
Author(s):  
Filip Fratev ◽  
Denisse A. Gutierrez ◽  
Renato J. Aguilera ◽  
suman sirimulla
Keyword(s):  
Virtual Screening ◽  
Success Rate ◽  
Protein Interactions ◽  
In Silico ◽  
Biological Data ◽  
In Vitro Binding ◽  
Vitro Binding ◽  
Screening Protocol ◽  
Screening Approaches

AKT1 is emerging as a useful target for treating cancer. Herein, we discovered a new set of ligands that inhibit the AKT1, as shown by in vitro binding and cell line studies, using a newly designed virtual screening protocol that combines structure-based pharmacophore and docking screens. Taking together with the biological data, the combination of structure based pharamcophore and docking methods demonstrated reasonable success rate in identifying new inhibitors (60-70%) proving the success of aforementioned approach. A detail analysis of the ligand-protein interactions was performed explaining observed activities.<br>

Inflammatory Biomarkers in Atrial Fibrillation

2019 ◽  
Vol 26 (5) ◽  
pp. 837-854 ◽  
Author(s):  
Effimia Zacharia ◽  
Nikolaos Papageorgiou ◽  
Adam Ioannou ◽  
Gerasimos Siasos ◽  
Spyridon Papaioannou ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Plasma Levels ◽  
Large Scale ◽  
Inflammatory Biomarkers ◽  
Inflammatory Pathways ◽  
Inflammatory State ◽  
Anti Inflammatory ◽  
Underlying Mechanisms

During the last few years, a significant number of studies have attempted to clarify the underlying mechanisms that lead to the presentation of atrial fibrillation (AF). Inflammation is a key component of the pathophysiological processes that lead to the development of AF; the amplification of inflammatory pathways triggers AF, and, in tandem, AF increases the inflammatory state. Indeed, the plasma levels of several inflammatory biomarkers are elevated in patients with AF. In addition, the levels of specific inflammatory biomarkers may provide information regarding to the AF duration. Several small studies have assessed the role of anti-inflammatory treatment in atrial fibrillation but the results have been contradictory. Large-scale studies are needed to evaluate the role of inflammation in AF and whether anti-inflammatory medications should be routinely administered to patients with AF.

scholarly journals TO010A NEW IMMUN-TOXICOLOGICAL TEST TO DETECT POLYSULFONE HYPERSENSITIVITY IN HEMODIALYSIS PATIENTS

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Joachim Beige ◽  
Ralph Wendt ◽  
Despina Rüssmann ◽  
Karl-Peter Ringel
Keyword(s):  
False Negative ◽  
False Negative Rate ◽  
Lymphocyte Transformation ◽  
Clinical Problem ◽  
Lymphocyte Transformation Test ◽  
Laboratory Research ◽  
Humoral Immune ◽  
Before And After ◽  
Positive Results

Abstract Background and Aims Incompatibility of dialysis procedure due to hypersensitivity against dialyzer material which currently is mainly based on polysulfone and derivatives can not be assessed by routine laboratory tests. Although the frequency of such symptoms is suspected to be low (below 2%) such resembles an important clinical problem because dialysis procedures are frequently accompanied by symptoms of non-tolerability with reasons not being entirely clear while circulatory reasons are suspected to play a major role. Method To enlighten the role of polysulfone hypersensitivity, we adapted known standardized material immune-toxicological tests (lymphocyte transformation test, basophil degranulation test) to the specific conditions of dialysis and polysulfone material sensitivity. We developed a method of polysulfone micronisation and measured humoral immune response of isolated patient´s lymphocytes when incubated with polysulfone dispersion. Results 39 samples from 103 patients with suspected polysulfone hypersensitivity showed positive results for type 1 (n=19), type 4 (n=18) or both type (n=2) reactions. There were no significant differences in the level of stimulation measured for DI, SI and lymphogenesis before and after dialysis (average delta -0.4; -0.28; - 1.74, p = 0.71; 0.34; 0.37) and with different dialyzer materials (Tab. 1). Patients with pos. type 4 results (LTT and lymphogenesis) showed highly correlated results in either LTT or lymphogenesis test (Fig. 1, R=0.87, p&lt;0.0001). 8 out of 8 samples from patients with repeated test on different PS showed positive results on either PS. One patient tested positive on PS showed no hypersensitivity with another non-PS (PMMA) material. Conclusion This is the first methodological report showing plausible in-vitro results of patients samples concerning polysulfone intolerance. On the first superficial view, a “false-negative” rate of 60% looks rather disappointing, because all samples derived from patients with suspicion of PS hypersensitivity. However, due to the clinical variability of intolerance symptoms and the high prevalence of any problems after HD initiation, mainly of circulatory origin after initiating extracorporeal circuit, this rate may obviously express the true frequency of isolated PS material hypersensitivity in suspected patients. Alternative pathophysiological pathways of material sensitivity like complement activation, remain to be elucidated and incorporated into a comprehensive future testing panel. Further clinical and laboratory research is needed to define true polysulfone hypersensitivity and to enlighten the field of hypothetic subclinical material incompatibility in patients with impaired dialysis tolerability.

Ability of PknA, a mycobacterial eukaryotic-type serine/threonine kinase, to transphosphorylate MurD, a ligase involved in the process of peptidoglycan biosynthesis

2008 ◽  
Vol 415 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Meghna Thakur ◽  
Pradip K. Chakraborti
Keyword(s):  
Protein Kinases ◽  
Solid Phase ◽  
Morphological Changes ◽  
Binding Assays ◽  
Serine Threonine Kinase ◽  
Threonine Kinase ◽  
Peptidoglycan Biosynthesis ◽  
Vitro Binding ◽  
Solid Phase Binding

Eukaryotic-type serine/threonine protein kinases in bacteria have been implicated in controlling a host of cellular activities. PknA is one of eleven such protein kinases from Mycobacterium tuberculosis which regulates morphological changes associated with cell division. In the present study we provide the evidence for the ability of PknA to transphosphorylate mMurD (mycobacterial UDP-N-acetylmuramoyl-L-alanine:D-glutamate-ligase), the enzyme involved in peptidoglycan biosynthesis. Its co-expression in Escherichia coli along with PknA resulted in phosphorylation of mMurD. Consistent with these observations, results of the solid-phase binding assays revealed a high-affinity in vitro binding between the two proteins. Furthermore, overexpression of m-murD in Mycobacterium smegmatis yielded a phosphorylated protein. The results of the present study therefore point towards the possibility of mMurD being a substrate of PknA.

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