scholarly journals Infectious RNA vaccine protects mice against chikungunya virus infection

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Inga Szurgot ◽  
Karl Ljungberg ◽  
Beate M. Kümmerer ◽  
Peter Liljeström
Keyword(s):  
Chikungunya Virus ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
High Dose ◽  
Vaccine Platform ◽  
Encoding Gene ◽  
Rna Replicon ◽  
Nsp3 Gene

AbstractWe describe a novel vaccine platform that can generate protective immunity to chikungunya virus (CHIKV) in C57BL/6J mice after a single immunization by employing an infectious RNA (iRNA), which upon introduction into a host cell launches an infectious attenuated virus. We and others have previously reported that an engineered deletion of 183 nucleotides in the nsP3 gene attenuates chikungunya virus (CHIKV) and reduces in vivo viral replication and viremia after challenge in mice, macaques and man. Here, we demonstrated that in vitro transfection of iRNA carrying the nsP3 deletion generated infectious viruses, and after intramuscular injection, the iRNA induced robust antibody responses in mice. The iRNA was superior at eliciting binding and neutralizing antibody responses as compared to a DNA vaccine encoding the same RNA (iDNA) or a non-propagating RNA replicon (RREP) lacking the capsid encoding gene. Subsequent challenge with a high dose of CHIKV demonstrated that the antibody responses induced by this vaccine candidate protected animals from viremia. The iRNA approach constitutes a novel vaccine platform with the potential to impact the spread of CHIKV. Moreover, we believe that this approach is likely applicable also to other positive-strand viruses.

scholarly journals Structural basis of Chikungunya virus inhibition by monoclonal antibodies

2020 ◽  
Vol 117 (44) ◽  
pp. 27637-27645
Author(s):  
Qun Fei Zhou ◽  
Julie M. Fox ◽  
James T. Earnest ◽  
Thiam-Seng Ng ◽  
Arthur S. Kim ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Chikungunya Virus ◽  
Neutralizing Antibody ◽  
Structural Basis ◽  
Chikv Infection ◽  
Receptor Binding Site ◽  
Viral Pathogen ◽  
Virus Attachment

Chikungunya virus (CHIKV) is an emerging viral pathogen that causes both acute and chronic debilitating arthritis. Here, we describe the functional and structural basis as to how two anti-CHIKV monoclonal antibodies, CHK-124 and CHK-263, potently inhibit CHIKV infection in vitro and in vivo. Our in vitro studies show that CHK-124 and CHK-263 block CHIKV at multiple stages of viral infection. CHK-124 aggregates virus particles and blocks attachment. Also, due to antibody-induced virus aggregation, fusion with endosomes and egress are inhibited. CHK-263 neutralizes CHIKV infection mainly by blocking virus attachment and fusion. To determine the structural basis of neutralization, we generated cryogenic electron microscopy reconstructions of Fab:CHIKV complexes at 4- to 5-Å resolution. CHK-124 binds to the E2 domain B and overlaps with the Mxra8 receptor-binding site. CHK-263 blocks fusion by binding an epitope that spans across E1 and E2 and locks the heterodimer together, likely preventing structural rearrangements required for fusion. These results provide structural insight as to how neutralizing antibody engagement of CHIKV inhibits different stages of the viral life cycle, which could inform vaccine and therapeutic design.

scholarly journals Chimpanzee SIV Envelope trimer: structure and deployment as an HIV vaccine template

2018 ◽  
Author(s):  
Raiees Andrabi ◽  
Jesper Pallesen ◽  
Joel Allen ◽  
Ge Song ◽  
Jinsong Zhang ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
Hiv Vaccine ◽  
Antibody Responses ◽  
Attractive Potential ◽  
Induced Responses ◽  
Potential Component ◽  
Broadly Neutralizing Antibody ◽  
Cross Neutralization

SummaryEpitope-targeted HIV vaccine design seeks to focus antibody responses to broadly neutralizing antibody (bnAb) sites by sequential immunization. Chimpanzee SIV Envelope (Env) shares a single bnAb site, the V2-apex, with HIV, suggesting its possible utility in an HIV immunization strategy. Accordingly, we generated a chimpanzee SIV Env trimer, MT145K, which displays selective binding to HIV V2-apex bnAbs and precursor versions, but no binding to other HIV specificities. We determined the structure of the MT145K trimer by cryo-EM and showed its architecture was remarkably similar to HIV Env. Immunization of an HIV V2-apex bnAb precursor Ab-expressing knock-in mouse with chimpanzee MT145K trimer induced HIV V2-specific neutralizing responses. Subsequent boosting with an HIV trimer cocktail induced responses exhibiting some virus cross-neutralization. Overall, the chimpanzee MT145K trimer behaves as expected from design both in vitro and in vivo and is an attractive potential component of a sequential immunization regimen to induce V2-apex bnAbs.

scholarly journals DNA Vaccine Administered by Cationic Lipoplexes or by In Vivo Electroporation Induces Comparable Antibody Responses against SARS-CoV-2 in Mice

Vaccines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 874
Author(s):  
Allegra Peletta ◽  
Eakachai Prompetchara ◽  
Kittipan Tharakhet ◽  
Papatsara Kaewpang ◽  
Supranee Buranapraditkun ◽  
...  
Keyword(s):  
Dna Vaccine ◽  
Neutralizing Antibody ◽  
T Cell Response ◽  
Antibody Responses ◽  
Effective Vaccine ◽  
Thin Film Layer ◽  
Plasmid Dna Vaccine ◽  
Film Layer

In view of addressing the global necessity of an effective vaccine in the SARS-CoV-2 pandemic, a plasmid DNA vaccine, expressing for the spike (S) protein and formulated in lipoplexes, was manufactured and tested for in vitro transfection and in vivo immunogenicity. Blank cationic liposomes of 130.9 ± 5.8 nm in size and with a zeta potential of +48 ± 12 mV were formulated using the thin-film layer rehydration method. Liposomes were complexed with pCMVkan-S at different N/P ratios. Ratios of 0.25:1 and 1:1 were selected according to their complex stability and controlled size compared to other ratios and tested in vitro for transfection studies and in vivo for immunogenicity. Both selected formulations showed enhanced neutralizing antibody responses compared to pCMVkan-S injected alone, as well as an increased T cell response. The titers observed were similar to those of intramuscular electroporation (IM-EP), which was set as an efficacy goal.

Significance of Platelet β-Adrenoceptors for Platelet Responses In Vivo and In Vitro

1992 ◽  
Vol 68 (06) ◽  
pp. 687-693 ◽  
Author(s):  
P T Larsson ◽  
N H Wallén ◽  
A Martinsson ◽  
N Egberg ◽  
P Hjemdahl
Keyword(s):  
Ex Vivo ◽  
High Dose ◽  
Platelet Aggregability ◽  
Adrenoceptor Agonist ◽  
Dose Infusion ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Factor Antigen

SummaryThe significance of platelet β-adrenoceptors for platelet responses to adrenergic stimuli in vivo and in vitro was studied in healthy volunteers. Low dose infusion of the β-adrenoceptor agonist isoprenaline decreased platelet aggregability in vivo as measured by ex vivo filtragometry. Infusion of adrenaline, a mixed α- and β-adrenoceptor agonist, increased platelet aggregability in vivo markedly, as measured by ex vivo filtragometry and plasma β-thromboglobulin levels. Adrenaline levels were 3–4 nM in venous plasma during infusion. Both adrenaline and high dose isoprenaline elevated plasma von Willebrand factor antigen levels β-Blockade by propranolol did not alter our measures of platelet aggregability at rest or during adrenaline infusions, but inhibited adrenaline-induced increases in vWf:ag. In a model using filtragometry to assess platelet aggregability in whole blood in vitro, propranolol enhanced the proaggregatory actions of 5 nM, but not of 10 nM adrenaline. The present data suggest that β-adrenoceptor stimulation can inhibit platelet function in vivo but that effects of adrenaline at high physiological concentrations are dominated by an α-adrenoceptor mediated proaggregatory action.

Methylprednisolone on circulating eicosanoids and vasomotor tone after endotoxin

1986 ◽  
Vol 61 (1) ◽  
pp. 185-191 ◽  
Author(s):  
C. A. Hales ◽  
R. D. Brandstetter ◽  
C. F. Neely ◽  
M. B. Peterson ◽  
D. Kong ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Vascular Resistance ◽  
Systemic Blood Pressure ◽  
Physiological Effect ◽  
High Dose ◽  
Systemic Blood ◽  
Eicosanoid Production ◽  
Circulating Levels

Acute pulmonary and systemic vasomotor changes induced by endotoxin in dogs have been related, at least in part, to the production of eicosanoids such as the vasoconstrictor thromboxane and the vasodilator prostacyclin. Steroids in high doses, in vitro, inhibit activation of phospholipase A2 and prevent fatty acid release from cell membranes to enter the arachidonic acid cascade. We, therefore, administered methylprednisolone (40 mg/kg) to dogs to see if eicosanoid production and the ensuing vasomotor changes could be prevented after administration of 150 micrograms/kg of endotoxin. The stable metabolites of thromboxane B2 (TxB2) and 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha) were measured by radioimmunoassay. Methylprednisolone by itself did not alter circulating eicosanoids but when given 2.5 h before endotoxin not only failed to inhibit endotoxin-induced eicosanoid production but actually resulted in higher circulating levels of 6-keto-PGF1 alpha (P less than 0.05) compared with animals receiving endotoxin alone. Indomethacin prevented the steroid-enhanced concentrations of 6-keto-PGF1 alpha after endotoxin and prevented the greater fall (P less than 0.05) in systemic blood pressure and systemic vascular resistance with steroid plus endotoxin than occurred with endotoxin alone. Administration of methylprednisolone immediately before endotoxin resulted in enhanced levels (P less than 0.05) of both TxB2 and 6-keto-PGF1 alpha but with a fall in systemic blood pressure and vascular resistance similar to the animals pretreated by 2.5 h. In contrast to the early steroid group in which all of the hypotensive effect was due to eicosanoids, in the latter group steroids had an additional nonspecific effect. Thus, in vivo, high-dose steroids did not prevent endotoxin-induced increases in eicosanoids but actually increased circulating levels of TxB2 and 6-keto-PGF1 alpha with a physiological effect favoring vasodilation.

scholarly journals High-dose rifampicin kills persisters, shortens treatment duration, and reduces relapse rate in vitro and in vivo

2015 ◽  
Vol 6 ◽  
Author(s):  
Yanmin Hu ◽  
Alexander Liu ◽  
Fatima Ortega-Muro ◽  
Laura Alameda-Martin ◽  
Denis Mitchison ◽  
...  
Keyword(s):  
Relapse Rate ◽  
Treatment Duration ◽  
High Dose

scholarly journals Effect of Synchronous Versus Sequential Regimens on the Pharmacokinetics and Biodistribution of Regorafenib with Irradiation

Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 386
Author(s):  
Tung-Hu Tsai ◽  
Yu-Jen Chen ◽  
Li-Ying Wang ◽  
Chen-Hsi Hsieh
Keyword(s):  
Stereotactic Body Radiation Therapy ◽  
In Vivo Studies ◽  
Control Group ◽  
High Dose ◽  
Dependent Manner ◽  
Hep G2 ◽  
Time Curve ◽  
Dose Dependent

This study was performed to evaluate the interaction between conventional or high-dose radiotherapy (RT) and the pharmacokinetics (PK) of regorafenib in concurrent or sequential regimens for the treatment of hepatocellular carcinoma. Concurrent and sequential in vitro and in vivo studies of irradiation and regorafenib were designed. The interactions of RT and regorafenib in vitro were examined in the human hepatoma Huh-7, HA22T and Hep G2 cell lines. The RT–PK phenomenon and biodistribution of regorafenib under RT were confirmed in a free-moving rat model. Regorafenib inhibited the viability of Huh-7 cells in a dose-dependent manner. Apoptosis in Huh-7 cells was enhanced by RT followed by regorafenib treatment. In the concurrent regimen, RT decreased the area under the concentration versus time curve (AUC)regorafenib by 74% (p = 0.001) in the RT2 Gy × 3 fraction (f’x) group and by 69% (p = 0.001) in the RT9 Gy × 3 f’x group. The AUCregorafenib was increased by 182.8% (p = 0.011) in the sequential RT2Gy × 1 f’x group and by 213.2% (p = 0.016) in the sequential RT9Gy × 1 f’x group. Both concurrent regimens, RT2Gy × 3 f’x and RT9Gy × 3 f’x, clearly decreased the biodistribution of regorafenib in the heart, liver, lung, spleen and kidneys, compared to the control (regorafenib × 3 d) group. The concurrent regimens, both RT2Gy × 3 f’x and RT9Gy × 3 f’x, significantly decreased the biodistribution of regorafenib, compared with the control group. The PK of regorafenib can be modulated both by off-target irradiation and stereotactic body radiation therapy (SBRT).

scholarly journals Translational Research in FLASH Radiotherapy—From Radiobiological Mechanisms to In Vivo Results

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 181
Author(s):  
Loredana G. Marcu ◽  
Eva Bezak ◽  
Dylan D. Peukert ◽  
Puthenparampil Wilson
Keyword(s):  
Dose Rate ◽  
High Dose Rate ◽  
Current Status ◽  
Therapeutic Window ◽  
High Dose ◽  
Linear Accelerators ◽  
Radiation Delivery ◽  
Tissue Sparing

FLASH radiotherapy, or the administration of ultra-high dose rate radiotherapy, is a new radiation delivery method that aims to widen the therapeutic window in radiotherapy. Thus far, most in vitro and in vivo results show a real potential of FLASH to offer superior normal tissue sparing compared to conventionally delivered radiation. While there are several postulations behind the differential behaviour among normal and cancer cells under FLASH, the full spectra of radiobiological mechanisms are yet to be clarified. Currently the number of devices delivering FLASH dose rate is few and is mainly limited to experimental and modified linear accelerators. Nevertheless, FLASH research is increasing with new developments in all the main areas: radiobiology, technology and clinical research. This paper presents the current status of FLASH radiotherapy with the aforementioned aspects in mind, but also to highlight the existing challenges and future prospects to overcome them.

scholarly journals CD44 Targeted Nanomaterials for Treatment of Triple-Negative Breast Cancer

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 898
Author(s):  
Ghazal Nabil ◽  
Rami Alzhrani ◽  
Hashem Alsaab ◽  
Mohammed Atef ◽  
Samaresh Sau ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
In Vivo Studies ◽  
High Dose ◽  
Luminal A ◽  
Combination Strategy ◽  
Ongoing Research

Identified as the second leading cause of cancer-related deaths among American women after lung cancer, breast cancer of all types has been the focus of numerous research studies. Even though triple-negative breast cancer (TNBC) represents 15–20% of the number of breast cancer cases worldwide, its existing therapeutic options are fairly limited. Due to the pivotal role of the presence/absence of specific receptors to luminal A, luminal B, HER-2+, and TNBC in the molecular classification of breast cancer, the lack of these receptors has accounted for the aforementioned limitation. Thereupon, in an attempt to participate in the ongoing research endeavors to overcome such a limitation, the conducted study adopts a combination strategy as a therapeutic paradigm for TNBC, which has proven notable results with respect to both: improving patient outcomes and survivability rates. The study hinges upon an investigation of a promising NPs platform for CD44 mediated theranostic that can be combined with JAK/STAT inhibitors for the treatment of TNBC. The ability of momelotinib (MMB), which is a JAK/STAT inhibitor, to sensitize the TNBC to apoptosis inducer (CFM-4.16) has been evaluated in MDA-MB-231 and MDA-MB-468. MMB + CFM-4.16 combination with a combination index (CI) ≤0.5, has been selected for in vitro and in vivo studies. MMB has been combined with CD44 directed polymeric nanoparticles (PNPs) loaded with CFM-4.16, namely CD44-T-PNPs, which selectively delivered the payload to CD44 overexpressing TNBC with a significant decrease in cell viability associated with a high dose reduction index (DRI). The mechanism underlying their synergism is based on the simultaneous downregulation of P-STAT3 and the up-regulation of CARP-1, which has induced ROS-dependent apoptosis leading to caspase 3/7 elevation, cell shrinkage, DNA damage, and suppressed migration. CD44-T-PNPs showed a remarkable cellular internalization, demonstrated by uptake of a Rhodamine B dye in vitro and S0456 (NIR dye) in vivo. S0456 was conjugated to PNPs to form CD44-T-PNPs/S0456 that simultaneously delivered CFM-4.16 and S0456 parenterally with selective tumor targeting, prolonged circulation, minimized off-target distribution.

scholarly journals Reduced High-Dose Radiation-Induced Residual Genotoxic Damage by Induction of Radioadaptive Response and Prophylactic Mild Dietary Restriction in Mice

Dose-Response ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 155932582098216
Author(s):  
Bing Wang ◽  
Kaoru Tanaka ◽  
Takanori Katsube ◽  
Kouichi Maruyama ◽  
Yasuharu Ninomiya ◽  
...  
Keyword(s):  
Dietary Restriction ◽  
High Dose ◽  
Cancer Treatments ◽  
Hematopoietic Stem ◽  
Beneficial Effects ◽  
Radiation Induced ◽  
Potential Strategy ◽  
Higher Doses

Radioadaptive response (RAR) describes a phenomenon in a variety of in vitro and in vivo systems that a low-dose of priming ionizing radiation (IR) reduces detrimental effects of a subsequent challenge IR at higher doses. Among in vivo investigations, studies using the mouse RAR model (Yonezawa Effect) showed that RAR could significantly extenuate high-dose IR-induced detrimental effects such as decrease of hematopoietic stem cells and progenitor cells, acute radiation hematopoietic syndrome, genotoxicity and genomic instability. Meanwhile, it has been demonstrated that diet intervention has a great impact on health, and dietary restriction shows beneficial effects on numerous diseases in animal models. In this work, by using the mouse RAR model and mild dietary restriction (MDR), we confirmed that combination of RAR and MDR could more efficiently reduce radiogenotoxic damage without significant change of the RAR phenotype. These findings suggested that MDR may share some common pathways with RAR to activate mechanisms consequently resulting in suppression of genotoxicity. As MDR could also increase resistance to chemotherapy and radiotherapy in normal cells, we propose that combination of MDR, RAR, and other cancer treatments (i.e., chemotherapy and radiotherapy) represent a potential strategy to increase the treatment efficacy and prevent IR risk in humans.

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