scholarly journals Attenuated replication and pathogenesis of SARS-CoV-2 B.1.1.529 Omicron

2021 ◽  
Author(s):  
Kwok-Yung Yuen ◽  
Huiping Shuai ◽  
Jasper Fuk-Woo Chan ◽  
Bingjie Hu ◽  
Yue Chai ◽  
...  
Keyword(s):  
Immune Escape ◽  
Vaccination Strategy ◽  
Body Weight Loss ◽  
Human Populations ◽  
Lung Pathology ◽  
Evolutionary Trajectory ◽  
In Vivo Models ◽  
Alpha Beta

Abstract SARS-CoV-2 Omicron emerged in November 2021 and is rapidly spreading among the human populations. The variant contains 34 changes in its spike protein including 15 substitutions at the receptor-binding domain (RBD). While recent reports reveal that the Omicron variant can robustly escape from vaccine and therapeutic neutralization antibodies, the pathogenicity of the virus remains unknown. Here, we investigate the virological features and pathogenesis of the Omicron variant using in vitro and in vivo models. Our results demonstrate that the replication of the Omicron variant is dramatically attenuated in Calu3 and Caco2 but not in VeroE6 cells. Further mechanistic investigations reveal that the Omicron variant is deficient in transmembrane serine protease 2 (TMPRSS2) usage in comparison to that of WT, Alpha, Beta, and Delta variant, which explained its inefficient replication in Calu3 and Caco2 cells. Importantly, the replication of the Omicron variant is markedly attenuated in both the upper and lower respiratory tract of infected K18-hACE2 mice in comparison to that of WT and Delta variant, which results in its dramatically ameliorated lung pathology. When compared with SARS-CoV-2 WT, Alpha, Beta, and Delta variant, infection by the Omicron variant causes the least body weight loss and mortality rate. Overall, our study demonstrates that the Omicron variant is significantly attenuated in virus replication and pathogenicity in comparison with WT and previous variants. Our data suggest the current global vaccination strategy has forced SARS-CoV-2 into a new evolutionary trajectory towards reduced replication fitness in exchange of better immune escape. These findings are critical for setting policy in the pandemic control and disease management of COVID-19.

scholarly journals A single dose of recombinant VSV-ΔG-spike vaccine provides protection against SARS-CoV-2 challenge

2020 ◽  
Author(s):  
Yfat Yahalom-Ronen ◽  
Hadas Tamir ◽  
Sharon Melamed ◽  
Boaz Politi ◽  
Ohad Shifman ◽  
...  
Keyword(s):  
Single Dose ◽  
Neutralizing Antibodies ◽  
Rapid Development ◽  
Body Weight Loss ◽  
Spike Protein ◽  
Effective Vaccine ◽  
Lung Pathology ◽  
Golden Syrian Hamster

AbstractThe COVID-19 pandemic caused by SARS-CoV-2 that emerged in December 2019 in China resulted in over 7.8 million infections and over 430,000 deaths worldwide, imposing an urgent need for rapid development of an efficient and cost-effective vaccine, suitable for mass immunization. Here, we generated a replication competent recombinant VSV-ΔG-spike vaccine, in which the glycoprotein of VSV was replaced by the spike protein of the SARS-CoV-2. In vitro characterization of the recombinant VSV-ΔG-spike indicated expression and presentation of the spike protein on the viral membrane with antigenic similarity to SARS-CoV-2. A golden Syrian hamster in vivo model for COVID-19 was implemented. We show that vaccination of hamsters with recombinant VSV-ΔG-spike results in rapid and potent induction of neutralizing antibodies against SARS-CoV-2. Importantly, single-dose vaccination was able to protect hamsters against SARS-CoV-2 challenge, as demonstrated by the abrogation of body weight loss of the immunized hamsters compared to unvaccinated hamsters. Furthermore, whereas lungs of infected hamsters displayed extensive tissue damage and high viral titers, immunized hamsters’ lungs showed only minor lung pathology, and no viral load. Taken together, we suggest recombinant VSV-ΔG-spike as a safe, efficacious and protective vaccine against SARS-CoV-2 infection.

scholarly journals ATRX Alteration Contributes to Tumor Growth and Immune Escape in Pleomorphic Sarcomas

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2151
Author(s):  
Lucie Darmusey ◽  
Gaëlle Pérot ◽  
Noémie Thébault ◽  
Sophie Le Guellec ◽  
Nelly Desplat ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Immune Escape ◽  
Adaptive Immune System ◽  
Tumor Growth Rate ◽  
In Vivo Models ◽  
Expression Of Genes ◽  
Alternative Lengthening ◽  
Poorly Differentiated

Whole genome and transcriptome sequencing of a cohort of 67 leiomyosarcomas has been revealed ATRX to be one of the most frequently mutated genes in leiomyosarcomas after TP53 and RB1. While its function is well described in the alternative lengthening of telomeres mechanism, we wondered whether its alteration could have complementary effects on sarcoma oncogenesis. ATRX alteration is associated with the down-expression of genes linked to differentiation in leiomyosarcomas, and to immunity in an additional cohort of 60 poorly differentiated pleomorphic sarcomas. In vitro and in vivo models showed that ATRX down-expression increases tumor growth rate and immune escape by decreasing the immunity load of active mast cells in sarcoma tumors. These data indicate that an alternative to unsuccessful targeting of the adaptive immune system in sarcoma could target the innate system. This might lead to a better outcome for sarcoma patients in terms of ATRX status.

Melatonin modifies tumor hypoxia and metabolism by inhibiting HIF-1α and energy metabolic pathway in the in vitro and in vivo models of breast cancer

2019 ◽  
Vol 2 (4) ◽  
pp. 83-98 ◽  
Author(s):  
André De Lima Mota ◽  
Bruna Vitorasso Jardim-Perassi ◽  
Tialfi Bergamin De Castro ◽  
Jucimara Colombo ◽  
Nathália Martins Sonehara ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Glucose Metabolism ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Carbonic Anhydrases ◽  
In Vivo Models ◽  
Ca Ix ◽  
Gene And Protein Expression

Breast cancer is the most common cancer among women and has a high mortality rate. Adverse conditions in the tumor microenvironment, such as hypoxia and acidosis, may exert selective pressure on the tumor, selecting subpopulations of tumor cells with advantages for survival in this environment. In this context, therapeutic agents that can modify these conditions, and consequently the intratumoral heterogeneity need to be explored. Melatonin, in addition to its physiological effects, exhibits important anti-tumor actions which may associate with modification of hypoxia and Warburg effect. In this study, we have evaluated the action of melatonin on tumor growth and tumor metabolism by different markers of hypoxia and glucose metabolism (HIF-1α, glucose transporters GLUT1 and GLUT3 and carbonic anhydrases CA-IX and CA-XII) in triple negative breast cancer model. In an in vitro study, gene and protein expressions of these markers were evaluated by quantitative real-time PCR and immunocytochemistry, respectively. The effects of melatonin were also tested in a MDA-MB-231 xenograft animal model. Results showed that melatonin treatment reduced the viability of MDA-MB-231 cells and tumor growth in Balb/c nude mice (p <0.05). The treatment significantly decreased HIF-1α gene and protein expression concomitantly with the expression of GLUT1, GLUT3, CA-IX and CA-XII (p <0.05). These results strongly suggest that melatonin down-regulates HIF-1α expression and regulates glucose metabolism in breast tumor cells, therefore, controlling hypoxia and tumor progression. 

Molecular iodine synergized and sensitized neuroblastoma cells to the antineoplastic effect of ATRA

2020 ◽  
Vol 27 (12) ◽  
pp. 699-710
Author(s):  
Irasema Mendieta ◽  
Gabriel Rodríguez-Gómez ◽  
Bertha Rueda-Zarazúa ◽  
Julia Rodríguez-Castelán ◽  
Winniberg Álvarez-León ◽  
...  
Keyword(s):  
Residual Disease ◽  
Neuroblastoma Cells ◽  
Survivin Expression ◽  
Body Weight Loss ◽  
Immunohistochemical Analysis ◽  
Molecular Iodine ◽  
Tyrosine Kinase Receptor ◽  
Adjuvant Effect

Neuroblastoma (NB) is the most common solid childhood tumor, and all-trans retinoic acid (ATRA) is used as a treatment to decrease minimal residual disease. Molecular iodine (I2) induces differentiation and/or apoptosis in several neoplastic cells through activation of PPARγ nuclear receptors. Here, we analyzed whether the coadministration of I2 and ATRA increases the efficacy of NB treatment. ATRA-sensitive (SH-SY5Y), partially-sensitive (SK-N-BE(2)), and non-sensitive (SK-N-AS) NB cells were used to analyze the effect of I2 and ATRA in vitro and in xenografts (Foxn1 nu/nu mice), exploring actions on cellular viability, differentiation, and molecular responses. In the SH-SY5Y cells, 200 μM I2 caused a 100-fold (0.01 µM) reduction in the antiproliferative dose of ATRA and promoted neurite extension and neural marker expression (tyrosine hydroxylase (TH) and tyrosine kinase receptor alpha (Trk-A)). In SK-N-AS, the I2 supplement sensitized these cells to 0.1 μM ATRA, increasing the ATRA-receptor (RARα) and PPARγ expression, and decreasing the Survivin expression. The I2 supplement increased the mitochondrial membrane potential in SK-N-AS suggesting the participation of mitochondrial-mediated mechanisms involved in the sensibilization to ATRA. In vivo, oral I2 supplementation (0.025%) synergized the antitumor effect of ATRA (1.5 mg/kg BW) and prevented side effects (body weight loss and diarrhea episodes). The immunohistochemical analysis showed that I2 supplementation decreased the intratumoral vasculature (CD34). We suggest that the I2 + ATRA combination should be studied in preclinical and clinical trials to evaluate its potential adjuvant effect in addition to conventional treatments.

Current Challenges in the Development of Vaccines and Drugs Against Emerging Vector-borne Diseases

2019 ◽  
Vol 26 (16) ◽  
pp. 2974-2986 ◽  
Author(s):  
Kwang-sun Kim
Keyword(s):  
New Host ◽  
In Vivo Models ◽  
Vector Borne Diseases ◽  
Novel Drugs ◽  
Huge Impact ◽  
Tick Borne Disease ◽  
Vector Borne ◽  
Living Organisms

Vectors are living organisms that transmit infectious diseases from an infected animal to humans or another animal. Biological vectors such as mosquitoes, ticks, and sand flies carry pathogens that multiply within their bodies prior to delivery to a new host. The increased prevalence of Vector-Borne Diseases (VBDs) such as Aedes-borne dengue, Chikungunya (CHIKV), Zika (ZIKV), malaria, Tick-Borne Disease (TBD), and scrub typhus has a huge impact on the health of both humans and livestock worldwide. In particular, zoonotic diseases transmitted by mosquitoes and ticks place a considerable burden on public health. Vaccines, drugs, and vector control methods have been developed to prevent and treat VBDs and have prevented millions of deaths. However, development of such strategies is falling behind the rapid emergence of VBDs. Therefore, a comprehensive approach to fighting VBDs must be considered immediately. In this review, I focus on the challenges posed by emerging outbreaks of VBDs and discuss available drugs and vaccines designed to overcome this burden. Research into promising drugs needs to be upgraded and fast-tracked, and novel drugs or vaccines being tested in in vitro and in vivo models need to be moved into human clinical trials. Active preventive tactics, as well as new and upgraded diagnostics, surveillance, treatments, and vaccination strategies, need to be monitored constantly if we are to manage VBDs of medical importance.

Potential for Treatment of Neurodegenerative Diseases with Natural Products or Synthetic Compounds that Stabilize Microtubules

2020 ◽  
Vol 26 (35) ◽  
pp. 4362-4372
Author(s):  
John H. Miller ◽  
Viswanath Das
Keyword(s):  
Natural Products ◽  
Neurodegenerative Diseases ◽  
In Vivo Models ◽  
Synthetic Compounds ◽  
Stabilizing Agents ◽  
Animal Models Of Disease ◽  
Model Studies ◽  
Models Of Disease

No effective therapeutics to treat neurodegenerative diseases exist, despite significant attempts to find drugs that can reduce or rescue the debilitating symptoms of tauopathies such as Alzheimer’s disease, Parkinson’s disease, frontotemporal dementia, amyotrophic lateral sclerosis, or Pick’s disease. A number of in vitro and in vivo models exist for studying neurodegenerative diseases, including cell models employing induced-pluripotent stem cells, cerebral organoids, and animal models of disease. Recent research has focused on microtubulestabilizing agents, either natural products or synthetic compounds that can prevent the axonal destruction caused by tau protein pathologies. Although promising results have come from animal model studies using brainpenetrant natural product microtubule-stabilizing agents, such as paclitaxel analogs that can access the brain, epothilones B and D, and other synthetic compounds such as davunetide or the triazolopyrimidines, early clinical trials in humans have been disappointing. This review aims to summarize the research that has been carried out in this area and discuss the potential for the future development of an effective microtubule stabilizing drug to treat neurodegenerative disease.

A Review on Opuntia Species and its Chemistry, Pharmacognosy, Pharmacology and Bioapplications

2020 ◽  
Vol 16 (8) ◽  
pp. 1227-1244
Author(s):  
Dharmendra Kumar ◽  
Pramod K. Sharma
Keyword(s):  
Human Consumption ◽  
In Vivo Models ◽  
Sugar Amino Acids ◽  
Opuntia Species ◽  
Therapeutic Uses ◽  
Anti Inflammatory ◽  
Online Library ◽  
Different Parts

Background:: Opuntia species, locally known as prickly pear was used for various purposes as food, medicine, beverage, source of dye and animal food. Many studies have revealed its pharmacology activity from time to time. This review is a collection of chemistry, pharmacognosy, pharmacology and bioapplications of the cactus family. Methods: Many sources were used to collect information about Opuntia species such as Pub med, Google scholar, Agris, science direct, Embase, Merk index, Wiley online library, books and other reliable sources. This review contains studies from 1812 to 2019. Results: The plants from the cactus family offer various pharmacological active compounds including phenolic compounds, carotenoids, betalains, vitamins, steroids, sugar, amino acids, minerals and fibers. These bioactive compounds serve various pharmacological activities such as anticancer, antiviral, anti-diabetic, Neuroprotective, anti-inflammatory, antioxidant, Hepatoprotective, antibacterial, antiulcer and alcohol hangover. According to various studies, Opuntia species offer many bioapplications such as fodder for animal, soil erosion, prevention, human consumption and waste water decontamination. Finally, different parts of plants are used in various formulations that offer many biotechnology applications. Conclusion: Different parts of Opuntia plant (fruits, seeds, flowers and cladodes) are used in various health problems which include wound healing, anti-inflammatory and urinary tract infection from ancient times. Nowadays, researches have extended several pharmacological and therapeutic uses of Opuntia species as discussed in this review. Many in-vitro and in-vivo models are also discussed in this review as the proofs of research findings. Various research gaps have been observed in current studies that require attention in the future.

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