scholarly journals A genetically attenuated malaria vaccine candidate based on P. falciparum b9/slarp gene-deficient sporozoites

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Ben C L van Schaijk ◽  
Ivo H J Ploemen ◽  
Takeshi Annoura ◽  
Martijn W Vos ◽  
Lander Foquet ◽  
...  
Keyword(s):  
Protective Efficacy ◽  
Human Hepatocytes ◽  
Attractive Alternative ◽  
Alternative Approach ◽  
Malaria Vaccine Candidate ◽  
Resistance Markers ◽  
High Level ◽  
Malaria Model

A highly efficacious pre-erythrocytic stage vaccine would be an important tool for the control and elimination of malaria but is currently unavailable. High-level protection in humans can be achieved by experimental immunization with Plasmodium falciparum sporozoites attenuated by radiation or under anti-malarial drug coverage. Immunization with genetically attenuated parasites (GAP) would be an attractive alternative approach. In this study, we present data on safety and protective efficacy using sporozoites with deletions of two genes, that is the newly identified b9 and slarp, which govern independent and critical processes for successful liver-stage development. In the rodent malaria model, PbΔb9ΔslarpGAP was completely attenuated showing no breakthrough infections while efficiently inducing high-level protection. The human PfΔb9ΔslarpGAP generated without drug resistance markers were infective to human hepatocytes in vitro and to humanized mice engrafted with human hepatocytes in vivo but completely aborted development after infection. These findings support the clinical development of a PfΔb9ΔslarpSPZ vaccine.

scholarly journals Kinetics of Targeted Phage Rescue in a Mouse Model of SystemicEscherichia coliK1

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
György Schneider ◽  
Nikolett Szentes ◽  
Marianna Horváth ◽  
Ágnes Dorn ◽  
Alysia Cox ◽  
...  
Keyword(s):  
Capsular Polysaccharide ◽  
Protective Efficacy ◽  
Lytic Bacteriophage ◽  
E Coli ◽  
Causative Agents ◽  
High Level ◽  
Systemic Infections ◽  
Kinetics Of

Escherichia (E.) coliK1 strains remain common causative agents of neonatal sepsis and meningitis. We have isolated a lytic bacteriophage (ΦIK1) againstE. colistrain IHE3034 and tested its specificityin vitro, as well as distribution and protective efficacyin vivo. The phage was shown to be specific to the K1 capsular polysaccharide. In the lethal murine model, a high level of protection was afforded by the phage with strict kinetics. A single dose of 1 x 108phage particles administered 10 and 60 minutes following the bacterial challenge elicited 100 % and 95 % survival, respectively. No mice could be rescued if phage administration occurred 3 hours postinfection. Tissue distribution surveys in the surviving mice revealed that the spleen was the primary organ in which accumulation of active ΦIK1 phages could be detected two weeks after phage administration. These results suggest that bacteriophages have potential as therapeutic agents in the control of systemic infections.

scholarly journals Salmonella Vaccine Vectors Displaying Delayed Antigen Synthesis InVivo To Enhance Immunogenicity

2010 ◽  
Vol 78 (9) ◽  
pp. 3969-3980 ◽  
Author(s):  
Shifeng Wang ◽  
Yuhua Li ◽  
Giorgio Scarpellini ◽  
Wei Kong ◽  
HuoYing Shi ◽  
...  
Keyword(s):  
Immune Responses ◽  
Fluorescent Protein ◽  
Protective Efficacy ◽  
Start Codon ◽  
Antibody Titers ◽  
Iga Antibody ◽  
Green Fluorescent ◽  
High Level

ABSTRACTWe have developed a regulated delayed antigen synthesis (RDAS) system for use in recombinant attenuatedSalmonellavaccine (RASV) strains to enhance immune responses by reducing the adverse effects of high-level antigen synthesis. This system includes a chromosomal repressor gene,lacI, expressed from the arabinose-regulatedaraCPBADpromoter. LacI serves to regulate expression from a plasmid promoter, Ptrc, that directs antigen synthesis. In the presence of arabinose LacI is produced, which binds to Ptrc, blocking antigen synthesis.In vivo, an arabinose-poor environment, the concentration of LacI decreases with each cell division, allowing increased antigen synthesis. To optimize the system and for comparison, we altered thelacIribosome-binding site, start codon, and/or codon content to construct RDAS strains χ9095, χ9959, and χ9241, synthesizing from low to high levels of LacI, respectively, and non-RDAS strain χ9555 as a control. We evaluated this system with two test antigens, the green fluorescent protein for initialin vitroassessment and theStreptococcus pneumoniaePspA protein for validation of our system in mice. All RASV strains expressing PspA generated high antilipopolysaccharide antibody titers, indicating that expression oflacIdid not interfere with the capacity to induce an immune response. Strain χ9241 induced significantly higher anti-PspA IgG and IgA antibody titers than strain χ9555, which expressed PspA constitutively. Anti-PspA antibody titers were inversely correlated to the level of LacI synthesis. Strain χ9241 also induced significantly greater protective efficacy against challenge with virulentS. pneumoniae. These results suggest that regulated delayed antigen synthesis is useful for improving immunogenicity of RASV strains.

scholarly journals Aberrantly high activation of a FoxM1–STMN1 axis contributes to progression and tumorigenesis in FoxM1-driven cancers

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Jun Liu ◽  
Jipeng Li ◽  
Ke Wang ◽  
Haiming Liu ◽  
Jianyong Sun ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Poor Prognosis ◽  
Soft Agar ◽  
Transcriptional Level ◽  
Regulation Mechanism ◽  
Strong Positive Correlation ◽  
Cell Viability Assay ◽  
High Level

AbstractFork-head box protein M1 (FoxM1) is a transcriptional factor which plays critical roles in cancer development and progression. However, the general regulatory mechanism of FoxM1 is still limited. STMN1 is a microtubule-binding protein which can inhibit the assembly of microtubule dimer or promote depolymerization of microtubules. It was reported as a major responsive factor of paclitaxel resistance for clinical chemotherapy of tumor patients. But the function of abnormally high level of STMN1 and its regulation mechanism in cancer cells remain unclear. In this study, we used public database and tissue microarrays to analyze the expression pattern of FoxM1 and STMN1 and found a strong positive correlation between FoxM1 and STMN1 in multiple types of cancer. Lentivirus-mediated FoxM1/STMN1-knockdown cell lines were established to study the function of FoxM1/STMN1 by performing cell viability assay, plate clone formation assay, soft agar assay in vitro and xenograft mouse model in vivo. Our results showed that FoxM1 promotes cell proliferation by upregulating STMN1. Further ChIP assay showed that FoxM1 upregulates STMN1 in a transcriptional level. Prognostic analysis showed that a high level of FoxM1 and STMN1 is related to poor prognosis in solid tumors. Moreover, a high co-expression of FoxM1 and STMN1 has a more significant correlation with poor prognosis. Our findings suggest that a general FoxM1-STMN1 axis contributes to cell proliferation and tumorigenesis in hepatocellular carcinoma, gastric cancer and colorectal cancer. The combination of FoxM1 and STMN1 can be a more precise biomarker for prognostic prediction.

Animal Models and Alternatives in the Quality Control of Vaccines: Are In Vitro Methods or In Vivo Methods the Scientific Equivalent of the Emperor's New Clothes?

1995 ◽  
Vol 23 (1) ◽  
pp. 61-73
Author(s):  
Coenraad Hendriksen ◽  
Johan van der Gun
Keyword(s):  
Quality Control ◽  
Test Methods ◽  
In Vitro Test ◽  
Large Numbers ◽  
Alternative Approach ◽  
Inactivated Vaccines ◽  
Vitro Test

In the quality control of vaccine batches, the potency testing of inactivated vaccines is one of the areas requiring very large numbers of animals, which usually suffer significant distress as a result of the experimental procedures employed. This article deals with the potency testing of diphtheria and tetanus toxoids, two vaccines which are used extensively throughout the world. The relevance of the potency test prescribed by the European Pharmacopoeia monographs is questioned. The validity of the potency test as a model for the human response, the ability of the test to be standardised, and the relevance of the test in relation to the quality of the product are discussed. It is concluded that the potency test has only limited predictive value for the antitoxin responses to be expected in recipients of these toxoids. An alternative approach for estimating the potency of toxoid batches is discussed, in which a distinction is made between estimation of the immunogenic potency of the first few batches obtained from a seed lot and monitoring the consistency of the quality of subsequent batches. The use of animals is limited to the first few batches. Monitoring the consistency of the quality of subsequent batches is based on in vitro test methods. Factors which hamper the introduction and acceptance of the alternative approach are considered. Finally, proposals are made for replacement, reduction and/or refinement (the Three Rs) in the use of animals in the routine potency testing of toxoids.

scholarly journals β-elemene alleviates airway stenosis via the ILK/Akt pathway modulated by MIR143HG sponging miR-1275

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Guoying Zhang ◽  
Cheng Xue ◽  
Yiming Zeng
Keyword(s):  
Cell Cycle ◽  
Cell Viability ◽  
Cell Model ◽  
Protective Efficacy ◽  
Rabbit Model ◽  
Akt Pathway ◽  
Loss Of Function ◽  
Airway Stenosis

Abstract Background We have previously found that β-elemene could inhibit the viability of airway granulation fibroblasts and prevent airway hyperplastic stenosis. This study aimed to elucidate the underlying mechanism and protective efficacy of β-elemene in vitro and in vivo. Methods Microarray and bioinformatic analysis were used to identify altered pathways related to cell viability in a β-elemene-treated primary cell model and to construct a β-elemene-altered ceRNA network modulating the target pathway. Loss of function and gain of function approaches were performed to examine the role of the ceRNA axis in β-elemene's regulation of the target pathway and cell viability. Additionally, in a β-elemene-treated rabbit model of airway stenosis, endoscopic and histological examinations were used to evaluate its therapeutic efficacy and further verify its mechanism of action. Results The hyperactive ILK/Akt pathway and dysregulated LncRNA-MIR143HG, which acted as a miR-1275 ceRNA to modulate ILK expression, were suppressed in β-elemene-treated airway granulation fibroblasts; β-elemene suppressed the ILK/Akt pathway via the MIR143HG/miR-1275/ILK axis. Additionally, the cell cycle and apoptotic phenotypes of granulation fibroblasts were altered, consistent with ILK/Akt pathway activity. In vivo application of β-elemene attenuated airway granulation hyperplasia and alleviated scar stricture, and histological detections suggested that β-elemene's effects on the MIR143HG/miR-1275/ILK axis and ILK/Akt pathway were in line with in vitro findings. Conclusions MIR143HG and ILK may act as ceRNA to sponge miR-1275. The MIR143HG/miR-1275/ILK axis mediates β-elemene-induced cell cycle arrest and apoptosis of airway granulation fibroblasts by modulating the ILK/Akt pathway, thereby inhibiting airway granulation proliferation and ultimately alleviating airway stenosis.

scholarly journals MiR-211 determines brain metastasis specificity through SOX11/NGN2 axis in triple-negative breast cancer

Oncogene ◽  
2021 ◽  
Author(s):  
Jhih-Kai Pan ◽  
Cheng-Han Lin ◽  
Yao-Lung Kuo ◽  
Luo-Ping Ger ◽  
Hui-Chuan Cheng ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Brain Metastasis ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Survival Outcomes ◽  
Poor Survival ◽  
Breast Cancer Brain Metastasis ◽  
High Level

AbstractBrian metastasis, which is diagnosed in 30% of triple-negative breast cancer (TNBC) patients with metastasis, causes poor survival outcomes. Growing evidence has characterized miRNAs involving in breast cancer brain metastasis; however, currently, there is a lack of prognostic plasma-based indicator for brain metastasis. In this study, high level of miR-211 can act as brain metastatic prognostic marker in vivo. High miR-211 drives early and specific brain colonization through enhancing trans-blood–brain barrier (BBB) migration, BBB adherence, and stemness properties of tumor cells and causes poor survival in vivo. SOX11 and NGN2 are the downstream targets of miR-211 and negatively regulate miR-211-mediated TNBC brain metastasis in vitro and in vivo. Most importantly, high miR-211 is correlated with poor survival and brain metastasis in TNBC patients. Our findings suggest that miR-211 may be used as an indicator for TNBC brain metastasis.

scholarly journals LINC00680 enhances hepatocellular carcinoma stemness behavior and chemoresistance by sponging miR-568 to upregulate AKT3

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Gege Shu ◽  
Huizhao Su ◽  
Zhiqian Wang ◽  
Shihui Lai ◽  
Yan Wang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Xenograft Model ◽  
Luciferase Reporter ◽  
Loss Of Function ◽  
Mechanism Study ◽  
Downstream Signaling ◽  
Mouse Xenograft Model ◽  
High Level

Abstract Background Hepatocellular carcinoma (HCC) has an extremely poor prognosis due to the development of chemoresistance, coupled with inherently increased stemness properties. Long non-coding RNAs (LncRNAs) are key regulators for tumor cell stemness and chemosensitivity. Currently the relevance between LINC00680 and tumor progression was still largely unknown, with only one study showing its significance in glioblastoma. The study herein was aimed at identifying the role of LINC00680 in the regulation HCC stemness and chemosensitivity. Methods QRT-PCR was used to detect the expression of LINC00680, miR-568 and AKT3 in tissue specimen and cell lines. Gain- or loss-of function assays were applied to access the function of LINC00680 in HCC cells, including cell proliferation and stemness properties. HCC stemness and chemosensitivity were determined by sphere formation, cell viability and colony formation. Luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull-down assays were performed to examine the interaction between LINC00680 and miR-568 as well as that between miR-568 and AKT3. A nude mouse xenograft model was established for the in vivo study. Results We found that LINC00680 was remarkably upregulated in HCC tissues. Patients with high level of LINC00680 had poorer prognosis. LINC00680 overexpression significantly enhanced HCC cell stemness and decreased in vitro and in vivo chemosensitivity to 5-fluorouracil (5-Fu), whereas LINC00680 knockdown led to opposite results. Mechanism study revealed that LINC00680 regulated HCC stemness and chemosensitivity through sponging miR-568, thereby expediting the expression of AKT3, which further activated its downstream signaling molecules, including mTOR, elF4EBP1, and p70S6K. Conclusion LINC00680 promotes HCC stemness properties and decreases chemosensitivity through sponging miR-568 to activate AKT3, suggesting that LINC00680 might be a potentially important HCC diagnosis marker and therapeutic target.

scholarly journals Alcohol-and-HIV-Induced Lysosomal Dysfunction Regulates Extracellular Vesicles Secretion in Vitro and in Liver-Humanized Mice

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 29
Author(s):  
Raghubendra Singh Dagur ◽  
Moses New-Aaron ◽  
Murali Ganesan ◽  
Weimin Wang ◽  
Svetlana Romanova ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Extracellular Vesicles ◽  
Treated Group ◽  
Human Hepatocytes ◽  
In Vivo Studies ◽  
People Living With Hiv ◽  
Humanized Mouse Model ◽  
And Function

Background: Alcohol abuse is common in people living with HIV-1 and dramaticallyenhances the severity of HIV-induced liver damage by inducing oxidative stress and lysosomaldysfunction in the liver cells. We hypothesize that the increased release of extracellular vesicles(EVs) in hepatocytes and liver humanized mouse model is linked to lysosome dysfunction. Methods:The study was performed on primary human hepatocytes and human hepatoma RLWXP-GFP (Huh7.5 cells stably transfected with CYP2E1 and XPack-GFP) cells and validated on ethanol-fed liverhumanizedfumarylacetoacetate hydrolase (Fah)-/-, Rag2-/-, common cytokine receptor gamma chainknockout (FRG-KO) mice. Cells and mice were infected with HIV-1ADA virus. Results: We observedan increase in the secretion of EVs associated with a decrease in lysosomal activity and expressionof lysosomal-associated membrane protein 1. Next-generation RNA sequencing of primary humanhepatocytes revealed 63 differentially expressed genes, with 13 downregulated and 50 upregulatedgenes in the alcohol–HIV-treated group. Upstream regulator analysis of differentially expressedgenes through Ingenuity Pathway Analysis identified transcriptional regulators affecting downstreamgenes associated with increased oxidative stress, lysosomal associated disease, and function andEVs biogenesis. Our in vitro findings were corroborated by in vivo studies on human hepatocytetransplantedhumanized mice, indicating that intensive EVs’ generation by human hepatocytes andtheir secretion to serum was associated with increased oxidative stress and reduction in lysosomalactivities triggered by HIV infection and ethanol diet. Conclusion: HIV-and-ethanol-metabolisminducedEVs release is tightly controlled by lysosome status in hepatocytes and participates in thedevelopment of double-insult-induced liver injury.

scholarly journals Synergistic In Vitro Antiretroviral Activity of a Humanized Monoclonal Anti-CD4 Antibody (TNX-355) and Enfuvirtide (T-20)

2006 ◽  
Vol 50 (6) ◽  
pp. 2231-2233 ◽  
Author(s):  
Xing-Quan Zhang ◽  
Meredith Sorensen ◽  
Michael Fung ◽  
Robert T. Schooley
Keyword(s):  
Viral Replication ◽  
Viral Entry ◽  
Antiretroviral Agents ◽  
Entry Inhibitors ◽  
High Level ◽  
Antiretroviral Activity

ABSTRACT Recently, antiretroviral agents directed at several steps involved in viral entry have been shown to reduce viral replication in vitro and in vivo. We have demonstrated a high level of in vitro synergistic antiretroviral activity for two entry inhibitors that are directed at sequential steps in the entry process.

scholarly journals Differential expression and regulation of Tdo2 during mouse decidualization

2013 ◽  
Vol 220 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Dang-Dang Li ◽  
Ying-Jie Gao ◽  
Xue-Chao Tian ◽  
Zhan-Qing Yang ◽  
Hang Cao ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Differential Expression ◽  
Stromal Cells ◽  
Real Time Pcr ◽  
Mouse Uterus ◽  
Decidual Cells ◽  
High Level ◽  
Rate Limiting

Tryptophan 2,3-dioxygenase (Tdo2) is a rate-limiting enzyme which directs the conversion of tryptophan to kynurenine. The aim of this study was to examine the expression and regulation of Tdo2 in mouse uterus during decidualization. Tdo2 mRNA was mainly expressed in the decidua on days 6–8 of pregnancy. By real-time PCR, a high level of Tdo2 expression was observed in the uteri from days 6 to 8 of pregnancy, although Tdo2 expression was observed on days 1–8. Simultaneously, Tdo2 mRNA was also detected under in vivo and in vitro artificial decidualization. Estrogen, progesterone, and 8-bromoadenosine-cAMP could induce the expression of Tdo2 in the ovariectomized mouse uterus and uterine stromal cells. Tdo2 could regulate cell proliferation and stimulate the expression of decidual marker Dtprp in the uterine stromal cells and decidual cells. Overexpression of Tdo2 could upregulate the expression of Ahr, Cox2, and Vegf genes in uterine stromal cells, while Tdo2 inhibitor 680C91 could downregulate the expression of Cox2 and Vegf genes in uterine decidual cells. These data indicate that Tdo2 may play an important role during mouse decidualization and be regulated by estrogen, progesterone, and cAMP.

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