Bioluminescence Intensity Research Articles

Korean Red Ginseng Enhances Immunotherapeutic Effects of NK Cells via Eosinophils in Metastatic Liver Cancer Model.

Metastasis decreases the survival rate of patients with liver cancer. Therefore, novel anti-metastatic strategies are needed. Korean Red Ginseng (KRG) is often ingested as a functional food with an immune-boosting effect. We investigated a combination of KRG and natural killer (NK) cells as a novel immunotherapy approach. SK-Hep1 cells were injected into the tail vein of NRGA mice to establish an experimental metastasis model. KRG, NK cells, or a combination of KRG and NK cells were administered. Tumor growth was observed using an in vivo imaging system, and metastatic lesions were evaluated by histological analysis and immunohistochemistry. Bioluminescence intensity was lower in the KRG and NK cell combination group than in the other groups, indicating that the combination treatment suppressed the progression of metastasis. CD56 expression was used as a NK cell marker and hematological analysis was performed. The combination treatment also decreased the expression of matrix metalloproteinases and the area of metastatic lesions in liver and bone tissues, as well as increased the eosinophil count. Expression of cytokines-related eosinophils and NK cells was determined by Western blotting analysis. The expression of interleukin 33 (IL33) was induced by the combination of KRG and NK cells. High IL33 expression was associated with prolonged overall survival in the Kaplan–Meier plotter. Our results suggest that KRG enhances the immune activity of NK cells by IL-33 through eosinophils and suppresses metastatic liver cancer progression.

Bioluminescence capability and intensity in the dinoflagellate Alexandrium species

Some species in the dinoflagellate genus Alexandrium are bioluminescent. Of the 33 formally described Alexandrium species, the bioluminescence capability of only nine species have been tested, and eight have been reported to be bioluminescent. The present study investigated the bioluminescence capability of seven Alexandrium species that had not been tested. Alexandrium mediterraneum, A. pohangense, and A. tamutum were bioluminescent, but A. andersonii, A. hiranoi, A. insuetum, and A. pseudogonyaulax were not. We also measured the bioluminescent intensity of A. affine, A. fraterculus, A. mediterraneum, A. ostenfeldii, A. pacificum, A. pohangense, A. tamarense, and A. tamutum. The mean 200-second-integrated bioluminescence intensity per cell ranged from 0.02 to 32.2 × 104 relative luminescence unit per cell (RLU cell-1), and the mean maximum bioluminescence intensity per cell per second (BLMax) ranged from 0.01 to 10.3 × 104 RLU cell-1 s-1-1. BLMax was significantly correlated with the maximum growth rates of Alexandrium species, except for A. tamarense. A phylogenetic tree based on large subunit ribosomal DNA (LSU rDNA) showed that the bioluminescent species A. affine, A. catenella, A. fraterculus, A. mediterraneum, A. pacificum, and A. tamarense formed a large clade. However, the toxicity or mixotrophic capability of these species was split. Thus, their bioluminescence capability in this clade was more consistent than their toxicity or mixotrophic capability. Phylogenetic trees based on LSU rDNA and the luciferase gene of Alexandrium were consistent except for A. pohangense. The results of the present study can provide a basis for understanding the interspecific diversity in bioluminescence of Alexandrium.

Reporting amyloid beta levels via bioluminescence imaging with amyloid reservoirs

AbstractBackgroundBioluminescence imaging has changed daily practice in preclinical research of cancers and other diseases in the last decades; however, it has been rarely applied in preclinical research of Alzheimer’s disease (AD).MethodIn this report, we demonstrated that bioluminescence imaging could be used to report the levels of amyloid beta (Ab) species in vivo. We hypothesized that AkaLumine, a newly discovered substrate for luciferase, could bind to Ab aggregates and plaques. We further speculated that the Ab species have the reservoir capacity to sequester and release AkaLumine to control the bioluminescence intensity, which could be used to report the levels of Abs.ResultsOur hypotheses have been validated via in vitro tests, mimic phantom imaging, and in vivo imaging using transgenic AD mice that were virally transduced with aka Luciferase (AkaLuc), a new luciferase that generates bioluminescence in the near infrared window. As expected, compared to the control group, we observed that the Ab group showed lower bioluminescence intensity due to AkaLumine sequestering at early time points, while higher intensity due to AkaLumine releasing at later time points. Lastly, we demonstrated that this method could be used to monitor AD progression and therapeutic effectiveness of avagacestat, a well‐studied gamma‐secretase inhibitor.ConclusionOur approach can be easily implanted into daily imaging experiments. We believe that our method has tremendous potential to change daily practice of preclinical AD research.

A rapid and non-destructive method for spatial\u2013temporal quantification of colonization by Pseudomonas syringae pv. tomato DC3000 in Arabidopsis and tomato

BackgroundThe bacterial leaf pathogen Pseudomonas syringae pv tomato (Pst) is the most popular model pathogen for plant pathology research. Previous methods to study the plant-Pst interactions rely on destructive quantification of Pst colonisation, which can be labour- and time-consuming and does not allow for spatial–temporal monitoring of the bacterial colonisation. Here, we describe a rapid and non-destructive method to quantify and visualise spatial–temporal colonisation by Pst in intact leaves of Arabidopsis and tomato.ResultsThe method presented here uses a bioluminescent Pst DC3000 strain that constitutively expresses the luxCDABE operon from Photorhabdus luminescens (Pst::LUX) and requires a common gel documentation (Gel Doc) system with a sensitive CCD/CMOS camera and imaging software (Photoshop or Image J). By capturing bright field and bioluminescence images from Pst::LUX-infected leaves, we imaged the spatiotemporal dynamics of Pst infection. Analysis of bioluminescence from live Pst bacteria over a 5-day time course after spray inoculation of Arabidopsis revealed transition of the bacterial presence from the older leaves to the younger leaves and apical meristem. Colonisation by Pst:LUX bioluminescence was obtained from digital photos by calculating relative bioluminescence values, which is adjusted for bioluminescence intensity and normalised by leaf surface. This method detected statistically significant differences in Pst::LUX colonisation between Arabidopsis genotypes varying in basal resistance, as well as statistically significant reductions in Pst::LUX colonisation by resistance-inducing treatments in both Arabidopsis and tomato. Comparison of relative bioluminescence values to conventional colony counting on selective agar medium revealed a statistically significant correlation, which was reproducible between different Gel Doc systems.ConclusionsWe present a non-destructive method to quantify colonisation by bioluminescent Pst::LUX in plants. Using a common Gel Doc system and imaging software, our method requires less time and labour than conventional methods that are based on destructive sampling of infected leaf material. Furthermore, in contrast to conventional strategies, our method provides additional information about the spatial–temporal patterns of Pst colonisation.

Development of Cellular and Enzymatic Bioluminescent Assay Systems to Study Low-Dose Effects of Thorium.

Thorium is one of the most widespread radioactive elements in natural ecosystems, along with uranium, it is the most important source of nuclear energy. However, the effects of thorium on living organisms have not been thoroughly studied. Marine luminescent bacteria and their enzymes are optimal bioassays for studying low-dose thorium exposures. Luminescent bioassays provide a quantitative measure of toxicity and are characterized by high rates, sensitivity, and simplicity. It is known that the metabolic activity of bacteria is associated with the production of reactive oxygen species (ROS). We studied the effects of thorium-232 (10−11–10−3 M) on Photobacterium phosphoreum and bacterial enzymatic reactions; kinetics of bacterial bioluminescence and ROS content were investigated in both systems. Bioluminescence activation was revealed under low-dose exposures (<0.1 Gy) and discussed in terms of “radiation hormesis”. The activation was accompanied by an intensification of the oxidation of a low-molecular reducer, NADH, during the enzymatic processes. Negative correlations were found between the intensity of bioluminescence and the content of ROS in bacteria and enzyme systems; an active role of ROS in the low-dose activation by thorium was discussed. The results contribute to radioecological potential of bioluminescence techniques adapted to study low-intensity radioactive exposures.

Curcumin Administered in Combination with Glu-GNPs Induces Radiosensitivity in Transplanted Tumor MDA-MB-231-luc Cells in Nude Mice.

Curcumin is a type of plant polyphenol extracted from Curcuma longa L. rhizome, which demonstrates antitumor activity in breast cancer cells in vitro. To investigate the combined effect and possible mechanism of curcumin and glucose-gold nanoparticles (Glu-GNPs), the radiosensitivity of breast carcinoma xenografts was assessed in nude mice. MDA-MB-231 cells labeled with firefly luciferase were inoculated into the mammary fatty pads of nude mice to establish a transplantation tumor model of human breast cancer. The tumor-bearing mice were treated with different drugs (curcumin, Glu-GNPs, and cisplatin) for 3 weeks prior to radiotherapy. The body weights and tumor volumes of the mice were measured in regular intervals. Tumor bioluminescence intensity was determined in real-time using an in vivo bioluminescence imaging system to monitor tumor growth. Transplanted tumor tissue samples were taken for hematoxylin and eosin (HE) staining, and the expression of VEGF, HSP90, HIF-1α, and MMP9 was evaluated via reverse transcription-quantitative PCR or immunohistochemistry. The results revealed that the breast tumor-bearing nude mouse model was successfully established, as evidenced by a stable expression of luciferase. Curcumin inhibited the growth of tumors without causing significant weight loss in mice. Furthermore, additive inhibition was demonstrated when curcumin was administered in combination with Glu-GNPs and irradiation. Tumor bioluminescence intensity was decreased in the model group following curcumin, Glu-GNPs, and irradiation treatment. HE staining demonstrated that transplanted tumors were malignant, with necrotic tissue exhibited centrally. It was concluded that curcumin administered in combination with Glu-GNPs and X-ray irradiation could reduce the protein expression of VEGF, HSP90, HIF-1α, and MMP9 in tumor tissue when compared with the model group. Curcumin and Glu-GNPs administered with X-ray irradiation significantly inhibited tumor growth and induced radiosensitivity, which may be associated with the inhibition of angiogenesis in tumor tissue.

Quantitative flow chamber system for evaluating in vitro biofilms and the kinetics of S. aureus biofilm formation in human plasma media

BackgroundIt has been well established that biofilm formation on orthopaedic implants is a critical event in the pathogenesis of orthopaedic infections, yet the natural history of this process with respect to bacterial adhesion, proliferation, and glycocalyx matrix production remains poorly understood. Moreover, there are no quantitative methods yet available to assess the differences in biofilm formation between different bacterial strains or implant materials. Consequently, this study aimed to investigate the natural history of S. aureus in in vitro biofilm formation in human plasma media using a flow chamber system. Bioluminescent S. aureus strains were used to better understand the bacterial growth and biofilm formation on orthopaedic materials. Also, the effects of human plasma media were assessed by loading the chamber with Tryptic Soy Broth with 10% human plasma (TSB + HP).ResultsScanning electron microscopy (SEM) was utilized to assess the morphological appearance of the biofilms, revealing that S. aureus inoculation was required for biofilm formation, and that the phenotypes of biofilm production after 24 h inoculation with three tested strains (SH1000, UAMS-1, and USA300) were markedly different depending on the culture medium. Time course study of the bioluminescence intensity (BLI) and biofilm production on the implants due to the UAMS-1 and USA300 strains revealed different characteristics, whereby UAMS-1 showed increasing BLI and biofilm growth until peaking at 9 h, while USA300 showed a rapid increase in BLI and biofilm formation at 6 h. The kinetics of biofilm formation for both UAMS-1 and USA300 were also supported and confirmed by qRT-PCR analysis of the 16S rRNA gene. Biofilms grown in our flow chamber in the plasma media were also demonstrated to involve an upregulation of the biofilm-forming-related genes icaA, fnbA, and alt. The BLI and SEM results from K-wire experiments revealed that the in vitro growth and biofilm formation by UAMS-1 and USA300 on stainless-steel and titanium surfaces were virtually identical.ConclusionWe demonstrated a novel in vitro model for S. aureus biofilm formation with quantitative BLI and SEM outcome measures, and then used this model to demonstrate the presence of strain-specific phenotypes and its potential use to evaluate anti-microbial surfaces.

Suppression effect of a dual cancer-specific oncolytic adenovirus on luciferase-labeled human melanoma cells in vitro and in vivo.

To explore the suppressive effect of Apoptin-loaded oncolytic adenovirus (Ad-VT) on luciferase-labeled human melanoma cells in vitro and in vivo. The stable luciferase-expressing human melanoma cells A375-luc or M14-luc were obtained by transfecting the plasmid pGL4.51 and selection with G418, followed by luciferase activity, genetic stability and bioluminescence intensity assays. In vitro, the inhibitory effects of Ad-VT on A375-luc or M14-luc were evaluated using the MTS cell proliferation, FITC-Annexin V apoptosis detection, transwell migration, Matrigel invasion and scratch assays. The inhibition pathway in Ad-VT-infected A375-luc and M14-luc cells were analyzed by JC-1 staining and Western-blot detection of mitochondrial apoptosis-related proteins. In vivo, the suppressive effects of Ad-VT on A375-luc or M14-luc were assessed by living imaging technology, tumor volume, bioluminescence intensity, survival curves and immunohistochemical analysis of the tumors from the xenograft tumor model BALB/c nude mice. The growth and migration of A375-luc and M14-luc were significantly inhibited by Ad-VT in vitro. The evaluations of A375-luc and M14-luc tumor models in BALB/c nude mice were successfully performed using living imaging technology. Ad-VT had an anti-tumor effect by reducing tumor growth and increasing survival in vivo. Ad-VT significantly changed the mitochondrial membrane potential by triggering the the mitochondrial release of apoptosis-related proteins, AIF (apoptosis inducing factor), ARTS (Apoptosis-Related Proteins), and Cyto-c (cytochrome c) from the mitochondria. Ad-VT reduced the mitochondrial membrane potential in A375-luc or M14-luc cells and induced the mitochondrial release of AIF, ARTS and Cyto-C. Ad-VT induced apoptosis in A375-luc or M14-luc cells via the mitochondrial apoptotic pathway.

An Autonomous Molecular Bioluminescent Reporter (AMBER) for Voltage Imaging in Freely Moving Animals.

Genetically encoded reporters have greatly increased our understanding of biology. While fluorescent reporters have been widely used, photostability and phototoxicity have hindered their use in long-term experiments. Bioluminescence overcomes some of these challenges but requires the addition of an exogenous luciferin limiting its use. Using a modular approach, Autonomous Molecular BioluminEscent Reporter (AMBER), an indicator of membrane potential is engineered. Unlike other bioluminescent systems, AMBER is a voltage-gated luciferase coupling the functionalities of the Ciona voltage-sensing domain (VSD) and bacterial luciferase, luxAB. When co-expressed with the luciferin-producing genes, AMBER reversibly switches the bioluminescent intensity as a function of membrane potential. Using biophysical and biochemical methods, it is shown that AMBER switches its enzymatic activity from an OFF to an ON state as a function of the membrane potential. Upon depolarization, AMBER switches from a low to a high enzymatic activity state, showing a several-fold increase in the bioluminescence output (ΔL/L). AMBER in the pharyngeal muscles and mechanosensory touch neurons of Caenorhabditis elegans is expressed. Using the compressed sensing approach, the electropharingeogram of the C. elegans pharynx is reconstructed, validating the sensor in vivo. Thus, AMBER represents the first fully genetically encoded bioluminescent reporter without requiring exogenous luciferin addition.

Bacterial bioluminescence assay for bioanalysis and bioimaging.

Bioluminescence occurs through a chemical reaction in organisms that spontaneously produce light. Luminescent bacteria are unique among bioluminescent organisms. Their bioluminescence intensity is an indicator of their metabolic activity, which can directly reflect the influence of environmental factors on cell viability. Moreover, the whole bioluminescence process is totally gene encoded without the addition of extra substrates. As a result, bacterial bioluminescence has been a powerful tool for whole-cell biosensors and bio-reporters in bioanalysis and bioimaging. This review aims to cover the applications of wild-type and recombinant luminescent bacteria to detect the toxicity of environmental pollutants and biological molecules. The bacterial bioluminescence analytical assay has characteristics such as high sensitivity, short-term detection, and easy operation. Meanwhile, due to the development of gene engineering and optical technology, bacterial luciferase as a reporter protein has been successfully expressed in prokaryotic and eukaryotic cells, tissues, and organs of animals. The major applications for bacterial luciferase-based bioluminescence imaging, such as infectious diseases, cancer therapy, and stem cell tracing, are discussed in this review.

Photodynamic inactivation of Escherichia coli bacteria by cationic photosensitizers

The aim of this work is the study of antibacterial photodynamic inactivation (APDI) of Escherichia coli (on the example of a model E. coli K12 TG1), the influence of the charge of photosensitizer (PS) molecules on the efficiency of binding with these Gram-negative bacteria. The results obtained confirm that PSs based on polycationic phthalocyanines and synthetic bacteriochlorins provide effective photodynamic inactivation of E. coli, much higher than monocationic methylene blue and electro-neutral bacteriochlorin derivative. The efficiency of APDI, assessed by the intensity of bioluminescence of model E. coli K12 TG1 bacteria, correlates with the charge of PS molecules and the efficiency of electrostatic binding of PS to bacterial cells.

Ratiometric Bioluminescent Indicator for a Simple and Rapid Measurement of Thrombin Activity Using a Smartphone.

Hemostasis is an essential function that repairs tissues and maintains the survival of living organisms. To prevent diseases caused by the abnormality of the blood coagulation mechanism, it is important to carry out a blood test periodically by a method that is convenient and less burdensome for examiners. Thrombin is a protease that catalyzes the conversion of fibrinogen, and its cleavage activity can be an index of coagulation activity. Here, we developed a ratiometric bioluminescent indicator, Thrombastor (thrombin activity sensing indicator), which reflects the thrombin cleavage activity in blood by changing the emission color from green to blue. Compared to the current thrombin activity indicator, the rapid color change of the emission indicated a 2.5-fold decrease in the Km for thrombin, and the cleavage rate was more than two times faster. By improving the absolute bioluminescence intensity, detection from a small amount of plasma could be achieved with a smartphone camera. Using Thrombastor and a versatile device, an effective diagnosis for preventing coagulation disorders can be provided.

An Ex Vivo Brain Slice Model to Study and Target Breast Cancer Brain Metastatic Tumor Growth.

Brain metastasis is a serious consequence of breast cancer for women as these tumors are difficult to treat and are associated with poor clinical outcomes. Preclinical mouse models of breast cancer brain metastatic (BCBM) growth are useful but are expensive, and it is difficult to track live cells and tumor cell invasion within the brain parenchyma. Presented here is a protocol for ex vivo brain slice cultures from xenografted mice containing intracranially injected breast cancer brain-seeking clonal sublines. MDA-MB-231BR luciferase tagged cells were injected intracranially into the brains of Nu/Nu female mice, and following tumor formation, the brains were isolated, sliced, and cultured ex vivo. The tumor slices were imaged to identify tumor cells expressing luciferase and monitor their proliferation and invasion in the brain parenchyma for up to 10 days. Further, the protocol describes the use of time-lapse microscopy to image the growth and invasive behavior of the tumor cells following treatment with ionizing radiation or chemotherapy. The response of tumor cells to treatments can be visualized by live-imaging microscopy, measuring bioluminescence intensity, and performing histology on the brain slice containing BCBM cells. Thus, this ex vivo slice model may be a useful platform for rapid testing of novel therapeutic agents alone or in combination with radiation to identify drugs personalized to target an individual patient's breast cancer brain metastatic growth within the brain microenvironment.

MP33-14 EFFICACY OF LOW INTENSITY ULTRASOUND-EXPOSED MAGNETOSOMES IN THE TREATMENT OF PROSTATE CANCER IN A XENOGRAFT MURINE MODEL

You have accessJournal of UrologyProstate Cancer: Basic Research & Pathophysiology I (MP33)1 Sep 2021MP33-14 EFFICACY OF LOW INTENSITY ULTRASOUND-EXPOSED MAGNETOSOMES IN THE TREATMENT OF PROSTATE CANCER IN A XENOGRAFT MURINE MODEL Cynthia El Hedjaj, Eric Barret, Imene Chebbi, and Edouard Alphandery Cynthia El HedjajCynthia El Hedjaj More articles by this author , Eric BarretEric Barret More articles by this author , Imene ChebbiImene Chebbi More articles by this author , and Edouard AlphanderyEdouard Alphandery More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002042.14AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: To ablate prostate tumors by intra-tumoral injection of magnetosomes and moderate ultrasound heating in a preclinical setting. METHODS: Nanoparticles used in this study were magnetosomes extracted and purified from magnetotactic bacteria. The resulting pure endotoxin free iron oxide minerals were coated with carboxy-methyl-dextran to yield stable coated magnetosome minerals (M-CMD). Treatment efficacy was tested on 4 groups of 10 mice each, bearing PC3-Luc tumours of ∼100 mm3. In vivo experiments followed the Charles Darwin ethical guidelines. Mice received intra-tumoral injection of isotonic solution (group 1), 3 µg per mm3 of tumour of M-CMD (group 2), the same injection of magnetosome as in group 2 followed by 10 sessions of 10 min (3 sessions per week), using a power of 1 W/cm2 and a frequency of 1 MHz (group 3), isotonic solution followed by the same sessions as in group 3 (group 4). Tumour growth after treatments was monitored by measurements of tumour volumes with a calliper and of tumour bioluminescence intensity (BLI). Histological analysis was carried out using Hematoxylin & Eosin/Pearl staining on tissues located in the region of the initial tumour following the various treatments. RESULTS: In group 3 mice, each session of ultrasound application led to an average tumour temperature of 45 °C during 8 minutes. The tumour volume decreased to 0 mm3, becoming un-palpable, and tumour BLI was undetectable 15 days following M-CMD administration. No tumour re-growth was observed during the 45 following days, suggesting full disappearance of the treated primary tumour. Histological analysis of collected tissues after the hyperthermia sessions revealed magnetosome cellular internalization, tumour cell apoptosis and necrosis, and an increase in the percentage of dead tumour cells with increasing number of hyperthermia sessions. In groups 1 and 2 not exposed to ultrasounds, tumours grew rapidly and mice had to be euthanized within one month following isotonic solution/M-CMD injection. In group 4 mice that had the same ultrasound sessions as in group 3 mice without M-CMD injection, a partial anti-tumour activity was observed. The treatment could not prevent tumour re-growth as in group 3. No major side effects were noted in the 4 groups. CONCLUSIONS: Intra-tumoral magnetosomes injection heated to a moderate temperature (45°) by low intensity ultrasounds is a safe and effective treatment of prostate cancer in a murine model. This technique appears promising for clinical applications since it is efficient on mice, relies on cheap and easy to use ultrasound device without a high level of focalisation. Source of Funding: Nanobacterie- 36 boulevard Flandrin, 75016 PARIS © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e612-e612 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Cynthia El Hedjaj More articles by this author Eric Barret More articles by this author Imene Chebbi More articles by this author Edouard Alphandery More articles by this author Expand All Advertisement Loading ...

MP33-19 TREATMENT OF PROSTATE CANCER USING LASER-IRRADIATED MAGNETOSOMES: A PRE-CLINICAL STUDY

You have accessJournal of UrologyProstate Cancer: Basic Research & Pathophysiology I (MP33)1 Sep 2021MP33-19 TREATMENT OF PROSTATE CANCER USING LASER-IRRADIATED MAGNETOSOMES: A PRE-CLINICAL STUDY Cynthia El Hedjaj, Eric Barret, Imene Chebbi, and Edouard Alphandery Cynthia El HedjajCynthia El Hedjaj More articles by this author , Eric BarretEric Barret More articles by this author , Imene ChebbiImene Chebbi More articles by this author , and Edouard AlphanderyEdouard Alphandery More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002042.19AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: To develop a prostate cancer treatment using laser irradiated bio-synthesized coated iron oxide minerals. METHODS: Nanoparticles used in this study were magnetosomes synthesized by magnetotactic bacteria, extracted and purified from these bacteria. The resulting pure endotoxin free iron oxide minerals were coated with carboxy-methyl-dextran to yield stable coated magnetosome minerals (M-CMD). In vivo experiments followed the Charles Darwin ethical guidelines. Treatment efficacy was tested on 4 groups of 10 mice bearing PC3-Luc tumours of∼100 mm3. Mice received isotonic solution (group 1), 30 µg per mm3 of tumour of M-CMD (group 2), the same condition as in group 2 followed by 10 sessions of 10 minutes of laser radiation of intensity 1.5 W/cm2 and excitation wavelength 808 nm (group 3), isotonic solution followed by the same irradiation as in group 3 (group 4). The evolution of the tumour following treatments was followed by measurements of tumour volumes with a calliper and of tumour Bioluminescence intensity (BLI). Histological studies were carried out using Hematoxylin-Eosin/Pearl staining on tissues located in the region of the initial tumour following the various treatments. RESULTS: In group 3, each session led to a temperature of 45°C for 10 minutes. In 50% of mice belonging to group 3, tumour volume decreased to 0mm3, tumour became un-palpable, and tumour BLI signal was undetectable 12 days following M-CMD administration. No tumour re-growth was observed during the 48 following days, suggesting full disappearance of the treated primary tumour for 50% of the mice in group 3. Histological analysis of tissues collected after the different hyperthermia sessions revealed magnetosome cellular internalization, tumour cell apoptosis and necrosis, and an increase in the percentage of dead tumour cells with increasing number of hyperthermia sessions. By contrast, in all other groups, tumours grew rapidly, and mice had to be euthanized within one month following isotonic solution/M-CMD injection. CONCLUSIONS: We present an efficient and safe method of prostate tumour treatment, which yields full tumour disappearance by exposing natural coated iron oxide minerals called magnetosomes to moderate tumour heating under laser radiation. Magnetosomes were selectively heated due to a coupling between magnetosome surface plasmon waves and laser light, hence minimizing laser heating outside of the magnetosome region, i.e. within the healthy tissues surrounding the tumour, limiting the risk of side effects. Source of Funding: Nanobacterie 36 bd Flandrin- 75016 PARIS © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e614-e614 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Cynthia El Hedjaj More articles by this author Eric Barret More articles by this author Imene Chebbi More articles by this author Edouard Alphandery More articles by this author Expand All Advertisement Loading ...

Field studies of bioluminescence in the Antarctic sector of the Atlantic Ocean in 2002 and 2020.

In this work, IBSS materials on seawater bioluminescence intensity changes in the Atlantic sector of the Antarctic Ocean (the Weddell Sea area) with an interval of almost 20 years are presented. Data were obtained using a single instrument, the hydrobiophysical system Salpa-M, in the area of 50-63°S, 62-49°W in March 2002 (183 soundings at 45 stations during cruise 7 on RV Gorizont) and in February 2020 (122 soundings at 18 stations during cruise 79 on RV Academic Mstislav Keldysh). The bioluminescence studies were coupled with the simultaneous measurement of temperature, electrical conductivity, and photosynthetically active radiation, and they were compared with the data from processing plankton samples. Over the past 20 years, as a consequence of the appearance of a large number of gelatinous organisms and the resulting changes in the structure of the plankton community, the bioluminescence of Antarctic waters in the euphotic layer of this region has decreased almost two-fold, currently being in the range 8.4 × 10-12 to 104.42 × 10-12 W·cm-2 ·L-1 .

Early Administration of Low-Dose IL-2 Intensify Graft-Versus-Leukemia Effect without Worsening GVHD through Sequential Enhancement of Effector T Cell and CD62L+ Regulatory T Cell Subset

Allogeneic hematopoietic stem cell transplantation (HSCT) is the curative treatment of many hematological malignancies, but the relapse is one of the major causes of treatment failure and mortality. Previous clinical studies have shown that low-dose IL-2 was well tolerated and could lower the relapse rate in human T cell depleted allogeneic BMT. On the other hand, we also demonstrated that low-dose IL-2 could preferentially enhance regulatory T cell (Treg) and improve the symptoms of chronic GVHD (NEJM 2011,Sci Trans Med 2013). In murine bone marrow transplantation (BMT) model showed that Treg can protect from lethal GVHD while preserving graft-versus-leukemia (GVL) effect. Especially, CD62L+ Tregs has a higher capacity in suppressing GVHD than their CD62L- counterpart. Our recent study reported that exogenous low-dose IL-2 induced the expression of PD-1 on Treg preferentially and it was most evident in CD44+CD62L+central-memory Treg (Blood 2016). However, the impact of CD62L+ Treg enhanced by low-dose IL-2 on GVHD and GVL has not been well investigated. In this study, we studied the effect of exogenous IL-2 on the lymphocyte phenotypic profiles including naïve- versus memory-type balance and also examined donor-derived immunity, especially GVHD and GVL, by using leukemia-bearing BMT model. Lethally irradiated B6D2F1 recipients were transplanted spleen cells and BM cells from B6 donors and 5000 IU Teceleukin (recombinant IL-2) was injected once a day for 14 days. The number of CD4+CD25+Foxp3+ Treg, CD4+CD25-Foxp3- conventional T cell (Tcon) and CD8+ T cell was compared between IL2- and vehicle-treated groups. The expressions of CD44, CD62L, CCR4, CCR7, Ki-67, PD-1, CTLA-4, LAG3, GITR, ICOS and TIM-3 in each subset were also examined. Lymphocytes profiling analysis showed that IL-2 treatment in the first 7 days resulted in the dominant expansion of effector T cells without Treg increase (Treg 0.10 vs 0.16,p=0.35, Tcon 2.83 vs 4.20, p=0.01, CD8 T cell 5.52 vs 10.4, p=0.01, million). On the contrary, the extended IL-2 treatment in the next 7 days increased CD62L+ Treg (21.5 vs 48.2 % of total Treg, p<0.001, 0.02 vs 0.07 million, p=0.006) without increasing effector T cells. PD-1 on Treg was very high in BMT-recipients even without receiving IL-2, so further enhancement of PD-1 expression by IL-2 was not observed. However, the expression of other inhibitory molecules including CTLA-4 (MFI, 6.61 vs 9.92, p=<0.001), LAG-3 (1.73 vs 2.17, p=0.04) and ICOS (2.41 vs 3.84, P<0.001) was enhanced by the IL-2 treatment. To elucidate the mechanisms of the increase in CD62L+ Treg, the in vivo violet dye dilution assay was performed. We first sorted out CD62L+ T cells by micro-beads from spleen cells, and then adaptively transferred into recipients. Five days treatment of low-dose IL-2 resulted in the enhancement of the division of CD62L+ Treg (% divided cells; 19.5 vs 29.8 % of Treg, p=0.005, 62.3 vs 108 in number, p=0.002). Interestingly, when CD62L- T cells were transferred, IL-2 treatment also induced the division of the cells and, of note, induced the phenotypic change of CD62L- into CD62L+ Treg (7.63 vs 19.8 % of Treg, p=0.009, 91.3 vs 361, p=0.01). These results suggested that IL-2 have the possibility to enhance the proliferative activity of Treg with the up-regulation of CD62L expression. Lastly, we transplanted lucipherase+P815 leukemia cells into this BMT model and evaluated the clinical impact of low-dose IL-2 on GVL by using in vivo bioluminescence system. To assesse the GVL and GVHD independently, we used two different tumor burden models. In the high tumor burden model, IL-2 injection decreased bioluminescence intensity (BLI) of P815 (BLI at week3, 8.3x10E7 vs 8.1x10E6 photon/second, p<0.001) and significantly extends overall survival. On the other hand, in the low tumor burden model, both treatment groups did not die from leukemia but vehicle-treated control group showed a significant higher clinical GVHD score and died from GVHD. These data demonstrated the clinical benefits on anti-tumor effect of IL-2, which could enhance the GVL activity without the detrimental effect on GVHD. In conclusion, our data indicate multiple effects of IL-2 on post-transplant immunity can coordinate to intensify GVL separately from GVHD on the mechanism of sequential enhancement of effector T cell and CD62L+ Treg in the different phases. These data provide the important information for developing Treg-targeted therapy. DisclosuresMaeda:Toko Pharmaceutical Industries: Other: Investigational drug is provided free of charge.

Construction and Immunological Evaluation of an Adenoviral Vector-Based Vaccine Candidate for Lassa Fever.

Lassa virus (LASV) is a rodent-borne arenavirus circulating in West African regions that causes Lassa fever (LF). LF is normally asymptomatic at the initial infection stage, but can progress to severe disease with multiorgan collapse and hemorrhagic fever. To date, the therapeutic choices are limited, and there is no approved vaccine for avoiding LASV infection. Adenoviral vector-based vaccines represent an effective countermeasure against LASV because of their safety and adequate immunogenicity, as demonstrated in use against other emerging viral infections. Here, we constructed and characterized a novel Ad5 (E1-, E3-) vectored vaccine containing the glycoprotein precursor (GPC) of LASV. Ad5-GPCLASV elicited both humoral and cellular immune responses in BALB/c mice. Moreover, a bioluminescent imaging-based BALB/c mouse model infected with GPC-bearing and luciferase-expressing replication-incompetent LASV pseudovirus was utilized to evaluate the vaccine efficacy. The bioluminescence intensity of immunized mice was significantly lower than that of control mice after being inoculated with LASV pseudovirus. This study suggests that Ad5-GPCLASV represents a potential vaccine candidate against LF.

Bioluminescence of ctenophores near the boundary of oxygen-depleted waters at the redoxcline of the Black Sea.

Vertical distribution of ctenophores near the boundary of oxygen-depleted waters of the Black Sea redoxcline was studied by use of video observations with real-time water sampling, horizontal MultiNet towing, and soundings using bathyphotometers with simultaneous vertical plankton net sampling. The results of the study showed for the first time that the daytime accumulation of ctenophores above the upper boundary of the suboxic zone changes the biophysical properties of the medium, causing an increase in the daytime intensity of bioluminescence near the redoxcline. The dynamics of this glow is in antiphase to that in the surface layers, where it is associated with the bioluminescence of phytoplankton. Therefore, in the deep-sea areas, two types of bioluminescence peaks differ in the light generation sources: the nighttime glow of phytoplankton in surface layers and the daytime glow of zooplankton in layers of oxygen-depleted waters at the redoxcline. The discovery of this new phenomenon allows the use of bioluminescent methods for the rapid assessment of the depth of the daytime zooplankton layers for the subsequent hauls of plankton nets. This significantly expands the possibilities of studying the structure and functioning of the pelagic ecosystem of the Black Sea and other marine basins with a redoxcline.

In situ measurements of bioluminescence response of Gonyaulax spinifera to various mechanical stimuli

A conspicuous bioluminescence during nighttime was reported in an aquaculture farm in the Cochin estuary due to Gonyaulax spinifera bloom on March 20, 2020. In situ measurements on bioluminescence was carried out during nighttime to quantify the response of G. spinifera to various mechanical stimuli. The bioluminescence intensity (BI) was measured using Glowtracka, an advanced single channel sensor, attached to a Conductivity–Temperature–Depth Profiler. In steady environment, without any external stimuli, the bioluminescence generated due to the movement of fishes and shrimps in the water column was not detected by the sensor. However, stimuli such as a hand splash, oar and swimming movements, and a mixer could generate measurable bioluminescence responses. An abundance of ~ 2.7 × 106 cells L−1 of G. spinifera with exceptionally high chlorophyll a of 25 mg m−3 was recorded. The BI in response to hand splash was recorded as high as 1.6 × 1011 photons cm−2 s−1. Similarly, BI of ~ 1–6 × 1010 photons cm−2 s−1 with a cumulative bioluminescence of ~ 2.51 × 1012 photons cm−2 (for 35 s) was recorded when there is a mixer with a constant force of 494 N/800 rpm min−1. The response of G. spinifera was spontaneous with no time lapse between application of stimuli and the bioluminescence response. Interestingly, in natural environment, application of stimulus for longer time periods (10 min) does not lower the bioluminescence intensity due to the replenishment of water thrusted in by the mixer from surrounding areas. We also demonstrated that the bioluminescence intensity decreases with increase in distance from the source of stimuli (mixer) (av. 1.84 × 1010 photons cm−2 s−1 at 0.2 m to av. 0.05 × 1010 photons cm−2 s−1 at 1 m). The BI was highest in the periphery of the turbulent wake generated by the stimuli (av. 3.1 × 1010 photons cm−2 s−1) compared to the center (av. 1.8 × 1010 photons cm−2 s−1). When the stimuli was applied vertically down, the BI decreased from 0.2 m (0.3 × 1010 photons cm−2 s−1) to 0.5 m (0.10 × 1010 photons cm−2 s−1). Our study demonstrates that the BI of G. spinifera increases with increase in mechanical stimuli and decreases with increase in distance from the stimuli.