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  1. Article ; Online: Inhibition of Francisella tularensis phagocytosis using a novel anti-LPS scFv antibody fragment

    Adva Mechaly / Uri Elia / Ron Alcalay / Hila Cohen / Eyal Epstein / Ofer Cohen / Ohad Mazor

    Scientific Reports, Vol 9, Iss 1, Pp 1-

    2019  Volume 9

    Abstract: Abstract Francisella tularensis (Ft), the causative agent of lethal tularemia, is classified as a category A biological warfare threat agent. While Ft infection is treatable by antibiotics, many failed antibiotic treatments were reported, highlighting ... ...

    Abstract Abstract Francisella tularensis (Ft), the causative agent of lethal tularemia, is classified as a category A biological warfare threat agent. While Ft infection is treatable by antibiotics, many failed antibiotic treatments were reported, highlighting the need for effective new treatments. It has been demonstrated that binding of antibody-coated bacteria to the Fc receptor located on phagocytic cells is a key process needed for efficient protection against Ft. Yet, Ft utilizes the same receptor to enter the phagocytic cells in order to escape the immune system. To address the question whether an anti-Ft LPS antibody lacking the ability to bind the Fc receptor may inhibit the entry of Ft into host cells, a soluble scFv (TL1-scFv) was constructed from an anti Ft-LPS antibody (TL1) that was isolated from an immune single-chain (scFv) phage-display library. Bacterial uptake was assessed upon infection of macrophages with Ft live attenuated strain (LVS) in the presence of either TL1 or TL1-scFv. While incubation of LVS in the presence of TL1 greatly enhanced bacterial uptake, LVS uptake was significantly inhibited in the presence of TL1-scFv. These results prompt further experiments probing the therapeutic efficacy of TL1-scFv, alone or in combination with antibiotic treatment.
    Keywords Medicine ; R ; Science ; Q
    Subject code 572
    Language English
    Publishing date 2019-08-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Humoral and T-Cell Response before and after a Fourth BNT162b2 Vaccine Dose in Adults ≥60 Years

    Erez Bar-Haim / Noa Eliakim-Raz / Amos Stemmer / Hila Cohen / Uri Elia / Asaf Ness / Muhammad Awwad / Nassem Ghantous / Neta Moskovits / Shahar Rotem / Salomon M. Stemmer

    Journal of Clinical Medicine, Vol 11, Iss 2649, p

    2022  Volume 2649

    Abstract: Both humoral and cellular anamnestic responses are significant for protective immunity against SARS-CoV-2. In the current study, the responses in elderly people before and after a fourth vaccine dose of BNT162b2 were compared to those of individuals ... ...

    Abstract Both humoral and cellular anamnestic responses are significant for protective immunity against SARS-CoV-2. In the current study, the responses in elderly people before and after a fourth vaccine dose of BNT162b2 were compared to those of individuals immunized with three vaccine doses. Although a boost effect was observed, the high response following the third administration questions the necessity of an early fourth boost.
    Keywords SARS-CoV-2 ; BNT162b2 ; COVID-19 ; Medicine ; R
    Language English
    Publishing date 2022-05-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Prolonged Protective Immunity Induced by Mild SARS-CoV-2 Infection of K18-hACE2 Mice

    Liat Bar-On / Moshe Aftalion / Efi Makdasi / David Gur / Ron Alcalay / Hila Cohen / Adi Beth-Din / Ronit Rosenfeld / Hagit Achdout / Erez Bar-Haim / Reut Falach / Theodor Chitlaru / Ofer Cohen

    Vaccines, Vol 10, Iss 613, p

    2022  Volume 613

    Abstract: Longevity of the immune response following viral exposure is an essential aspect of SARS-CoV-2 infection. Mild SARS-CoV-2 infection of K18-hACE2 mice was implemented for evaluating the mounting and longevity of a specific memory immune response. We show ... ...

    Abstract Longevity of the immune response following viral exposure is an essential aspect of SARS-CoV-2 infection. Mild SARS-CoV-2 infection of K18-hACE2 mice was implemented for evaluating the mounting and longevity of a specific memory immune response. We show that the infection of K18-hACE2 mice induced robust humoral and cellular immunity (systemic and local), which persisted for at least six months. Virus-specific T cells and neutralizing antibody titers decreased over time, yet their levels were sufficient to provide sterile immunity against lethal rechallenge six months post-primary infection. The study substantiates the role of naturally induced immunity against SARS-CoV-2 infection for preventing recurring morbidity.
    Keywords SARS-CoV-2 ; COVID-19 ; K18-hACE2 mice ; mild infection ; Medicine ; R
    Language English
    Publishing date 2022-04-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article: A biolayer interferometry-based assay for rapid and highly sensitive detection of biowarfare agents

    Mechaly, Adva / Hila Cohen / Ofer Cohen / Ohad Mazor

    Analytical biochemistry. 2016 Aug. 01, v. 506

    2016  

    Abstract: Biolayer interferometry (BLI) is an optical technique that uses fiber-optic biosensors for label-free real-time monitoring of protein–protein interactions. In this study, we coupled the advantages of the Octet Red BLI system (automation, fluidics-free, ...

    Abstract Biolayer interferometry (BLI) is an optical technique that uses fiber-optic biosensors for label-free real-time monitoring of protein–protein interactions. In this study, we coupled the advantages of the Octet Red BLI system (automation, fluidics-free, and on-line monitoring) with a signal enhancement step and developed a rapid and sensitive immunological-based method for detection of biowarfare agents. As a proof of concept, we chose to demonstrate the efficacy of this novel assay for the detection of agents representing two classes of biothreats, proteinaceous toxins, and bacterial pathogens: ricin, a lethal plant toxin, and the gram-negative bacterium Francisella tularensis, the causative agent of tularemia. The assay setup consisted of biotinylated antibodies immobilized to the biosensor coupled with alkaline phosphatase-labeled antibodies as the detection moiety to create nonsoluble substrate crystals that precipitate on the sensor surface, thereby inducing a significant wavelength interference. It was found that this BLI-based assay enables sensitive detection of these pathogens (detection limits of 10 pg/ml and 1 × 104 pfu/ml ricin and F. tularensis, respectively) within a very short time frame (17 min). Owing to its simplicity, this assay can be easily adapted to detect other analytes in general, and biowarfare agents in particular, in a rapid and sensitive manner.
    Keywords antibodies ; automation ; biosensors ; crystals ; detection limit ; fiber optics ; Francisella tularensis ; Gram-negative bacteria ; interferometry ; microbial detection ; monitoring ; pathogens ; protein-protein interactions ; ricin ; toxins ; tularemia ; wavelengths
    Language English
    Dates of publication 2016-0801
    Size p. 22-27.
    Publishing place Elsevier Inc.
    Document type Article
    ZDB-ID 1110-1
    ISSN 1096-0309 ; 0003-2697
    ISSN (online) 1096-0309
    ISSN 0003-2697
    DOI 10.1016/j.ab.2016.04.018
    Database NAL-Catalogue (AGRICOLA)

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  5. Article ; Online: Evaluation of the European Committee on Antimicrobial Susceptibility Testing Guidelines for Rapid Antimicrobial Susceptibility Testing of Bacillus anthracis -, Yersinia pestis - and Francisella tularensis -Positive Blood Cultures

    Ohad Shifman / Tamar Aminov / Moshe Aftalion / David Gur / Hila Cohen / Elad Bar-David / Ofer Cohen / Emanuelle Mamroud / Haim Levy / Ronit Aloni-Grinstein / Ida Steinberger-Levy / Shahar Rotem

    Microorganisms, Vol 9, Iss 1055, p

    2021  Volume 1055

    Abstract: Rapid determination of bacterial antibiotic susceptibility is important for proper treatment of infections. The European Committee on Antimicrobial Susceptibility Testing (EUCAST) has recently published guidelines for rapid antimicrobial susceptibility ... ...

    Abstract Rapid determination of bacterial antibiotic susceptibility is important for proper treatment of infections. The European Committee on Antimicrobial Susceptibility Testing (EUCAST) has recently published guidelines for rapid antimicrobial susceptibility testing (RAST) performed directly from positive blood culture vials. These guidelines, however, were only published for a limited number of common pathogenic bacteria. In this study, we evaluated the applicability of these guidelines to three Tier 1 bioterror agents ( Bacillus anthracis , Yersinia pestis and Francisella tularensis ) that require prompt antibiotic treatment to mitigate morbidity and mortality. We used spiked-in human blood incubated in a BACTEC™ FX40 system to determine the proper conditions for RAST using disc-diffusion and Etest assays. We found that reliable disc-diffusion inhibition diameters and Etest MIC values could be obtained in remarkably short times. Compared to the EUCAST-recommended disc-diffusion assays that will require adjusted clinical breakpoint tables, Etest-based RAST was advantageous, as the obtained MIC values were similar to the standard MIC values, enabling the use of established category breakpoint tables. Our results demonstrate the promising applicability of the EUCAST RAST for B. anthracis -, Y. pestis - or F. tularensis -positive blood cultures, which can lead to shorter diagnostics and prompt antibiotic treatment of these dangerous pathogens.
    Keywords blood culture ; Bacillus anthracis ; Yersinia pestis ; Francisella tularensis ; rapid antimicrobial susceptibility testing ; RAST ; Biology (General) ; QH301-705.5
    Language English
    Publishing date 2021-05-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article ; Online: Comparative Analysis of the Global Transcriptomic Response to Oxidative Stress of Bacillus anthracis htrA -Disrupted and Parental Wild Type Strains

    Galia Zaide / Uri Elia / Inbar Cohen-Gihon / Ma’ayan Israeli / Shahar Rotem / Ofir Israeli / Sharon Ehrlich / Hila Cohen / Shirley Lazar / Adi Beth-Din / Avigdor Shafferman / Anat Zvi / Ofer Cohen / Theodor Chitlaru

    Microorganisms, Vol 8, Iss 1896, p

    2020  Volume 1896

    Abstract: We previously demonstrated that the HtrA (High Temperature Requirement A) protease/chaperone active in the quality control of protein synthesis, represents an important virulence determinant of Bacillus anthracis . Virulence attenuation of htrA - ... ...

    Abstract We previously demonstrated that the HtrA (High Temperature Requirement A) protease/chaperone active in the quality control of protein synthesis, represents an important virulence determinant of Bacillus anthracis . Virulence attenuation of htrA -disrupted Bacillus anthracis strains was attributed to susceptibility of Δ htrA strains to stress insults, as evidenced by affected growth under various stress conditions. Here, we report a comparative RNA-seq transcriptomic study generating a database of differentially expressed genes in the B. anthracis htrA -disrupted and wild type parental strains under oxidative stress. The study demonstrates that, apart from protease and chaperone activities, HtrA exerts a regulatory role influencing expression of more than 1000 genes under stress. Functional analysis of groups or individual genes exhibiting strain-specific modulation, evidenced (i) massive downregulation in the Δ htrA and upregulation in the WT strains of various transcriptional regulators, (ii) downregulation of translation processes in the WT strain, and (iii) downregulation of metal ion binding functions and upregulation of sporulation-associated functions in the Δ htrA strain. These modulated functions are extensively discussed. Fifteen genes uniquely upregulated in the wild type strain were further interrogated for their modulation in response to other stress regimens. Overexpression of one of these genes, encoding for MazG (a nucleoside triphosphate pyrophosphohydrolase involved in various stress responses in other bacteria), in the Δ htrA strain resulted in partial alleviation of the H 2 O 2 -sensitive phenotype.
    Keywords Bacillus anthracis ; anthrax ; oxidative stress ; HtrA ; transcriptomics ; RNA-seq ; Biology (General) ; QH301-705.5
    Subject code 570
    Language English
    Publishing date 2020-11-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Implementation of Adenovirus-Mediated Pulmonary Expression of Human ACE2 in HLA Transgenic Mice Enables Establishment of a COVID-19 Murine Model for Assessment of Immune Responses to SARS-CoV-2 Infection

    Theodor Chitlaru / Erez Bar-Haim / Liat Bar-On / Shahar Rotem / Hila Cohen / Uri Elia / David Gur / Moshe Aftalion / Ron Alkalay / Efi Makdasi / Yentl Evgy / Reut Falach / Ma’ayan Israeli / Adi Bercovich-Kinori / Hagit Achdout / Yfat Yahalom-Ronen / Ronit Rosenfeld / Ofer Cohen

    Pathogens, Vol 10, Iss 940, p

    2021  Volume 940

    Abstract: HLA transgenic mice are instrumental for evaluation of human-specific immune responses to viral infection. Mice do not develop COVID-19 upon infection with SARS-CoV-2 due to the strict tropism of the virus to the human ACE2 receptor. The aim of the ... ...

    Abstract HLA transgenic mice are instrumental for evaluation of human-specific immune responses to viral infection. Mice do not develop COVID-19 upon infection with SARS-CoV-2 due to the strict tropism of the virus to the human ACE2 receptor. The aim of the current study was the implementation of an adenovirus-mediated infection protocol for human ACE2 expression in HLA transgenic mice. Transient pulmonary expression of the human ACE2 receptor in these mice results in their sensitisation to SARS-CoV-2 infection, consequently providing a valuable animal model for COVID-19. Infection results in a transient loss in body weight starting 3 days post-infection, reaching 20–30% loss of weight at day 7 and full recovery at days 11–13 post-infection. The evolution of the disease revealed high reproducibility and very low variability among individual mice. The method was implemented in two different strains of HLA immunized mice. Infected animals developed strong protective humoral and cellular immune responses specific to the viral spike-protein, strictly depending on the adenovirus-mediated human ACE2 expression. Convalescent animals were protected against a subsequent re-infection with SARS-CoV-2, demonstrating that the model may be applied for assessment of efficacy of anti-viral immune responses.
    Keywords adenovirus vector ; human ACE2 ; SARS-CoV-2 ; COVID-19 ; HLA transgenic mice ; Medicine ; R
    Language English
    Publishing date 2021-07-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article ; Online: Nonconsensus Protein Binding to Repetitive DNA Sequence Elements Significantly Affects Eukaryotic Genomes.

    Ariel Afek / Hila Cohen / Shiran Barber-Zucker / Raluca Gordân / David B Lukatsky

    PLoS Computational Biology, Vol 11, Iss 8, p e

    2015  Volume 1004429

    Abstract: Recent genome-wide experiments in different eukaryotic genomes provide an unprecedented view of transcription factor (TF) binding locations and of nucleosome occupancy. These experiments revealed that a large fraction of TF binding events occur in ... ...

    Abstract Recent genome-wide experiments in different eukaryotic genomes provide an unprecedented view of transcription factor (TF) binding locations and of nucleosome occupancy. These experiments revealed that a large fraction of TF binding events occur in regions where only a small number of specific TF binding sites (TFBSs) have been detected. Furthermore, in vitro protein-DNA binding measurements performed for hundreds of TFs indicate that TFs are bound with wide range of affinities to different DNA sequences that lack known consensus motifs. These observations have thus challenged the classical picture of specific protein-DNA binding and strongly suggest the existence of additional recognition mechanisms that affect protein-DNA binding preferences. We have previously demonstrated that repetitive DNA sequence elements characterized by certain symmetries statistically affect protein-DNA binding preferences. We call this binding mechanism nonconsensus protein-DNA binding in order to emphasize the point that specific consensus TFBSs do not contribute to this effect. In this paper, using the simple statistical mechanics model developed previously, we calculate the nonconsensus protein-DNA binding free energy for the entire C. elegans and D. melanogaster genomes. Using the available chromatin immunoprecipitation followed by sequencing (ChIP-seq) results on TF-DNA binding preferences for ~100 TFs, we show that DNA sequences characterized by low predicted free energy of nonconsensus binding have statistically higher experimental TF occupancy and lower nucleosome occupancy than sequences characterized by high free energy of nonconsensus binding. This is in agreement with our previous analysis performed for the yeast genome. We suggest therefore that nonconsensus protein-DNA binding assists the formation of nucleosome-free regions, as TFs outcompete nucleosomes at genomic locations with enhanced nonconsensus binding. In addition, here we perform a new, large-scale analysis using in vitro TF-DNA preferences obtained from the ...
    Keywords Biology (General) ; QH301-705.5
    Subject code 612
    Language English
    Publishing date 2015-08-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article ; Online: Effective Treatment of Atrophic and Icepick Acne Scars Using Deep Non-Ablative Radiofrequency and Multisource Fractional RF Skin Resurfacing

    Monica Elman / Ido Frank / Hila Cohen-Froman / Yoram Harth

    Journal of Cosmetics, Dermatological Sciences and Applications, Vol 02, Iss 04, Pp 267-

    2012  Volume 272

    Abstract: Background and Objectives: Effective treatment for atrophic (depressed) and icepick acne scars requires treatment of both epidermis—for roughness, texture and hyperpigmentation, and the dermis—for collagen remodeling. All first generation radiofrequency ... ...

    Abstract Background and Objectives: Effective treatment for atrophic (depressed) and icepick acne scars requires treatment of both epidermis—for roughness, texture and hyperpigmentation, and the dermis—for collagen remodeling. All first generation radiofrequency systems allow nonablative RF treatment while a few others allow simple bipolar Fractional RF skin resurfacing. The FDA cleared multisource radiofrequency therapy system (EndyMed PRO, EndyMed Ltd., Cesarea, Israel) allows, for the first time, phase controlled multisource RF for both deep (up to 11 mm) non ablative RF and fractional RF skin resurfacing on the same treatment device. Study Design/Materials and Methods: Ten subjects with atrophic acne scars were enrolled in the study. Patients were photographed using standardized methods. In each treatment session, each patient received a full face 3DEEP non ablative skin tightening treatment followed by a Fractional skin resurfacing treatment. The treatment sessions were repeated once a month to a total of up to 4 treatments. Results: All subjects experienced mild-moderate edema and erythema as an immediate response to treatment. Edema resolved after up to three hours post treatment and erythema lasted up to 2 days. Micro ablative crusts were formed 1 - 2 days post treatments and lasted up to 5 days on facial areas. Patients' photographs—before each treatment session and 1 and 3 months after the last session—were graded according to the accepted Cosmetic Improvement Scale. All patients obtained significant skin improvement. Seventy percent of patients had 50% - 75% improvement one month after the third treatment session while the other thirty percent experienced a 25% - 50%. Discussion and Conclusions: The presented results describe for the first time a new treatment system (EndyMed PRO TM ) that allows both deep non ablative RF delivery and Fractional skin resurfacing on the same treatment platform. This work shows the synergy of combining these two applications for the improvement of acne scars, as well as for some secondary possible pigmentation and vascular improvement.
    Keywords Fractional Radio Frequency ; Skin Resurfacing ; Acne Scars ; Chemistry ; QD1-999 ; Science ; Q ; DOAJ:Chemistry (General) ; DOAJ:Chemistry
    Subject code 616
    Language English
    Publishing date 2012-12-01T00:00:00Z
    Publisher Scientific Research Publishing
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article: Protection of vaccinated mice against pneumonic tularemia is associated with an early memory sentinel-response in the lung

    Bar-On, Liat / Hila Cohen / Uri Elia / Shahar Rotem / Adi Bercovich-Kinori / Erez Bar-Haim / Theodor Chitlaru / Ofer Cohen

    Vaccine. 2017,

    2017  

    Abstract: Francisella tularensis is the intracellular bacterial pathogen causing the respiratory life-threatening disease tularemia. Development of tularemia vaccines has been hampered by an incomplete understanding of the correlates of immunity. Moreover, the ... ...

    Abstract Francisella tularensis is the intracellular bacterial pathogen causing the respiratory life-threatening disease tularemia. Development of tularemia vaccines has been hampered by an incomplete understanding of the correlates of immunity. Moreover, the importance of lung cellular immunity in vaccine-mediated protection against tularemia is a controversial matter. Live attenuated vaccine strains of F. tularensis such as LVS (Live Vaccine Strain), elicit an immune response protecting mice against subsequent challenge with the virulent SchuS4 strain, yet the protective immunity against pulmonary challenge is limited in its efficacy and longevity. We established a murine intra-nasal immunization model which distinguishes between animals fully protected, challenged at 4 weeks post double-vaccination (200 inhalation Lethal Dose 50%, LD50, of SchuS4), and those which do not survive the lethal SchuS4 infection, challenged at 8 weeks post double vaccination. Early in the recall immune response in the lung (before day 3), disease progression and bacterial dissemination differed considerably between protected and non-protected immunized mice. Pre-challenge analysis, revealed that protected mice, exhibited significantly higher numbers of lung Ft-specific memory T cells compared to non-protected mice. Quantitative PCR analysis established that a higher magnitude, lung T cells response was activated in the lungs of the protected mice already at 24 h post-challenge. The data imply that an early memory response within the lung is strongly associated with protection against the lethal SchuS4 bacteria presumably by restricting the dissemination of the bacteria to internal organs. Thus, future prophylactic strategies to countermeasure F. tularensis infection may require modulation of the immune response within the lung.
    Keywords Francisella tularensis ; T-lymphocytes ; bacteria ; breathing ; cell-mediated immunity ; disease course ; immune response ; lethal dose 50 ; live vaccines ; longevity ; lungs ; mice ; models ; pathogens ; quantitative polymerase chain reaction ; tularemia ; vaccination ; virulence
    Language English
    Size p. .
    Publishing place Elsevier Ltd
    Document type Article
    Note Pre-press version
    ZDB-ID 605674-x
    ISSN 1873-2518 ; 0264-410X
    ISSN (online) 1873-2518
    ISSN 0264-410X
    DOI 10.1016/j.vaccine.2017.10.053
    Database NAL-Catalogue (AGRICOLA)

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