A broadly ranging, simple and rapid method for counting cells on carriers is described and exemplified using Fibra-Cel macro carriers. Authors show employment of the method as part of the development of SARS-CoV-2 vaccine to track cell adsorption, cell growth and viability on carriers. The method provides comprehensive details necessary for process control of viral vaccine production in cells and can be easily implemented in any cell-based processes and other unique platforms for measuring growth of encapsulated cells.
Published: Biotechnology & Bioengineering, 10 of June, 2021
An in vitro binding assay between the receptor binding domain (RBD) of SARS-CoV-2 and ACE2 was developed, and applied to identify inhibitors by screening of two compound libraries for COVID-19 drug repurposing. Three compounds, heparin sodium, aurintricarboxylic acid (ATA), and ellagic acid, were found to exert an effective binding inhibition. A plaque reduction assay in Vero E6 cells infected with VSV-SARS-CoV-2-S, a SARS-CoV-2 surrogate virus, confirmed the inhibition efficacy of heparin sodium and ATA. Molecular docking analysis located potential binding sites of these compounds in the RBD.
Published: Molecules, 27 of May 2021
Here we report the isolation, characterization, and recombinant production of 12 neutralizing human mAbs, targeting three distinct epitopes on the spike N-terminal domain of the virus. Neutralization mechanism of these antibodies involves receptors other than the canonical hACE2 on target cells, relying both on amino acid and N-glycan epitope recognition, suggesting alternative viral cellular portals. Two selected mAbs demonstrated full protection of K18-hACE2 transgenic mice when administered at low doses and late postexposure, demonstrating the high potential of the mAbs for therapy of SARSCoV-2 infection.
Published: iScience. 21 of May 2021
Coronaviruses developed varied mechanisms to repress host mRNA translation to allow the translation of viral mRNAs and concomitantly block the cellular innate immune response. Yet, comprehensive picture of the effects of SARS-CoV-2 infection on cellular gene expression is lacking. In a collaboration study between scientists at the IIBR and the Weizmann Institute of Science, we combined RNA-sequencing, ribosome profiling and metabolic labeling of newly synthesized RNA, to comprehensively define the mechanisms that are utilized by SARS-CoV-2 to shutoff cellular protein synthesis. We show that infection leads to accelerated degradation of cytosolic cellular mRNAs which facilitates viral takeover of the mRNA pool in infected cells. Moreover, we reveal that the translation of transcripts whose expression is induced in response to infection, including innate immune genes, is impaired. We demonstrate this impairment is likely mediated by inhibition of nuclear mRNA export, preventing newly transcribed cellular mRNAs from accessing ribosomes. Overall, our results uncover the multipronged strategy employed by SARS-CoV-2 to commandeer the translation machinery and to suppress host defenses.
Published: Nature, 21 Of May 2021
The current study documents the successful identification and recombinant production of a set of anti-RBD and anti-NTD-specific mAbs isolated by a single-cell sorting strategy of lymphocytes collected from rabbits immunized with different spike-derived antigens. These antibodies were characterized as having high specificity and affinity profiles. Anti-RBD antibodies showed in vitro neutralizing potency against SARS-CoV-2 directed to a novel epitope within the RBD. These antibodies may represent the basis for future development of immunodiagnostics and immunotherapy.
Publishe: Viruses, 26 of March, 2021
In the present study, we characterized and further evaluated the recently identified human monoclonal MD65 antibody for its ability to provide protection against a lethal SARS-CoV-2 infection of K18-hACE2 transgenic mice. 75% of the untreated mice succumbed 6-9 days post-infection while administration of the MD65 antibody as late as 3 days after exposure, rescued all infected animals. The data unprecedentedly demonstrate, the therapeutic value of human monoclonal antibodies as a life-saving treatment of severe COVID-19 infection.
Published: Nature Communications, 11 February 2021
A development of a novel assay for SARS-CoV-2 identification using LC-MS/MS analysis. A multi-step procedure for the rational down-selection of a set of markers has leaded to the discovery of six SARS-CoV-2 specific and sensitive markers, enabling the reliable identification of the virus. A rapid and simple assay was developed, successfully applied to clinical nasopharyngeal samples. The assay may potentially serve as a complementary approach for SARS-CoV-2 identification.
Published: American chemical Society, 26 January 2021
We report the genome sequences and the identification of genetic variations in eight clinical samples of SARS-CoV-2 collected from individuals from elderly and infirm persons in Israel. The variant calling process revealed a total of 51 substitutions that were previously documented, and one non-synonymous replacement, that has not been documented before, and is located in the nucleocapsid protein. Mapping and identification of new mutations may contribute to a better understanding of the viral factors related to the clinical outcomes of the disease.
Published: Microbiology Resource Announcements, 7 January 2021
A vaccine against SARS-CoV-2 based on a recombinant virus expressing the SARS-CoV-2 spike protein was developed. The efficacy of the vaccine was demonstrated by a rapid and potent induction of neutralizing antibodies against SARS-CoV-2. Moreover, a single dose vaccination was able to protect hamsters against SARS-CoV-2.
Published: Natune communications, 16 December 2020
This is our vaccine's story from research to production
An important milestone was completed.
To estimate the risk of SARS-CoV-2 transmission to humans by surface contact, we examined the stability of the virus on variety of surfaces, typical of urban environment or patient environment. We used PCR to detect the virus, tissue culture based growth test to determine virus viability and ability to infect new host. At room temperature, SARS-CoV-2 gradually loss its viability and decay completely at day 4. The decay rate increases at higher temperatures. About 50% of the samples from the patient surrounding were PCR positive while none of them was viable (0/97), therefore, aerosol or indirect transmission from inanimate surfaces around hospitalized or quarantined COVID-19 patients is not supported by the data presented in this study. Fomite transmission may still be a possibility with heavily contaminated surfaces around patients during their most contagious stages of infection, and in closed and crowded environments.
Published: Clinical Microbiology and Infection, 10 September 2020
A research collaboration between the Israel Institute for Biological Research, in Ness Ziona and the Weizmann Institute of Science, Israel uncovered the coding capacity of the SARS CoV-2 virus. The researchers applied an innovative method of tracking translating ribosomes on their RNA template and converting the data into a translational-map of all the proteins being translated in the infected cells. Using this innovative method, resulted in the identification of 23 new short protein (peptide) sequences in the SARS-CoV-2 genome that can contribute in a regulatory function, but four were full-fledged proteins and might serve as new tools in diagnostic, prevention or treatment of COVID-19.
Published: Nature 9 September 2020
IIBR scientists have isolated and characterized a panel of human neutralizing monoclonal antibodies targeting the SARS-CoV-2 receptor-binding domain (RBD). These antibodies were selected from a phage display library constructed using peripheral circulatory lymphocytes collected from patients at the acute phase of the disease. These neutralizing antibodies are shown to recognize distinct epitopes on the viral spike RBD, therefore they represent a promising basis for the design of efficient combined treatment of COVID-19 patients or for prophylaxis immunization.
Published: Nature Comminications, 27 August 2020
Selected excerpts from IIBR’s Director General, Prof. Shmuel C. Shapira’s session to the Science and Technology Committee at The Knesset
SARS-Cov-2 genetic identification is based on viral RNA extraction prior to RT -qPCR assay. Our findings show advantage for the extraction procedure, however a direct no-buffer approach might be an alternative, since it identified up to 70% pf positive clinical specimens.
Published: International Journal of Infectious Diseases, 5 August 2020
We announce the genome sequences of two strains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolated in Israel, one imported by a traveler who returned from Japan and the second strain collected from a patient infected by a traveler returning from Italy. The sequences obtained are valuable as early manifestations for future follow-up of the local spread of the virus in Israel.
Published: Microbiology Resource Announcements, 9 July 2020
We tested the efficacy of face shields as a substitution for medical masks in blocking cough-like generated spray. Our results imply that blocking efficacy of face shields is similar, and for some parts of the face, even higher, than the efficacy of medical masks. This is even truer for fine particles, which are blocked much more efficiently by a shield. Considering other advantages of shields, public health policy makers may consider the usage of face shields as an alternative to medical masks for the general population.
A new study examined the antiviral effect of two specific inhibitors of GlucosylCeramide synthase (GCS): (1). an analogue of the FDA-approved drug Cerdelga®, (2) an analogue of venglustat which is currently in phase III clinical trials. Our findings show that both inhibitors inhibit the replication of four different enveloped RNA viruses of different genus, organ-target and transmission route, including SARS-Cov-2. The fact that these inhibitors have an antiviral effect on viruses of four different families, suggests a key role of the glycosphingolipid synthesis pathway in viral infection. Targeting host proteins or pathways utilized by multiple viruses is less prone to the development of resistance to the drug through mutations.
It is not clear what mechanism enables infection by pre-symptomatic COVID-19 individuals, especially in indoors environments. IIBR scientists have answered this question by formulating an evidence-based mathematical model. The major infection mechanism was found to be physical person-to-person contact. Infection may be induced by touching fomites (small, frequently touched surfaces) but it is highly unlikely to be infected by airborne route. Both contact routes are induced by pre-symptomatic individuals touching their facial membranes with their hand and then touching other people or fomites. The conclusion is that the social distance directive should be clarified in order to emphasize the importance of refrain from any physical contact.
IIBR will continue to characterize these antibodies and others and a biological manufacture would be sought to mass produce it for clinical use.
A joint ongoing study led by IIBR researchers and physicians from Laniado and Assuta Ashdod hospitals tested the viability of corona virus in patient‘s environment surfaces. The study reveals low probability of being infected due to surface contact.
IIBR, using its Biology division's well-established platform for antibody engineering, have managed to isolate a monoclonal antibody against the virus, from blood samples that were obtain from severe COVID19 patients. It was also demonstrated that this antibody was able to effectively neutralize the virus. Parallel efforts are being made worldwide. Some have managed to isolate antibodies that neutralize other closely related viruses and even anti-SARS-CoV-2 monoclonal antibodies, but IIBR is the first to demonstrate that the antibody that was isolated from COVID19 patient can indeed neutralize this pathogen. IIBR will continue to characterize this antibody and others and a biological manufacture would be sought to mass produce it for clinical use.
IIBR Director General, Professor Shmuel Shapira, informed Prime Minister Benjamin Netanyahu of "significant progress" in designing a vaccine prototype and that the institute "is now preparing a model for commencing an animal trial".
The Israel institute for biological research is assigned by the Israeli Prime mister, Mr. Benjamin Netanyahu, to produce a vaccine and antibody for the Novel Coronavirus.