Posters

Oxford Symposia - 6th Annual

OLIGO 2020 OXFORD | Virtual

Antisense & Therapeutic Nucleic Acids

03rd December 2020

Twitter: @LPMHealthcare, #OligoOx20V

Posters and guidelines

Thank you for considering to present your work as a poster at Oligo 2020 (Oxford) Virtual.


Digital poster submission deadline: Prepare your poster as you would normally do for printing, and submit your final poster as both PDF and JPG/PNG files via the link below no later than 27th November 2020. Late posters may not be included in the conference programme. Please DO NOT send your poster files by email.


Naming your poster files: Name your poster files as follows: <your surname>-Oligo20V-Poster.pdf | <your surname>-Oligo20V-Poster.png | <your surname>-Oligo20V-Poster.jpg, etc. For example, for David Jones, name your file as Jones-Oligo20V-Poster.pdfDO NOT name your poster files as, e.g.,  Oxford-poster, Oligo2020v, Oxford-Oligo-poster. Such files will be automatically rejected.


Poster presentation: Posters will be made available via a secure page to the symposium participants before the meeting. There will be two ways to interact with the poster presenters:

  • the participants will be able to ask questions via the Zoom chatbox during the mid-conference break ; and/or
  • the participants can post their questions on Twitter at any time using the meeting hashtag #OligoOx20V, as well as the poster specific hashtag (given under each poster abstract) – do tag @LPMHealthcare in your tweets.

 

The poster presenters should regularly check Twitter for any questions about their posters before, during and after the meeting, and post their answers on Twitter using appropriate hashtags, as above.

Any further information about the poster presentations at this digital meeting will be available in the future.


Before uploading your poster, you must make sure that you follow ALL of the instructions above!

Upload your poster


(Presenters in Bold)

Accepted poster abstracts (Unedited) will be published below. If your abstract has been accepted for presentation but it does not appear in the list below, please let us know as soon as possible by email at OligoOxford@gmail.com.


Using attenuated anthrax toxin to mediate the cytosolic delivery of a peptide designed to inhibit androgen-dependent mitogenic signaling in prostate cancer

(#Abdelrahman, #OligoOx20V)

Hadeer KS Abdelrahman, Nourhan AM Mahmoud, Benedita KL Feron and Simon CW Richardson

Exogenix Laboratory, School of Science, University of Greenwich, Central Avenue, Chatham Maritime, Kent, UK, ME4 4TB

Prostate cancer is the second leading cause of cancer-related death in men. Previous studies have documented androgen and sarcoma (Src) receptor activation as a key contributor to the development of prostate cancer. Based on these findings, a peptide (IP-1) was developed to inhibit the association between sarcoma and androgen receptors. The purpose of this study was to assess the impact of intracellular compartmentalization upon IP-1 bioavailability. To this end, cytosolic delivery technology derived from attenuated anthrax toxin was used. This consisted of Bacillus anthracis protective antigen (PA) of 83 KDa (PA83) and the N-terminal 255 amino acids of Bacillus anthracis lethal factor (LFn). To mediate delivery, IP-1 was fused-in-frame with LFn (LFn-IP1) and co-incubated with PA83. HeLa cells were used to evaluate the impact of the delivery system upon the cytosolic distribution of LFn-IP1. Cells were treated with 50 µg/ml PA83 and 50µg/ml Texas Red (TxR)-labelled LFn-IP1. Following incubation periods of 1, 4 and 24h, LFn-IP1-TxR appeared in the peri-nuclear region; after which the protein was documented diffusing across the cytosol overtime. Cytosolic translocation of the complex was shown to be dependent upon PA83 by repeating the previous live cell imaging experiment without PA83. Under these conditions, LFn-IP1 was imaged within perinuclear endocytic LAMP1-positive vesicles but did not translocate to the cytosol. These data demonstrate for the first time that PA can mediate the delivery of IP1-TxR into the cytosol through the PA pore. In conclusion, these data indicate the potential utility of a cytosolic delivery system to improve upon protein therapeutic bioavailability.


Targeting Zika Virus (MR-766) with siRNA Using Polygenix Intracellular Delivery Technology

(#Feron, #OligoOx20V)

Benedita KL Feron, Joachim J Bugert1 and Simon CW Richardson

Exogenix Laboratory, School of Science, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK. 1Institut für Mikrobiologie der Bundeswehr, Munich, Germany

Here we present empirical data documenting the siRNA-mediated protection of cells after Zika virus (ZIKV) MR-766 infection. These siRNA sequences were designed to target well-conserved sequences across the ZIKV genome. Several delivery technologies were utilised. After the electroporation of 100nM siRNA into human hepatocyte-derived carcinoma (Huh7) cells, the Feron Zv-2 sequence (specific to the ZIKV NS3 gene) yielded a cell viability of 150.3±7.4% (SEM: n=4) (p=0.0004) relative to cells treated only with virus (33.9±12%, SEM: n=4). Further, 100nM siRNA Feron Zv-4 (specific to ZIKV 3’UTR) resulted in 119.1±11.2% cell viability (SEM: n=4) relative to the control cells treated with ZIKV (p=0.0021). Cells were electroporated with siRNA prior to ZIKV infection and viability was monitored 4 days after this. Additionally, two novel siRNA delivery systems were tested. The first utilized recombinant Bacillus anthracis PA83 (octomer forming mutants) co-incubated with the N-terminal 255 amino acids of B.anthracis lethal factor (LFn) fused-in-frame with the RNA binding domain for human protein kinase R (LFn-PKR) at a concentration of 50µg/ml (each). Here, baby hamster kidney (BHK) cells treated with 100nM siRNA Feron Zv-1 yielded 79.0±4.0% viability relative to the control (50.2±1.7%, SEM: n=3), 3 days after exposure to ZIKV (p=0.0096). Finally, HeLa exosomes loaded with siRNA Feron-Zv2 were incubated with Huh7 cells prior to ZIKV infection. For the siRNA-exosome treated cells, a viability of 123±46% (SEM: n=18) relative to 8±16% (SEM: n=18) for the same concentration of control HeLa exosomes was recorded (p=0.0416). In each instance, 0.3 MoI was used and cell viability monitored using the PierceTM Firefly Luciferase Glow Assay Kit by Thermo ScientificTM.  Here, it has been shown for the first time that siRNA can significantly reduce ZIKV-derived cell kill. Future work will require quantitating ZIKV mRNA in relation to siRNA treatment as well as testing the siRNAs and delivery systems within more complex models.


Attenuated anthrax toxin mediated siRNA cytosolic translocation requires intraluminal vesicles

(#Mahmoud, #OligoOx20V)

Nourhan AM Mahmoud, Hadeer KS Abdelrahman, Benedita KL Feron and Simon CW Richardson*

Exogenix Laboratory, School of Science, University of Greenwich, Central Avenue, Chatham Maritime, Kent, UK

Post-endocytic intracellular trafficking is an established rate limit for the effective use of membrane non-permeant drugs such as plasmids, gene editing proteins, small-interfering RNA (siRNA) and antisense oligonucleotides (ASOs). Of the many proposed solutions to this problem, we have focused on the use of attenuated, recombinant Bacillus anthracis toxin (ATxn) which, when fused-in-frame to an RNA binding protein domain can enhance the activity of siRNA and ASOs by ~300%, without any measurable toxicity. Wildtype ATxn has been shown to utilize intraluminal vesicles (ILV) for the efficient cytosolic delivery of lethal factor (LF). Here, it was hypothesized that specific inhibitors of ILV formation or function, would reduce the cytosolic translocation efficiency of the ATxn-mediated delivery of siRNA (via the formation of a PA83 : LF truncation (LFn) fused to either the RNA binding domain for protein kinase R (LFnPKR)) or a protein, i.e. diphtheria toxin A chain (LFnDTA). The possibility that wheat germ agglutinin (WGA) may inhibit ILV formation reducing cytosolic translocation efficiency was considered, due to the protein’s ability to cross-link cell membrane. WGA’s ability to reduce cytosolic access was tested by treating HeLa cells with 50 µg/ml PA83 and 10 µg/ml LFnDTA and monitoring cell viability recorded as 23.0±0.5 % (n=3±SEM). After the addition of 5 µg/ml WGA prior to PA83 and LFnDTA cell viability recorded as being 112.9±0.3% (n=3±SEM). Having established that WGA could inhibit PA translocase activity, WGAs effect on siRNA translocation was evaluated by monitoring siRNA activity in HEK293 (SC008) cells overexpressing beta-galactosidase. In this instance, gene knockdown was achieved using 100nM siRNA, 50 µg/ml PA83 and 50 µg/ml LFn-PKR and measured 48h after transfection. This resulted in 11.5 ± 0.3% target gene expression (n=3±SEM). Optimal inhibition of PA::LFnPKR::siRNA translocation by WGA was documented at 3µg/ml, resulting in 48.2±2.1% target gene expression (n=3±SEM), revealing significant reduction in siRNA activity (p=0.008). These findings support the hypothesis that WGA inhibits ILV formation and that ILV formation is required for the efficient PA83-mediated translocation of both LFnDTA and LFnPKR::siRNA into the cytosol via ILVs. This would indicate that PA is not simply destabilizing the limiting membrane of the endosome in order to facilitate cytosolic access.


Development of DNA aptamers against enzymes of the methylerythritol phosphate pathway

(#CRoca, #OligoOx20V)

Carlota Roca1,2, Santiago Imperial1, Xavier Fernàndez-Busquets2

1Department of Biochemistry and Molecular Biomedicine, School of Biology, University of Barcelona. Av. Diagonal 643, ES08028-Barcelona, Spain

2Nanomalaria Joint Unit. Institute for Bioengineering of Catalonia (IBEC) and Barcelona Institute for Global Health (ISGlobal). Centre Esther Koplowitz, planta 1, ISGlobal, Rosselló 149-153, ES08036 Barcelona, Spain

Malaria is a disease caused by parasites of the genus Plasmodium and transmitted by female Anopheles mosquitoes. According to the most recent data, it is estimated that 228 million cases of malaria occurred worldwide in 2018, which led to 405,000 deaths. Due to the resistance acquired by Plasmodium to antimalarial drugs, the global technical strategy against malaria (World Health Organization, Strategic Plan 2016-2030) contemplates the search for solutions to the threat of the emerging resistance to antimalarials. Plasmodium parasites have an organelle called apicoplast, which offers numerous new targets for drug therapy because it contains a range of metabolic pathways and enzymes not found in human cells. Of these pathways, the enzymes required for biosynthesis of isoprenoid precursors, isopentenyl diphosphate and its isomer dimethylallyl diphosphate are particularly attractive because they are essential for the survival of the parasite. These precursors are produced in Plasmodium from pyruvate and D-glyceraldehyde 3-phosphate via the methylerythritol phosphate (MEP) pathway. Thus, as an antimalarial therapeutic alternative, we propose the development of aptamers inhibiting key enzymes of the MEP pathway. Several methods have been optimized, such as: (i) the production of MEP pathway enzymes, (ii) the development of aptamers by Systematic Evolution of Ligands by Exponential Enrichment, (iii) the cloning of aptamers, (iv) the establishment of an Electrophoretic Motility Shift Assay for the identification of interactions between selected aptamers and their target enzymes, and (v) methods for the in vitro evaluation of enzymatic activity. Among the most outstanding results, we have identified an aptamer that in preliminary analyses interact with the enzyme 1-deoxy-D-xylulose-5-phosphate reductoisomerase, a key enzyme of the MEP pathway. Taking everything into account, this aptamer shows potential applications as a Plasmodium falciparum biomarker and in malaria therapeutics.