Publications by authors named "Aadil El Turabi"

13 Publications

  • Page 1 of 1

Type of RNA Packed in VLPs Impacts IgG Class Switching-Implications for an Influenza Vaccine Design.

Vaccines (Basel) 2019 Jun 4;7(2). Epub 2019 Jun 4.

The Jenner Institute, Oxford University, Oxford OX3 7BN, UK.

Nucleic acid packed within virus-like particles (VLPs) is shown to shape the immune response and to induce stronger B cell responses in different immunisation models. Here, using a VLP displaying the highly conserved extracellular domain of the M2 protein (M2e) from the influenza viruses as an antigen, we demonstrate that the type of RNA packaged into VLPs can alter the quality of the induced humoral response. By comparing prokaryotic RNA (pRNA), eukaryotic RNA (eRNA) and transfer RNA (tRNA), we find that pRNA induces the most protective IgG subclasses using a murine influenza model. We provide evidence that this process is predominantly dependent on endosomal Toll-like receptor (TLR7), and rule out a role for cytoplasmic mitochondrial antiviral signalling protein (MAVS) and its upstream retinoic acid-inducible gene-I-like receptors (RIG-I). Our findings provide considerations for the rational design of VLP-based vaccines and the immunomodulation exerted by TLR7 ligands packaged within the particles. Based on this work, we conclude that VLPs packing prokaryotic RNA must be preferred whenever a response dominated by IgG2 is desired, while eukaryotic RNA should be employed in order to induce a response dominated by IgG1.
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http://dx.doi.org/10.3390/vaccines7020047DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6630894PMC
June 2019

Targeting Mutated Plus Germline Epitopes Confers Pre-clinical Efficacy of an Instantly Formulated Cancer Nano-Vaccine.

Front Immunol 2019 15;10:1015. Epub 2019 May 15.

Nuffield Department of Medicine, Jenner Institute, University of Oxford, Oxford, United Kingdom.

Personalized cancer vaccines hold promises for future cancer therapy. Targeting neoantigens is perceived as more beneficial compared to germline, non-mutated antigens. However, it is a practical challenge to identify and vaccinate patients with neoantigens. Here we asked whether two neoantigens are sufficient, and whether the addition of germline antigens would enhance the therapeutic efficacy. We developed and used a personalized cancer nano-vaccine platform based on virus-like particles loaded with toll-like receptor ligands. We generated three sets of multi-target vaccines (MTV) to immunize against the aggressive B16F10 murine melanoma: one set based on germline epitopes (GL-MTV) identified by immunopeptidomics, another set based on mutated epitopes (Mutated-MTV) predicted by whole exome sequencing and a last set combines both germline and mutated epitopes (Mix-MTV). Our results demonstrate that both germline and mutated epitopes induced protection but the best therapeutic effect was achieved with the combination of both. Our platform is based on Cu-free click chemistry used for peptide-VLP coupling, thus enabling bedside production of a personalized cancer vaccine, ready for clinical translation.
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http://dx.doi.org/10.3389/fimmu.2019.01015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6532571PMC
September 2020

Correction to: Vaccination with nanoparticles combined with micro-adjuvants protects against cancer.

J Immunother Cancer 2019 May 23;7(1):137. Epub 2019 May 23.

Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK.

Following publication of the original article [1], the author reported an author's family name has been misspelled. Paul Engroff should be replace Paul Engeroff.Furthermore, there are two mistake in two affiliations: 9) Department of dermatology, University of Zurich, Bern, Switzerland and 10) Department of Oncology, University of Lausanne, Bern,Switzerland should be replace with 9) Department of dermatology, University of Zurich, Zurich, Switzerland.10) Department of Oncology, University of Lausanne, Lausanne, Switzerland.
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http://dx.doi.org/10.1186/s40425-019-0616-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6532182PMC
May 2019

Vaccination with nanoparticles combined with micro-adjuvants protects against cancer.

J Immunother Cancer 2019 04 26;7(1):114. Epub 2019 Apr 26.

Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK.

Background: Induction of strong T cell responses, in particular cytotoxic T cells, is a key for the generation of efficacious therapeutic cancer vaccines which yet, remains a major challenge for the vaccine developing world. Here we demonstrate that it is possible to harness the physiological properties of the lymphatic system to optimize the induction of a protective T cell response. Indeed, the lymphatic system sharply distinguishes between nanoscale and microscale particles. The former reaches the fenestrated lymphatic system via diffusion, while the latter either need to be transported by dendritic cells or form a local depot.

Methods: Our previously developed cucumber-mosaic virus-derived nanoparticles termed (CuMV-VLPs) incorporating a universal Tetanus toxoid epitope TT830-843 were assessed for their draining kinetics using stereomicroscopic imaging. A nano-vaccine has been generated by coupling p33 epitope as a model antigen to CuMV-VLPs using bio-orthogonal Cu-free click chemistry. The CuMV-p33 nano-sized vaccine has been next formulated with the micron-sized microcrystalline tyrosine (MCT) adjuvant and the formed depot effect was studied using confocal microscopy and trafficking experiments. The immunogenicity of the nanoparticles combined with the micron-sized adjuvant was next assessed in an aggressive transplanted murine melanoma model. The obtained results were compared to other commonly used adjuvants such as B type CpGs and Alum.

Results: Our results showed that CuMV-VLPs can efficiently and rapidly drain into the lymphatic system due to their nano-size of ~ 30 nm. However, formulating the nanoparticles with the micron-sized MCT adjuvant of ~ 5 μM resulted in a local depot for the nanoparticles and a longer exposure time for the immune system. The preclinical nano-vaccine CuMV-p33 formulated with the micron-sized MCT adjuvant has enhanced the specific T cell response in the stringent B16F10p33 murine melanoma model. Furthermore, the micron-sized MCT adjuvant was as potent as B type CpGs and clearly superior to the commonly used Alum adjuvant when total CD8, specific p33 T cell response or tumour protection were assessed.

Conclusion: The combination of nano- and micro-particles may optimally harness the physiological properties of the lymphatic system. Since the nanoparticles are well defined virus-like particles and the micron-sized adjuvant MCT has been used for decades in allergen-specific desensitization, this approach may readily be translated to the clinic.
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http://dx.doi.org/10.1186/s40425-019-0587-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6485085PMC
April 2019

Active immunisation targeting nerve growth factor attenuates chronic pain behaviour in murine osteoarthritis.

Ann Rheum Dis 2019 05 12;78(5):672-675. Epub 2019 Mar 12.

Kennedy Institute of Rheumatology, University of Oxford, Oxford, UK

Objectives: Nerve growth factor (NGF) has emerged as a key driver of pain in osteoarthritis (OA) and antibodies to NGF are potent analgesics in human disease. Here, we validate a novel vaccine strategy to generate anti-NGF antibodies for reversal of pain behaviour in a surgical model of OA.

Methods: Virus-like particles were derived from the cucumber mosaic virus (CuMV) and coupled to expressed recombinant NGF to create the vaccine. 10-week-old male mice underwent partial meniscectomy to induce OA or sham-surgery. Spontaneous pain behaviour was measured by Linton incapacitance and OA severity was quantified using OARSI histological scoring. Mice (experimental and a sentinel cohort) were inoculated with CuMVtt (Vax) or CuMVtt (Mock) either before surgery or once pain was established. Efficacy of anti-NGF from the plasma of sentinel vaccinated mice was measured in vitro using a neurite outgrowth assay in PC12 cells.

Results: Anti-NGF titres were readily detectable in the vaccinated but not mock vaccinated mice. Regular boosting with fresh vaccine was required to maintain anti-NGF titres as measured in the sentinel cohort. Both prophylactic and therapeutic vaccination demonstrated a reversal of pain behaviour by incapacitance testing, and a meta-analysis of the two studies showing analgesia at peak anti-NGF titres was highly statistically significant. Serum anti-NGF was able to inhibit neurite outgrowth equivalent to around 150 ug/mL of recombinant monoclonal antibody.

Conclusions: This study demonstrates therapeutic efficacy of a novel NGF vaccine strategy that reversibly alleviates spontaneous pain behaviour in surgically induced murine OA.
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http://dx.doi.org/10.1136/annrheumdis-2018-214489DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6517802PMC
May 2019

The Prospects of an Active Vaccine Against Asthma Targeting IL-5.

Front Microbiol 2018 24;9:2522. Epub 2018 Oct 24.

Department of Immunology, RIA, University Hospital Bern, Bern, Switzerland.

Allergen-specific T helper type 2 (Th2) responses followed by eosinophilic inflammation of the lung are important causes of allergic asthma. Interleukin-5 (IL-5) is a master regulator of eosinophil differentiation as well as activation. Blocking IL-5 using monoclonal antibodies (mAbs) against IL-5 is a powerful way to improve asthmatic symptoms in patients with an eosinophilic component of the disease. We have previously shown that vaccination against IL-5 can abrogate eosinophilic inflammation of the lung in allergic mice. More recently, we have demonstrated that eosinophil-mediated skin disease in horses with insect bite hypersensitivity can be strongly reduced by vaccination against IL-5. Here we would like to propose the development of a similar vaccine for the treatment of asthma in humans.
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http://dx.doi.org/10.3389/fmicb.2018.02522DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6207595PMC
October 2018

Incorporation of tetanus-epitope into virus-like particles achieves vaccine responses even in older recipients in models of psoriasis, Alzheimer's and cat allergy.

NPJ Vaccines 2017 23;2:30. Epub 2017 Oct 23.

HealVax GmbH, Bahnhofstrasse, 138808 Pfäffikon Switzerland.

Monoclonal antibodies are widely used to treat non-infectious conditions but are costly. Vaccines could offer a cost-effective alternative but have been limited by sub-optimal T-cell stimulation and/or weak vaccine responses in recipients, for example, in elderly patients. We have previously shown that the repetitive structure of virus-like-particles (VLPs) can effectively bypass self-tolerance in therapeutic vaccines. Their efficacy could be increased even further by the incorporation of an epitope stimulating T cell help. However, the self-assembly and stability of VLPs from envelope monomer proteins is sensitive to geometry, rendering the incorporation of foreign epitopes difficult. We here show that it is possible to engineer VLPs derived from a non human-pathogenic plant virus to incorporate a powerful T-cell-stimulatory epitope derived from Tetanus toxoid. These VLPs (termed CMV) retain self-assembly as well as long-term stability. Since Th cell memory to Tetanus is near universal in humans, CMV-based vaccines can deliver robust antibody-responses even under limiting conditions. By way of proof of concept, we tested a range of such vaccines against chronic inflammatory conditions (model: psoriasis, antigen: interleukin-17), neurodegenerative (Alzheimer's, β-amyloid), and allergic disease (cat allergy, Fel-d1), respectively. Vaccine responses were uniformly strong, selective, efficient , observed even in old mice, and employing low vaccine doses. In addition, randomly ascertained human blood cells were reactive to CMV-VLPs, confirming recognition of the incorporated Tetanus epitope. The CMV-VLP platform is adaptable to almost any antigen and its features and performance are ideally suited for the design of vaccines delivering enhanced responsiveness in aging populations.
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http://dx.doi.org/10.1038/s41541-017-0030-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5653761PMC
October 2017

Preclinical development of a vaccine against oligomeric alpha-synuclein based on virus-like particles.

PLoS One 2017 10;12(8):e0181844. Epub 2017 Aug 10.

The Jenner Institute, Nuffield Department of Medicine, The Henry Wellcome Building for Molecular Physiology, University of Oxford, Roosevelt Drive, Oxford, United Kingdom.

Parkinson's disease (PD) is a progressive and currently incurable neurological disorder characterised by the loss of midbrain dopaminergic neurons and the accumulation of aggregated alpha-synuclein (a-syn). Oligomeric a-syn is proposed to play a central role in spreading protein aggregation in the brain with associated cellular toxicity contributing to a progressive neurological decline. For this reason, a-syn oligomers have attracted interest as therapeutic targets for neurodegenerative conditions such as PD and other alpha-synucleinopathies. In addition to strategies using small molecules, neutralisation of the toxic oligomers by antibodies represents an attractive and highly specific strategy for reducing disease progression. Emerging active immunisation approaches using vaccines are already being trialled to induce such antibodies. Here we propose a novel vaccine based on the RNA bacteriophage (Qbeta) virus-like particle conjugated with short peptides of human a-syn. High titres of antibodies were successfully and safely generated in wild-type and human a-syn over-expressing (SNCA-OVX) transgenic mice following vaccination. Antibodies from vaccine candidates targeting the C-terminal regions of a-syn were able to recognise Lewy bodies, the hallmark aggregates in human PD brains. Furthermore, antibodies specifically targeted oligomeric and aggregated a-syn as they exhibited 100 times greater affinity for oligomeric species over monomer a-syn proteins in solution. In the SNCA-OVX transgenic mice used, vaccination was, however, unable to confer significant changes to oligomeric a-syn bioburden. Similarly, there was no discernible effect of vaccine treatment on behavioural phenotype as compared to control groups. Thus, antibodies specific for oligomeric a-syn induced by vaccination were unable to treat symptoms of PD in this particular mouse model.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0181844PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5552317PMC
October 2017

Virus-Like Particle (VLP) Plus Microcrystalline Tyrosine (MCT) Adjuvants Enhance Vaccine Efficacy Improving T and B Cell Immunogenicity and Protection against Plasmodium berghei/vivax.

Vaccines (Basel) 2017 May 2;5(2). Epub 2017 May 2.

The Jenner Institute, Nuffield Department of Medicine, Centre for Cellular and Molecular Physiology (CCMP), University of Oxford, Oxford OX3 7BN, UK.

Vaccination is the most effective prophylactic tool against infectious diseases. Despite continued efforts to control malaria, the disease still generally represents a significant unmet medical need. Microcrystalline tyrosine (MCT) is a well described depot used in licensed allergy immunotherapy products and in clinical development. However, its proof of concept in prophylactic vaccines has only recently been explored. MCT has never been used in combination with virus-like particles (VLPs), which are considered to be one of the most potent inducers of cellular and humoral immune responses in mice and humans. In the current study we assessed the potential of MCT to serve as an adjuvant in the development of a vaccine against malaria either alone or combined with VLP using thrombospondin-related adhesive protein (TRAP) as a target antigen. We chemically coupled PvTRAP to VLPs derived from the cucumber mosaic virus fused to a universal T-cell epitope of the tetanus toxin (CMVtt), formulated with MCT and compared the induced immune responses to PvTRAP formulated in PBS or Alum. The protective capacity of the various formulations was assessed using expressing PvTRAP. All vaccine formulations using adjuvants and/or VLP increased humoral immunogenicity for PvTRAP compared to the antigen alone. The most proficient responder was the group of mice immunized with the vaccine formulated with PvTRAP-VLP + MCT. The VLP-based vaccine formulated in MCT also induced the strongest T cell response and conferred best protection against challenge with recombinant . Thus, the combination of VLP with MCT may take advantage of the properties of each component and appears to be an alternative biodegradable depot adjuvant for development of novel prophylactic vaccines.
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http://dx.doi.org/10.3390/vaccines5020010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5492007PMC
May 2017

Adjusted Particle Size Eliminates the Need of Linkage of Antigen and Adjuvants for Appropriated T Cell Responses in Virus-Like Particle-Based Vaccines.

Front Immunol 2017 6;8:226. Epub 2017 Mar 6.

The Jenner Institute, Oxford University, Oxford, UK; Immunology, Inselspital, Bern, Switzerland.

Since the discovery of the first virus-like particle (VLP) derived from hepatitis B virus in 1980 (1), the field has expanded substantially. Besides successful use of VLPs as safe autologous virus-targeting vaccines, the powerful immunogenicity of VLPs has been also harnessed to generate immune response against heterologous and even self-antigens (2-4). Linking adjuvants to VLPs displaying heterologous antigen ensures simultaneous delivery of all vaccine components to the same antigen-presenting cells. As a consequence, antigen-presenting cells, such as dendritic cells, will process and present the antigen displayed on VLPs while receiving costimulatory signals by the VLP-incorporated adjuvant. Similarly, antigen-specific B cells recognizing the antigen linked to the VLP are simultaneously exposed to the adjuvant. Here, we demonstrate in mice that physical association of antigen, carrier (VLPs), and adjuvant is more critical for B than T cell responses. As a model system, we used the E7 protein from human papilloma virus, which spontaneously forms oligomers with molecular weight ranging from 158 kDa to 10 MDa at an average size of 50 nm. E7 oligomers were either chemically linked or simply mixed with VLPs loaded with DNA rich in non-methylated CG motifs (CpGs), a ligand for toll-like receptor 9. E7-specific IgG responses were strongly enhanced if the antigen was linked to the VLPs. In contrast, both CD4 and CD8 T cell responses as well as T cell-mediated protection against tumor growth were comparable for linked and mixed antigen formulations. Therefore, our data show that B cell but not T cell responses require antigen-linkage to the carrier and adjuvant for optimal vaccination outcome.
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http://dx.doi.org/10.3389/fimmu.2017.00226DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5337491PMC
March 2017

Evaluation of Plasmodium vivax Cell-Traversal Protein for Ookinetes and Sporozoites as a Preerythrocytic P. vivax Vaccine.

Clin Vaccine Immunol 2017 Apr 5;24(4). Epub 2017 Apr 5.

The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom

Four different vaccine platforms, each targeting the human malaria parasite cell-traversal protein for ookinetes and sporozoites (CelTOS), were generated and assessed for protective efficacy. These platforms consisted of a recombinant chimpanzee adenoviral vector 63 (ChAd63) expressing CelTOS (Ad), a recombinant modified vaccinia virus Ankara expressing CelTOS (MVA), CelTOS conjugated to bacteriophage Qβ virus-like particles (VLPs), and a recombinant CelTOS protein expressed in eukaryotic HEK293T cells (protein). Inbred BALB/c mice and outbred CD-1 mice were immunized using the following prime-boost regimens: Ad-MVA, Ad-VLPs, and Ad-protein. Protective efficacy against sporozoite challenge was assessed after immunization using a novel chimeric rodent parasite (CelTOS). This chimeric parasite expresses CelTOS in place of the endogenous CelTOS and produces fully infectious sporozoites. A single Ad immunization in BALB/c and CD-1 mice induced anti-CelTOS antibodies which were boosted efficiently using MVA, VLP, or protein immunization. CelTOS-specific gamma interferon- and tumor necrosis factor alpha-producing CD8 T cells were induced at high frequencies by all prime-boost regimens in BALB/c mice but not in CD-1 mice; in CD-1 mice, they were only marginally increased after boosting with MVA. Despite the induction of anti-CelTOS antibodies and CelTOS-specific CD8 T-cell responses, only low levels of protective efficacy against challenge with CelTOS sporozoites were obtained using any immunization strategy. In BALB/c mice, no immunization regimens provided significant protection against a CelTOS chimeric sporozoite challenge. In CD-1 mice, modest protective efficacy against challenge with chimeric sporozoites expressing either CelTOS or CelTOS was observed using the Ad-protein vaccination regimen.
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http://dx.doi.org/10.1128/CVI.00501-16DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5382829PMC
April 2017

Accelerating the clinical development of protein-based vaccines for malaria by efficient purification using a four amino acid C-terminal 'C-tag'.

Int J Parasitol 2017 06 30;47(7):435-446. Epub 2017 Jan 30.

The Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK. Electronic address:

Development of bespoke biomanufacturing processes remains a critical bottleneck for translational studies, in particular when modest quantities of a novel product are required for proof-of-concept Phase I/II clinical trials. In these instances the ability to develop a biomanufacturing process quickly and relatively cheaply, without risk to product quality or safety, provides a great advantage by allowing new antigens or concepts in immunogen design to more rapidly enter human testing. These challenges with production and purification are particularly apparent when developing recombinant protein-based vaccines for difficult parasitic diseases, with Plasmodium falciparum malaria being a prime example. To that end, we have previously reported the expression of a novel protein vaccine for malaria using the ExpreSDrosophila melanogaster Schneider 2 stable cell line system, however, a very low overall process yield (typically <5% recovery of hexa-histidine-tagged protein) meant the initial purification strategy was not suitable for scale-up and clinical biomanufacture of such a vaccine. Here we describe a newly available affinity purification method that was ideally suited to purification of the same protein which encodes the P. falciparum reticulocyte-binding protein homolog 5 - currently the leading antigen for assessment in next generation vaccines aiming to prevent red blood cell invasion by the blood-stage parasite. This purification system makes use of a C-terminal tag known as 'C-tag', composed of the four amino acids, glutamic acid - proline - glutamic acid - alanine (E-P-E-A), which is selectively purified on a CaptureSelect™ affinity resin coupled to a camelid single chain antibody, called NbSyn2. The C-terminal fusion of this short C-tag to P. falciparum reticulocyte-binding protein homolog 5 achieved >85% recovery and >70% purity in a single step purification directly from clarified, concentrated Schneider 2 cell supernatant under mild conditions. Biochemical and immunological analysis showed that the C-tagged and hexa-histidine-tagged P. falciparum reticulocyte-binding protein homolog 5 proteins are comparable. The C-tag technology has the potential to form the basis of a current good manufacturing practice-compliant platform, which could greatly improve the speed and ease with which novel protein-based products progress to clinical testing.
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http://dx.doi.org/10.1016/j.ijpara.2016.12.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5482323PMC
June 2017

Tandem fusion of hepatitis B core antigen allows assembly of virus-like particles in bacteria and plants with enhanced capacity to accommodate foreign proteins.

PLoS One 2015 1;10(4):e0120751. Epub 2015 Apr 1.

School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom.

The core protein of the hepatitis B virus, HBcAg, assembles into highly immunogenic virus-like particles (HBc VLPs) when expressed in a variety of heterologous systems. Specifically, the major insertion region (MIR) on the HBcAg protein allows the insertion of foreign sequences, which are then exposed on the tips of surface spike structures on the outside of the assembled particle. Here, we present a novel strategy which aids the display of whole proteins on the surface of HBc particles. This strategy, named tandem core, is based on the production of the HBcAg dimer as a single polypeptide chain by tandem fusion of two HBcAg open reading frames. This allows the insertion of large heterologous sequences in only one of the two MIRs in each spike, without compromising VLP formation. We present the use of tandem core technology in both plant and bacterial expression systems. The results show that tandem core particles can be produced with unmodified MIRs, or with one MIR in each tandem dimer modified to contain the entire sequence of GFP or of a camelid nanobody. Both inserted proteins are correctly folded and the nanobody fused to the surface of the tandem core particle (which we name tandibody) retains the ability to bind to its cognate antigen. This technology paves the way for the display of natively folded proteins on the surface of HBc particles either through direct fusion or through non-covalent attachment via a nanobody.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0120751PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4382129PMC
December 2015