scholarly journals Chemical modification of the adeno-associated virus capsid to improve gene delivery

2020 ◽  
Vol 11 (4) ◽  
pp. 1122-1131 ◽  
Author(s):  
Mathieu Mével ◽  
Mohammed Bouzelha ◽  
Aurélien Leray ◽  
Simon Pacouret ◽  
Mickael Guilbaud ◽  
...  
Keyword(s):  
Gene Delivery ◽  
Chemical Modification ◽  
Neutralizing Antibodies ◽  
Cell Tropism ◽  
Amino Groups ◽  
Chemical Modifications ◽  
Virus Capsid ◽  
Adeno Associated Virus

Bioconjugated AAV vectors, achieved by coupling of ligands on amino groups of the capsid, are of great interest for gene delivery. Chemical modifications can be used to enhance cell tropism and to decrease interactions with neutralizing antibodies.

scholarly journals Examining the cross-reactivity and neutralization mechanisms of a panel of mAbs against adeno-associated virus serotypes 1 and 5

2012 ◽  
Vol 93 (2) ◽  
pp. 347-355 ◽  
Author(s):  
Carole E. Harbison ◽  
Wendy S. Weichert ◽  
Brittney L. Gurda ◽  
John A. Chiorini ◽  
Mavis Agbandje-McKenna ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Gene Delivery ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Viral Infections ◽  
Cross Reactivity ◽  
Adeno Associated Virus ◽  
Viral Capsids ◽  
Serotype 1 ◽  
Antigenic Epitopes

Neutralizing antibodies play a central role in the prevention and clearance of viral infections, but can be detrimental to the use of viral capsids for gene delivery. Antibodies present a major hurdle for ongoing clinical trials using adeno-associated viruses (AAVs); however, relatively little is known about the antigenic epitopes of most AAV serotypes or the mechanism(s) of antibody-mediated neutralization. We developed panels of AAV mAbs by repeatedly immunizing mice with AAV serotype 1 (AAV1) capsids, or by sequentially immunizing with AAV1 followed by AAV5 capsids, in order to examine the efficiency and mechanisms of antibody-mediated neutralization. The antibodies were not cross-reactive between heterologous AAV serotypes except for a low level of recognition of AAV1 capsids by the AAV5 antibodies, probably due to the initial immunization with AAV1. The neutralization efficiency of different IgGs varied and Fab fragments derived from these antibodies were generally poorly neutralizing. The antibodies appeared to display various alternative mechanisms of neutralization, which included inhibition of receptor-binding and interference with a post-attachment step.

scholarly journals High-Resolution Structural Characterization of a New Adeno-associated Virus Serotype 5 Antibody Epitope toward Engineering Antibody-Resistant Recombinant Gene Delivery Vectors

2018 ◽  
Vol 93 (1) ◽  
Author(s):  
Ariana Jose ◽  
Mario Mietzsch ◽  
J. Kennon Smith ◽  
Justin Kurian ◽  
Paul Chipman ◽  
...  
Keyword(s):  
High Resolution ◽  
Gene Delivery ◽  
Neutralizing Antibodies ◽  
Immune Escape ◽  
The United States ◽  
Adeno Associated Virus ◽  
Virus Serotype ◽  
Serotype 5 ◽  
Density Map

ABSTRACTAdeno-associated virus serotype 5 (AAV5) is being developed as a gene delivery vector for several diseases, including hemophilia and Huntington’s disease, and has a demonstrated efficient transduction in liver, lung, skeletal muscle, and the central nervous system. One limitation of AAV gene delivery is preexisting neutralizing antibodies, which present a significant challenge for vector effectiveness in therapeutic applications. Here, we report the cryo-electron microscopy (cryo-EM) and image-reconstructed structure of AAV5 in complex with a newly generated monoclonal antibody, HL2476, at 3.1-Å resolution. Unlike other available anti-AAV5 capsid antibodies, ADK5a and ADK5b, with epitopes surrounding the 5-fold channel of the capsid, HL2476 binds to the 3-fold protrusions. To elucidate the capsid-antibody interactions, the heavy and light chains were sequenced and their coordinates, along with the AAV5 viral protein, assigned to the density map. The high resolution of the complex enabled the identification of interacting residues at the 3-fold protrusions of the capsid, including R483, which forms two hydrogen bonds with the light chain of HL2476. A panel of AAV5 variants was generated and analyzed by native dot immunoblot and transduction assays. This identified variants with antibody escape phenotypes that maintain infectivity.IMPORTANCEBiologics based on recombinant AAVs (rAAVs) are increasingly becoming attractive human gene delivery vehicles, especially after the approval of Glybera in Europe and Luxturna in the United States. However, preexisting neutralizing antibodies against the AAV capsids in a large percentage of the human population limit wide-spread utilization of these vectors. To circumvent this problem, stealth vectors must be generated that are undetectable by these antibodies. This study details the high-resolution characterization of a new antigenic region on AAV5, a vector being developed for numerous delivery applications. The structure of AAV5 complexed with HL2476, a novel antibody, was determined by cryo-EM to 3.1-Å resolution. The resolution of the density map enabled the identification of interacting residues between capsid and antibody and the determinants of neutralization. Thus, the information obtained from this study can facilitate the generation of host immune escape vectors.

Recent advances in the analysis full/empty capsid ratio and genome integrity of adeno-associated virus (AAV) gene delivery vectors

2020 ◽  
Vol 20 ◽  
Author(s):  
L. Hajba ◽  
A. Guttman
Keyword(s):  
Gene Delivery ◽  
High Efficiency ◽  
Analytical Techniques ◽  
Viral Gene ◽  
Adeno Associated Virus ◽  
Gene Delivery Vectors ◽  
Empty Capsid ◽  
Purification Methods ◽  
Viral Gene Delivery

: Adeno-associated virus (AAV) is one of the most promising viral gene delivery vectors with long-term gene expression and disease correction featuring high efficiency and excellent safety in human clinical trials. During the production of AAV vectors,there are several quality control (QC)parameters that should be rigorously monitored to comply with clini-cal safety and efficacy. This review gives a short summary of the most frequently used AVV production and purification methods,focusing on the analytical techniques applied to determine the full/empty capsid ratio and the integrity of the encapsidated therapeutic DNA of the products.

scholarly journals Carbon Dot Nanoparticles: Exploring the Potential Use for Gene Delivery in Ophthalmic Diseases

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 935
Author(s):  
Manas R. Biswal ◽  
Sofia Bhatia
Keyword(s):  
Gene Delivery ◽  
Therapeutic Option ◽  
Retinal Dystrophy ◽  
Retinal Cells ◽  
Adeno Associated Virus ◽  
Inherited Retinal Dystrophies ◽  
Retinal Dystrophies ◽  
Efficient Gene ◽  
New Type ◽  
Viral Nanoparticles

Ocular gene therapy offers significant potential for preventing retinal dystrophy in patients with inherited retinal dystrophies (IRD). Adeno-associated virus (AAV) based gene transfer is the most common and successful gene delivery approach to the eye. These days, many studies are using non-viral nanoparticles (NPs) as an alternative therapeutic option because of their unique properties and biocompatibility. Here, we discuss the potential of carbon dots (CDs), a new type of nanocarrier for gene delivery to the retinal cells. The unique physicochemical properties of CDs (such as optical, electronic, and catalytic) make them suitable for biosensing, imaging, drug, and gene delivery applications. Efficient gene delivery to the retinal cells using CDs depends on various factors, such as photoluminescence, quantum yield, biocompatibility, size, and shape. In this review, we focused on different approaches used to synthesize CDs, classify CDs, various pathways for the intake of gene-loaded carbon nanoparticles inside the cell, and multiple studies that worked on transferring nucleic acid in the eye using CDs.

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