Biology subjects

Zabaleta, N.

Publications and source records attributed to Zabaleta, N..

3 recordsLinked to original sources

bioRxiv2023

Correlating physicochemical and biological properties to define critical quality attributes of a recombinant AAV vaccine candidate

Recombinant adeno-associated viruses (rAAVs) are a preferred vector system in clinical gene transfer. A fundamental challenge to formulate and deliver rAAVs as stable and efficacious vaccines is to elucidate interrelationships between the vectors physicochemical properties and biological potency. To this end, we evaluated an rAAV-based COVID-19 vaccine candidate which encodes the Spike antigen (AC3) and is produced by an industrially-compatible process. First, state-of-the-art analytical techniques were employed to determine key structural attributes of AC3 including primary and higher-order structures, particle size, empty/full capsid ratios, aggregates and multi-step thermal degradation pathway analysis. Next, several quantitative potency measures for AC3 were implemented and data were correlated with the physicochemical analyses on thermal-stressed and control samples. Results demonstrate links between decreasing AC3 physical stability profiles, in vitro transduction efficiency in a cell-based assay, and importantly, in vivo immunogenicity in a mouse model. These findings are discussed in the general context of future development of rAAV-based vaccines candidates as well as specifically for the rAAV vaccine application under study.

immunology↗

bioRxiv2021

Immunogenicity of an AAV-based, room-temperature stable, single dose COVID-19 vaccine in mice and non-human primates

The SARS-CoV-2 pandemic has affected more than 70 million people worldwide and resulted in over 1.5 million deaths. A broad deployment of effective immunization campaigns to achieve population immunity at global scale will depend on the biological and logistical attributes of the vaccine. Here, two adeno-associated viral (AAV)-based vaccine candidates demonstrate potent immunogenicity in mouse and nonhuman primates following a single injection. Peak neutralizing antibody titers remain sustained at 5 months and are complemented by functional memory T-cells responses. The AAVrh32.33 capsid of the AAVCOVID vaccine is an engineered AAV to which no relevant pre-existing immunity exists in humans. Moreover, the vaccine is stable at room temperature for at least one month and is produced at high yields using established commercial manufacturing processes in the gene therapy industry. Thus, this methodology holds as a very promising single dose, thermostable vaccine platform well-suited to address emerging pathogens on a global scale.

immunology↗

bioRxiv2020

In vitro and In vivo Genetic Disease Modelling via NHEJ precise deletions using CRISPR/Cas9

Development of advanced gene and cell therapies for the treatment of genetic diseases requires confident animal and cellular models to test their efficacy and is crucial in the cases where no primary samples from patients are available. CRISPR/Cas9 technology, has become one of the most spread endonuclease tools for editing the genome at will. Moreover, it is known that the use of two guides tends to produce the precise deletion between the guides via NHEJ. Different distances between guides were tested (from 8 to 500 base pairs). We found that distances between the two cutting sites and orientation of Cas9 protein-DNA interaction are important for the efficiency within the optimal range (30-60 bp), we could obtain new genetically reproducible models for two rare disease, a Pyruvate Kinase Deficiency model, using human primary cells, and a (for in vivo primary hyperoxaluria therapeutic mouse model. We demonstrate that the use of a 2-guideRNAs at the optimal distance and orientation is a powerful strategy for disease modelling in those diseases where the availability of primary cells is limited.

bioengineering↗