scholarly journals Proteomic Landscape of Adeno-Associated Virus (AAV)-Producing HEK293 Cells

2021 ◽  
Vol 22 (21) ◽  
pp. 11499
Author(s):  
Lisa Strasser ◽  
Stefano Boi ◽  
Felipe Guapo ◽  
Nicholas Donohue ◽  
Niall Barron ◽  
...  

Adeno-associated viral (AAV) vectors are widely used for gene therapy, providing treatment for diseases caused by absent or defective genes. Despite the success of gene therapy, AAV manufacturing is still challenging, with production yields being limited. With increased patient demand, improvements in host cell productivity through various engineering strategies will be necessary. Here, we study the host cell proteome of AAV5-producing HEK293 cells using reversed phase nano-liquid chromatography and tandem mass spectrometry (RPLC-MS/MS). Relative label-free quantitation (LFQ) was performed, allowing a comparison of transfected vs. untransfected cells. Gene ontology enrichment and pathway analysis revealed differential expression of proteins involved in fundamental cellular processes such as metabolism, proliferation, and cell death. Furthermore, changes in expression of proteins involved in endocytosis and lysosomal degradation were observed. Our data provides highly valuable insights into cellular mechanisms involved during recombinant AAV production by HEK293 cells, thus potentially enabling further improvements of gene therapy product manufacturing.

2020 ◽  
Vol 94 (19) ◽  
Author(s):  
Qingxin Chen ◽  
Robin Njenga ◽  
Barbara Leuchs ◽  
Susanna Chiocca ◽  
Jürgen Kleinschmidt ◽  
...  

ABSTRACT Adeno-associated virus (AAV) has proven to be a promising candidate for gene therapy due to its nonpathogenic nature, ease of production, and broad tissue tropism. However, its transduction capabilities are not optimal due to the interaction with various host factors within the cell. In a previous study, we identified members of the small ubiquitin-like modifier (SUMO) pathway as significant restriction factors in AAV gene transduction. In the present study, we explored the scope of this restriction by focusing on the AAV capsid and host cell proteins as targets. We show that during vector production, the capsid protein VP2 becomes SUMOylated, as indicated by deletion and point mutations of VP2 or the obstruction of its N terminus via the addition of a tag. We observed that SUMOylated AAV capsids display higher stability than non-SUMOylated capsids. Prevention of capsid SUMOylation by VP2 mutations did not abolish transduction restriction by SUMOylation; however, it reduced activation of gene transduction by shutdown of the cellular SUMOylation pathway. This indicates a link between capsid SUMOylation and SUMOylation of cellular proteins in restricting gene transduction. Infection with AAV triggers general SUMOylation of cellular proteins. In particular, the DAXX protein, a putative host cell restriction factor that can become SUMOylated, is able to restrict AAV gene transduction by reducing the intracellular accumulation of AAV vectors. We also observe that the coexpression of a SUMOylation inhibitor with an AAV2 reporter gene vector increased gene transduction significantly. IMPORTANCE Host factors within the cell are the major mode of restriction of adeno-associated virus (AAV) and keep it from fulfilling its maximum potential as a gene therapy vector. A better understanding of the intricacies of restriction would enable the engineering of better vectors. Via a genome-wide short interfering RNA screen, we identified that proteins of the small ubiquitin-like modifier (SUMO) pathway play an important role in AAV restriction. In this study, we investigate whether this restriction is targeted to the AAV directly or indirectly through host cell factors. The results indicate that both targets act in concert to restrict AAV.


2014 ◽  
Vol 14 (2) ◽  
pp. 86-100 ◽  
Author(s):  
Balaji Balakrishnan ◽  
Giridhara Jayandharan

2017 ◽  
Vol 17 (3) ◽  
Author(s):  
Giedrius Kalesnykas ◽  
Emmi Kokki ◽  
Laura Alasaarela ◽  
Hanna P. Lesch ◽  
Timo Tuulos ◽  
...  

2020 ◽  
Vol 20 ◽  
Author(s):  
Weihong Qu ◽  
Jianguo Zhao ◽  
Yaqing Wu ◽  
Ruian Xu ◽  
Shaowu Liu

Background:: Lung cancer remains the most common cause of cancer-related deaths in China and worldwide. Traditional surgery and chemotherapy do not offer an effective cure although gene therapy may be a promising future alter-native. Kallistatin (Kal) is an endogenous inhibitor of angiogenesis and tumorigenesis. Recombinant adeno-associated virus (rAAV) is considered the most promising vector for gene therapy of many diseases due to persistent and long-term transgen-ic expression. Objective:: The aim of this study was to investigate whether rAAV9-Kal inhibited NCI-H446 subcutaneous xenograft tumor growth in mice. Method:: The subcutaneous xenograft mode were induced by subcutaneous injection of 2×106 H446 cells into the dorsal skin of BALB/c nude mice. The mice were administered with ssrAAV9-Kal (single-stranded rAAV9) or dsrAAV9-Kal (double-stranded rAAV9)by intraperitoneal injection (I.P.). Tumor microvessel density (MVD) was examined by anti-CD34 stain-ing to evaluate tumor angiogenesis. Results:: Compared with the PBS (blank control) group, tumor growth in the high-dose ssrAAV9-Kal group was inhibited by 40% by day 49, and the MVD of tumor tissues was significantly decreased. Conclusion:: The results indicate that this therapeutic strategy is a promising approach for clinical cancer therapy and impli-cate rAAV9-Kal as a candidate for gene therapy of lung cancer.


Author(s):  
Jared S. Bee ◽  
Kristin O'Berry ◽  
Yu (Zoe) Zhang ◽  
Megan Kuhn Phillippi ◽  
Akanksha Kaushal ◽  
...  

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 704
Author(s):  
Qian Yu ◽  
Pengfei Chang ◽  
Xiaoxuan Liu ◽  
Peng Lü ◽  
Qi Tang ◽  
...  

Recombinant adeno-associated virus (AAV) vectors have broad application prospects in the field of gene therapy. The establishment of low-cost and large-scale manufacturing is now the general agenda for industry. The baculovirus-insect cell/larva expression system has great potential for these applications due to its scalability and predictable biosafety. To establish a more efficient production system, Bombyx mori pupae were used as a new platform and infected with recombinant Bombyx mori nuclear polyhedrosis virus (BmNPV). The production of a chimeric recombinant adeno-associated virus (rAAV) serotype 2/human bocavirus type-1 (HBoV1) vector was used to evaluate the efficiency of this new baculovirus expression vector (BEV)–insect expression system. For this purpose, we constructed two recombinant BmNPVs, which were named rBmNPV/AAV2Rep-HBoV1Cap and rBmNPV/AAV2ITR-eGFP. The yields of rAAV2/HBoV1 derived from the rBmNPV/AAV2Rep-HBoV1Cap and rBmNPV/AAV2ITR-eGFP co-infected BmN cells exceeded 2 × 104 vector genomes (VG) per cell. The rBmNPV/AAV2Rep-HBoV1Cap and rBmNPV/AAV2ITR-eGFP can express stably for at least five passages. Significantly, rAAV2/HBoV1 could be efficiently generated from BmNPV-infected silkworm larvae and pupae at average yields of 2.52 × 1012 VG/larva and 4.6 × 1012 VG/pupa, respectively. However, the vectors produced from the larvae and pupae had a high percentage of empty particles, which suggests that further optimization is required for this platform in the future. Our work shows that silkworm pupae, as an efficient bioreactor, have great potential for application in the production of gene therapy vectors.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 586
Author(s):  
Liam Cole ◽  
Diogo Fernandes ◽  
Maryam T. Hussain ◽  
Michael Kaszuba ◽  
John Stenson ◽  
...  

Viruses are increasingly used as vectors for delivery of genetic material for gene therapy and vaccine applications. Recombinant adeno-associated viruses (rAAVs) are a class of viral vector that is being investigated intensively in the development of gene therapies. To develop efficient rAAV therapies produced through controlled and economical manufacturing processes, multiple challenges need to be addressed starting from viral capsid design through identification of optimal process and formulation conditions to comprehensive quality control. Addressing these challenges requires fit-for-purpose analytics for extensive characterization of rAAV samples including measurements of capsid or particle titer, percentage of full rAAV particles, particle size, aggregate formation, thermal stability, genome release, and capsid charge, all of which may impact critical quality attributes of the final product. Importantly, there is a need for rapid analytical solutions not relying on the use of dedicated reagents and costly reference standards. In this study, we evaluate the capabilities of dynamic light scattering, multiangle dynamic light scattering, and SEC–MALS for analyses of rAAV5 samples in a broad range of viral concentrations (titers) at different levels of genome loading, sample heterogeneity, and sample conditions. The study shows that DLS and MADLS® can be used to determine the size of full and empty rAAV5 (27 ± 0.3 and 33 ± 0.4 nm, respectively). A linear range for rAAV5 size and titer determination with MADLS was established to be 4.4 × 1011–8.7 × 1013 cp/mL for the nominally full rAAV5 samples and 3.4 × 1011–7 × 1013 cp/mL for the nominally empty rAAV5 samples with 3–8% and 10–37% CV for the full and empty rAAV5 samples, respectively. The structural stability and viral load release were also inferred from a combination of DLS, SEC–MALS, and DSC. The structural characteristics of the rAAV5 start to change from 40 °C onward, with increasing aggregation observed. With this study, we explored and demonstrated the applicability and value of orthogonal and complementary label-free technologies for enhanced serotype-independent characterization of key properties and stability profiles of rAAV5 samples.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 750
Author(s):  
Maxim A. Korneyenkov ◽  
Andrey A. Zamyatnin

Today, adeno-associated virus (AAV) is an extremely popular choice for gene therapy delivery. The safety profile and simplicity of the genome organization are the decisive advantages which allow us to claim that AAV is currently among the most promising vectors. Several drugs based on AAV have been approved in the USA and Europe, but AAV serotypes’ unspecific tissue tropism is still a serious limitation. In recent decades, several techniques have been developed to overcome this barrier, such as the rational design, directed evolution and chemical conjugation of targeting molecules with a capsid. Today, all of the abovementioned approaches confer the possibility to produce AAV capsids with tailored tropism, but recent data indicate that a better understanding of AAV biology and the growth of structural data may theoretically constitute a rational approach to most effectively produce highly selective and targeted AAV capsids. However, while we are still far from this goal, other approaches are still in play, despite their drawbacks and limitations.


Sign in / Sign up

Export Citation Format

Share Document