scholarly journals Scalable Generation of High-Titer Recombinant Adeno-Associated Virus Type 5 in Insect Cells

2006 ◽  
Vol 80 (4) ◽  
pp. 1874-1885 ◽  
Author(s):  
Masashi Urabe ◽  
Takayo Nakakura ◽  
Ke-Qin Xin ◽  
Yoko Obara ◽  
Hiroaki Mizukami ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Virus Type ◽  
Insect Cells ◽  
High Titer ◽  
Expression Patterns ◽  
Hek293 Cells ◽  
Expression Vectors ◽  
Inverted Terminal Repeat ◽  
Adeno Associated Virus ◽  
Vector Genome

ABSTRACT We established a method for production of recombinant adeno-associated virus type 5 (rAAV5) in insect cells by use of baculovirus expression vectors. One baculovirus harbors a transgene between the inverted terminal repeat sequences of type 5, and the second expresses Rep78 and Rep52. Interestingly, the replacement of type 5 Rep52 with type 1 Rep52 generated four times more rAAV5 particles. We replaced the N-terminal portion of type 5 VP1 with the equivalent portion of type 2 to generate infectious AAV5 particles. The rAAV5 with the modified VP1 required α2-3 sialic acid for transduction, as revealed by a competition experiment with an analog of α2-3 sialic acid. rAAV5-GFP/Neo with a 4.4-kb vector genome produced in HEK293 cells or Sf9 cells transduced COS cells with similar efficiencies. Surprisingly, Sf9-produced humanized Renilla green fluorescent protein (hGFP) vector with a 2.4-kb vector genome induced stronger GFP expression than the 293-produced one. Transduction of murine skeletal muscles with Sf9-generated rAAV5 with a 3.4-kb vector genome carrying a human secreted alkaline phosphatase (SEAP) expression cassette induced levels of SEAP more than 30 times higher than those for 293-produced vector 1 week after injection. Analysis of virion DNA revealed that in addition to a 2.4- or 3.4-kb single-stranded vector genome, Sf9-rAAV5 had more-abundant forms of approximately 4.7 kb, which appeared to correspond to the monomer duplex form of hGFP vector or truncated monomer duplex SEAP vector DNA. These results indicated that rAAV5 can be generated in insect cells, although the difference in incorporated virion DNA may induce different expression patterns of the transgene.

scholarly journals A human expression system based on HEK293 for the stable production of recombinant erythropoietin

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Christine Lin Chin ◽  
Justin Bryan Goh ◽  
Harini Srinivasan ◽  
Kaiwen Ivy Liu ◽  
Ali Gowher ◽  
...  
Keyword(s):  
Recombinant Proteins ◽  
High Titer ◽  
Expression System ◽  
Mass Spectrometry Analysis ◽  
Hek293 Cells ◽  
Expression Vectors ◽  
Methionine Sulfoximine ◽  
Mammalian Host ◽  
Recombinant Erythropoietin ◽  
Cellular Expression

AbstractMammalian host cell lines are the preferred expression systems for the manufacture of complex therapeutics and recombinant proteins. However, the most utilized mammalian host systems, namely Chinese hamster ovary (CHO), Sp2/0 and NS0 mouse myeloma cells, can produce glycoproteins with non-human glycans that may potentially illicit immunogenic responses. Hence, we developed a fully human expression system based on HEK293 cells for the stable and high titer production of recombinant proteins by first knocking out GLUL (encoding glutamine synthetase) using CRISPR-Cas9 system. Expression vectors using human GLUL as selection marker were then generated, with recombinant human erythropoietin (EPO) as our model protein. Selection was performed using methionine sulfoximine (MSX) to select for high EPO expression cells. EPO production of up to 92700 U/mL of EPO as analyzed by ELISA or 696 mg/L by densitometry was demonstrated in a 2 L stirred-tank fed batch bioreactor. Mass spectrometry analysis revealed that N-glycosylation of the produced EPO was similar to endogenous human proteins and non-human glycan epitopes were not detected. Collectively, our results highlight the use of a human cellular expression system for the high titer and xenogeneic-free production of EPO and possibly other complex recombinant proteins.

scholarly journals Upstream AP1- and CREB-Binding Sites Confer High Basal Activity on the Adeno-Associated Virus Type 5 Capsid Gene Promoter

2007 ◽  
Vol 81 (6) ◽  
pp. 2605-2613 ◽  
Author(s):  
Chaoyang Ye ◽  
David J. Pintel
Keyword(s):  
Virus Type ◽  
Binding Sites ◽  
Core Promoter ◽  
Gene Promoter ◽  
Capsid Gene ◽  
Upstream Region ◽  
Inverted Terminal Repeat ◽  
Gene Promoters ◽  
Adeno Associated Virus ◽  
Basal Activity

ABSTRACT In contrast to the prototype adeno-associated virus type 2 (AAV2), the capsid gene P41 promoter of AAV5, within viral constructs that lack inverted terminal repeat sequences, displays a high basal level of expression in 293 cells in the absence of coinfecting adenovirus. Here we demonstrate that this was due to differences in the relative strengths of the core promoter elements and to the presence of active binding sites for the transcription factors CREB and AP1 within the upstream region of P41 that are absent from the AAV2 capsid gene promoter P40. These differences also governed the relative basal activity of the AAV capsid gene promoters within near-full-length viral genomes.

scholarly journals Adeno-Associated Virus Type 2 p5 Promoter: a Rep-Regulated DNA Switch Element Functioning in Transcription, Replication, and Site-Specific Integration

2007 ◽  
Vol 81 (8) ◽  
pp. 3721-3730 ◽  
Author(s):  
Mary Murphy ◽  
Janette Gomos-Klein ◽  
Marko Stankic ◽  
Erik Falck-Pedersen
Keyword(s):  
Virus Type ◽  
Transcriptional Control ◽  
Helper Virus ◽  
Inverted Terminal Repeat ◽  
Sequence Element ◽  
Adeno Associated Virus ◽  
Site Specific ◽  
Site Specific Integration ◽  
Rep Proteins

ABSTRACT The large Rep proteins, p68 and p78, function as master controllers of the adeno-associated virus type 2 (AAV2) life cycle, involved in transcriptional control, in latency, in rescue, and in viral DNA replication. The p5 promoter may be the nucleic acid complement to the large Rep proteins. It drives expression of the large Rep proteins, it undergoes autoregulation by Rep, it undergoes induction by helper virus, it is a target substrate for Rep-mediated site-specific integration (RMSSI), and it can function as a replicative origin. To better understand the relationship between each of the p5 functions, we have determined the effects of p5 promoter mutations (p5 integration efficiency element, or p5IEE) on transcription, integration, and replication using RMSSI transfection protocols in HeLa cells. The data demonstrate that the organization of the p5 promoter provides a unique platform for regulated AAV2 template transcription and subsequent repression by Rep through direct and indirect mechanisms. The elements of the p5IEE that define its function as a promoter also define its function as a highly optimized substrate for Rep-mediated site-specific integration and replication. The p5 Rep binding element (RBE) is essential in RMSSI and Rep-dependent replication; however, replacement of the p5 RBE with either the AAV2 inverted terminal repeat or the AAVS1 RBE sequence elements neither enhances nor severely compromises RMSSI activity of p5IEE. The RBE by itself or in combination with the YY1+1 initiator/terminal resolution sequence element does not mediate efficient site-specific integration. We found that replication and integration were highly sensitive to sequence manipulations of the p5 TATA/RBE/YY1+1 core structure in a manner that reflects the function of these elements in transcription. The data presented support a model where, depending on the state of the cell (Rep expression and helper virus influences), the p5IEE operates as a transcription/integration switch sequence element.

scholarly journals Induction of Robust Immune Responses against Human Immunodeficiency Virus Is Supported by the Inherent Tropism of Adeno-Associated Virus Type 5 forDendritic Cells

2006 ◽  
Vol 80 (24) ◽  
pp. 11899-11910 ◽  
Author(s):  
Ke-Qin Xin ◽  
Hiroaki Mizukami ◽  
Masashi Urabe ◽  
Yoshihiko Toda ◽  
Kaori Shinoda ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Immune Responses ◽  
Virus Type ◽  
Antigen Presenting Cells ◽  
Hek293 Cells ◽  
Specific Cell ◽  
Adeno Associated Virus ◽  
Virus Serotype ◽  
Immunodeficiency Virus ◽  
Antigen Presenting

ABSTRACT The ability of adeno-associated virus serotype 1 to 8 (AAV1 to AAV8) vectors expressing the human immunodeficiency virus type 1 (HIV-1) Env gp160 (AAV-HIV) to induce an immune response was evaluated in BALB/c mice. The AAV5 vector showed a higher tropism for both mouse and human dendritic cells (DCs) than did the AAV2 vector, whereas other AAV serotype vectors transduced DCs only poorly. AAV1, AAV5, AAV7, and AAV8 were more highly expressed in muscle cells than AAV2. An immunogenicity study of AAV serotypes indicates that AAV1, AAV5, AAV7, and AAV8 vectors expressing the Env gp160 gene induced higher HIV-specific humoral and cell-mediated immune responses than the AAV2 vector did, with the AAV5 vector producing the best responses. Furthermore, mice injected with DCs that had been transduced ex vivo with an AAV5 vector expressing the gp160 gene elicited higher HIV-specific cell-mediated immune responses than did DCs transduced with AAV1 and AAV2 vectors. We also found that AAV vectors produced by HEK293 cells and insect cells elicit similar levels of antigen-specific immune responses. These results demonstrate that the immunogenicity of AAV vectors depends on their tropism for both antigen-presenting cells (such as DCs) and non-antigen-presenting cells (such as muscular cells) and that AAV5 is a better vector than other AAV serotypes. These results may aid in the development of AAV-based vaccine and gene therapy.

scholarly journals Binding of Adeno-associated Virus Type 5 to 2,3-Linked Sialic Acid Is Required for Gene Transfer

2001 ◽  
Vol 276 (23) ◽  
pp. 20610-20616 ◽  
Author(s):  
Robert W. Walters ◽  
Su Min P. Yi ◽  
Shaf Keshavjee ◽  
Kevin E. Brown ◽  
Michael J. Welsh ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Gene Transfer ◽  
Virus Type ◽  
Adeno Associated Virus
Sign in / Sign up

Export Citation Format

Share Document