Replication-competent adenoviral vectors
Inventors
Peng, Bo • Voltan, Rebecca • Ensoli, Barbara • Robert-Guroff, Marjorie
Assignees
Istituto Superiore di Sanita ISS • US Department of Health and Human Services
Publication Number
US-8926987-B2
Publication Date
2015-01-06
Expiration Date
2025-11-17
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
This invention provides improved replication-competent adenoviral vectors. The improved vectors have both a hybrid regulatory unit that provides for high level transgene expression. The vectors can be use, e.g., for therapeutic or prophylactic purposes.
Core Innovation
This invention provides improved replication-competent adenoviral vectors that include a hybrid regulatory unit comprising a human cytomegalovirus (CMV) immediate early promoter and an adenovirus tripartite leader sequence, resulting in greatly enhanced gene expression. These vectors are capable of high-level transgene expression and can be used for therapeutic or prophylactic purposes, including vaccination strategies.
The problem being solved arises from previous adenoviral vectors, especially replication-competent adenovirus vectors, which did not achieve high-level expression of transgenes. Prior art showed conflicting results regarding the necessity of heterologous promoters in replication-competent adenoviruses; some transgenes had poor translation and low protein expression. The present invention overcomes these limitations by incorporating both the CMV promoter and tripartite leader sequence into replication-competent adenovirus vectors, thereby achieving significantly increased and more efficient transgene expression than previous vectors.
Specifically, the hybrid regulatory unit enables constitutive production of high amounts of tripartite leader-containing mRNA, while the adenovirus major late promoter provides viral-related mRNA in every replication cycle. This combination increases transcription and translation efficiency in replication-competent adenoviruses. The vectors can control expression of any gene of interest, including HIV genes such as tat and nef, and are adaptable to different adenovirus serotypes, including types 2, 4, 5, and 7. This innovation allows for the production of high-level expression of immunogenic proteins to induce protective immune responses in vivo, reducing the necessary viral dose and potentially lessening adverse effects.
Claims Coverage
The patent contains a single independent claim detailing an immunizing composition comprising a replication-competent adenovirus vector with a hybrid expression cassette including a CMV immediate early promoter and two adenovirus tripartite leader sequences, and a pharmaceutically acceptable carrier.
Replication-competent adenovirus vector with hybrid expression cassette
An adenovirus vector that is replication competent and comprises a hybrid expression cassette including a CMV immediate early promoter, a second adenovirus tripartite leader sequence, and a transgene, operably linked in a manner to enhance transgene expression.
Use of an endogenous and a second adenovirus tripartite leader sequence
The hybrid expression cassette includes both an endogenous adenovirus tripartite leader sequence and a second, often spliced, adenovirus tripartite leader sequence, enhancing the translation efficiency of the transgene.
Inclusion of transgene encoding HIV genes with specific modifications
The transgene can be an HIV gene including HIV regulatory genes such as nef or tat, where nef may be non-myristoylated and tat may lack transactivation function, or structural genes such as gag or env.
Deletion of non-essential adenovirus regions for insertion of transgene
The vector may lack a functional E3 region, with the hybrid expression cassette and transgene inserted into the deleted E3 region to accommodate the transgene without impairing replication competence.
Broad applicability to adenovirus serotypes
The adenovirus vector can be derived from adenovirus types 2, 4, 5, or 7, enabling use of the invention across multiple serotypes.
Overall, the claims cover a replication-competent adenovirus vector immunizing composition that employs a unique hybrid expression cassette combining CMV promoter and adenovirus tripartite leader sequences to achieve high-level expression of transgenes, including HIV-specific genes, with adaptability across various adenovirus serotypes and vector genome modifications.
Stated Advantages
The vectors provide high levels of transgene expression relative to previous replication-competent adenovirus vectors, enabling effective gene expression in vivo at lower viral doses.
Reduced adenovirus dosage decreases adverse immunopathology associated with high replication-defective virus doses.
Replication-competent vectors stimulate production of pro-inflammatory cytokines, enhancing immune responses to encoded antigens.
The invention allows transgene expression in adenovirus non-permissive cells and is adaptable to various adenovirus serotypes.
Vectors carrying HIV transgenes such as tat and nef can elicit potent cellular immune responses and enhance immune responses to co-administered antigens.
Documented Applications
Use of replication-competent adenoviral vectors for high-level in vivo expression of therapeutic or prophylactic proteins.
Vaccines against HIV/AIDS employing replication-competent adenovirus vectors encoding HIV regulatory and structural proteins including tat and nef to elicit protective immune responses.
Immunization of mammals, including humans and non-human primates, with vector compositions to induce cellular and humoral immunity.
Use in gene transfer for therapeutic gene expression in target cells for immunological or therapeutic effect.
Interested in licensing this patent?