Ad5 E1-E2b- Viral Vector for Repeated Immunotherapy
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Solution Overview
Problem
First-generation adenovirus vector vaccines, such as Ad5 [E1-] vectors, face limitations due to pre-existing anti-adenovirus neutralizing antibodies and immune responses, leading to inadequate immune stimulation and adverse effects, particularly in individuals with prior adenovirus exposure, limiting their use for repeated vaccinations and cancer immunotherapy.
Innovation Solution
Development of second-generation adenovirus vectors with deletions in the E1 and E2b regions, specifically Ad5 [E1-, E2b-] vectors, which reduce late phase viral protein expression, minimize immune responses to viral proteins, and allow for multiple vaccinations by inducing potent antigen-specific immune responses even in immune-hosts, while maintaining safety and efficacy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If first-generation Ad5 vectors are used for vaccination, then robust T-cell-mediated immune responses can be induced, but pre-existing anti-Ad5 neutralizing antibodies and immune responses eliminate the vector and transduced cells, limiting repeated vaccinations
Solution Approach 1:
The patent extracts and removes the E2b gene region from the adenovirus vector, which encodes viral proteins that trigger strong immune responses. By deleting this region, the vector maintains its ability to deliver therapeutic genes while reducing immunogenicity, allowing repeated administrations without being eliminated by pre-existing immunity
Solution Approach 2:
The patent modifies the viral vector by deleting the E2b gene region, fundamentally changing the vector's properties. This genetic modification reduces the expression of viral proteins that trigger immune responses, transforming the vector from one that is rapidly eliminated to one that can sustain long-term transgene expression and withstand repeated administrations
2Reliability
If adenovirus vectors are used to deliver tumor-associated antigens, then cancer immunotherapy survival benefits can be achieved, but host immune responses eliminate the vector and virally transduced cells, reducing sustained long-term expression
Solution Approach 1:
By extracting and removing the E2b gene region from the adenovirus vector, the patent reduces the expression of viral proteins that are targets of host immune responses. This allows the vector to evade immune detection and elimination, enabling sustained long-term transgene expression necessary for effective cancer immunotherapy
Solution Approach 2:
The patent applies partial deletion of the adenovirus genome (specifically the E2b region) rather than complete removal. This partial modification is sufficient to reduce immunogenicity and enable long-term expression while maintaining the vector's essential functions for gene delivery and immune response induction against tumor antigens
3Power
If vaccine doses are increased to overcome pre-existing immunity and induce desired CMI responses, then immune response can be enhanced, but unacceptable adverse effects result
Solution Approach 1:
The patent changes the immunogenicity parameter of the vector by deleting the E2b gene region. This modification allows the vector to induce desired cell-mediated immunity responses at lower, safer doses by reducing the immune response against viral proteins themselves, thereby separating the therapeutic immune response from the harmful adverse effects
Data Source
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AI summary
Methods for generating immune responses using adenovirus vectors that allow multiple vaccinations with the same adenovirus vector and vaccinations in individuals with preexisting immunity to adenovirus are provided.