Hexon Charge Modification in Adenoviral Vectors to Reduce PF4 Binding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current adenovirus vectors face safety issues such as pre-existing immunity and the generation of replication-competent adenoviruses, and there is a risk of adverse effects like thrombosis due to interactions with PF4, which are not fully understood.
Innovation Solution
Mutate negatively charged amino acids in the hexon protein of adenovirus vectors to neutral or positively charged amino acids, particularly in the hypervariable regions, to reduce interactions with PF4 and maintain structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If adenovirus vectors are used for vaccine delivery, then immunogenicity and gene delivery efficiency are improved, but safety risks increase due to pre-existing immunity and thrombosis
Solution Approach 1:
The patent applies parameter changes by modifying the charge distribution on the adenovirus surface through amino acid substitutions in the hexon protein. Specifically, negatively charged amino acids (aspartic acid and glutamic acid) are replaced with neutral or positively charged amino acids at positions 144, 159, 171, 175, 177, 265, 423, 425, 427, and 429. This parameter change in surface charge reduces the interaction with negatively charged PF4, thereby mitigating thrombosis risk while preserving vaccine efficacy
Solution Approach 2:
The patent applies local quality by making targeted modifications only in specific regions of the hexon protein, particularly in hypervariable regions (HVRs) where surface-exposed amino acids are located. This localized modification approach allows the virus to maintain its overall structure and immunogenicity while changing the local charge properties at the virus-PF4 interface to reduce harmful interactions
2Adaptability or versatility
If chimpanzee adenovirus vectors are used to avoid pre-existing immunity, then vaccine coverage is improved, but thrombosis risk increases due to PF4 interaction
Solution Approach 1:
The patent applies parameter changes by systematically modifying the charge distribution on the chimpanzee adenovirus surface through amino acid substitutions in the hexon protein. Specifically, negatively charged amino acids (aspartic acid and glutamic acid) are replaced with neutral or positively charged amino acids at positions 144, 159, 171, 175, 177, 265, 423, 425, 427, and 429. This parameter change in surface charge reduces the interaction with negatively charged PF4, thereby mitigating thrombosis risk while preserving vaccine efficacy
Solution Approach 2:
The patent converts the harmful interaction between adenovirus and PF4 into a beneficial outcome by modifying the virus surface charge. The modification strategy transforms the original harmful electrostatic attraction into reduced interaction, effectively converting the thrombosis risk into a safe vaccine platform that maintains immunogenicity
3Object-affected harmful factors
If adenovirus surface charge is reduced to decrease PF4 interaction, then safety is improved, but structural integrity and stability may be affected
Solution Approach 1:
The patent applies local quality by making targeted modifications only in specific regions of the hexon protein, particularly in hypervariable regions (HVRs) where surface-exposed amino acids are located. This localized modification approach allows the virus to maintain its overall structure and immunogenicity while changing the local charge properties at the virus-PF4 interface to reduce harmful interactions
Solution Approach 2:
The patent applies parameter changes by modifying the charge distribution on the adenovirus surface through amino acid substitutions in the hexon protein. Specifically, negatively charged amino acids (aspartic acid and glutamic acid) are replaced with neutral or positively charged amino acids at positions 144, 159, 171, 175, 177, 265, 423, 425, 427, and 429. This parameter change in surface charge reduces the interaction with negatively charged PF4, thereby mitigating thrombosis risk while preserving vaccine efficacy
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Provided are a modified recombinant adenoviral vector, and a preparation method and use thereof. The modified adenoviral vector can reduce the negative charge level on the surface of adenovirus particles, so as to reduce interaction between the adenoviral vector and PF4 (platelet factor 4). By administering the modified adenovirus vector, the risk of thrombus can be reduced, vaccine safety and effectiveness are improved, and the vaccine is more suitable for high-risk crowds such as elder people, children and pregnant women. The recombinant adenovirus can be widely used for gene therapy, tumor immunization and/or antiviral vaccination, including the use of initiating a primary immune response in a human or mammal to initiate a reinforced immune response for destroying the tolerance of a host to an autoantigen. The modified recombinant adenovirus can be used for developing a mucosal administration formulation. Compared with injection, the mucosal administration formulation has compliance and also lower dosage, and can generate triple protection effects of humoral immunity, cellular immunity and mucosal immunity.