Recombinant HSV-1 Truncation for Interferon-Resistant Oncolysis
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Solution Overview
Problem
Existing oncolytic herpes simplex viruses (HSV) with γ134.5 gene deletion face challenges in replicating effectively within cancer cells and activating systemic antitumor immunity due to host defenses, leading to incomplete tumor eradication and potential re-growth.
Innovation Solution
A recombinant HSV-1 expressing only the C-terminal portion of the γ134.5 protein, combined with deletions or replacements of non-essential genes, enhances viral replication and immune activation in cancer cells while avoiding wild-type protein expression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the γ134.5 gene is deleted to reduce viral virulence and enhance immune activation, then antitumor immunity is improved, but viral replication efficiency in cancer cells deteriorates
Solution Approach 1:
The γ134.5 gene is segmented into two functional domains: the N-terminal domain (residues 1-146) that mediates virulence by inhibiting PKR, and the C-terminal domain (residues 147-263) that maintains essential functions for viral replication. By deleting only the N-terminal domain while retaining the C-terminal domain, the invention achieves segmentation of the gene function, allowing viral replication to continue while eliminating the immunosuppressive virulence effect.
Solution Approach 2:
The invention applies local quality modification by selectively removing only the harmful N-terminal portion of the γ134.5 protein (residues 1-146) while preserving the functional C-terminal portion (residues 147-263). This localized modification allows the virus to maintain replication competence in cancer cells while reducing virulence to enhance immune system activation against the tumor.
2Object-generated harmful factors
If the γ134.5 gene is completely deleted to eliminate virulence, then immune response is enhanced, but viral growth in tumor cells is inhibited
Solution Approach 1:
The invention extracts and removes only the harmful N-terminal domain (residues 1-146) of the γ134.5 protein that is responsible for virulence through PKR inhibition, while retaining the essential C-terminal domain (residues 147-263) required for viral replication and tumor cell lysis. This selective extraction eliminates the harmful virulence factor while preserving the beneficial oncolytic activity.
3Productivity
If wild-type HSV-1 is used to achieve rapid tumor cell destruction, then oncolytic activity is improved, but systemic immune activation deteriorates
Solution Approach 1:
Instead of using wild-type HSV-1 that fully expresses the immunosuppressive γ134.5 protein, the invention inverts the approach by creating a mutant virus with a truncated γ134.5 protein (lacking residues 1-146). This inversion removes the immunosuppressive function while maintaining oncolytic activity, thereby achieving both tumor cell destruction and systemic immune activation simultaneously.
Data Source
AI summary
A method for treating a subject with cancer by administering to the subject a therapeutically effective amount of a recombinant Herpes Simplex Virus-1 (HSV-1) that expresses only a C-terminal portion of γ134.5 protein (e.g., amino acid residues 147-263) with no wild-type or intact γ134.5 protein expression is provided. The recombinant HSV-1 of this invention instigates immune activation, selectively replicates in cancer cells, and resists clearance by interferon.