Mutated VSV-G Glycoprotein for Tumor-Selective Viral Entry
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Solution Overview
Problem
VSV-G pseudotyped lentiviruses exhibit broad tropism due to the ubiquitous distribution of LDL-R receptors, limiting their therapeutic use, particularly in oncotherapy where specific targeting of tumor cells is desired.
Innovation Solution
A mutated VSV-G protein with specific amino acid substitutions at positions 8, 47, 209, and/or 354, retaining membrane fusion ability but losing interaction with LDL membrane receptors, allowing targeted delivery to tumor cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If VSV-G pseudotyped lentiviruses use LDL-R receptors for entry, then broad tropism is achieved, but specific targeting of tumor cells is lost
Solution Approach 1:
The invention modifies specific amino acid residues (H8, K47, Y209, R354) in the VSV-G protein to create local changes in binding specificity. These localized mutations allow the virus to lose affinity for LDL-R receptors while maintaining fusion capability, thereby achieving specific targeting of tumor cells that express alternative receptors such as CAR.
Solution Approach 2:
The invention changes the molecular parameters of the VSV-G protein by introducing specific amino acid substitutions at positions 8, 47, 209, and/or 354. These parameter changes in the protein sequence alter the receptor binding properties, enabling the virus to switch from broad tropism (via LDL-R) to specific tumor targeting (via CAR or other tumor-specific receptors).
2Productivity
If VSV-G protein interacts with LDL membrane receptors, then efficient viral entry is achieved, but tumor cell specificity is lost
Solution Approach 1:
The invention extracts or removes the interaction capability with LDL-R receptors by mutating specific amino acid residues (H8, K47, Y209, R354) in the VSV-G protein. This extraction of LDL-R binding function allows the virus to maintain efficient entry through alternative tumor-specific receptors while eliminating the harmful non-specific binding to LDL-R.
Solution Approach 2:
Instead of enhancing LDL-R interaction to improve entry efficiency, the invention inverts the approach by reducing or eliminating LDL-R interaction and relying on tumor-specific receptors. This inversion of the traditional strategy achieves both efficient entry (through tumor-specific receptors) and specific targeting.
3Reliability
If VSV-G protein maintains wild-type sequence, then membrane fusion ability is preserved, but receptor specificity is lost
Solution Approach 1:
The invention segments the VSV-G protein function into distinct domains: the fusion domain (residues 1-150) that maintains membrane fusion capability, and the receptor binding domain (residues 151-422) that undergoes specific mutations. This segmentation allows independent optimization of fusion function (preserved as wild-type) and receptor specificity (modified through targeted mutations at positions 8, 47, 209, and/or 354).
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The mutated VSV-G protein enables specific targeting of tumor cells while maintaining membrane fusion capability, enhancing the therapeutic efficacy of oncolytic viruses.
Implementation Method 1
G plays a critical role during the initial steps of virus infection. First, it is responsible for virus attachment to specific receptors. After binding, virions enter the cell by a clathrin-mediated endocytic pathway.
Implementation Method 2
In the acidic environment of the endocytic vesicle, G triggers the fusion between the viral and endosomal membranes, which releases the genome in the cytosol for the subsequent steps of infection. Fusion is catalyzed by a low-pH-induced large structural transition from a pre-toward a post-fusion conformation.
Data Source
AI summary
The invention relates to an isolated non-naturally occurring protein comprising the amino acid sequence as set forth in SEQ ID NO: 1, and wherein the amino acid in position 8, 47, 209 and/or 354 is substituted by any amino acid different from the amino acid indicated at that position in said sequence SEQ ID NO: 1.