Mutant hAce2 Decoy Protein for SARS-CoV-2 Neutralization

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Solution Overview

Problem

Current therapeutic and prophylactic measures lack effectiveness in preventing COVID-19 symptoms and infection, particularly in reducing viral replication, due to limitations in targeting the ACE2 receptor effectively.

Innovation Solution

Development of a recombinant AAV (rAAV) vector encoding a mutant hAce2 soluble decoy protein, which includes specific amino acid sequences and an immunoglobulin Fc region, designed to be expressed as a fusion protein to effectively bind and neutralize SARS-CoV-2 and other betacoronaviruses by targeting the ACE2 receptor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If soluble ACE2 is administered to block viral entry, then viral attachment is reduced, but the therapeutic effectiveness is insufficient due to limitations in targeting efficiency

Engineering Contradiction:

Improvetherapeutic effectivenessVSAvoidtargeting efficiency

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies parameter changes by introducing specific amino acid substitutions (K31N, Q34P, Q493H, Q496P) into the ACE2 protein sequence to enhance binding affinity to the SARS-CoV-2 spike protein. These parameter changes in the molecular structure directly improve targeting efficiency while maintaining the therapeutic function of blocking viral entry.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite structure by fusing ACE2 with immunoglobulin Fc regions (IgG1, IgG2, IgG3, or IgG4) to form chimeric proteins. This composite approach combines the viral binding capability of ACE2 with the extended half-life and enhanced stability of antibody Fc regions, thereby improving both targeting efficiency and therapeutic effectiveness.

Inventive Principle:

Principle #40Composite materials

2Reliability

If mutant hAce2 decoy protein is expressed to neutralize virus, then viral replication is reduced, but the complexity of protein engineering increases

Engineering Contradiction:

Improveviral neutralization capabilityVSAvoidprotein engineering complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the ACE2 protein into modular components that can be independently engineered and recombined. The Fc fusion constructs allow separation of the viral-binding domain (ACE2) from the effector domain (Fc region), enabling systematic optimization of each component's function and simplifying the overall engineering process through modular assembly.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent achieves universality by designing ACE2 variants with multiple functional capabilities: viral binding, neutralization, and extended circulation half-life through Fc-mediated mechanisms. The same basic construct design can be adapted across different ACE2 variants and Fc types, reducing engineering complexity through a universal platform approach.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If ACE2 binding affinity to spike protein is increased, then neutralizing activity is enhanced, but the risk of off-target effects may increase

Engineering Contradiction:

Improveneutralizing activityVSAvoidoff-target effects

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by making specific, targeted amino acid substitutions at precise positions (K31, Q34, Q493, Q496) within the ACE2 sequence that directly contact the viral spike protein. These localized modifications enhance binding affinity at the virus-ACE2 interface without altering the overall structure or potential off-target interactions of the protein.

Inventive Principle:

Principle #3Local quality

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 rAAV vector provides a potent and specific mechanism to prevent viral attachment and replication by expressing a mutant hAce2 decoy protein that maintains tight binding and neutralizing activity against SARS-CoV-2 variants, including Omicron, and other ACE2-dependent coronaviruses, offering a promising therapeutic and prophylactic solution.

Implementation Method 1

The S1 domain of the viral spike protein of SARS CoV-2 binds to host cells via the ACE2 receptor with low nanomolar affinity

Methodology Applied

Scientific EffectReceptor-ligand binding:

Implementation Method 2

optionally fused to an immunoglobulin Fc region

Methodology Applied

Scientific EffectProtein-protein interaction:

Data Source

PatentUS20230338478A1Compositions and method of use of mutant ace2 decoy variants

Publication Date: 2023.10.26 THE TRUSTEES OF THE UNIV OF PENNSYLVANIA

AI summary

A mutant soluble human Ace2 (hAce2) protein useful in preventing infection with betacoronaviruses, including SARS-CoV2 is provided, as are compositions useful in treating disease associated with betacoronavirus, including, e.g, COVID-19. Also provided are compositions containing same formulated for intranasal and/or intrapulmonary delivery, methods of making same and assays. The use of the rAAV compositions for preventing symptoms of COVID-19 infection in humans is provided.