RSV F Protein Stabilization via Amino Acid Substitutions

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Solution Overview

Problem

There is an unmet need for viral membrane fusion proteins stabilized by designed amino acid substitutions, particularly for Respiratory Syncytial Virus (RSV), to improve thermal stability, conformational stability, antigenicity, and immunogenicity in vaccine design.

Innovation Solution

Recombinant polypeptides comprising an engineered ectodomain of the RSV fusion (F) protein with specific amino acid substitutions and a C-terminal alpha-helical segment that stabilize the protein in a prefusion conformation, forming stable alpha-helical homotrimers, and self-assembling protein nanostructures for enhanced immune response.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the RSV F protein is stabilized in prefusion conformation using designed amino acid substitutions, then thermal stability and conformational stability are improved, but the complexity of protein engineering increases

Engineering Contradiction:

Improvethermal stability and conformational stabilityVSAvoidprotein engineering complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by introducing specific amino acid substitutions (e.g., S155C, S290C, S190F, V207L) at defined positions in the RSV F protein sequence to stabilize the prefusion conformation. This systematic modification of protein parameters achieves enhanced thermal and conformational stability while maintaining a manageable engineering complexity through rational design.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs preliminary action by pre-stabilizing the F protein in its prefusion conformation through engineered amino acid substitutions before vaccination. This preliminary structural stabilization ensures that the immunogen presents the correct conformational epitopes to the immune system, improving vaccine efficacy without requiring complex post-formulation stabilization strategies.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If amino acid substitutions are introduced to stabilize prefusion conformation, then immunogenicity is improved, but manufacturing precision requirements increase

Engineering Contradiction:

ImproveimmunogenicityVSAvoidamino acid substitution precision

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by introducing amino acid substitutions at specific local positions (e.g., positions 155, 290, 190, 207) within the F protein sequence. Each substitution is strategically placed to stabilize particular structural elements or interaction interfaces, achieving enhanced immunogenicity through localized modifications rather than global changes, thereby simplifying manufacturing precision requirements.

Inventive Principle:

Principle #3Local quality

3Reliability

If the F protein is displayed on protein nanostructures, then antigen presentation is enhanced, but device complexity increases

Engineering Contradiction:

Improveantigen presentationVSAvoidnanostructure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies merging by combining the stabilized prefusion F protein with protein nanostructure platforms to create integrated vaccine immunogens. This fusion merges the advantages of conformational stabilization with the enhanced antigen presentation capabilities of nanostructures, achieving improved immunogenicity while managing overall device complexity through modular design.

Inventive Principle:

Principle #5Merging (Combining)

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 modified RSV F protein ectodomain exhibits improved thermal stability and immunogenicity, leading to enhanced immune responses and potentially more effective vaccines by maintaining critical epitopes in the prefusion conformation.

Implementation Method 1

the segment forms a stable alpha-helical homotrimer

Methodology Applied

Scientific EffectAlpha-helical structure formation: Helix

Implementation Method 2

amino acid substitutions selected such that the segment forms a stable alpha-helical homotrimer

Methodology Applied

Scientific EffectHydrophobic interactions: Hydrophobe

Implementation Method 3

stable alpha-helical homotrimer formation

Methodology Applied

Scientific EffectHydrogen bonding:

Implementation Method 4

improve thermal stability, conformational stability, antigenicity, and/or immunogenicity

Methodology Applied

Scientific EffectThermal stability:

Implementation Method 5

self-assembling protein nanostructures that include such RSV F ectodomain polypeptides

Methodology Applied

Scientific EffectSelf-assembly: Self-Assembly

Data Source

PatentUS20250090651A1Respiratory syncytial virus f proteins and nanostructures and uses thereof

Publication Date: 2025.03.20 ICOSAVAX INC

AI summary

Provided herein are recombinant polypeptides comprising an engineered ectodomain of a Respiratory Syncytial Virus (RSV) fusion (F) protein, wherein the ectodomain comprises an engineered C-terminal alpha-helical segment and/or amino acid substitutions that stabilize the F protein in a prefusion conformation. The disclosure also provides a two-component protein nanostructure comprising first trimeric component and second pentameric component. Provided herein are a composition for use in vaccinating, generating an immune response, or treating or preventing RSV disease.