Protein A Variants With Reduced VH3 Binding for Staphylococcal Vaccines

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Solution Overview

Problem

Current vaccines and antibiotic treatments for staphylococcal infections, particularly those caused by Staphylococcus aureus and Staphylococcus epidermidis, face challenges due to increasing antibiotic resistance and limited efficacy, necessitating the development of alternative immunological approaches to stimulate effective immune responses.

Innovation Solution

Development of Protein A variants with specific amino acid substitutions, such as SpAQ9,10K/S33E and SpAQ9,10K/S33T, that reduce binding to VH3 of immunoglobulins, minimizing toxicity and anaphylactic shock risk, while stimulating humoral immune responses to prevent colonization and decolonization of Staphylococcus bacteria.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If Protein A is used to stimulate immune responses against Staphylococcus bacteria, then humoral immune response is improved, but binding to VH3 of immunoglobulins causes toxicity and anaphylactic shock

Engineering Contradiction:

Improveimmune response efficacyVSAvoidtoxicity and anaphylactic shock

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by modifying specific amino acid residues in the Protein A sequence (positions 9, 10, and 33 in domain D) to alter its binding characteristics. The mutations Q9K, Q10K, and S33E/S33T change the protein's interaction with VH3 while preserving its ability to stimulate humoral immune responses, thereby reducing toxicity without sacrificing efficacy

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by making targeted modifications at specific locations within the Protein A structure (domains A-E at positions 9, 10, and 33). These localized changes specifically affect the VH3 binding interface while leaving the rest of the protein's immune-stimulating properties intact, demonstrating precise control over protein function

Inventive Principle:

Principle #3Local quality

2Reliability

If traditional antibiotic treatments are used for staphylococcal infections, then infection treatment is effective, but antibiotic resistance is increasing

Engineering Contradiction:

Improveinfection treatment efficacyVSAvoidantibiotic resistance

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent converts the harmful effect of Protein A's strong VH3 binding (which causes toxicity) into a beneficial property by selectively mutating specific residues. The mutations reduce harmful binding while preserving the beneficial immune stimulation capability, effectively converting a toxic protein into a safe vaccine candidate

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent uses Protein A as an intermediary antigen that can be modified to serve as a vaccine candidate. By creating attenuated variants through specific mutations, the protein acts as a mediator that stimulates immune responses without causing the harmful effects of the wild-type protein, thus enabling safe vaccination against staphylococcal infections

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12514914B2Methods and compositions comprising <i>Staphylococcus </i>protein a (SpA) variants

Publication Date: 2026.01.06 UNIVERSITY OF CHICAGO

AI summary

Embodiments concern methods and composition for preventing or treating a bacterial infection, particularly infection by a Staphylococcus bacterium. The embodiments concern improved non-toxigenic Protein A (SpA) variant.