HBs Antigen Probe Detecting Escape Mutants
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Solution Overview
Problem
Conventional HBs antigen test reagents using monoclonal antibodies to the common 'a' determinant fail to detect escape mutants with mutations on the 'a' determinant, leading to potential HBV transmission through blood transfusion and false-negative results, especially in HBs antibody-positive samples.
Innovation Solution
A probe recognizing an epitope on the amino acid sequence from positions 26 to 80 of the HBs antigen, which is less susceptible to neutralizing antibodies and patient antibodies, is used to detect HBs antigen, including escape mutants, by denaturing lipid bilayers to expose the epitope for recognition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional monoclonal antibodies to the common 'a' determinant are used for HBs antigen detection, then the detection method is simple and widely applicable, but escape mutants with mutations on the 'a' determinant cannot be detected
Solution Approach 1:
The invention segments the HBs antigen detection by identifying and targeting a specific epitope region (amino acid positions 26-80) within the larger antigen structure. This segmentation allows the probe to detect HBs antigen through a different region than the common 'a' determinant, enabling detection of escape mutants that have mutated at the conventional target site while maintaining detection capability through the novel epitope.
Solution Approach 2:
The invention introduces a novel probe as an intermediary detection tool that recognizes the epitope at amino acid positions 26-80. This intermediary probe serves as a bridge between the HBs antigen and detection systems, providing an alternative detection pathway that bypasses the limitation of conventional antibodies that fail to recognize mutated escape variants.
2Reliability
If patient antibodies to the common 'a' determinant are present, then the immune response is active, but false-negative detection results occur
Solution Approach 1:
The invention extracts the detection target from the common 'a' determinant region that is subject to neutralizing antibodies and patient immune responses. By focusing on the epitope at amino acid positions 26-80, the detection system isolates a target region that is less susceptible to interference from patient antibodies, thereby eliminating the harmful effect of false-negative results in antibody-positive samples.
Solution Approach 2:
Instead of detecting the common 'a' determinant that is targeted by patient antibodies (which leads to false negatives), the invention inverts the approach by detecting a different epitope region (positions 26-80) that is not the primary target of patient immune responses. This inversion of the detection target allows for accurate detection even in the presence of patient antibodies.
3Reliability
If the epitope is located inside the lipid bilayer, then the probe can detect HBs antigen in viral particles, but the epitope is not accessible for recognition
Solution Approach 1:
The invention applies preliminary action by using denaturants to disrupt the lipid bilayer structure before the probe recognizes the epitope. This preliminary disruption of the viral particle structure makes the previously hidden epitope at amino acid positions 26-80 accessible to the probe, allowing detection to proceed effectively.
Solution Approach 2:
The invention changes the physical-chemical parameters of the system by introducing denaturants that alter the lipid bilayer structure. This parameter change transitions the epitope from an inaccessible state (buried within the intact viral particle) to an accessible state (exposed after denaturation), enabling probe binding and detection.
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 probe allows for reliable detection of HBs antigen even in the presence of patient antibodies and effectively identifies escape mutants, enhancing the sensitivity and accuracy of HBV infection diagnosis.
Implementation Method 1
A probe recognizing an epitope on the amino acid sequence from positions 26 to 80 of the HBs antigen
Implementation Method 2
by denaturing lipid bilayers to expose the epitope for recognition
Data Source
AI summary
[PROBLEMS] To provide a probe useful in the detection of HBV or HBs antigen by which an escape mutant of hepatitis B virus (HBV) possibly occurring in a specimen can be detected; and a method of using the same.[MEANS FOR SOLVING PROBLEMS] A probe capable of recognizing an epitope located on a peptide comprising the amino acid sequence of SEQ ID NO:1; and a method of detecting hepatitis B virus or hepatitis B virus s antigen by using this probe.