Measuring TCR Diversity via Multiplex PCR and Single-Molecule Sequencing

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Solution Overview

Problem

Current methods are inadequate for accurately assessing the diversity of T cell receptor (TCR) CDR3 sequences in the adaptive immune system, which is crucial for understanding immunocompetence and diagnosing immune-related disorders, as they rely on extrapolation from limited subsets and lack precision.

Innovation Solution

A method involving multiplex PCR and single-molecule DNA sequencing is developed to directly quantify TCR CDR3 diversity by using specific primers for V and J segments, allowing for the amplification and sequencing of millions of TCRβ CDR3 regions from peripheral blood T cells, enabling precise measurement of TCRβ chain diversity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If extrapolation from limited subsets of TCR sequences is used, then the assessment process is simpler and requires fewer resources, but the measurement precision and accuracy of TCR diversity estimation deteriorates

Engineering Contradiction:
ImproveTCR diversity estimation accuracyVSAvoidsequencing and analysis complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the TCR diversity assessment into distinct components: (1) high-throughput sequencing of TCR beta chain CDR3 regions from sorted T cell subsets, (2) computational processing to identify unique sequences and estimate diversity, and (3) statistical analysis to generate diversity metrics. This segmentation enables precise measurement while managing complexity through systematic breakdown of the assessment process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary actions by sorting T cells into specific subsets (e.g., naive, memory, effector) before sequencing, and by pre-processing the sequence data to identify unique CDR3 sequences and estimate diversity. These preliminary steps are performed on fresh or frozen samples before extensive analysis, reducing subsequent complexity while maintaining high measurement precision.

Inventive Principle:
Principle #10Preliminary action

2Quantity of substance

If high-throughput sequencing of TCR CDR3 regions is performed, then the quantity of TCR sequences analyzed increases significantly, but the loss of time and resources required for sequencing and analysis increases

Engineering Contradiction:
Improvenumber of TCR sequences analyzedVSAvoidsequencing and analysis time
Core Design Contradiction:
Quantity of substanceVSLoss of time

Solution Approach 1:

The patent employs periodic action by using cycles of thermal PCR amplification to exponentially amplify TCR CDR3 sequences from limited starting material, followed by periodic sequencing runs that process multiple samples in parallel. The computational analysis also uses periodic processing steps to handle large datasets efficiently, balancing high sequence quantity with manageable time investment.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent creates copies of TCR CDR3 sequences through PCR amplification, generating millions of copies from a small number of original T cell DNA templates. This copying process enables high-throughput sequencing of numerous TCR sequences without requiring proportional increases in sample material or analysis time, as the amplified copies can be processed simultaneously.

Inventive Principle:
Principle #26Copying

3Adaptability or versatility

If diverse T cell subsets are sorted and analyzed separately, then the adaptability and comprehensiveness of immune system assessment improves, but the device complexity and procedural difficulty increases

Engineering Contradiction:
Improveimmune system assessment comprehensivenessVSAvoidsample processing difficulty
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent applies universality by developing a standardized protocol that can assess multiple T cell subsets (naive, memory, effector, regulatory) using the same basic sequencing and analysis approach. The same CDR3 sequencing methodology and diversity estimation algorithms are universally applied across different T cell types, enabling comprehensive immune assessment without requiring separate specialized procedures for each subset, thus maintaining ease of operation while achieving adaptability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

This approach provides a significantly higher and more accurate estimate of TCRβ CDR3 diversity, revealing a vast repertoire of unique sequences, particularly in antigen-experienced cells, and allows for the identification of shared TCR sequences between individuals, which can serve as biomarkers for diseases.

Implementation Method 1

combining the V segment and J segment primers with a sample of genomic DNA to permit amplification of a CDR3 region by a multiplex polymerase chain reaction (PCR) to produce a multiplicity of amplified DNA molecules

Methodology Applied
Scientific EffectPCR amplification:

Implementation Method 2

A method involving multiplex PCR and single-molecule DNA sequencing is developed to directly quantify TCR CDR3 diversity

Methodology Applied
Scientific EffectDNA sequencing:

Data Source

PatentUS11905511B2Method of measuring adaptive immunity
Publication Date: 2024.02.20 FRED HUTCHINSON CANCER CENT

AI summary

A method of measuring immunocompetence is described. This method provides a means for assessing the effects of diseases or conditions that compromise the immune system and of therapies aimed to reconstitute it. This method is based on quantifying T-cell diversity by calculating the number of diverse T-cell receptor (TCR) beta chain variable regions from blood cells.