U2OS Cell Line Assay for HPV Replication Monitoring

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Solution Overview

Problem

Current methods for screening anti-HPV substances are limited by the inability to effectively monitor all phases of Human Papillomavirus (HPV) replication, particularly initial amplification, stable maintenance, and vegetative amplification, in existing cell-based assay systems, which hampers the development of effective HPV inhibitors.

Innovation Solution

A novel U2OS-based model system using modified cell lines that stably express Firefly luciferase and GFP2 proteins, along with marker genome plasmids for HPV18 and HPV5, allows for the quantitative measurement of HPV replication phases through Renilla luciferase expression regulated by viral promoters, enabling high-throughput screening for compounds inhibiting HPV replication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing cell-based assay systems are used for screening anti-HPV substances, then the screening process can be performed, but the ability to effectively monitor all phases of HPV replication (initial amplification, stable maintenance, and vegetative amplification) is limited

Engineering Contradiction:

Improvemonitoring capability of HPV replication phasesVSAvoidcomprehensiveness of replication phase coverage

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent divides the HPV replication process into three distinct phases (initial amplification, stable maintenance, and vegetative amplification), each monitored by specific reporter gene constructs. This segmentation allows comprehensive monitoring of all replication phases simultaneously, resolving the contradiction between measurement precision and adaptability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent creates a universal cell-based assay system using U2OS cells that can monitor all HPV replication phases through multiple reporter genes (luciferase, GFP, RFP) integrated into the HPV genome. This multi-functional system simultaneously tracks different replication phases, achieving both precise measurement and comprehensive coverage.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Productivity

If a model system is developed to maintain viral replication for high-throughput analysis, then screening efficiency improves, but the complexity of the system increases

Engineering Contradiction:

Improvescreening throughputVSAvoidsystem complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical and procedural systems (manual monitoring of replication phases) with a biological reporting system using luciferase, GFP, and RFP genes. This substitution enables automated, high-throughput monitoring of all replication phases, dramatically improving productivity while the modular nature of the reporter system keeps complexity manageable.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If luciferase expression is used as a reporter to monitor HPV replication, then quantitative measurement is enabled, but the expression may not reflect actual changes in replication accurately if not controlled by viral promoters

Engineering Contradiction:

Improvequantitative measurement capabilityVSAvoidaccuracy of replication reflection

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent uses viral promoters (E1/E2 promoters during initial amplification, L1/L2 promoters during vegetative amplification) as intermediaries to control reporter gene expression. This ensures that luciferase, GFP, and RFP expression accurately reflects the actual state of HPV replication at different phases, maintaining both measurement precision and reliability.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 system enables the rapid and quantitative assessment of HPV replication phases, maintaining replication capacity over time, and is capable of identifying compounds inhibiting initial amplification, stable maintenance, or vegetative amplification, thus facilitating the development of effective HPV inhibitors.

Implementation Method 1

modified cell lines that stably express Firefly luciferase and GFP2 proteins, along with marker genome plasmids for HPV18 and HPV5, allows for the quantitative measurement of HPV replication phases through Renilla luciferase expression

Methodology Applied

Scientific EffectBioluminescence: Bioluminescence

Implementation Method 2

modified cell lines that stably express Firefly luciferase and GFP2 proteins

Methodology Applied

Scientific EffectFluorescence: Fluorescence

Data Source

PatentUS10954545B2Assay system to identify HPV replication inhibitors in HT-screen

Publication Date: 2021.03.23 ICOSAGEN CELL FACTORY

AI summary

A U2OS-based model system using luciferase reporters to monitor the genome replication of alpha and beta HPVs is provided. A modified U2OS cell line is disclosed that expresses Firefly luciferase to measure toxicity of the screened compounds. In addition, provided are HPV18, HPV 16 and HPV5 marker genomes that express Renilla luciferase under the control of viral promoters used to measure changes in the viral copy number. This ready-to-use model system is capable of being used in high-throughput screens to identify compounds inhibiting initial amplification and stable maintenance as well as vegetative phase of various HPV subtypes.