Cell Capture Assay for High-Producer CHO Cell Line Selection
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Solution Overview
Problem
Current methods for high-throughput screening of antibodies that interact with membrane proteins in their natural environment are inefficient, often requiring antibodies to be expressed and tested outside their native context, leading to potential mischaracterization of antibody functionality.
Innovation Solution
Development of a cell capture assay that allows for the assessment of recombinant antibody binding to antigens in their natural environment on microplates, enabling the selection of high-producer cell lines that express antibodies binding to CD34 membrane-protein during amplification and adaptation in serum-free conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If standard ELISA methods are used to screen cell lines for antibody productivity, then high expression levels can be identified, but the binding functionality to membrane proteins in their natural environment cannot be assessed
Solution Approach 1:
The screening process is segmented into two distinct stages: first, high-throughput ELISA-based selection for high antibody productivity; second, functional validation using cell capture assay to assess binding to membrane proteins. This segmentation allows each method to be optimized for its specific purpose without compromising the other.
Solution Approach 2:
The cell capture assay serves as an intermediary validation step between antibody production and functional application. It provides a bridge by testing whether antibodies produced in high quantities actually bind to their target membrane proteins in their natural environment, preventing premature acceptance of non-functional antibodies.
2Measurement precision
If FACS or immunofluorescence microscopy are used to verify antibody binding, then binding functionality can be assessed, but the process becomes time-consuming and not suitable for high-throughput screening
Solution Approach 1:
The cell capture assay creates a simplified functional copy of the membrane protein binding interaction that can be performed in high-throughput formats. Instead of using complex FACS or microscopy methods, the assay uses a streamlined approach where antibody binding to membrane proteins is quantified in a manner compatible with high-throughput screening, reducing time while maintaining functional assessment.
3Productivity
If membrane proteins are expressed recombinantly in soluble form for screening, then high-throughput screening is enabled, but the antibodies cannot interact with the antigen in its natural membrane environment
Solution Approach 1:
The method performs preliminary high-throughput screening using recombinant soluble membrane proteins to identify high-productivity cell lines. Once these lines are identified, the same cell lines are then tested in the cell capture assay with actual membrane proteins to verify functional interaction. This preliminary action allows efficient initial selection without sacrificing final functional validation.
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 cell capture assay effectively selects and characterizes recombinant anti-CD34 antibodies, ensuring their functionality and high yield, as demonstrated by the generation of stable CHO cell lines producing antibodies that bind to CD34 in the cell membrane, facilitating improved production processes.
Implementation Method 1
The cell capture assay effectively selects and characterizes recombinant anti-CD34 antibodies, ensuring their functionality and high yield, as demonstrated by the generation of stable CHO cell lines producing antibodies that bind to CD34 in the cell membrane
Data Source
AI summary
The present invention relates to cell capture assay for the selection of a high producer cell line expressing anti-CD34 antibodies that recognize the CD34 membrane-protein in the cell membrane. The monoclonal antibody secreted by the hybridoma cell line 9C5/9069 binds to human CD34 and is used to isolate stem cells. The DNA sequences encoding for the antibody heavy and light chain have been identified, isolated from the hybridoma cells and cloned into appropriate expression vectors. After co-transfection of the heavy and light chain genes into HEK293T or in CHO cells either conditioned medium or purified antibody were assessed for binding to CD34 protein located in the cell membrane in different cell capture assays. The binding of the antibody to CD34-positive cells could be shown with these assays for several cell lines.