Modified Feeder Cells for Human B Cell Expansion
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Solution Overview
Problem
Current methods for producing monoclonal antibodies, such as hybridoma technology and EBV-transformed B cell lines, face limitations including the need for 'humanization' to reduce immune responses and species-specific immune reactions, limiting their application in human therapy and diagnosis.
Innovation Solution
A method for expanding and differentiating human B cells in culture to produce monoclonal antibodies without antigen exposure, using modified feeder cells expressing CD154 and BLyS, or a combination with IL-21, enabling significant proliferation and differentiation of B cells for high-level antibody production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hybridoma technology is used to produce monoclonal antibodies, then antibody production capability is improved, but the need for humanization to reduce immune responses increases complexity
Solution Approach 1:
The patent uses human B cells as the source material instead of mouse hybridoma cells, directly copying the desired human antibody production system. This eliminates the need for humanization processes while maintaining high antibody production capability, as the B cells are already of human origin and can be expanded and differentiated to produce human monoclonal antibodies
Solution Approach 2:
The patent segments the antibody production process into distinct phases: B cell isolation, expansion using feeder cells, differentiation into antibody-secreting cells, and antibody production. This segmentation allows each step to be optimized independently, achieving high productivity without requiring complex humanization procedures
2Productivity
If EBV-transformed B cell lines are used, then antibody production is improved, but species-specific immune responses limit therapeutic application
Solution Approach 1:
The patent changes the species parameter by using human B cells instead of mouse B cells that are transformed by EBV. This parameter change ensures that the produced antibodies are human in origin, eliminating species-specific immune responses and expanding therapeutic applicability while maintaining high antibody production through the expansion and differentiation protocol
3Loss of time
If B cells are expanded in culture without antigen exposure, then production time is reduced, but antibody specificity may be compromised
Solution Approach 1:
The patent performs preliminary selection of antigen-specific B cells from the donor's blood or lymphoid tissue before expansion. These pre-selected B cells are then expanded without antigen exposure, maintaining their specificity while reducing the time required for in vitro antigen stimulation. The feeder cells support expansion while preserving the original antigen specificity of the selected B cells
4Productivity
If modified feeder cells expressing CD154 and BLyS are used, then B cell proliferation is improved, but culture system complexity increases
Solution Approach 1:
The patent introduces modified feeder cells as an intermediary component that secretes CD154 and BLyS to support B cell expansion. This intermediary approach simplifies the overall system by using a cell-based delivery mechanism rather than requiring direct addition of multiple cytokines and growth factors, making the culture system more manageable while achieving high proliferation rates
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 method allows for efficient production of monoclonal antibodies, achieving a 10^4-fold expansion of B cells in less than two weeks, facilitating characterization and overcoming previous limitations in human B cell expansion and antibody production.
Implementation Method 1
modified feeder cells expressing CD154 and BLyS, or a combination with IL-21, enabling significant proliferation and differentiation of B cells
Implementation Method 2
modified feeder cells expressing CD154 and BLyS, or a combination with IL-21, enabling significant proliferation and differentiation of B cells
Implementation Method 3
The feeder cells of the disclosure support significant proliferation and differentiation of B cells of mammalian species, including human B cells and murine B cells, without the need to add (i.e., in the absence of) exogenous antigen or exogenous IL-4 when B cells are cultured in the presence of the modified feeder cells in vitro
Data Source
Figure 1A
Figure 1B
Figure 2A~2B
AI summary
Provided are feeder cell lines that can be used to expand and differentiate B cells in vitro, a method for expanding B cells in vitro comprising culturing the B cells with the feeder cell line, and a method for producing monoclonal antibody in vitro comprising culturing a single B cell with the feeder cell line under sufficient conditions a nd for sufficient time to induce expansion and differentiation of the B cell into a B cell clone secreting antibody.