MHCII Restricted Regulatory T Cell Generation via Rapamycin and TGF-beta
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Solution Overview
Problem
Current methods for generating and expanding MHCII restricted CD4+ Foxp3+ regulatory T cells face challenges such as impurity due to contamination with effector T cells, functional alteration during expansion, and conversion into TH-17 cells in inflammatory conditions, which affects their therapeutic efficacy in cancer and autoimmune disease treatments.
Innovation Solution
A method involving culturing CD3+ CD4+ CD25− T cells with a TCRαβ cell activator, cAMP activator, TGFβ pathway activator, and mTOR inhibitor, along with cytokines like IL-2, IL-7, and IL-15, to generate and expand MHCII restricted CD4+ Foxp3+ regulatory T cells that remain stable in inflammatory conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If regulatory T cells are purified using CD25 and CD127 markers, then purification is achieved, but purity is reduced due to contamination with effector T cells
Solution Approach 1:
The patent changes the purification parameters by using Foxp3 intracellular staining combined with CD4 and CD25 surface markers instead of the conventional CD25/CD127 surface marker combination. This parameter change enables accurate identification and isolation of true regulatory T cells while excluding effector T cells, thereby achieving high purity without compromising ease of manufacture.
2Quantity of substance
If in vitro expansion is performed to generate sufficient regulatory T cells, then cell quantity increases, but functional alteration occurs resulting in loss of suppressive function
Solution Approach 1:
The patent modifies the expansion culture conditions by optimizing the combination of TGF-β, IL-2, and rapamycin, along with controlling cell density and culture duration. These parameter changes enable robust cell expansion while preserving the suppressive function of regulatory T cells, achieving both increased quantity and maintained reliability.
Solution Approach 2:
The patent uses rapamycin as an intermediary substance during expansion that modulates the mTOR pathway to prevent differentiation into effector cells while allowing proliferation. This intermediary agent enables expansion without functional loss by mediating a balance between cell division and functional preservation.
3Measurement precision
If regulatory T cells are isolated from human peripheral blood, then antigen-specific cells can be obtained, but isolation is challenging due to low frequency and limited availability of peptide-MHC multimers
Solution Approach 1:
The patent extracts antigen-specific regulatory T cells from a mixed population by using tetramer staining with peptide-MHC multimers followed by flow cytometry sorting. This extraction approach isolates the rare antigen-specific subset from peripheral blood without requiring complex enrichment procedures, achieving precise isolation with manageable complexity.
Solution Approach 2:
The patent replaces complex mechanical separation methods with immunological recognition systems (tetramer staining). By using antibody-tetramer complexes that specifically bind to T cell receptors recognizing antigen-MHC complexes, the method achieves precise isolation of antigen-specific regulatory T cells through biochemical specificity rather than mechanical complexity.
4Productivity
If regulatory T cells are cultured in inflammatory context, then expansion occurs, but conversion into TH-17 cells happens resulting in pro-inflammatory cytokine production
Solution Approach 1:
The patent applies preliminary anti-action by pre-treating regulatory T cells with TGF-β and rapamycin before exposure to inflammatory conditions, and by maintaining these agents throughout expansion. This preemptive approach establishes a protective state that prevents conversion to TH-17 cells even in the presence of inflammatory cytokines, blocking the harmful transformation pathway before it can occur.
Solution Approach 2:
The patent changes the biochemical parameters of the culture system by optimizing the concentration ratios of TGF-β, IL-2, and rapamycin, and by controlling the timing and intensity of inflammatory stimulus exposure. These parameter changes create a culture environment that supports expansion while maintaining regulatory phenotype stability, preventing pro-inflammatory differentiation.
Data Source
AI summary
The present invention relates to a method for ex vivo generating and expanding MHCII restricted CD4+ Foxp3+ regulatory T cells, and therapeutic uses thereof. The inventors here demonstrated the optimal conditions for inducing Foxp3 expression in naive CD3+ CD4+ TCRαβ+ MHCII restricted T following polyclonal or following antigen-specific activation. They also developed an experimental procedure to generate autologous CD8+ T cell lines functionally committed to lyse tumor-antigen specific FOXP3 expressing TCRαβ+ MHCII restricted T cells, pathogenic CD4+ T cells that favour tumor cell immune evasion. In particular, the present invention relates to a method for generating ex vivo MHCII restricted CD4+ Foxp3+ regulatory T cells having the following phenotype: CD3+ CD4+ Foxp3+.