Alloantigen-specific regulatory T cells generated with a chimeric antigen receptor

Area of Science:

• Immunology
• Cell Therapy
• Transplantation Immunology

Background:

• Adoptive immunotherapy using regulatory T cells (Tregs) shows promise for allograft rejection and graft-versus-host disease (GVHD).
• Antigen-specific Tregs offer potential advantages over polyclonal Tregs, including reduced cell numbers and less nonspecific immune suppression.
• Current methods for generating alloantigen-specific Tregs are complex, requiring donor/recipient cells and MHC matching.

Purpose of the Study:

• To develop a novel method for generating alloantigen-specific Tregs using chimeric antigen receptor (CAR) technology.
• To create an HLA-A2-specific CAR (A2-CAR) for generating antigen-specific human Tregs.
• To evaluate the therapeutic potential of A2-CAR-engineered Tregs in preclinical models.

Main Methods:

• Engineered human Tregs with an HLA-A2-specific CAR (A2-CAR).
• Assessed Treg phenotype and suppressive function in vitro after CAR-mediated stimulation.
• Evaluated the efficacy of A2-CAR Tregs in preventing xenogeneic GVHD in mouse models.

Main Results:

• A2-CAR-expressing Tregs maintained their phenotype and suppressive function post-stimulation.
• Human A2-CAR Tregs demonstrated superior efficacy in preventing HLA-A2+ T cell-mediated xenogeneic GVHD compared to control Tregs.
• CAR technology successfully generated stable and functional alloantigen-specific Tregs.

Conclusions:

• CAR technology provides a powerful platform for generating potent, functional, and stable alloantigen-specific Tregs.
• This approach significantly enhances the therapeutic potential of Tregs in transplantation.
• Antigen-specific Treg generation via CARs holds promise for treating various immune-mediated diseases.