HLA-A*02:01-directed chimeric antigen receptor/forkhead box P3-engineered CD4+ T cells adopt a regulatory phenotype and suppress established graft-versus-host disease

Background aimsTo investigate the feasibility of using CD4 + T cells genetically modified to express an allo-HLA directed CAR and FOXP3 suppress cell proliferation cytokine secretion in GvHD. Methods: Human CD4+ from A*02:01 negative donors were transduced A*02 co-cultured mixed lymphocyte reaction assays demonstrate suppression. A*02- CAR/FOXP then injected into mice engrafted with allogeneic a GvHD mouse model.ResultsCD4+ allo-HLA-directed proliferate rapidly, downregulate CD127 interferon-γ, high CD25 Helios convert stable antigen-dependent suppressive phenotype. In assays, these potently suppressed T-cell secreted IL-10. graft-versus-host disease model, A*02-CAR/FOXP3 outperformed polyclonal Tregs by reducing liver lung inflammation, inhibiting pro-inflammatory production limiting grafted CD3+ expansion.ConclusionsCD4 expressing allo-antigen HLA-specific act as potent, specific suppressors inflammation that out-perform their Treg counterparts both vitro vivo.