T cell engineering using V(D)J recombination allows tumor growth inhibition in mice

T cell therapies have shown clinical success in hematological malignancies, but they rely on prolonged, expensive ex-vivo manipulations and their efficacy is hampered by T cell exhaustion. We propose “VDJ targeting”: a novel immunotherapy approach targeting AAV-delivered immune genes into the genome using V(D)J recombination in developing T cells.

We use AAV vectors coding for a transgenic TCR/CAR gene followed by a recognition signal sequence (RSS) for the recombination activating gene (RAG) complex, which is active only during T cell development. We targeted ex vivo differentiated T cells of human (CB and BM) and mouse BM. Mouse BM cells were transduced with AAV-DJ vector coding for a CAR gene against CD19. Human CB or BM derived HSPCs were transduced with AAV6 vector coding for either a CAR anti CD19 or a TCR targeting an NY-ESO1 peptide presented on HLA2-a2.

Following transduction, HSPCs from mouse BM CD3+ cells were found to express CAR and was activated against CD19 expressing cancer cells. Similarly, Human CB and BM derived HSPCs CD3+ cells were found to express TCR and was activated against NY ESO-1 expressing cancer cells. Human T cells, engineered by VDJ recombination to express the TCR, were adoptively transferred into immunodeficient mice bearing melanoma cell line expressing NY-ESO1. We demonstrate tumor growth inhibition and prolonged survival.

VDJ targeting is produces potent naïve T cells that may transplanted in lower numbers and have increased persistence what make it an efficient T cell engineering technology applicable in the autologous, allogeneic and in vivo settings.