Artificial Antigen Presenting Cells With Preclustered anti-CD28/-CD3/-LFA-1 Monoclonal Antibodies Are Highly Effective To Induce The Ex-Vivo Expansion Of Functional Human Antitumor T Cells

Abstract Effective adoptive T cell therapy requires the ex-vivo generation of functional T lymphocytes with a long lifespan in-vivo. We evaluated in-vitro T cell expansion by artificial antigen presenting cells (aAPC) generated with activating (human anti-CD3), co-stimulating (human anti-CD28) and adhesion (human anti-LFA-1) monoclonal antibodies pre-clustered in microdomains (MDs) held by a liposome scaffold. The co-localization of T cell ligands in MDs and the targeting of an adhesion protein, increasing the efficiency of immunological synapse formations, represent the novelties of our system. These aAPCs allowed increased expansion of polyclonal CD4+ and CD8+ T cells and of tumor antigen-specific CD8+ T cells compared to anti-CD28- and anti-CD3-coated microbeads and to immobilized anti-CD3. These aAPCs allowed the generation of T cells displaying an immunophenotype consistent with long-term in-vivo persistence, without increasing the frequency of regulatory T cells. Finally, our aAPCs proved to be suitable for large scale T cell expansion required in immunotherapy trials.