The effect of artificial antigen-presenting cells with preclustered anti-CD28/-CD3/-LFA-1 monoclonal antibodies on the induction of ex vivo expansion of functional human antitumor T cells

1 "C. Gandini" Medical Oncology, Bone Marrow Transplantation Unit 2 "Human Tumor Immunobiology Unit, Fondazione IRCCS Istituto Nazionale per lo Studio e la Cura dei Tumori, Milan, Italy 3 Chair of Medical Oncology, University of Milan, Milan, Italy 4 ’Stephen Chair, Arizona Arthritis Center, University of Arizona, Tucson, AZ, USA Correspondence: Massimo Di Nicola, "Cristina Gandini" Bone Marrow Transplantation Unit, Istituto Nazionale per lo Studio e la Cura dei Tumori, Via Venezian 1, 20133 Milan, Italy. E-mail: massimo.dinicola{at}istitutotumori.mi.it Background: Adoptive cell therapy with ex vivo expanded autologous antitumor cytotoxic T lymphocytes represents an important therapeutic option as an anticancer strategy. In order to identify a reliable method for producing adequate amounts of functional antitumor cytotoxic T lymphocytes with a potentially long in vivo lifespan, we tested the T-cell expansion efficiency of a new artificial antigen-presenting cell-based system. Design and Methods: Our artificial antigen-presenting cells were generated with activating (anti-CD3), co-stimulating (anti-CD28) and adhesion (anti-LFA-1) biotinylated monoclonal antibodies preclusterted in microdomains held on a liposome scaffold by neutravidin rafts. The co-localization of T-cell ligands in microdomains and the targeting of an adhesion protein, increasing the efficiency of immunological synapse formation, represent the novelties of our system. The activity of our artificial antigen-presenting cells was compared with that of anti-CD3/-CD28 coated immunomagnetic microbeads and immobilized anti-CD3 monoclonal antibody (OKT3 clone), the only two commercially available artificial systems. Results: Our artificial antigen-presenting cells expanded both polyclonal T cells and MART-1-specific CD8 + T cells in a more efficient manner than the other systems. Stimulation with artificial antigen-presenting cells allows for the generation of viable T cells displaying an immunophenotype consistent with in vivo potential for persistence, without increasing the frequency of regulatory T cells. The starting specificity of anti MART-1 CD8 + T cells was preserved after stimulation with artificial antigen-presenting cells and it was statistically greater when compared to the activity of the same cells expanded with the other systems. Finally, our artificial antigen-presenting cells proved to be suitable for large-scale application, minimizing the volume and the costs of T-cell expansio