Combining Adhesive Nanostructured Surfaces and Costimulatory Signals to Increase T Cell Activation.

Adoptive cell therapies are showing very promising results in the fight against cancer. However, these therapies are expensive and technically challenging in part due to the need of a large number of specific T cells, which must be activated and expanded in vitro. Here we describe a method to activate primary human T cells using a combination of nanostructured surfaces functionalized with the stimulating anti-CD3 antibody and the peptidic sequence arginine-glycine-aspartic acid, as well as costimulatory agents (anti-CD28 antibody and a cocktail of phorbol 12-myristate 13-acetate, ionomycin, and protein transport inhibitors). Thus, we propose a method that combines nanotechnology with cell biology procedures to efficiently produce T cells in the laboratory, challenging the current state-of-the-art expansion methodologies.

Integrin-Assisted T-Cell Activation on Nanostructured Hydrogels.

Adoptive cell therapy (ACT) has shown very promising results as treatment for cancer in a few clinical trials, such as the complete remissions of otherwise terminal leukemia patients. Nevertheless, the introduction of ACT into clinics requires overcoming not only medical but also technical challenges, such as the ex vivo expansion of large amounts of specific T-cells. Nanostructured surfaces represent a novel T-cell stimulation technique that enables us to fine-tune the density and orientation of activating molecules presented to the cells. In this work, we studied the influence of integrin-mediated cell-adhesion on T-cell activation, proliferation, and differentiation using nanostructured surfaces, which provide a well-defined system at the nanoscale compared with standard cultures. Specifically, we synthesized a polymeric polyethylene glycol (PEG) hydrogel cross-linked with two fibronectin-derived peptides, cyclic Arg-Gly-Asp (cRGD) and cyclic Leu-Asp-Val (cLDV), that are known to activate different integrins. Moreover, the hydrogels were decorated with a quasi-hexagonal array of gold nanoparticles (AuNPs) functionalized with the activating antibody CD3 to initiate T-cell activation. Both cLDV and cRGD hydrogels showed higher T-cell activation (CD69 expression and IL-2 secretion) than nonfunctionalized PEG hydrogels. However, only the cRGD hydrogels clearly supported proliferation giving a higher proportion of cells with memory (CD4+CD45RO+) than naïve (CD4+CD45RA+) phenotypes when interparticle distances smaller than 150 nm were used. Thus, T-cell proliferation can be enhanced by the activation of integrins through the RGD sequence.