Aptamers as stimulating agents. Dimerized OX40-specific RNA aptamers show activating effects on the OX40 receptor in vitro and in vivo. The OX40 receptor on the surface of activated T cells undergoes receptor oligomerization and provides a costimulatory signal for T cell activation. Downstream factors (e.g., TRAF-2, IKK and NF-κB) of the signaling cascade are activated leading to an enhanced proliferation of T cells and an increased anti-tumor immune response.
