α-Type-1 Polarized Dendritic Cells

TLDR

Develop a serum‑free protocol that generates human dendritic cells with full maturity, chemokine responsiveness, and high IL‑12p70 production to induce type‑1 immunity. The method employs functional polarization of DCs, combining IFN‑α, poly I:C, and a classical cytokine cocktail (TNFα/IL‑1β/IFNγ) to produce α‑type‑1 polarized DCs (αDC1). αDC1 exhibit strong CCR7‑ligand migration, secrete substantially more IL‑12p70 than standard DCs, and stimulate up to 40‑fold higher long‑lived CTLs against melanoma antigens, enabling their first clinical application as potent anticancer vaccines.

Abstract

Abstract Using the principle of functional polarization of dendritic cells (DCs), we have developed a novel protocol to generate human DCs combining the three features critical for the induction of type-1 immunity: (a) fully mature status; (b) responsiveness to secondary lymphoid organ chemokines; and (c) high interleukin-12p70 (IL-12p70)-producing ability. We show that IFN-α and polyinosinic:polycytidylic acid (p-I:C) synergize with the “classical” type-1-polarizing cytokine cocktail [tumor necrosis factor α (TNFα)/IL-1β/IFNγ], allowing for serum-free generation of fully mature type-1-polarized DCs (DC1). Such “α-type-1-polarized DC(s)” (αDC1) show high migratory responses to the CCR7 ligand, 6C-kine but produce much higher levels of IL-12p70 as compared to TNFα/IL-1β/IL-6/prostaglandin E2 (PGE2)-matured DCs (sDC), the current “gold standard” in DC-based cancer vaccination. A single round of in vitro sensitization with αDC1 (versus sDCs) induces up to 40-fold higher numbers of long-lived CTLs against melanoma-associated antigens: MART-1, gp100, and tyrosinase. Serum-free generation of αDC1 allows, for the first time, the clinical application of DCs that combine the key three features important for their efficacy as anticancer vaccines.