Combinatorial Design of Fatty Acid-Incorporated Plasmid Lipid Nanoparticles Drives Dendritic Cell Hyperactivation for Enhanced Cancer Immunotherapy.

Abstract

As a bridge between innate sensing and adaptive immunity, the functional state of dendritic cells (DCs) is a critical determinant of protective immune responses. Inflammasome activation can induce a "hyperactive" state characterized by highly activated DCs with preserved viability, enhanced antigen presentation, migration capacity, and IL-1β secretion, representing an ideal condition for eliciting robust cytotoxic T lymphocyte (CTL) responses. However, attempts to apply this state in cancer vaccines face constraints including safety concerns, formulation complexity, and limited control over stimulation strength. Here, we develop a lipid nanoparticle (LNP) platform that combines plasmid DNA (pDNA) with fatty acids to optimize the inflammasome activity and direct DCs toward hyperactivation. Following the establishment and screening of the fatty acid-incorporated plasmid lipid nanoparticle (FA-pLNP) library, a palmitic acid formulation designated PA15 is identified as the lead candidate to induce DC hyperactivation. Mechanistic studies reveal that pDNA provides nuclear factor kappa B (NF-κB)-mediated priming, while palmitic acid promotes NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome assembly, enabling effective interleukin-1β (IL-1β) release and subsequent immune activation. Therapeutic vaccination with PA15 demonstrated significant antitumor efficacy in mouse tumor models. Collectively, this work provides a practical strategy for inducing hyperactive DCs and establishes a general design principle for next-generation cancer vaccines.