Poloxamer-Based Th1-Biased NKT Cell Nano-Agonist for Tumor Immunotherapy.

Abstract

Background: Natural killer T (NKT) cells bridge innate and adaptive immunity and are promising targets for tumor immunotherapy. However, its agonist α-GalCer induces NKT cells to secrete both Th1-type and Th2-type cytokines. Coupled with the challenges of in vivo delivery, these drawbacks collectively limit its clinical application.

Methods: In this study, we constructed Th1-biased NKT cell nano-agonists (LGCP Ms) by using Th1-preferred glycolipids (Lys-α-GalCer) and Poloxamer through thin-film hydration combined with probe sonication to enhance NKT cell-mediated anti-tumor immunity.

Results: LGCP Ms exhibited a uniform spherical morphology with a mean size of 109.1 ± 0.85 nm, a Zeta potential of -15.7 ± 1.2 mV. In vitro and in vivo results demonstrated that the nano-agonist efficiently activated NKT cells and significantly elevated Th1-type cytokine levels. In a murine Hepa1-6 cell tumor model, intraperitoneal injection of LGCP Ms significantly promoted Th1-type cytokine secretion, increased the proportions of NKT cells and CD8⁺ T cells in the spleen, and enhanced the infiltration of CD8⁺ T cells into tumor tissues. Finally, LGCP Ms showed considerably better anticancer activity compared to free α-GalCer both in vitro and in vivo.

Conclusion: These findings demonstrated that the LGCP Ms nanodelivery system features facile preparation, high encapsulation efficiency, and favorable stability. LGCP Ms induced robust cytokine secretion and modulated NKT cell proportions, confirming effective NKT‑cell stimulation. This potent activation translates into substantial anti‑tumor immunity, positioning LGCP Ms as a promising strategy for cancer immunotherapy.