Novel mRNA adjuvant ImmunER enhances prostate cancer tumor-associated antigen mRNA therapy via augmenting T cell activity

Oncoimmunology. 2024 Jun 27;13(1):2373526. doi: 10.1080/2162402X.2024.2373526. eCollection 2024.

Abstract

Prostate cancer (PCa) is characterized as a "cold tumor" with limited immune responses, rendering the tumor resistant to immune checkpoint inhibitors (ICI). Therapeutic messenger RNA (mRNA) vaccines have emerged as a promising strategy to overcome this challenge by enhancing immune reactivity and significantly boosting anti-tumor efficacy. In our study, we synthesized Tetra, an mRNA vaccine mixed with multiple tumor-associated antigens, and ImmunER, an immune-enhancing adjuvant, aiming to induce potent anti-tumor immunity. ImmunER exhibited the capacity to promote dendritic cells (DCs) maturation, enhance DCs migration, and improve antigen presentation at both cellular and animal levels. Moreover, Tetra, in combination with ImmunER, induced a transformation of bone marrow-derived dendritic cells (BMDCs) to cDC1-CCL22 and up-regulated the JAK-STAT1 pathway, promoting the release of IL-12, TNF-α, and other cytokines. This cascade led to enhanced proliferation and activation of T cells, resulting in effective killing of tumor cells. In vivo experiments further revealed that Tetra + ImmunER increased CD8+T cell infiltration and activation in RM-1-PSMA tumor tissues. In summary, our findings underscore the promising potential of the integrated Tetra and ImmunER mRNA-LNP therapy for robust anti-tumor immunity in PCa.

Keywords: Immunotherapy; lipid nanoparticles; mRNA vaccine; prostate cancer; tumor-associated antigens.

MeSH terms

  • Adjuvants, Immunologic* / administration & dosage
  • Adjuvants, Immunologic* / pharmacology
  • Animals
  • Antigens, Neoplasm* / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • Cancer Vaccines* / administration & dosage
  • Cancer Vaccines* / immunology
  • Cell Line, Tumor
  • Dendritic Cells* / immunology
  • Humans
  • Immunotherapy / methods
  • Lymphocyte Activation / drug effects
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Prostatic Neoplasms* / drug therapy
  • Prostatic Neoplasms* / genetics
  • Prostatic Neoplasms* / immunology
  • Prostatic Neoplasms* / pathology
  • Prostatic Neoplasms* / therapy
  • RNA, Messenger* / administration & dosage
  • RNA, Messenger* / genetics
  • RNA, Messenger* / metabolism
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism
  • mRNA Vaccines

Substances

  • Antigens, Neoplasm
  • Adjuvants, Immunologic
  • RNA, Messenger
  • Cancer Vaccines
  • mRNA Vaccines

Grants and funding

This work was supported by The National Natural Science Foundation of China (82272689 to J.P.) Sanming Project of Medicine in Shenzhen (SZSM202011011 to J.P.) The research start-up fund of part-time PI, SAHSYSU (ZSQYJZPI202003 to J.P.) Shenzhen Medical Research Fund (D2301013 to G.F.Z.)