Novel calreticulin-nanoparticle in combination with focused ultrasound induces immunogenic cell death in melanoma to enhance antitumor immunity.

Abstract

Rationale: Some studies have shown that the local activation of immunogenic cell death (ICD) by upregulating calreticulin (CRT) expression in solid tumors can improve antitumor effects. Although a promising approach, a key current challenge in ICD tumor therapy is the absence of a clinically translatable method for reproducibly inducing the CRT expression. Herein, we report a novel calreticulin-nanoparticle (CRT-NP) that enhances ICD and synergizes with focused ultrasound (FUS) to achieve local and systemic antitumor effects. Methods: Full-length clone DNA of calreticulin was encapsulated in NPs made from DOTAP and cholesterol. Three CRT-NP intratumoral injections of 20 µg each were given 2 days apart, and FUS heating (42-45°C, ~15min) was applied sequentially 24h after each injection to induce ICD. To investigate ICD specific immune effect, the splenocytes of mice vaccinated with CRT-NP (± FUS) treated B16F10 cells were evaluated ex-vivo for TRP-2 antigen specific immunity. Additionally, the long-term protection was evaluated by re-challenging with the melanoma cells in the flank regions of tumor bearing mice. Results: CRT-NP plus FUS (CFUS) upregulated CRT expression, expanded the population of melanoma TRP-2 specific functional CD4+ and CD8+ T cells and tumor-suppressing M1 phenotype, and increased PD-1 and PD-L1 marker expression in the T cells. Therapeutically, CFUS suppressed B16 melanoma growth by >85% vs. that seen in untreated controls, and >~50% vs. CRT-NP or FUS alone, and prevented tumor growth in distal untreated sites. Conclusions: CRT-NP amplifies the FUS and ICD therapeutic outcomes against melanoma, suggesting that the proposed combinatorial methodology may be clinically translatable.

• Authors: Sri Nandhini Sethuraman, Mohit Pratap Singh, Girish Patil, Shitao Li, Steven Fiering, P Jack Hoopes, Chandan Guha, Jerry Malayer, Ashish Ranjan
• Journal: Theranostics (Theranostics) Vol. 10 Issue 8 Pg. 3397-3412 ( 2020) ISSN: 1838-7640 [Electronic] Australia
• PMID: 32206098 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: © The author(s).

Chemical References

• B7-H1 Antigen
• CALR protein, human
• CD274 protein, human
• CD47 Antigen
• Calreticulin
• Cytokines

Topics

• Adaptive Immunity (drug effects)
• Animals
• B7-H1 Antigen (metabolism)
• CD47 Antigen (immunology)
• CD8-Positive T-Lymphocytes (immunology)
• Calreticulin (therapeutic use)
• Cell Membrane (metabolism)
• Combined Modality Therapy
• Cytokines (immunology)
• Humans
• Immunogenic Cell Death
• Lymph Nodes (immunology)
• Melanoma, Experimental (immunology, therapy)
• Mice
• Nanoparticles (therapeutic use)
• Spleen (immunology)
• Tumor-Associated Macrophages (immunology)
• Ultrasonic Therapy (methods)
• Xenograft Model Antitumor Assays