1
|
Domankevich V, Cohen A, Efrati M, Schmidt M, Rammensee HG, Nair SS, Tewari A, Kelson I, Keisari Y. Combining alpha radiation-based brachytherapy with immunomodulators promotes complete tumor regression in mice via tumor-specific long-term immune response. Cancer Immunol Immunother 2019; 68:1949-1958. [PMID: 31637474 PMCID: PMC6877484 DOI: 10.1007/s00262-019-02418-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 10/10/2019] [Indexed: 12/11/2022]
Abstract
Diffusing alpha-emitters radiation therapy (DaRT) is the only known method for treating solid tumors with highly destructive alpha radiation. More importantly, as a monotherapy, DaRT has been shown to induce a systemic antitumor immune response following tumor ablation. Here, immunomodulatory strategies to boost the antitumor immune response induced by DaRT, and the response specificity, were investigated in the colon cancer CT26 mouse model. Local treatment prior to DaRT, with the TLR3 agonist poly I:C, was sufficient to inhibit tumor growth relative to poly I:C or DaRT alone. DaRT used in combination with the TLR9 agonist CpG, or with the TLR1/2 agonist XS15 retarded tumor growth and increased tumor-rejection rates, compared to DaRT alone, curing 41% and 20% of the mice, respectively. DaRT in combination with CpG, the Treg inhibitor cyclophosphamide, and the MDSC inhibitor sildenafil, cured 51% of the animals, compared to only 6% and 0% cure when immunomodulation or DaRT was used alone, respectively. Challenge and Winn assays revealed that these high cure rates involved a specific immunological memory against CT26 antigens. We suggest that DaRT acts in synergy with immunomodulation to induce a specific and systemic antitumor immune response. This strategy may serve as a safe and efficient method not only for tumor ablation, but also for in situ vaccination of cancer patients.
Collapse
Affiliation(s)
- Vered Domankevich
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, P.O. Box 39040, 6997801, Tel Aviv, Israel
| | - Adi Cohen
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, P.O. Box 39040, 6997801, Tel Aviv, Israel
| | - Margalit Efrati
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, P.O. Box 39040, 6997801, Tel Aviv, Israel
| | - Michael Schmidt
- School of Physics and Astronomy, Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
- Alpha Tau Medical, Tel Aviv, Israel
| | - Hans-Georg Rammensee
- Department of Immunology, Institute for Cell Biology, University of Tübingen, Tübingen, Germany
| | - Sujit S Nair
- Department of Urology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ashutosh Tewari
- Department of Urology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Itzhak Kelson
- School of Physics and Astronomy, Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
- Alpha Tau Medical, Tel Aviv, Israel
| | - Yona Keisari
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel Aviv University, P.O. Box 39040, 6997801, Tel Aviv, Israel.
- Alpha Tau Medical, Tel Aviv, Israel.
| |
Collapse
|