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Raman V, Howell LM, Bloom SMK, Hall CL, Wetherby VE, Minter LM, Kulkarni AA, Forbes NS. Intracellular Salmonella delivery of an exogenous immunization antigen refocuses CD8 T cells against cancer cells, eliminates pancreatic tumors and forms antitumor immunity. Front Immunol 2023; 14:1228532. [PMID: 37868996 PMCID: PMC10585021 DOI: 10.3389/fimmu.2023.1228532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 09/12/2023] [Indexed: 10/24/2023] Open
Abstract
Introduction Immunotherapies have shown great promise, but are not effective for all tumors types and are effective in less than 3% of patients with pancreatic ductal adenocarcinomas (PDAC). To make an immune treatment that is effective for more cancer patients and those with PDAC specifically, we genetically engineered Salmonella to deliver exogenous antigens directly into the cytoplasm of tumor cells. We hypothesized that intracellular delivery of an exogenous immunization antigen would activate antigen-specific CD8 T cells and reduce tumors in immunized mice. Methods To test this hypothesis, we administered intracellular delivering (ID) Salmonella that deliver ovalbumin as a model antigen into tumor-bearing, ovalbumin-vaccinated mice. ID Salmonella delivers antigens by autonomously lysing in cells after the induction of cell invasion. Results We showed that the delivered ovalbumin disperses throughout the cytoplasm of cells in culture and in tumors. This delivery into the cytoplasm is essential for antigen cross-presentation. We showed that co-culture of ovalbumin-recipient cancer cells with ovalbumin-specific CD8 T cells triggered a cytotoxic T cell response. After the adoptive transfer of OT-I CD8 T cells, intracellular delivery of ovalbumin reduced tumor growth and eliminated tumors. This effect was dependent on the presence of the ovalbumin-specific T cells. Following vaccination with the exogenous antigen in mice, intracellular delivery of the antigen cleared 43% of established KPC pancreatic tumors, increased survival, and prevented tumor re-implantation. Discussion This response in the immunosuppressive KPC model demonstrates the potential to treat tumors that do not respond to checkpoint inhibitors, and the response to re-challenge indicates that new immunity was established against intrinsic tumor antigens. In the clinic, ID Salmonella could be used to deliver a protein antigen from a childhood immunization to refocus pre-existing T cell immunity against tumors. As an off-the-shelf immunotherapy, this bacterial system has the potential to be effective in a broad range of cancer patients.
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Affiliation(s)
- Vishnu Raman
- Department of Chemical Engineering, University of Massachusetts, Amherst, MA, United States
- Ernest Pharmaceuticals, LLC, Hadley, MA, United States
| | - Lars M. Howell
- Department of Chemical Engineering, University of Massachusetts, Amherst, MA, United States
| | - Shoshana M. K. Bloom
- Department of Chemical Engineering, University of Massachusetts, Amherst, MA, United States
| | - Christopher L. Hall
- Department of Chemical Engineering, University of Massachusetts, Amherst, MA, United States
- Ernest Pharmaceuticals, LLC, Hadley, MA, United States
| | | | - Lisa M. Minter
- Molecular and Cell Biology Program, University of Massachusetts, Amherst, MA, United States
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA, United States
- Institute for Applied Life Science, University of Massachusetts, Amherst, MA, United States
| | - Ashish A. Kulkarni
- Department of Chemical Engineering, University of Massachusetts, Amherst, MA, United States
- Institute for Applied Life Science, University of Massachusetts, Amherst, MA, United States
| | - Neil S. Forbes
- Department of Chemical Engineering, University of Massachusetts, Amherst, MA, United States
- Molecular and Cell Biology Program, University of Massachusetts, Amherst, MA, United States
- Institute for Applied Life Science, University of Massachusetts, Amherst, MA, United States
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Raman V, Van Dessel N, Hall CL, Wetherby VE, Whitney SA, Kolewe EL, Bloom SMK, Sharma A, Hardy JA, Bollen M, Van Eynde A, Forbes NS. Intracellular delivery of protein drugs with an autonomously lysing bacterial system reduces tumor growth and metastases. Nat Commun 2021; 12:6116. [PMID: 34675204 PMCID: PMC8531320 DOI: 10.1038/s41467-021-26367-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 10/01/2021] [Indexed: 12/25/2022] Open
Abstract
Critical cancer pathways often cannot be targeted because of limited efficiency crossing cell membranes. Here we report the development of a Salmonella-based intracellular delivery system to address this challenge. We engineer genetic circuits that (1) activate the regulator flhDC to drive invasion and (2) induce lysis to release proteins into tumor cells. Released protein drugs diffuse from Salmonella containing vacuoles into the cellular cytoplasm where they interact with their therapeutic targets. Control of invasion with flhDC increases delivery over 500 times. The autonomous triggering of lysis after invasion makes the platform self-limiting and prevents drug release in healthy organs. Bacterial delivery of constitutively active caspase-3 blocks the growth of hepatocellular carcinoma and lung metastases, and increases survival in mice. This success in targeted killing of cancer cells provides critical evidence that this approach will be applicable to a wide range of protein drugs for the treatment of solid tumors.
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Affiliation(s)
- Vishnu Raman
- Department of Chemical Engineering, University of Massachusetts, Amherst, Amherst, MA, USA
- Ernest Pharmaceuticals, LLC, Hadley, MA, USA
| | - Nele Van Dessel
- Department of Chemical Engineering, University of Massachusetts, Amherst, Amherst, MA, USA
- Ernest Pharmaceuticals, LLC, Hadley, MA, USA
| | - Christopher L Hall
- Department of Chemical Engineering, University of Massachusetts, Amherst, Amherst, MA, USA
- Ernest Pharmaceuticals, LLC, Hadley, MA, USA
| | | | - Samantha A Whitney
- Department of Chemical Engineering, University of Massachusetts, Amherst, Amherst, MA, USA
| | - Emily L Kolewe
- Department of Chemical Engineering, University of Massachusetts, Amherst, Amherst, MA, USA
| | - Shoshana M K Bloom
- Department of Chemical Engineering, University of Massachusetts, Amherst, Amherst, MA, USA
| | - Abhinav Sharma
- Department of Chemical Engineering, University of Massachusetts, Amherst, Amherst, MA, USA
| | - Jeanne A Hardy
- Department of Chemistry, University of Massachusetts, Amherst, Amherst, MA, USA
- Molecular and Cell Biology Program, University of Massachusetts, Amherst, Amherst, MA, USA
- Institute for Applied Life Science, University of Massachusetts, Amherst, Amherst, MA, USA
| | - Mathieu Bollen
- Laboratory of Biosignaling & Therapeutics, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Aleyde Van Eynde
- Laboratory of Biosignaling & Therapeutics, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Neil S Forbes
- Department of Chemical Engineering, University of Massachusetts, Amherst, Amherst, MA, USA.
- Ernest Pharmaceuticals, LLC, Hadley, MA, USA.
- Molecular and Cell Biology Program, University of Massachusetts, Amherst, Amherst, MA, USA.
- Institute for Applied Life Science, University of Massachusetts, Amherst, Amherst, MA, USA.
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