Centering Digital Health Equity During Technology Innovation: Protocol for a Comprehensive Scoping Review of Evidence-Based Tools and Approaches.

BACKGROUND: In the rush to develop health technologies for the COVID-19 pandemic, the unintended consequence of digital health inequity or the inability of priority communities to access, use, and receive equal benefits from digital health technologies was not well examined. OBJECTIVE: This scoping review will examine tools and approaches that can be used during digital technology innovation to improve equitable inclusion of priority communities in the development of digital health technologies. The results from this study will provide actionable insights for professionals in health care, health informatics, digital health, and technology development to proactively center equity during innovation. METHODS: Based on the Arksey and O'Malley framework, this scoping review will consider priority communities' equitable involvement in digital technology innovation. Bibliographic databases in health, medicine, computing, and information sciences will be searched. Retrieved citations will be double screened against the inclusion and exclusion criteria using Covidence (Veritas Health Innovation). Data will be charted using a tailored extraction tool and mapped to a digital health innovation pathway defined by the Centre for eHealth Research roadmap for eHealth technologies. An accompanying narrative synthesis will describe the outcomes in relation to the review's objectives. RESULTS: This scoping review is currently in progress. The search of databases and other sources returned a total of 4868 records. After the initial screening of titles and abstracts, 426 studies are undergoing dual full-text review. We are aiming to complete the full-text review stage by May 30, 2024, data extraction in October 2024, and subsequent synthesis in December 2024. Funding was received on October 1, 2023, from the Centre for Health Equity Incubator Grant Scheme, University of Melbourne, Australia. CONCLUSIONS: This paper will identify and recommend a series of validated tools and approaches that can be used by health care stakeholders and IT developers to produce equitable digital health technology across the Centre for eHealth Research roadmap. Identified evidence gaps, possible implications, and further research will be discussed. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/53855.

Intracellular delivery of oncolytic viruses with engineered Salmonella causes viral replication and cell death.

As therapies, oncolytic viruses regress tumors and have the potential to induce antitumor immune responses that clear hard-to-treat and late-stage cancers. Despite this promise, clearance from the blood prevents treatment of internal solid tumors. To address this issue, we developed virus-delivering Salmonella (VDS) to carry oncolytic viruses into cancer cells. The VDS strain contains the PsseJ-lysE delivery circuit and has deletions in four homologous recombination genes (ΔrecB, ΔsbcB, ΔsbcCD, and ΔrecF) to preserve essential hairpins in the viral genome required for replication and infectivity. VDS delivered the genome for minute virus of mice (MVMp) to multiple cancers, including breast, pancreatic, and osteosarcoma. Viral delivery produced functional viral particles that are cytotoxic and infective to neighboring cells. The release of mature virions initiated new rounds of infection and amplified the infection. Using Salmonella for delivery will circumvent the limitations of oncolytic viruses and will provide a new therapy for many cancers.

Intracellular Salmonella delivery of an exogenous immunization antigen refocuses CD8 T cells against cancer cells, eliminates pancreatic tumors and forms antitumor immunity.

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.

Bacterial delivery of therapeutic proteins to the nuclei of cancer cells.

Targeting nucleic targets with therapeutic proteins would enhance the treatment of hard-to-treat cancers. However, exogenous proteins are excluded from the nucleus by both the cellular and nuclear membranes. We have recently developed Salmonella that deliver active proteins into the cytoplasm of cancer cells. Here, we hypothesized that bacterially delivered proteins accumulate within nuclei, nuclear localization sequences (NLSs) increase delivery, and bacterially delivered proteins kill cancer cells. To test this hypothesis, we developed intranuclear delivering (IND) Salmonella and quantified the delivery of three model proteins. IND Salmonella delivered both ovalbumin and green fluorescent protein to nuclei of MCF7 cancer cells. The amount of protein in nuclei was linearly dependent on the amount delivered to the cytoplasm. The addition of a NLSs increased both the amount of protein in each nucleus and the number of nuclei that received protein. Delivery of Omomyc, a protein inhibitor of the nuclear transcript factor, Myc, altered cell physiology, and significantly induced cell death. These results show that IND Salmonella deliver functional proteins to the nucleus of cancerous cells. Extending this method to other transcription factors will increase the number of accessible targets for cancer therapy.

Intracellular delivery of protein drugs with an autonomously lysing bacterial system reduces tumor growth and metastases.

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.