PMID- 36096527 OWN - NLM STAT- MEDLINE DCOM- 20220914 LR - 20221004 IS - 2051-1426 (Electronic) IS - 2051-1426 (Linking) VI - 10 IP - 9 DP - 2022 Sep TI - Label-free metabolic imaging for sensitive and robust monitoring of anti-CD47 immunotherapy response in triple-negative breast cancer. LID - 10.1136/jitc-2022-005199 [doi] LID - e005199 AB - BACKGROUND: Immunotherapy is revolutionizing cancer treatment from conventional radiotherapies and chemotherapies to immune checkpoint inhibitors which use patients' immune system to recognize and attack cancer cells. Despite the huge clinical success and vigorous development of immunotherapies, there is a significant unmet need for a robust tool to identify responders to specific immunotherapy. Early and accurate monitoring of immunotherapy response is indispensable for personalized treatment and effective drug development. METHODS: We established a label-free metabolic intravital imaging (LMII) technique to detect two-photon excited autofluorescence signals from two coenzymes, NAD(P)H (reduced nicotinamide adenine dinucleotide (phosphate) hydrogen) and FAD (flavin adenine dinucleotide) as robust imaging markers to monitor metabolic responses to immunotherapy. Murine models of triple-negative breast cancer (TNBC) were established and tested with different therapeutic regimens including anti-cluster of differentiation 47 (CD47) immunotherapy to monitor time-course treatment responses using the developed metabolic imaging technique. RESULTS: We first imaged the mechanisms of the CD47-signal regulatory protein alpha pathway in vivo, which unravels macrophage-mediated antibody-dependent cellular phagocytosis and illustrates the metabolism of TNBC cells and macrophages. We further visualized the autofluorescence of NAD(P)H and FAD and found a significant increase during tumor growth. Following anti-CD47 immunotherapy, the imaging signal was dramatically decreased demonstrating the sensitive monitoring capability of NAD(P)H and FAD imaging for therapeutic response. NAD(P)H and FAD intravital imaging also showed a marked decrease after chemotherapy and radiotherapy. A comparative study with conventional whole-body bioluminescence and fluorescent glucose imaging demonstrated superior sensitivity of metabolic imaging. Flow cytometry validated metabolic imaging results. In vivo immunofluorescent staining revealed the targeting ability of NAD(P)H imaging mainly for tumor cells and a small portion of immune-active cells and that of FAD imaging mainly for immunosuppressive cells such as M2-like tumor-associated macrophages. CONCLUSIONS: Collectively, this study showcases the potential of the LMII technique as a powerful tool to visualize dynamic changes of heterogeneous cell metabolism of cancer cells and immune infiltrates in response to immunotherapy thus providing sensitive and complete monitoring. Leveraged on ability to differentiate cancer cells and immunosuppressive macrophages, the presented imaging approach provides particularly useful imaging biomarkers for emerged innate immune checkpoint inhibitors such as anti-CD47 therapy. CI - (c) Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. FAU - Yang, Minfeng AU - Yang M AUID- ORCID: 0000-0001-8277-8139 AD - Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hung Hom, Hong Kong. FAU - Mahanty, Arpan AU - Mahanty A AUID- ORCID: 0000-0001-8389-8212 AD - Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hung Hom, Hong Kong. FAU - Jin, Chunjing AU - Jin C AD - The Affiliated Chuzhou Hospital of Anhui Medical University, The First People's Hospital of Chuzhou, Chuzhou, China. FAU - Wong, Alex Ngai Nick AU - Wong ANN AUID- ORCID: 0000-0003-2789-350X AD - Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hung Hom, Hong Kong. FAU - Yoo, Jung Sun AU - Yoo JS AUID- ORCID: 0000-0002-8865-0424 AD - Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hung Hom, Hong Kong jungsun.yoo@polyu.edu.hk. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't PL - England TA - J Immunother Cancer JT - Journal for immunotherapy of cancer JID - 101620585 RN - 0 (Immune Checkpoint Inhibitors) RN - 0 (Immunologic Factors) RN - 0U46U6E8UK (NAD) RN - 146-14-5 (Flavin-Adenine Dinucleotide) SB - IM MH - Animals MH - Flavin-Adenine Dinucleotide/metabolism MH - Humans MH - Immune Checkpoint Inhibitors MH - Immunologic Factors MH - Immunotherapy/methods MH - Mice MH - NAD MH - *Triple Negative Breast Neoplasms/diagnostic imaging/drug therapy PMC - PMC9472253 OTO - NOTNLM OT - Biomarkers, Tumor OT - Immunity, Cellular OT - Immunity, Innate OT - Immunotherapy OT - Metabolic Networks and Pathways COIS- Competing interests: None declared. EDAT- 2022/09/13 06:00 MHDA- 2022/09/15 06:00 PMCR- 2022/09/12 CRDT- 2022/09/12 20:52 PHST- 2022/08/15 00:00 [accepted] PHST- 2022/09/12 20:52 [entrez] PHST- 2022/09/13 06:00 [pubmed] PHST- 2022/09/15 06:00 [medline] PHST- 2022/09/12 00:00 [pmc-release] AID - jitc-2022-005199 [pii] AID - 10.1136/jitc-2022-005199 [doi] PST - ppublish SO - J Immunother Cancer. 2022 Sep;10(9):e005199. doi: 10.1136/jitc-2022-005199.