Sir Peter MacCallum Department of Oncology - Research Publications

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Author: Darcy, Phillip × Author: Keam, Simon × Author: Neeson, Paul × End date: 2021 × Start date: 2020 × Type: Journal Article ×

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    MAIT cells regulate NK cell-mediated tumor immunity
    Petley, E ; Koay, H-F ; Henderson, MA ; Sek, K ; Todd, KL ; Keam, SP ; Lai, J ; House, IG ; Li, J ; Zethoven, M ; Chen, AXY ; Oliver, AJ ; Michie, J ; Freeman, AJ ; Giuffrida, L ; Chan, JD ; Pizzolla, A ; Mak, JYW ; McCulloch, TR ; Souza-Fonseca-Guimaraes, F ; Kearney, CJ ; Millen, R ; Ramsay, RG ; Huntington, ND ; McCluskey, J ; Oliaro, J ; Fairlie, DP ; Neeson, PJ ; Godfrey, D ; Beavis, PA ; Darcy, PK (NATURE PORTFOLIO, 2021-08-06)
    The function of MR1-restricted mucosal-associated invariant T (MAIT) cells in tumor immunity is unclear. Here we show that MAIT cell-deficient mice have enhanced NK cell-dependent control of metastatic B16F10 tumor growth relative to control mice. Analyses of this interplay in human tumor samples reveal that high expression of a MAIT cell gene signature negatively impacts the prognostic significance of NK cells. Paradoxically, pre-pulsing tumors with MAIT cell antigens, or activating MAIT cells in vivo, enhances anti-tumor immunity in B16F10 and E0771 mouse tumor models, including in the context of established metastasis. These effects are associated with enhanced NK cell responses and increased expression of both IFN-γ-dependent and inflammatory genes in NK cells. Importantly, activated human MAIT cells also promote the function of NK cells isolated from patient tumor samples. Our results thus describe an activation-dependent, MAIT cell-mediated regulation of NK cells, and suggest a potential therapeutic avenue for cancer treatment.
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    Myeloma natural killer cells are exhausted and have impaired regulation of activation
    D'Souza, C ; Keam, SP ; Yeang, HXA ; Neeson, M ; Richardson, K ; Hsu, AK ; Canfield, R ; Bezman, N ; Robbins, M ; Quach, H ; Ritchie, DS ; Harrison, SJ ; Trapani, JA ; Prince, HM ; Beavis, PA ; Darcy, PK ; Neeson, PJ (FERRATA STORTI FOUNDATION, 2021-09)
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    High dose-rate brachytherapy of localized prostate cancer converts tumors from cold to hot
    Keam, SP ; Halse, H ; Nguyen, T ; Wang, M ; Van Kooten Losio, N ; Mitchell, C ; Caramia, F ; Byrne, DJ ; Haupt, S ; Ryland, G ; Darcy, PK ; Sandhu, S ; Blombery, P ; Haupt, Y ; Williams, SG ; Neeson, PJ (BMJ PUBLISHING GROUP, 2020)
    BACKGROUND: Prostate cancer (PCa) has a profoundly immunosuppressive microenvironment and is commonly immune excluded with few infiltrative lymphocytes and low levels of immune activation. High-dose radiation has been demonstrated to stimulate the immune system in various human solid tumors. We hypothesized that localized radiation therapy, in the form of high dose-rate brachytherapy (HDRBT), would overcome immune suppression in PCa. METHODS: To investigate whether HDRBT altered prostate immune context, we analyzed preradiation versus postradiation human tissue from a cohort of 24 patients with localized PCa that received HDRBT as primary treatment (RadBank cohort). We performed Nanostring immune gene expression profiling, digital spatial profiling, and high-throughput immune cell multiplex immunohistochemistry analysis. We also resolved tumor and nontumor zones in spatial and bioinformatic analyses to explore the immunological response. RESULTS: Nanostring immune profiling revealed numerous immune checkpoint molecules (eg, B7-H3, CTLA4, PDL1, and PDL2) and TGFβ levels were increased in response to HDRBT. We used a published 16-gene tumor inflammation signature (TIS) to divide tumors into distinct immune activation states (high:hot, intermediate and low:cold) and showed that most localized PCa are cold tumors pre-HDRBT. Crucially, HDRBT converted 80% of these 'cold'-phenotype tumors into an 'intermediate' or 'hot' class. We used digital spatial profiling to show these HDRBT-induced changes in prostate TIS scores were derived from the nontumor regions. Furthermore, these changes in TIS were also associated with pervasive changes in immune cell density and spatial relationships-in particular, between T cell subsets and antigen presenting cells. We identified an increased density of CD4+ FOXP3+ T cells, CD68+ macrophages and CD68+ CD11c+ dendritic cells in response to HDRBT. The only subset change specific to tumor zones was PDL1- macrophages. While these immune responses were heterogeneous, HDRBT induced significant changes in immune cell associations, including a gained T cell and HMWCK+ PDL1+ interaction in tumor zones. CONCLUSION: In conclusion, we showed HDRBT converted "cold" prostate tumors into more immunologically activated "hot" tissues, with accompanying spatially organized immune infiltrates and signaling changes. Understanding and potentially harnessing these changes will have widespread implications for the future treatment of localized PCa, including rational use of combination radio-immunotherapy.