LAUSR

As a promising alternative platform for cellular immunotherapy, natural killer cells (NK) have recently gained attention as an important type of innate immune regulatory cell. NK cell immunotherapy approaches have been translated into clinical applications, and clinical trials of NK cell infusion in patients with hematological malignancies (HM) and solid tumors have thus far yielded many encouraging clinical results. Understanding the pattern of NK expression and the relationship to different states of NK cells may have direct relevance for immune responses in cancer. Approaches capable of simultaneously detecting NK cells with detailed information on NK differentiation state, however, remain limited. In this study, we used MultiOmyx hyperplexed immunofluorescence (IF) assay to classify and characterize the spatial arrangement of NK cell markers in a pan-cancer cohort including 9 tissue microarrays (TMAs) from breast, head and neck, prostrate, colon, bladder, lung, kidney, ovarian and melanoma indications. The panel includes CD3, CD4, CD8, CD16, CD45, CD56, CD57, CD137, FoxP3, Granzyme B, HLA-E, NKG2A, NKP46 and tumor segmentation marker. The panel enables the detection of NK cells expressing CD56 and/or NKP46 in the 9 different tumor indications. We also studied the expression of activating and inhibiting receptors, such as CD16 and NKG2A, in NK cell population. The active cytotoxic subsets of mature NK cells were evaluated using co-expression of NK cell surface markers with CD57 and the cytotoxic molecule expression in NK cells was assessed using co-expression with Granzyme B. Using proprietary deep-learning-based image analysis, we were able to quantify the densities of these different NK cell population and study the prevalence of these NK cells in different cancer indications included in this study. Many strategies have been developed for exploiting NK-mediated anti-tumor activities. CAR-NK cell therapy and antibodies that directly target NK cell inhibitory receptors such as NKG2A and TIGIT, are currently being evaluated in the clinical trials. The MultiOmyx NK cell panel reported in this study enables the comprehensive profiling of the NK population and can provide greater understanding of NK cell biology during cancer progression. The panel can be further used to explore the efficacy of the NK cell-based immune therapy. Citation Format: Erinn A. Parnell, Jiong Fei, Harry Nunns, Eric Leones, Elaine Yeung, Blair Russell, Flora Sahafi, Qingyan Au. Comprehensive analysis of natural killer cell-associated markers using MultiOmyxTM immunofluorescence assay. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4688.