Conventional type 1 dendritic cells and natural killer cells demonstrate strong correlation to cytotoxic T lymphocyte infiltration in cervical cancer tumors

Abstract

Abstract Professional antigen presenting cells such as dendritic cells (DCs) are vital for priming naive CD8+ T cells and developing a sustainable anti-tumor immune response. Natural killer (NK) cells within the tumor microenvironment (TME) recruit a specific population of DCs called conventional type 1 DCs (cDC1s). However, these cells are low in abundance making their detection in the tissue context challenging. To interrogate the presence of cDC1 and NK cells in the TME and reveal their spatial relationship to each other we utilized the highly sensitive and specific RNAscope Multiplex Fluorescence in situ hybridization (ISH) assay. NK cells and cDC1 cells were identified by using cell specific marker probes in 4 cervical cancer samples. Similarly, CTLs were visualized to determine if there is a correlation between the presence of cDC1 and NK cells and infiltration of CTLs within the cervical cancer tumors. Our results revealed a strong correlation between the presence of NK cells, cDC1 cells, and CTLs within 3 out of 4 cervical cancer samples. The NK cells showed expression of the chemokines XCL1 and CCL5, suggesting that the XCR1+/CCR5+ cDC1 cells may have been potentially recruited by these NK cells in the TME. Regions high in cDC1 and NK cells also showed significantly higher levels of CTL recruitment, indicated by the presence of CD8+/IFNG+ T cells. Conversely, 1 of the 4 cervical cancer samples demonstrated relatively lower levels of NK cells which correlated with lower cDC1 cells and in turn lower CTL infiltration. In conclusion, by utilizing the RNAscope Multiplex ISH assay we identified and visualized the spatial relationship between NK cells, CTLs, and cDC1 cells, highlighting the strength of this technology to spatially interrogate the TME.