Characterizing tumor-infiltrating group 1 innate lymphoid cells in PyMT breast tumors.

Breast cancer is the most common cancer in women and continues to have a significant impact in cancer-associated deaths worldwide. Investigating the complex roles of infiltrating immune subsets within the tumor microenvironment (TME) will enable a better understanding of disease progression and reveal novel therapeutic strategies for patients with breast cancer. The mammary-specific expression of polyomavirus middle T oncoprotein (MMTV-PyMT) was first established in 1992 by William Muller and is the most commonly used genetically engineered mouse model (GEMM) for breast cancer research. Innate lymphoid cells (ILCs) are composed of a diverse family of effector cells known to play important roles in defense against pathogens, tissue homeostasis, and tumor immunity. In mice, group 1 ILCs are composed of NK cells and ILC1s, which have been shown to have differential roles within the TME. Here, we provide a detailed methodology in characterizing tumor-infiltrating NK cells and ILC1s in MMTV-PyMT breast tumor model.