The immune cell atlas reveals mechanisms of immune evasion and LAG3 as a novel target in mouse models of breast cancer metastasis

However, only a minority of patients respond, and there are no biomarkers for patient stratification and prediction of response. Temporal and spatial characterization of the host immune response was interrogated using single cell RNAseq of immune cells from mouse models of TNBC, which covers 5 tissues and 4 time points ranging from tumor-free to late metastatic disease.

Profound changes were observed in immune composition of the bone marrow, lymph nodes, lung and blood at the earliest time point with small tumors and no metastatic disease. In addition, functional markers were altered during tumor progression suggesting broad subversion of immune function in every cell type examined, particularly in the tumor tissue itself. However, evidence of a beneficial immune response was found in lymph nodes but was clearly inactivated in tumor and lung tissues.