CITE-Seq analysis of intratumoral immune cells from YUMM1.7 melanoma treated with anti-PD-1 therapy.

Investigations to identify underlying mechanisms focus on T cells or the immunosuppressive tumormicroenvironment (TME). Tumor-associated macrophages (TAMs) make up a large fraction of the TME and high levels of TAM have been associated with poor survival of cancer patients.

In this study, the subcutaneous YUMM1.7 melanoma model was used to investigate the responsiveness to anti-PD-1 therapy. The tumor cell line was injected into GRf/f and GRf/f-LysMCre mice to enable insights into glucocorticoid-dependent effects within the myeloid compartment and how they contribute to the responsiveness to anti-PD-1 immunotherapy. Therefore, we profiled sorted CD45+ immune cells from tumors of GRf/f and GRf/f-LysMCre treated with anti-PD-1 therapy or an isotype control antibody via the cellular indexing of transcriptomes and epitomes-method (CITE-Seq).