Research progress on immunotherapeutics for triple-negative breast cancer from a single-cell perspective.

Triple-negative breast cancer (TNBC) is a highly heterogeneous subtype with no effective therapeutic targets. Recent advances in immunotherapy, particularly PD-1/PD-L1 inhibitors and CTLA-4 antibodies, have yielded promising clinical outcomes in some patients. Additionally, cell-based therapies and tumor vaccines show substantial potential. Evidence increasingly supports the superior efficacy of combination therapies integrating immunotherapy with antitumor agents over traditional monotherapies. Single-cell and spatial multi-omics technologies, including scRNA-seq and scATAC-seq, as well as spatial transcriptomics, have provided insights into how therapeutic agents remodel the tumor microenvironment (TME), revealing mechanisms of action and TNBC's cellular heterogeneity. This review integrates the latest advances in single-cell multi-omics and pharmacology to summarize progress in TNBC immunotherapy development, highlighting new therapeutic targets and optimized drug combinations. Furthermore, it discusses how the TME influences immunotherapy resistance from a single-cell perspective. Overall, single-cell-guided immunotherapy represents an innovative approach for better clinical translation, advancing precision medicine, and potentially transforming clinical practice.