METHODS: Flow cytometry was utilized to investigate the effects of Taraxacum officinale extract (TOE) in combination with PD-1/PD-L1 inhibitor 2 on the immune microenvironment of triple-negative breast cancer (TNBC). Active compounds and their potential targets were identified through an integrative approach involving GeneCards, OMIM, and DisGeNET databases, as well as UPLC-Q-Orbitrap MS analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted, followed by molecular docking to explore compound-target interactions. The anti-proliferative effects of isochlorogenic acid A (ICGA-A) and chicoric acid (CRA) on MDA-MB-231 and 4T1 cells were evaluated using the CCK-8 assay. RESULTS: TOE and its active constituents, ICGA-A and CRA, demonstrate potential in augmenting PD-1 blockade therapy for TNBC. This study investigated the combination of ICGA-A and PD-1/PD-L1 inhibitor 2, which significantly enhanced the infiltration of macrophages and CD8+ T cells into tumors in murine models, while concurrently reducing the population of exhausted T cells. Furthermore, CRA notably increased the frequency of CD8+ T cells. Both ICGA-A and CRA therapies were also found to suppress tumor proliferation by inhibiting the FAK/PI3K/AKT/mTOR signaling pathway. These findings highlight the potential of ICGA-A and CRA as effective adjuvants to improve the therapeutic efficacy of PD-1 inhibitor-based immunotherapy in TNBC. DISCUSSION: ICGA-A and CRA, bioactive compounds from