Deciphering the immunomodulatory mechanisms of Bojungikki-tang via systematic transcriptomic and immune cell interaction network analysis

Bojungikki-tang (BJIKT), a traditional herbal formula with immunomodulatory properties, has synergistic effects with immune checkpoint inhibitors. However, the detailed molecular mechanisms underlying its effects on various immune cell types remain largely unexplored. Therefore, in this study, we aimed to propose a framework for understanding how herbal medicine modulates immunity through a systematic analysis of the drug-induced transcriptome and immune cell interaction networks. We obtained large-scale RNA-seq data for distinct five immune cell types (T cells, natural killer cells, B cells, macrophages, and dendritic cells) treated with BJIKT and its four major constituent herbs, totaling 180 sequenced samples. Transcriptomic analysis indicated that BJIKT significantly upregulated interferon-γ, TNF-α, and inflammatory pathways in B cells, macrophages, and dendritic cells. Although BJIKT did not directly activate T cells, it indirectly modulated their function through immune cell-cell interactions. The reconstructed network and cytokine assays identified IL-1β, IL-6, IL-8, MIP-1β, CXCL9, CXCL10, and TNF-α as critical cytokines influenced by BJIKT, playing pivotal roles in activating and recruiting various immune cells. Our findings provide insights into the immunomodulatory mechanisms of BJIKT and the unique actions of its constituent herbs. We highlight the potential for combining traditional herbal medicine with omics technologies to explore the therapeutic mechanisms of natural products as complementary therapies for advancing cancer immunotherapy.