Dihydroartemisinin remodels tumor micro-environment and improves cancer immunotherapy through inhibiting cyclin-dependent kinases.

Cancer immunotherapies are ineffective in nonresponding patients due to absence of immune responses. Here, we identified that dihydroartemisinin (DHA) induced immunogenic cell death (ICD) in hepatocellular carcinoma (HCC), proved by release or surface expose of damage-associated molecular patterns and in vivo protective vaccine activity. Mechanistically, DHA can inhibit cyclin-dependent kinases (CDKs), leading to a buildup of intracellular reactive oxygen species (ROS), which induces immunogenic cell death. In both Hepa1-6 and H22 tumor bearing mice, DHA exerted anti-tumor activity through increasing tumor-infiltrating CD8+ T cells with expression of activation makers (CD25 and CD69), secretion of intracellular cytokines (IFN-γ and TNF-α) and activated dendritic cells expressing MHCⅡ, CD80 and CD86. In hepa1-6 tumor bearing mice, DHA decreased immunosuppressive myeloid-derived suppressor cells. Furthermore, DHA enhanced the anti-PD-1 antibody and chimeric antigen receptor (CAR) T cell-mediated tumor suppression through recruitment and activation of endogenous CD8+ T cells. Overall, we demonstrated that by inhibiting CDKs, DHA can remodel tumor micro-environment to amplify anti-tumor immune responses in HCC. These findings provide a promising therapy option for HCC patients.

Decoding the transcriptional heterogeneity, differentiation lineage, clinical significance in tissue-resident memory CD8 T cell of the small intestine by single-cell analysis.

Resident memory T (Trm) cells which are specifically located in non-lymphoid tissues showed distinct phenotypes and functions compared to circulating memory T cells and were vital for the initiation of robust immune response within tissues. However, the heterogeneity in the transcriptional features, development pathways, and cancer response of Trm cells in the small intestine was not demonstrated. Here, we integrated scRNA-seq and scTCR-seq data pan-tissue T cells to explore the heterogeneity of Trm cells and their development pathways. Trm were enriched in tissue-specific immune response and those in the DUO specially interacted with B cells via TNF and MHC-I signatures. T cell lineage analyses demonstrated that Trm might be derived from the T_CD4/CD8 subset within the same organ or migrated from spleen and mesenteric lymph nodes. We compared the immune repertoire of Trm among organs and implied that clonotypes in both DUO and ILE were less expanded and hydrophilic TRB CDR3s were enriched in the DUO. We further demonstrated that Trm in the intestine infiltrated the colorectal cancer and several effector molecules were highly expressed. Finally, the TCGA dataset of colorectal cancer implied that the infiltration of Trm from the DUO and the ILE was beneficial for overall survival and the response to immune checkpoint blockade.