Jing Zhang

BACKGROUND: Non-inflamed tumors, including immune-excluded and immune-desert tumors, are commonly resistant to anti-PD-1/PD-L1 (α-PD-1/PD-L1) therapy. Our previous study reported the potent antitumor activity of anti-TGF-β/PD-L1 bispecific antibody YM101 in immune-excluded tumors. However, YM101 had limited antitumor activity in immune-desert models. MSA-2 is a novel oral stimulator of interferon genes (STING) agonist, which activates the innate immune system and may synergize with YM101 in overcoming immunotherapy resistance. METHODS: The dose-dependent effect of MSA-2 on STING signaling was determined by interferon-β level. The maturation and function of dendritic cell (DC) were measured by flow cytometry, RNA-seq, one-way mixed lymphocyte reaction (MLR), OVA peptide pulse, and cytokine/chemokine detection. The synergistic effect between MSA-2 and YM101 was assessed by one-way MLR. The macrophage activation was measured by flow cytometry and cytokine/chemokine detection. The in vivo antitumor activity of MSA-2 combined with YM101 was explored in syngeneic murine tumor models. After treatments, the alterations in the tumor microenvironment (TME) were detected by flow cytometry, immunohistochemistry staining, immunofluorescence staining, RNA-seq, and single-cell RNA-seq (scRNA-seq). RESULTS: MSA-2 could promote the maturation and antigen presentation capability of murine DC. In the one-way MLR assay, MSA-2 synergized with YM101 in enhancing naive T cell activation. Moreover, MSA-2 stimulated the classical activation of macrophage, without significant influence on alternative activation. Further in vivo explorations showed that MSA-2 increased multiple proinflammatory cytokines and chemokines in the TME. MSA-2 combined with YM101 remarkedly retarded tumor growth in immune-excluded and immune-desert models, with superior antitumor activity to monotherapies. Flow cytometry, bulk RNA-seq, and scRNA-seq assays indicated that the combination therapy simultaneously boosted the innate and adaptive immunity, promoted antigen presentation, improved T cell migration and chemotaxis, and upregulated the numbers and activities of tumor-infiltrating lymphocytes. CONCLUSION: Our results demonstrate that MSA-2 synergizes with YM101 in boosting antitumor immunity. This immune cocktail therapy effectively overcomes immunotherapy resistance in immune-excluded and immune-desert models.

TNFα and IL-1β are two proinflammatory cytokines that play critical roles in many diseases, including rheumatoid arthritis and infectious diseases. How TNFα- and IL-1β-mediated signaling is finely tuned is not fully elucidated. Here, we identify tripartite-motif protein 38 (TRIM38) as a critical negative regulator of TNFα- and IL-1β-triggered signaling. Overexpression of TRIM38 inhibited activation of NF-κB and induction of downstream cytokines following TNFα and IL-1β stimulation, whereas knockdown or knockout of TRIM38 had the opposite effects. TRIM38 constitutively interacted with critical components TGF-β-activated kinase 1 (TAK1)-binding protein 2/3 (TAB2/3) and promoted lysosome-dependent degradation of TAB2/3 independent of its E3 ubiquitin ligase activity. Consistently, deficiency of TRIM38 resulted in abolished translocation of TAB2 to the lysosome, increased level of TAB2 in cells, and enhanced activation of TAK1 after TNFα and IL-1β stimulation. We conclude that TRIM38 negatively regulates TNFα- and IL-1β-induced signaling by mediating lysosome-dependent degradation of TAB2/3, two critical components in TNFα- and IL-1β-induced signaling pathways. Our findings reveal a previously undiscovered mechanism by which cells keep the inflammatory response in check to avoid excessive harmful immune response triggered by TNFα and IL-1β.

Abstract The microenvironment of lymph node metastasized tumors (LNMT) determines tumor progression and response to therapy, but a systematic study of LNMT is lacking. Here, we generate single-cell maps of primary tumors (PTs) and paired LNMTs in 8 breast cancer patients. We demonstrate that the activation, cytotoxicity, and proliferation of T cells are suppressed in LNMT compared with PT. CD4 + CXCL13 + T cells in LNMT are more likely to differentiate into an exhausted state. Interestingly, LAMP3 + dendritic cells in LNMT display lower T cell priming and activating ability than in PT. Additionally, we identify a subtype of PLA2G2A + cancer-associated fibroblasts enriched in HER2 + breast cancer patients that promotes immune infiltration. We also show that the antigen-presentation pathway is downregulated in malignant cells of the metastatic lymph node. Altogether, we characterize the microenvironment of LNMT and PT, which may shed light on the individualized therapeutic strategies for breast cancer patients with lymph node metastasis.

(-)-Daphnilongeranin B and (-)-daphenylline are two hexacyclic Daphniphyllum alkaloids, each containing a complex cagelike backbone. Described herein are the first asymmetric total synthesis of (-)-daphnilongeranin B and a bioinspired synthesis of (-)-daphenylline with an unusual E ring embedded in a cagelike framework. The key features include an intermolecular [3+2] cycloaddition, a late-stage aldol cyclization to install the F ring of daphnilongeranin B, and a bioinspired cationic rearrangement leading to the tetrasubstituted benzene ring of daphenylline.