Biliary tract cancer (BTC) has a poor prognosis with limited treatment options. This phase 2 trial randomized 80 patients with unresectable/metastatic BTC 1:1 to sintilimab, anlotinib, and gemcitabine/cisplatin (SAGC) or chemotherapy alone (GC). At 13.4-month median follow-up, SAGC significantly improved median progression-free survival (8.5 vs. 6.3 months; HR 0.48, 95% CI 0.22-0.64, p = 0.005) and objective response rate (51.4% vs. 29.4%), with higher grade 3/4 adverse events (75.0% vs. 43.6%). Post hoc analysis showed enhanced efficacy with anlotinib 8 mg versus 10 mg (ORR 54.5% vs. 38.8%). In AKT/YAP tumor models, low-dose anlotinib (3 mg/kg) combined with sintilimab improved vascular perfusion, T-cell cytotoxicity, and cytokine secretion compared to high-dose (6 mg/kg). These findings demonstrate improved efficacy and manageable toxicity with SAGC, particularly at the 8 mg anlotinib dose, suggesting low-dose regimens may optimize antitumor response while mitigating adverse effects. Trial registration number ClinicalTrials.gov Identifier: NCT04300959.
© 2025. The Author(s).

Hypoxia in the tumor microenvironment hinders antitumor immunity. Increasing tumor oxygenation may promote T cell infiltration and tumor control by immune checkpoint blockade (ICB). We found that a radiosensitizer, myo-inositol trispyrophosphate (ITPP), caused oxygen unloading from hemoglobin in CT26 and 4T1 tumors as indicated by photoacoustic imaging (PAI). This change in hypoxia detected by PAI was correlated with strong positive correlations with CD8+ and CD4+ FoxP3- effector T cell (Teff), and negative correlations with monocyte frequencies, indicating that ITPP promoted more immunogenic tumor microenvironments in both models. Combination ITPP and ICB improved tumor control and survival in both models. Therefore, imaging ITPP-modulated tumor hypoxia with PAI was related to ICB treatment response in these studies. Future combination immunotherapy regimens may benefit from monitoring hypoxia using molecular imaging with PAI.
© 2025. The Author(s).

T cells have a remarkable capacity to clonally expand, a process that is intricately linked to their effector activities. As vigorously proliferating T cell also incur substantial DNA lesions, how the dividing T cells safeguard their genomic integrity to allow the generation of T effector cells remains largely unknown. Here we report the identification of the apurinic/apyrimidinic endonuclease-1 (Apex1) as an indispensable molecule for the induction of cytopathic T effectors in mouse models. We demonstrate that conditional deletion of Apex1 in T cells resulted in a remarkable accumulation of baseless DNA sites in the genome of proliferating T cells, which further led to genomic instability and apoptotic cell death. Consequently, Apex1-deleted T cells failed to acquire any effector features after activation and failed to mediate autoimmune diseases and allergic tissue damages. Detailed mutational analyses pinpointed the importance of its endonuclease domain in the generation of T effector cells. We provide further evidence that inhibiting the base repair activities of Apex1 with chemical inhibitors similarly abrogated the induction of autoimmune diseases. Collectively, our study suggests that Apex1 serves as a gatekeeper for the generation of cytopathic T cells and that therapeutically targeting Apex1 may have important clinical implications in the treatment of autoimmune diseases.

Current cancer immunotherapy predominately focuses on eliciting type 1 immune responses fighting cancer; however, long-term complete remission remains uncommon1,2. A pivotal question arises as to whether type 2 immunity can be orchestrated alongside type 1-centric immunotherapy to achieve enduring response against cancer3,4. Here we show that an interleukin-4 fusion protein (Fc-IL-4), a typical type 2 cytokine, directly acts on CD8+ T cells and enriches functional terminally exhausted CD8+ T (CD8+ TTE) cells in the tumour. Consequently, Fc-IL-4 enhances antitumour efficacy of type 1 immunity-centric adoptive T cell transfer or immune checkpoint blockade therapies and induces durable remission across several syngeneic and xenograft tumour models. Mechanistically, we discovered that Fc-IL-4 signals through both signal transducer and activator of transcription 6 (STAT6) and mammalian target of rapamycin (mTOR) pathways, augmenting the glycolytic metabolism and the nicotinamide adenine dinucleotide (NAD) concentration of CD8+ TTE cells in a lactate dehydrogenase A-dependent manner. The metabolic modulation mediated by Fc-IL-4 is indispensable for reinvigorating intratumoural CD8+ TTE cells. These findings underscore Fc-IL-4 as a potent type 2 cytokine-based immunotherapy that synergizes effectively with type 1 immunity to elicit long-lasting responses against cancer. Our study not only sheds light on the synergy between these two types of immune responses, but also unveils an innovative strategy for advancing next-generation cancer immunotherapy by integrating type 2 immune factors.
© 2024. The Author(s).

T cell immunity is critical for human defensive immune response. Exploring the key molecules during the process provides new targets for T cell-based immunotherapies. CMC1 is a mitochondrial electron transport chain (ETC) complex IV chaperon protein. By establishing in-vitro cell culture system and Cmc1 gene knock out mice, we evaluated the role of CMC1 in T cell activation and differentiation. The B16-OVA tumor model was used to test the possibility of targeting CMC1 for improving T cell anti-tumor immunity. We identified CMC1 as a positive regulator in CD8+T cells activation and terminal differentiation. Meanwhile, we found that CMC1 increasingly expressed in exhausted T (Tex) cells. Genetic lost of Cmc1 inhibits the development of CD8+T cell exhaustion in mice. Instead, deletion of Cmc1 in T cells prompts cells to differentiate into metabolically and functionally quiescent cells with increased memory-like features and tolerance to cell death upon repetitive or prolonged T cell receptor (TCR) stimulation. Further, the in-vitro mechanistic study revealed that environmental lactate enhances CMC1 expression by inducing USP7, mediated stabilization and de-ubiquitination of CMC1 protein, in which a mechanism we propose here that the lactate-enriched tumor microenvironment (TME) drives CD8+TILs dysfunction through CMC1 regulatory effects on T cells. Taken together, our study unraveled the novel role of CMC1 as a T cell regulator and its possibility to be utilized for anti-tumor immunotherapy.
© 2024 The Author(s). Published with license by Taylor & Francis Group, LLC.