Patients with hepatocellular carcinoma (HCC) confront a high incidence of tumor recurrence after curative surgical resection. Hepatic ischemia-reperfusion injury (IRI) is the major consequence of surgical stress during hepatectomy. Although it has been suggested that hepatic IRI-induced immunosuppression could contribute to tumor relapse after surgery, the underlying mechanisms have not been fully defined. Here, using a multiplex cytokine array, we found that levels of postoperative IFNα serve as an independent risk factor for tumor recurrence in 100 patients with HCC with curative hepatectomy. Plasmacytoid dendritic cells (pDC), the major source of IFNα, were activated after surgery and correlated with poor disease-free survival. Functionally, IFNα was responsible for mobilization of myeloid-derived suppressor cells (MDSC) following hepatic IRI. Conditioned medium from IFNα-treated hepatocytes mediated the migration of MDSCs in vitro. Mechanistically, IFNα upregulated IRF1 to promote hepatocyte expression of CX3CL1, which subsequently recruited CX3CR1+ monocytic MDSCs. Knockdown of Irf1 or Cx3cl1 in hepatocytes significantly inhibited the accumulation of monocytic MDSCs in vivo. Therapeutically, elimination of pDCs, IFNα, or CX3CR1 could restore the tumor-killing activity of CD8+ T cells, hence limiting tumor growth and lung metastasis following hepatic IRI. Taken together, these data suggest that IFNα-producing pDCs drive CX3CR1+ MDSC recruitment via hepatocyte IRF1/CX3CL1 signaling and lead to tumor recurrence after hepatectomy in HCC. Targeting pDCs and the IFNα/CX3CL1/CX3CR1 axis could inhibit surgical stress–induced HCC recurrence by attenuating postoperative immunosuppression. Significance: IFNα secreted by plasmacytoid dendritic cells drives postoperative immunosuppression and early recurrence of hepatocellular carcinoma, providing new biomarkers and therapeutic targets to improve patient outcomes after surgical resection.

A variety of state-of-the-art nanovaccines (NV) combined with immunotherapies have recently been developed to treat malignant tumors, showing promising results. However, immunosuppression in the tumor microenvironment (TME) restrains cytotoxic T-cell infiltration and limits the efficacy of immunotherapies in solid tumors. Therefore, tactics for enhancing antigen cross-presentation and reshaping the TME need to be explored to enhance the activity of NVs. Here, we developed photo-enhanceable inflammasome-activating NVs (PIN) to achieve precise in situ delivery of a tumor antigen and a hydrophobic small molecule activating the nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain–containing protein 3 inflammasome (NLRP3) pathway. Near-infrared light irradiation promoted PIN accumulation in tumor sites through photo-triggered charge reversal of the nanocarrier. Systematic PIN administration facilitated intratumoral NLRP3 inflammasome activation and antigen cross-presentation in antigen-presenting cells upon light irradiation at tumor sites. Furthermore, PIN treatment triggered immune responses by promoting the production of proinflammatory cytokines and activating antitumor immunity without significant systematic toxicity. Importantly, the PIN enhanced the efficacy of immune checkpoint blockade and supported the establishment of long-term immune memory in mouse models of melanoma and hepatocellular carcinoma. Collectively, this study reports a safe and efficient photoresponsive system for codelivery of antigens and immune modulators into tumor tissues, with promising therapeutic potential. Significance: The development of a photoresponsive nanovaccine with spatiotemporal controllability enables robust tumor microenvironment modulation and enhances the efficacy of immune checkpoint blockade, providing an effective immunotherapeutic strategy for cancer treatment. See related commentary by Zhen and Chen, p. 3709

Despite growing evidence linking pretransplant exposure to immune checkpoint inhibitors (ICIs) to increased allograft rejection risk after liver transplantation (LT), a lack of comparative studies to definitively establish the correlation between ICI exposure and adverse short-term outcomes after LT exists. This study aimed to analyze the impact of preoperative ICI exposure on short-term post-LT prognosis and allograft rejection risk. This retrospective cohort study included 121 recipients who underwent LT for hepatocellular carcinoma (HCC) between June 2019 and March 2023. The recipients were categorized into ICI (n = 35) and non-ICI (n = 86) exposure groups based on pretransplant ICI exposure. Demographics, clinical characteristics, and short-term outcomes were compared between the cohorts. Kaplan-Meier analysis evaluated the impact of ICI exposure on graft survival. Univariate and multivariate logistic regression models assessed the impact of patient characteristics on allograft rejection. Recipients with or without ICI exposure exhibited comparable demographic baseline characteristics. The incidences of early allograft dysfunction and biliary and vascular complications were similar between both groups. Post-transplant infection incidence was 37.1% and 20.9% in the ICI and non-ICI groups, respectively (P = 0.064). Allograft rejection rates were significantly higher in the ICI group than in the non-ICI group (22.9% vs. 5.8%, P = 0.015). The ICI group exhibited a higher 90-day post-transplant mortality rate than that of the non-ICI group (14.3% vs. 2.3%, P = 0.034). Logistic regression analyses demonstrated that allograft rejection independently correlated with 90-day post-transplant mortality, with ICI exposure being an independent risk factor for allograft rejection. In recipients with ICI exposure, a shorter interval between ICIs and LT (washout period) was significantly associated with a higher allograft rejection risk, with the optimal washout period identified as 21 days for predicting 90-day rejection-free survival (P = 0.0001). Moreover, in recipients with allograft rejection, the peripheral CD4⁺/CD8⁺ T cell ratio was much lower in the ICI group than in the non-ICI group. Pretransplant ICI exposure was an independent risk factor for allograft rejection and was significantly associated with 90-day post-transplant mortality after LT for HCC. A ≤21-day washout period was significantly associated with allograft rejection. Future multicenter studies with larger cohorts and prospective designs are essential to validate these findings, confirm causality, and establish standardized clinical guidelines for ICI use before transplantation. ClinicalTrials.gov NCT05913583.

Background and Aims—Transforming growth factor-beta (TGF-β) signaling orchestrates tumorigenesis and one of the family members, TGF-β receptor type III (TGFβR3), are distinctively under-expressed in numerous malignancies. Currently, the clinical impact of TGFβR3 down-regulation and the underlying mechanism remains unclear in hepatocellular carcinoma (HCC). Here, we aimed to identify the tumor-promoting roles of decreased TGFβR3 expression in HCC progression. Materials and Methods—For clinical analysis, plasma and liver specimens were collected from 100 HCC patients who underwent curative resection for the quantification of TGFβR3 by q-PCR and ELISA. To study the tumor-promoting mechanism of TGFβR3 downregulation, HCC mouse models and TGFβR3 knockout cell lines were applied. Results—Significant downregulation of TGFβR3 and its soluble form (sTGFβR3) were found in HCC tissues and plasma compared to healthy individuals (p < 0.01). Patients with <9.4 ng/mL sTGFβR3 exhibited advanced tumor stage, higher recurrence rate and shorter disease-free survival (p < 0.05). The tumor-suppressive function of sTGFβR3 was further revealed in an orthotopic mouse HCC model, resulting in 2-fold tumor volume reduction. In TGFβR3 knockout hepatocyte and HCC cells, increased complement component C5a was observed and strongly correlated with shorter survival and advanced tumor stage (p < 0.01). Interestingly, C5a activated the tumor-promoting Th-17 response in tumor associated macrophages. Conclusion—TGFβR3 suppressed tumor progression, and decreased expression resulted in poor prognosis in HCC patients through upregulation of tumor-promoting complement C5a.