CD1d-restricted invariant natural killer T (iNKT) cells actively patrol the liver and possess valuable antitumor potential. However, clinical trials evaluating administration of iNKT cell–specific agonist α-galactosylceramide (α-GalCer) have failed to achieve obvious tumor regression. Improving the efficacy of iNKT cell–based immunotherapy requires a better understanding of the factors restraining the clinical benefits. In the context of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), we found circulating and hepatic iNKT cells were hyperactivated but demonstrated imbalances in ratio and defective α-GalCer responsiveness. Exogenous IL2 helped to expand residual α-GalCer–responsive clones with reduced T-cell receptor diversity. However, transcriptome-wide analysis revealed activation of the senescence-associated secretory phenotype and dampened cytotoxicity in iNKT cells, weakening their immune surveillance capacity. The senescent status of iNKT cells from the patients was further illustrated by cell-cycle arrest, impaired telomere maintenance, perturbed calcium transport-related biological processes, and altered metabolism. Lipidomic profiling revealed the accumulation of long-chain acylcarnitines (LCAC) and aberrant lipid metabolism in HCC tissue. Exogenous LCACs, especially palmitoyl-carnitine and stearoyl-carnitine, inhibited iNKT cell expansion and promoted senescence. Collectively, our results provide deeper insights into iNKT cell dysregulation and identify a cell senescence–associated challenge for iNKT cell–based immunotherapy in HBV-related HCC. The mechanistic links between iNKT cell senescence and accumulated LCACs suggest new targets for anti-HCC immunotherapies. Significance: Patients with HBV-related HCC exhibit a cell senescence–associated dysregulation of invariant natural killer cells that is related to altered lipid metabolism and accumulated LCACs in tumor tissue.

Background: Idiopathic pulmonary fibrosis (IPF) is characterised by significant but poorly understood immune and antibody responses. This study examines the spatial transcriptomes and microenvironmental niches of antibody-producing plasma cells and tertiary lymphoid structures in IPF lungs, and the molecular pathways influencing antibody accumulation and pulmonary fibrosis.Methods: Explant lung tissues from IPF patients and control normal lungs were used for spatial transcriptome assays and validating RNAscope and immunofluorescence assays. Fibroblasts derived from IPF and control lungs were examined for their ability to attract plasma cells. Neutralising antibodies were administered to investigate molecules affecting pulmonary plasma cell accumulation and fibrosis in bleomycin-treated mice.Results: Human IPF lungs exhibited a remarkably widespread distribution of plasma cells and local antibodies in the fibrotic regions, disseminating from plasma cell-generating tertiary lymphoid structures. Novel mural cells wrapped the vessels in tertiary lymphoid structure regions, expressing C-C motif chemokine receptor 7 (CCR7) ligands that attracted T-cells into tertiary lymphoid structures to promote plasma cell generation. Distinct IPF-associated fibroblasts further secreted C-X-C motif chemokine ligand 12 (CXCL12), providing an extramedullary niche to foster the dissemination and accumulation of plasma cells in the fibrotic regions. Neutralisation of CCR7 ligands or CXCL12 reduced plasma cell and local antibody accumulation in the lungs of bleomycin-treated mice, leading to reduced transforming growth factor β concentrations and alleviated pulmonary fibrosis.Conclusions: Plasma cells and local antibodies are widely distributed in the fibrotic regions of IPF lungs. Distinct subsets of IPF-associated mural cells and fibroblasts promote pathological plasma cell and antibody accumulation. These findings have potential implications for strategies aimed at targeting immune and antibody responses to combat IPF.

Activation of invariant NKT (iNKT) cells manifests antiviral immune responses in vivo. However, clinical trials have failed to show consistent hepatitis B virus (HBV) DNA reduction postadministration of iNKT cell–specific agonist α-galactosylceramide (α-GalCer). In this study, we aimed to investigate HBV infection–related iNKT cell defects and explore iNKT cell–based therapeutic potential for chronic hepatitis B (CHB). Liver specimens from 30 HBV-infected hepatocellular carcinoma patients were collected for CD1d/hepatitis B surface Ag (HBsAg) staining and/or intrahepatic iNKT cell assay. Two hundred and six chronic HBV-infected patients (including 130 CHB patients) were enrolled in the study of circulating iNKT cell frequency and function. We found that liver and hepatoma tissue that positively stained for HBsAg had higher CD1d expression as compared with HBsAg negatively stained counterparts. The elevated CD1d expression in infected tissue is supposed to facilitate the iNKT cell–based antiviral effects locally. However, iNKT cell defects that related with disease progression suggested iNKT cells attenuated their effects during chronic HBV infection. The residual iNKT cells in CHB patients showed aberrant activation and hyporesponsiveness to α-GalCer. Exogenous IL-2 fully rescued α-GalCer–induced expansion of iNKT cells from CHB patients, and synergistic effects of IL-2 and IL-15 helped to recover the CD1d-dependent IFN-γ production. In conclusion, our results highlight the increased CD1d expression in HBV-infected liver and differential iNKT cell defects associated with disease progression during chronic HBV infection. The reversibility of iNKT cell defects suggests protective immune responses could be partially recovered in CHB.

Suppressing immune responses promotes allograft survival but also favours tumour progression and recurrence. Selectively suppressing allograft rejection while maintaining or even enhancing antitumor immunity is challenging. Here, we show loss of allograft-related rejection in mice deficient in Setdb1, an H3K9 methyltransferase, while antitumor immunity remains intact. RNA sequencing shows that Setdb1-deficiency does not affect T-cell activation or cytokine production but induces an increase in Treg-cell-associated gene expression. Depletion of Treg cells impairs graft acceptance in Setdb1-deficient mice, indicating that the Treg cells promote allograft survival. Surprisingly, Treg cell-specific Setdb1 deficiency does not prolong allograft survival, suggesting that Setdb1 may function prior to Foxp3 induction. Using single-cell RNA sequencing, we find that Setdb1 deficiency induces a new Treg population in the thymus. This subset of Treg cells expresses less IL-1R2 and IL-18R1. Mechanistically, during Treg cell induction, Setdb1 is recruited by transcription factor ATF and altered histone methylation. Our data thus define Setdb1 in T cells as a hub for Treg cell differentiation, in the absence of which suppressing allograft rejection is uncoupled from maintaining antitumor immunity.

This study aims to investigate the potential prognostic value of albumin-bilirubin (ALBI) score in breast cancer patients with liver metastasis after surgery. This was a retrospective study of 178 breast cancer patients with liver metastasis after surgery. ALBI score was calculated by the following formula: (log10 bilirubin × 0.66) − (albumin × 0.085). The optimal cutoff value of ALBI score was assessed by X-tile. The clinical influence of ALBI score on survival outcomes using Kaplan-Meier method, Log-rank test, Cox proportional hazards regression model. The calibration curves, decision curve analysis and time-dependent ROC curve were used to assess the predictive performance of the nomogram's models. The classifications of 178 breast cancer patients with liver metastasis after surgery were as follows: low ALBI score group (＜−3.36) vs. high ALBI score group (≥−3.36). The Cox proportional hazards regression model indicated that ALBI score was a potential predictor. Kaplan-Meier survival curve performed that the median disease free survival (p = 0.0029) and overall survival (p＜0.0001) in low ALBI score group were longer than in high ALBI score group. The ALBI-based nomograms had good predictive performance. The ALBI score has high prognostic ability for survival time in breast cancer with liver metastasis after surgery. These models will be valuable in discriminating patients at high risks of liver metastasis.