Characteristics of immune checkpoint regulators and potential role of soluble TIM-3 and LAG-3 in male patients with alcohol-associated liver disease

The involvement of immune checkpoint regulators (ICs) in alcohol-associated liver diseases (ALDs) is still largely unknown. Here, we analyzed the levels of 16 soluble ICs (sICs) in male patients with ALD to determine their clinical significance. The 16 sICs were measured using a luminex-based multiplex assay in 115 patients with ALD and 47 healthy controls (HCs). The expressions of membrane-type (m) PD-1 and mCTLA-4 on CD4+ and CD8+ T lymphocytes and NK cells of 28 patients with ALD and 8 HCs were also measured. Correlation test and risk assessment were also conducted to evaluate biomarkers of ALD in clinical practice. Our results show that four sICs were upregulated (sCTLA-4, sTIM-3, sCD27, and sGITR) and two sICs were downregulated (sLAG-3 and sHVEM) in ALD. mPD-1 expression was significantly more greatly increased on CD4+T lymphocytes in the ALD group than in the HC group (p = 0.009). sTIM-3 was positively correlated, while sLAG-3 was negatively correlated with non-invasive liver fibrosis markers (AST/ALT, APRI, GPR, and FIB-4) and Maddrey discriminant function score. Risk factor analysis showed that sTIM-3 was consistently associated with ALD severity in both MDF and FIB-4 scores, and sLAG-3 was associated with FIB-4 scores. This study revealed the involvement of sCTLA-4, sTIM-3, sCD27, sGITRL, sLAG-3, and sHVEM in discriminating male patients with ALD. Expressions of sTIM-3 and sLAG-3 were correlated with liver fibrosis markers and significantly associated with ALD severity, which can be further studied as diagnostic markers and therapeutic targets in ALD.

Functional and Clinical Characterization of Tumor-Infiltrating T Cell Subpopulations in Hepatocellular Carcinoma

Tumor-infiltrating T-lymphocytes are defined as T-lymphocytes that infiltrated into tumor tissues; however, their composition, clinical significance, and underlying mechanism in hepatocellular carcinoma (HCC) and adjacent non-tumor tissues are still not completely understood. Herein, we collected marker genes of T cell subpopulations from a previous study and estimated their relative infiltrating levels in HCC and adjacent non-tumor tissues. Specifically, the infiltrating levels of all the T cells were significantly reduced in HCC as compared with non-tumor tissues. Unsupervised clustering of the HCC samples by the T cell infiltrating levels revealed that the HCC samples could be clearly classified into two groups. The driver genes, including PTK2B, ATM, PIK3C2B, and KIT, and several CNAs were observed to be associated with reduced T cell infiltrating levels. Particularly, deletion of TP53 more frequently occurred in low T cell infiltration HCC samples and resulted in its downregulation and cell cycle progression, indicating that cell cycle progression was closely associated with reduced T cell infiltration. In contrast, for the samples with high infiltration T cells, its immune evasion might be regulated by the immune checkpoint regulators, such as PD-1/PD-L1 and CTLA4. Moreover, Olaparib, one of the PARP inhibitors, and immune checkpoint inhibitors might be therapeutic candidates for the samples from the two T cell infiltrating clusters. Clinically, the tumor-infiltrating levels of cytotoxic CD4 cell, Mucosal associated invariant T (MAIT) cell, and exhausted CD8⁺ T cell might be used as predictors for vascular invasion, recurrence, and overall survival. Collectively, we systematically evaluated the clinical significance and potential molecular mechanisms of tumor-infiltrating T cell subpopulations in hepatocellular carcinoma, which might broaden our insights into the immunological features of HCC and provide potential immunotherapeutic targets.