Targeting Stress Sensor Kinases in Hepatocellular Carcinoma-Infiltrating Human NK Cells as a Novel Immunotherapeutic Strategy for Liver Cancer

Natural killer (NK) cells may become functionally exhausted entering hepatocellular carcinoma (HCC), and this has been associated with tumor progression and poor clinical outcome. Hypoxia, low nutrients, immunosuppressive cells, and soluble mediators characterize the intratumor microenvironment responsible for the metabolic deregulation of infiltrating immune cells such as NK cells. HCC-infiltrating NK cells from patients undergoing liver resection for HCC were sorted, and genome-wide transcriptome profiling was performed. We have identified a marked general upregulation of gene expression profile along with metabolic impairment of glycolysis, OXPHOS, and autophagy as well as functional defects of NK cells. Targeting p38 kinase, a stress-responsive mitogen-activated protein kinase, we could positively modify the metabolic profile of NK cells with functional restoration in terms of TNF-α production and cytotoxicity. We found a metabolic and functional derangement of HCC-infiltrating NK cells that is part of the immune defects associated with tumor progression and recurrence. NK cell exhaustion due to the hostile tumor microenvironment may be restored with p38 inhibitors with a selective mechanism that is specific for tumor-infiltrating-not affecting liver-infiltrating-NK cells. These results may represent the basis for the development of a new immunotherapeutic strategy to integrate and improve the available treatments for HCC.

Differences between exhausted CD8+ T cells in hepatocellular carcinoma patients with and without uremia

The purpose of this study was to explore the differences between exhausted CD8⁺ T cells in hepatocellular carcinoma (HCC) patients with and without uremia. We enrolled 45 uremic patients who were recently diagnosed with HCC into the HCC + uremia cohort and similar patients with HCC but without uremia into the HCC-only cohort. Lymphocytes were obtained from the two cohorts, and exhausted CD8⁺ T cells, comprising PD-1⁺CD8⁺, TIM-3⁺CD8⁺, and LAG-3⁺CD8⁺ T cells, were sorted and expanded in vitro. After expansion, the proportions of PD-1⁺CD8⁺, TIM-3⁺CD8⁺, and LAG-3⁺CD8⁺ T cells were significantly higher in the HCC-only cohort than in the HCC + uremia cohort. CD8⁺ T cells expressing PD-1, TIM-3, or LAG-3 showed increased tumor reactivity and release of interferon-γ in vitro; however, these cells demonstrated weaker anti-tumor activity in HCC + uremia patients than in HCC-only patients. Among the expanded lymphocytes, only the decreased proportion of PD-1⁺CD8⁺ T cells significantly correlated with the HCC + uremia cohort (odds ratio of 2.731, p = 0.009). We concluded that peripheral CD8⁺ T cells expressing PD-1, TIM-3, or LAG-3 from the HCC + uremia cohort were dysfunctional in vitro. Among these populations, PD-1⁺CD8⁺ T cells were most evident in HCC patients with uremia.

Differential expression of Tim-3, PD-1, and CCR5 on peripheral T and B lymphocytes in hepatitis C virus-related hepatocellular carcinoma and their impact on treatment outcomes

BACKGROUND AND OBJECTIVE

Activation of the immune checkpoints and expression of chemokines and chemokine receptors have been reported to promote HCC progression. This study aimed to assess the differential expression of Tim-3, PD-1, and CCR5 on peripheral blood lymphocytes from patients with HCV-related HCC and correlate their expression with the treatment outcomes.

PATIENTS AND METHODS

The study incorporated 40 patients with chronic HCV-related HCC and 40 healthy controls. Patients were radiologically assessed for hepatic focal lesions and portal vein thrombosis. Response to HCC treatment and overall survival (OS) outcomes were determined. The expression of Tim-3, PD-1, and CCR5 among CD19⁺, CD4⁺, and CD8⁺ lymphocytes was assessed by flow cytometry.

RESULTS

Higher frequencies of CD4⁺ and CD8⁺ cells expressing each of Tim-3 and PD-1 and PD-1⁺CD19⁺ cells were observed in the HCV-related HCC patients in comparison with controls. The highest expression of Tim-3 and PD-1 was by the CD8⁺ cells. Strong relations were detected among PD-1⁺CD19⁺, PD-1⁺CD4⁺ and PD-1⁺CD8⁺ cells. Elevated levels of PD-1⁺ lymphocytes were significantly associated with poor treatment response and shorter OS.

CONCLUSION

Modulation of the expression of immune checkpoints as Tim-3 and PD-1, and of CCR5 on T cells is somehow related to HCC. CD8⁺ T cells expressing PD-1 were the most relevant to HCC prognosis (OS and treatment response) and could represent a promising target for immune therapy against HCC. Future studies need to focus on exploring PD-1⁺ B cells and Tim-3⁺CD4⁺ cells, which seem to play a significant role in the pathogenesis of HCC.