BMI1-induced CD127+KLRG1+ memory T cells enhance the efficacy of liver cancer immunotherapy

m6A epitranscriptomic modification in hepatocellular carcinoma: implications for the tumor microenvironment and immunotherapy

Hepatocellular carcinoma (HCC) is the most prevalent primary liver malignancy and a leading cause of cancer-related deaths globally. The asymptomatic progression of early-stage HCC often results in diagnosis at advanced stages, significantly limiting therapeutic options and worsening prognosis. Immunotherapy, with immune checkpoint inhibitors (ICIs) at the forefront, has revolutionized HCC treatment. Nevertheless, tumor heterogeneity, immune evasion, and the presence of immunosuppressive components within the tumor immune microenvironment (TIME) continue to compromise its efficacy. Furthermore, resistance or non-responsiveness to ICIs in some patients underscores the urgent need to unravel the complexities of the TIME and to design innovative strategies that enhance immunotherapeutic outcomes. Emerging evidence has revealed the pivotal role of N6-methyladenosine (m6A), a prominent RNA methylation modification, in shaping the TIME in HCC. By regulating RNA stability and translation, m6A influences immune-related factors, including cytokines and immune checkpoint molecules. This modification governs PD-L1 expression, facilitating immune escape and contributing to resistance against ICIs. Advances in this field have also identified m6A-related regulators as promising biomarkers for predicting immunotherapy response and as potential therapeutic targets for optimizing treatment efficacy. This review examines the regulatory mechanisms of m6A modification within the TIME of HCC, with a focus on its impact on immune cells and cytokine dynamics. It also explores the therapeutic potential of targeting m6A pathways to improve immunotherapy efficacy and outlines emerging directions for future research. These insights aim to provide a foundation for developing novel strategies to overcome immune resistance and advance HCC treatment.

The T-cell receptor β chain CDR3 insights of bovine liver immune repertoire under heat stress

OBJECTIVE

The liver plays a dual role in regulating temperature and immune responses. Examining the influence of heat stress (HS) on liver T cells contributes significantly to understanding the intricate interplay between the immune system and hepatic tissues under thermal stress. This study focused on investigating the characteristics of the T-cell receptor (TCR) β chain CDR3 repertoire in bovine liver samples under both HS and pairfed (PF) environmental conditions.

METHODS

Sequencing data from six samples sourced from the GEO database underwent annotation. Utilizing immunarch and VDJtool software, the study conducted comprehensive analyses encompassing basic evaluation, clonality assessment, immune repertoire comparison, diversity estimation, gene usage profiling, VJ gene segment pairing scrutiny, clonal tracking, and Kmers analysis.

RESULTS

All four TCR chains, namely α, β, γ, and δ, were detected, with the α chains exhibiting the highest detection frequency, followed closely by the β chains. The prevalence of αβ TCRs in bovine liver samples underscored their crucial role in governing hepatic tissue's physiological functions. The TCR β CDR3 repertoire showcased substantial inter-individual variability, featuring diverse clonotypes exhibiting distinct amino acid lengths. Intriguingly, HS cattle displayed heightened diversity and clonality, suggesting potential peripheral T cell migration into the liver under environmental conditions. Notably, differential VJ gene pairings were observed in HS cattle compared to the PF, despite individual variations in V and J gene utilization. Additionally, while most high-frequency amino acid 5-mers remained consistent between the HS and PF, GELHF, and YDYHF were notably prevalent in the HS group. Across all samples, a prevalent trend of high-frequency 5mers skewed towards polar and hydrophobic amino acids was evident.

CONCLUSION

This study elucidates the characteristics of liver TCR β chain CDR3 repertoire under HS conditions, enhancing our understanding of HS implications.

Revisiting the CXCL13/CXCR5 axis in the tumor microenvironment in the era of single-cell omics: Implications for immunotherapy

As one of the important members of the family of chemokines and their receptors, the CXCL13/CXCR5 axis is involved in follicle formation in normal lymphoid tissues and the establishment of somatic cavity immunity under physiological conditions, as well as being associated with a wide range of infectious, autoimmune, and tumoral diseases. Here in this review, we focus on its role in tumors. Traditional studies have found the axis to be both pro- and anti-tumorigenic, involving a variety of immune cells, including the tumor cells themselves and those in the tumor microenvironment (TME), and the prognostic significance of this axis is clinical context-dependent. With the development of techniques at the single-cell level, we were able to explain in detail the status of the CXCL13/CXCR5 axis in the TME based on real clinical samples and found that it involves a range of crucial intrinsic anti-tumor immune processes in the TME and is therefore important in tumor immunotherapy. We summarize the cellular subsets, physiological functions, and prognostic significance associated with this axis in the most promising immune checkpoint inhibitor (ICI) therapies of the day and summarize possible therapeutic ideas based on this axis. As with any TME study, the most important takeaway is that the complexity of the CXCL13/CXCR5 axis in TME suggests the importance of personalized therapy in tumor therapy.

MATR3 promotes liver cancer progression by suppressing DHX58-mediated type I interferon response

MATR3 is a nuclear matrix protein implicated in various cancers; however, its specific role in tumor progression remains unclear. The study utilized the TCGA database to reveal that MATR3 expression is upregulated in liver cancer and is correlated with poor prognosis. Functionally, MATR3 promoted liver cancer cell proliferation and metastasis. Comprehensive RNA sequencing analysis showed that MATR3 significantly affected the type I IFN signaling pathway and DHX58 is a downstream target of MATR3. Further experiments showed that MATR3 bound to DHX58 mRNA through its RRM structural domain and recruited YTHDF2, an m6A reader, leading to degradation of DHX58 mRNA and suppression of the type I IFN signaling pathway. The knockout of MATR3 in liver cancer cells triggered a natural immune response that stimulated CD8+ T cells to eliminate liver cancer cells. This study demonstrated that MATR3 downregulates type I IFN signaling in liver cancer cells through m6A modification and inhibits immune cell infiltration within tumors. These findings expand our understanding of the role of MATR3 in liver cancer.

Hepatocellular carcinoma-specific epigenetic checkpoints bidirectionally regulate the antitumor immunity of CD4 + T cells

Hepatocellular carcinoma (HCC) is a highly malignant tumor with significant global health implications. The role of CD4+ T cells, particularly conventional CD4+ T cells (Tconvs), in HCC progression remains unexplored. Furthermore, epigenetic factors are crucial in immune regulation, yet their specific role in HCC-infiltrating Tconv cells remains elusive. This study elucidates the role of MATR3, an epigenetic regulator, in modulating Tconv activity and immune evasion within the HCC microenvironment. Reanalysis of the scRNA-seq data revealed that early activation of CD4+ T cells is crucial for establishing an antitumor immune response. In vivo and in vitro experiments revealed that Tconv enhances cDC1-induced CD8+ T-cell activation. Screening identified MATR3 as a critical regulator of Tconv function, which is necessary for antitumour activity but harmful when overexpressed. Excessive MATR3 expression exacerbates Tconv exhaustion and impairs function by recruiting the SWI/SNF complex to relax chromatin in the TOX promoter region, leading to aberrant transcriptional changes. In summary, MATR3 is an HCC-specific epigenetic checkpoint that bidirectionally regulates Tconv antitumour immunity, suggesting new therapeutic strategies targeting epigenetic regulators to enhance antitumour immunity in HCC.

M6A modification and T cells in adipose tissue inflammation

Adipose tissue in the obese state can lead to low-grade chronic inflammation while inducing or exacerbating obesity-related metabolic diseases and impairing overall health.T cells, which are essential immune cells similar to macrophages, are widely distributed in adipose tissue and perform their immunomodulatory function; they also cross-talk with other cells in the vascular stromal fraction. Based on a large number of studies, it has been found that N6 methyl adenine (m6A) is one of the most representative of epigenetic modifications, which affects the crosstalk between T cells, as well as other immune cells, in several ways and plays an important role in the development of adipose tissue inflammation and related metabolic diseases. In this review, we first provide an overview of the widespread presence of T cells in adipose tissue and summarize the key role of T cells in adipose tissue inflammation. Next, we explored the effects of m6A modifications on T cells in adipose tissue from the perspective of adipose tissue inflammation. Finally, we discuss the impact of m6a-regulated crosstalk between T cells and immune cells on the prospects for improving adipose tissue inflammation research, providing additional new ideas for the treatment of obesity.

Hepatic Stellate Cell-Targeting Micelle Nanomedicine for Early Diagnosis and Treatment of Liver Fibrosis

Diagnosing and treating liver fibrosis is a challenging yet crucial endeavor due to its complex pathogenesis and risk of deteriorating into cirrhosis, liver failure, and even hepatic cancer. Herein, a silica cross-linked micelles (SCLMs) based nano-system is developed for both diagnosing and treating liver fibrosis. The SCLMs are first modified with peptide CTCE9908 (CT-SCLMs) and can actively target CXCR4, which is overexpressed in activated hepatic stellate cells (HSCs). To enable diagnosis, an ONOO--responded near-infrared fluorescent probe NOF2 is loaded into the CT-SCLMs. This nano-system can target the aHSCs and diagnose the liver fibrosis particularly in CCl4-induced liver damage, by monitoring the reactive nitrogen species. Furthermore, a step is taken toward treatment by co-encapsulating two anti-fibrosis drugs, silibinin and sorafenib, within the CT-SCLMs. This combined approach results in a significant alleviation of liver injury. Symptoms associated with liver fibrosis, such as deposition of collagen, expression of hydroxyproline, and raised serological indicators show notable improvement. In summary, the CXCR4-targeted nano-system can serve as a promising theragnostic system of early warning and diagnosis for liver fibrosis, offering hope against progression of this serious liver condition.

N6-methyladenosine (m6A) modification in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the deadliest cancers of human, the tumor-related death of which ranks third among the common malignances. N6-methyladenosine (m6A) methylation, the most abundant internal modification of RNA in mammals, participates in the metabolism of mRNA and interrelates with ncRNAs. In this paper, we overviewed the complex function of m6A regulators in HCC, including regulating the tumorigenesis, progression, prognosis, stemness, metabolic reprogramming, autophagy, ferroptosis, drug resistance and tumor immune microenvironment (TIME). Furthermore, we elucidated the interplay between m6A modification and non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs). Finally, we summarized the potential of m6A regulators as diagnostic biomarkers. What's more, we reviewed the inhibitors targeting m6A enzymes as promising therapeutic targets of HCC. We aimed to help understand the function of m6A methylation in HCC systematically and comprehensively so that more effective strategies for HCC treatment will be developed.