Increased interleukin-17A-producing γδT cells predict favorable survival in elderly patients with LUAD and LUSC

T-Cell Senescence: Unlocking the Tumor Immune "Dark Box" - A Multidimensional Analysis from Mechanism to Tumor Immunotherapeutic Intervention

Immunosenescence is the dysfunction of the immune system that occurs with age, a process that is complex and characterized by several features, of which T-cell senescence is one of the key manifestations. In the tumor microenvironment, senescent T cells lead to the inability of tumor cells to be effectively eliminated, triggering immunosuppression, which in turn affects the efficacy of immunotherapy. This is a strong indication that T-cell senescence significantly weakens the immune function of the body, making individuals, especially elderly patients with cancer, more vulnerable to cancer attacks. Despite the many challenges, T-cell senescence is important as a potential therapeutic target. This review provides insights into the molecular mechanisms of T-cell senescence and its research advances in patients with cancer, especially in older adults, and systematically analyzes potential intervention strategies, including molecular mechanism-based interventions, the use of immune checkpoint inhibitors, and CAR-T cell therapy. It is hoped that this will establish a theoretical framework for T-cell senescence in the field of tumor immunology and provide a scientific and prospective reference basis for subsequent in-depth research and clinical practice on senescent T cells.

T-cell Senescence in the Tumor Microenvironment

T-cell senescence occurs in the tumor microenvironment (TME) and influences cancer outcomes as well as the effectiveness of immunotherapies. The TME triggers this T-cell senescence via multiple pathways, including persistent stimulation with tumor-associated antigens, altered metabolic pathways, and activation of chronic inflammatory responses. Senescent T cells exhibit characteristics such as genomic instability, loss of protein homeostasis, metabolic dysregulation, and epigenetic alterations. Direct cross-talk between senescent T cells and other immune cells further exacerbates the immunosuppressive TME. This immune-tumor cell interaction within the TME contributes to impaired tumor antigen recognition and surveillance by T cells. The presence of senescent T cells is often associated with poor prognosis and reduced efficacy of immunotherapies; thus, targeting the tumor-promoting mechanisms of T-cell senescence may provide novel insights into improving tumor immunotherapy and patient outcomes. This review explores the contributors to tumor-derived T-cell senescence, the link between T-cell senescence and tumor prognosis, and the potential for targeting T-cell senescence to enhance tumor immunotherapy.

Considerations and Approaches for Cancer Immunotherapy in the Aging Host

Advances in cancer immunotherapy are improving treatment successes in many distinct cancer types. Nonetheless, most tumors fail to respond. Age is the biggest risk for most cancers, and the median population age is rising worldwide. Advancing age is associated with manifold alterations in immune cell types, abundance, and functions, rather than simple declines in these metrics, the consequences of which remain incompletely defined. Our understanding of the effects of host age on immunotherapy mechanisms, efficacy, and adverse events remains incomplete. A deeper understanding of age effects in all these areas is required. Most cancer immunotherapy preclinical studies examine young subjects and fail to assess age contributions, a remarkable deficit given the known importance of age effects on immune cells and factors mediating cancer immune surveillance and immunotherapy efficacy. Notably, some cancer immunotherapies are more effective in aged versus young hosts, while others fail despite efficacy in the young. Here, we review our current understanding of age effects on immunity and associated nonimmune cells, the tumor microenvironment, cancer immunotherapy, and related adverse effects. We highlight important knowledge gaps and suggest areas for deeper enquiries, including in cancer immune surveillance, treatment response, adverse event outcomes, and their mitigation.

Comprehensive analysis of the immunogenic cell death-related signature for predicting prognosis and immunotherapy efficiency in patients with lung adenocarcinoma

BACKGROUND

Although immunotherapy has been considered as a potent strategy for lung adenocarcinoma (LUAD), only a small part of patients was served as potentially clinical benefiters. Immunogenic cell death (ICD), a type of regulated cell death (RCD), which enable to reshape the tumor immune microenvironment and contribute to the immunotherapy efficiency. Developing a novel ICD-based signature may be a potential strategy to differentiate prognosis of patients with LUAD and predict efficacy of immunotherapy.

METHODS

In this study, 34 ICD-related genes (ICDRGs) were identified and analyzed in LUAD samples from the Cancer Genome Atlas (TCGA). 572 patients with LUAD were divided into two distinct clusters according to ICDRGs expression levels. Patients were subsequently classified into two distinct gene subtypes based on differentially expressed genes (DEGs) analyzed between two ICD-related clusters. We further developed and validated a novel ICD-related score (ICDRS) followed by comprehensive investigation about the landscape of the prognosis, immune-based features, immunotherapautic responses and sensitivity of target drugs in patients with LUAD.

RESULTS

After confirming transcriptomic aberrations and appraising prognostic value of ICDRGs, two ICD-associated subtypes were initially determined by consensus clustering in accordance with differentially expressional levels of ICDRGs. It was shown that patients in the ICD high-subtype possessed the superior clinical prognosis, abundant immune cell infiltration and higher involvement in immune-related signaling compared with the ICD low-subtype. A signature of ICD-related score (ICDRS) was further established and validated, which was served as an independent prognostic indicator for LUAD patients. These comprehensive results revealed that the high-score patients represented better clinical prognosis, higher immune infiltration-related characteristics, stronger expression of immune checkpoints, and better response to immune checkpoint inhibitor therapy and multiple targeted drugs. To further verify our analysis, we selected TLR4 as the representative of ICDRGs and evaluated its expression on the lung normal cells and cancer cells in vitro. Then, relative animal experiments were performed in vivo, with results of that the stimulation of TLR4 suppressed the growth of lung cancer.

CONCLUSIONS

In conclusion, our comprehensive analysis of ICDRGs in LUAD demonstrated their function in serving as a biomarker of predicting prognosis and clinical effects of immunotherapy and targeted drugs, which is meaningful to improve our understanding of ICDRGs and brought inspirations about evaluating prognosis and developing effective therapeutic strategies to patients with LUAD.

A Pyroptosis-Related Signature Predicts Overall Survival and Immunotherapy Responses in Lung Adenocarcinoma

Background: Lung adenocarcinoma (LUAD) is a highly malignant cancer with a bleak prognosis. Pyroptosis is crucial in LUAD. The present study investigated the prognostic value of a pyroptosis-related signature in LUAD.

Methods: LUAD’s genomic data were downloaded from TCGA and GEO databases. K-means clustering was used to classify the data based on pyroptosis-related genes (PRGs). The features of tumor microenvironment were compared between the two subtypes. Differentially expressed genes (DEGs) were identified between the two subtypes, and functional enrichment and module analysis were carried out. LASSO Cox regression was used to build a prognostic model. Its prognostic value was assessed.

Results: In LUAD, genetic and transcriptional changes in PRGs were found. A total of 30 PRGs were found to be differentially expressed in LUAD tissues. Based on PRGs, LUAD patients were divided into two subgroups. Subtype 1 has a higher overall survival rate than subtype 2. The tumor microenvironment characteristics of the two subtypes differed significantly. Compared to subtype 1, subtype 2 had strong immunological infiltration. Between the two groups, 719 DEGs were discovered. WGCNA used these DEGs to build a co-expression network. The network modules were analyzed. A prognostic model based on seven genes was developed, including FOSL1, KRT6A, GPR133, TMPRSS2, PRDM16, SFTPB, and SFTA3. The developed model was linked to overall survival and response to immunotherapy in patients with LUAD.

Conclusion: In LUAD, a pyroptosis-related signature was developed to predict overall survival and treatment responses to immunotherapy.

Distribution and Clinical Significance of IL-17A in Tumor-Infiltrating Lymphocytes of Non-Small Cell Lung Cancer Patients

Objective: To investigate the distribution of IL-17A and its clinical significance in tumor infiltrating lymphocytes (TILs) of patients with non-small cell lung cancer (NSCLC).

Methods: Expression level of IL-17A in TILs of 3 paired NSCLC and paracancerous specimens was measured by qRT-PCR. The distribution of IL-17A in immune cell subsets of 15 paired NSCLC and paracancerous specimens was examined by flow cytometry. The correlation between IL-17A and clinical features of NSCLC was identified.

Results: IL-17A was significantly upregulated in TILs of NSCLC specimens than those of paracancerous ones (p < 0.0001). Meanwhile, T helper 17 cells (Th17 cells, p < 0.001), IL-17-secreting CD8⁺ T cells (Tc17 cells, p < 0.001) and IL-17-producing cells (γδT17 cells, p < 0.0001) were significantly abundant in TILs of NSCLC specimens than those of controls, and the higher abundance of the latter was much pronounced than that of the former two. Moreover, γδT17 cells in TILs were significantly correlated with lymphatic metastasis and CYFRA 21-1 level of NSCLC patients (p < 0.05).

Conclusion: Tumor infiltrated γδT cells are the main source of IL-17 in early-stage NSCLC, and IL-17 may be a vital regulator involved in the development of NSCLC.

Targeting Cytokine Signals to Enhance γδT Cell-Based Cancer Immunotherapy

γδT cells represent a small percentage of T cells in circulation but are found in large numbers in certain organs. They are considered to be innate immune cells that can exert cytotoxic functions on target cells without MHC restriction. Moreover, γδT cells contribute to adaptive immune response via regulating other immune cells. Under the influence of cytokines, γδT cells can be polarized to different subsets in the tumor microenvironment. In this review, we aimed to summarize the current understanding of antigen recognition by γδT cells, and the immune regulation mediated by γδT cells in the tumor microenvironment. More importantly, we depicted the polarization and plasticity of γδT cells in the presence of different cytokines and their combinations, which provided the basis for γδT cell-based cancer immunotherapy targeting cytokine signals.

Genetically Modified T Cells for Esophageal Cancer Therapy: A Promising Clinical Application

Esophageal cancer is an exceedingly aggressive and malignant cancer that imposes a substantial burden on patients and their families. It is usually treated with surgery, chemotherapy, radiotherapy, and molecular-targeted therapy. Immunotherapy is a novel treatment modality for esophageal cancer wherein genetically engineered adoptive cell therapy is utilized, which modifies immune cells to attack cancer cells. Using chimeric antigen receptor (CAR) or T cell receptor (TCR) modified T cells yielded demonstrably encouraging efficacy in patients. CAR-T cell therapy has shown robust clinical results for malignant hematological diseases, particularly in B cell-derived malignancies. Natural killer (NK) cells could serve as another reliable and safe CAR engineering platform, and CAR-NK cell therapy could be a more generalized approach for cancer immunotherapy because NK cells are histocompatibility-independent. TCR-T cells can detect a broad range of targeted antigens within subcellular compartments and hold great potential for use in cancer therapy. Numerous studies have been conducted to evaluate the efficacy and feasibility of CAR and TCR based adoptive cell therapies (ACT). A comprehensive understanding of genetically-modified T cell technologies can facilitate the clinical translation of these adoptive cell-based immunotherapies. Here, we systematically review the state-of-the-art knowledge on genetically-modified T-cell therapy and provide a summary of preclinical and clinical trials of CAR and TCR-transgenic ACT.