Hepatocellular carcinoma cell sensitivity to Vγ9Vδ2 T lymphocyte-mediated killing is increased by zoledronate

Immune Regulatory Networks and Therapy of γδ T Cells in Liver Cancer: Recent Trends and Advancements

The roles of γδ T cells in liver cancer, especially in the potential function of immunotherapy due to their direct cytotoxic effects on tumor cells and secretion of important cytokines and chemokines, have aroused research interest. This review briefly describes the basic characteristics of γδ T cells, focusing on their diverse effects on liver cancer. In particular, different subtypes of γδ T cells have diverse or even opposite effects on liver cancer. We provide a detailed description of the immune regulatory network of γδ T cells in liver cancer from two aspects: immune components and nonimmune components. The interactions between various components in this immune regulatory network are dynamic and pluralistic, ultimately determining the biological effects of γδ T cells in liver cancer. We also integrate the current knowledge of γδ T-cell immunotherapy for liver cancer treatment, emphasizing the potential of these cells in liver cancer immunotherapy.

γδ T Cells: A Game Changer in the Future of Hepatocellular Carcinoma Immunotherapy

Hepatocellular carcinoma (HCC) remains a global health challenge with limited treatment options and a poor prognosis for advanced-stage patients. Recent advancements in cancer immunotherapy have generated significant interest in exploring novel approaches to combat HCC. One such approach involves the unique and versatile subset of T cells known as γδ T cells. γδ T cells represent a distinct subset of T lymphocytes that differ from conventional αβ T cells in terms of antigen recognition and effector functions. They play a crucial role in immunosurveillance against various malignancies, including HCC. Recent studies have demonstrated that γδ T cells can directly recognize and target HCC cells, making them an attractive candidate for immunotherapy. In this article, we aimed to explore the role exerted by γδ T cells in the context of HCC. We investigate strategies designed to maximize the therapeutic effectiveness of these cells and examine the challenges and opportunities inherent in applying these research findings to clinical practice. The potential to bring about a revolutionary shift in HCC immunotherapy by capitalizing on the unique attributes of γδ T cells offers considerable promise for enhancing patient outcomes, warranting further investigation.

Biological characteristics of γδT cells and application in tumor immunotherapy

Human γδT cells are a special immune cell type which exist in small quantities in the body, do not require processing and presentation for antigen recognition, and have non-major histocompatibility complex (MHC)-restricted immune response. They play an important role in the body's anti-tumor, anti-infection, immune regulation, immune surveillance and maintenance of immune tolerance. This article reviews the generation and development of human γδT cells, genetic characteristics, classification, recognition and role of antigens, and research progress in tumor immunotherapy.

Aerosol inhalation of Mycobacterium bovis can reduce the Th2 dominant immune response induced by ovalbumin sensitization

OBJECTIVE

To investigate whether M. vaccae inhalation affects asthma via γδ T cell regulation.

METHODS

Forty male Balb/c mice were randomly divided into 4 groups: normal group, asthma group, control group and intervention group. The normal group was given no treatment. For the asthma group, control group and intervention group, the mice were sensitized and stimulated with ovalbumin (OVA) to establish asthma models. Mice in the asthma group were not treated. Mice in the control group were treated with γδ T cell suspension from normal mice, and those in the intervention group were treated with γδ T cell suspension from mice intervened by Mycobacterium bovis. ELISA assay was adopted for quantification of IL-4 and IFN-γ in mouse alveolar fluid (BALF), and flow cytometry for determining the percentage of IL-4 and IFN-γ from mononuclear cells of lung tissues.

RESULTS

The airway responsiveness of the asthma group was higher than that of the normal group. The degree of airway inflammation in the intervention group was lighter than that in the control group, and it was significantly alleviated compared with the asthma group (P<0.05). Compared with the asthma group, the level of IL-4 in the BALF of the control group and the intervention group decreased significantly, while the level of IFN-γ increased significantly (P<0.05). Compared with the control group, the level of IL-4 in the BALF of the intervention group was significantly lower, while the level of IFN-γ was significantly higher (P<0.05). In addition, the results of flow cytometry were basically consistent with the results of Elisa.

CONCLUSION

Aerosol inhalation of Mycobacterium bovis can alleviate the Th2 dominant immune response induced by OVA sensitization and regulate the Th1/Th2 immune imbalance in patients with asthma.

Characterisation and induction of tissue-resident gamma delta T-cells to target hepatocellular carcinoma

Immunotherapy is now the standard of care for advanced hepatocellular carcinoma (HCC), yet many patients fail to respond. A major unmet goal is the boosting of T-cells with both strong HCC reactivity and the protective advantages of tissue-resident memory T-cells (TRM). Here, we show that higher intratumoural frequencies of γδ T-cells, which have potential for HLA-unrestricted tumour reactivity, associate with enhanced HCC patient survival. We demonstrate that γδ T-cells exhibit bona fide tissue-residency in human liver and HCC, with γδTRM showing no egress from hepatic vasculature, persistence for >10 years and superior anti-tumour cytokine production. The Vγ9Vδ2 T-cell subset is selectively depleted in HCC but can efficiently target HCC cell lines sensitised to accumulate isopentenyl-pyrophosphate by the aminobisphosphonate Zoledronic acid. Aminobisphosphonate-based expansion of peripheral Vγ9Vδ2 T-cells recapitulates a TRM phenotype and boosts cytotoxic potential. Thus, our data suggest more universally effective HCC immunotherapy may be achieved by combining aminobisphosphonates to induce Vγ9Vδ2TRM capable of replenishing the depleted pool, with additional intratumoural delivery to sensitise HCC to Vγ9Vδ2TRM-based targeting.

The potential of adoptive transfer of γ9δ2 T cells to enhance blinatumomab's antitumor activity against B-cell malignancy

Blinatumomab, a bispecific T cell engager (BiTE) antibody targeting CD19 and CD3ε, can redirect T cells toward CD19-positive tumor cells and has been approved to treat relapsed/refractory B-cell acute lymphoblastic leukemia (R/R B-ALL). However, chemotherapeutic regimens can severely reduce T cells' number and cytotoxic function, leading to an inadequate response to blinatumomab treatment in patients. In addition, it was reported that a substantial portion of R/R B-ALL patients failing blinatumomab treatment had the extramedullary disease, indicating the poor ability of blinatumomab in treating extramedullary disease. In this study, we investigated whether the adoptive transfer of ex vivo expanded γ9δ2 T cells could act as the effector of blinatumomab to enhance blinatumomab's antitumor activity against B-cell malignancies in vivo. Repeated infusion of blinatumomab and human γ9δ2 T cells led to more prolonged survival than that of blinatumomab or human γ9δ2 T cells alone in the mice xenografted with Raji cells. Furthermore, adoptive transfer of γ9δ2 T cells reduced tumor mass outside the bone marrow, indicating the potential of γ9δ2 T cells to eradicate the extramedullary disease. Our results suggest that the addition of γ9δ2 T cells to the blinatumomab treatment regimens could be an effective approach to enhancing blinatumomab's therapeutic efficacy. The concept of this strategy may also be applied to other antigen-specific BiTE therapies for other malignancies.

In respond to commensal bacteria: γδT cells play a pleiotropic role in tumor immunity

γδT cells are a mixture of innate programming and acquired adaptability that bridge the adaptive and innate immune systems. γδT cells are mainly classified as tissue-resident Vδ1 or circulating Vδ2 γδT cells. In the tumor microenvironment, tumor immunity is influenced by the increased quantity and phenotype plasticity of γδT cells. Commensal bacteria are ubiquitous in the human body, and they have been confirmed to exist in various tumor tissues. With the participation of commensal bacteria, γδT cells maintain homeostasis and are activated to affect the development and progression of tumors. Here, we summarize the relationship between γδT cells and commensal bacteria, the potential protumor and antitumor effects underlying γδT cells, and the new developments in γδT cell-based tumor therapy which is expected to open new opportunities for tumor immunotherapy.

Diverse Functions of γδ T Cells in the Progression of Hepatitis B Virus and Hepatitis C Virus Infection

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are primary risk factors for a wide spectrum of liver diseases that severely affect human health. The liver is an immunological organ that has an abundance of immune cells. Thus, various innate or adaptive immune cells are involved in the progression of HBV or HCV infection. Among those cells, a unique kind of immune cell, the γδ T cell, contributes to promoting or inhibiting the progression of liver diseases. To reveal the diverse roles of γδ T cells in HBV or HCV infection, the properties and functions of these cells in human and mouse models are analyzed. Here, we briefly describe the characteristics and functions of γδ T cells subsets in liver diseases. Then, we fully discuss the diverse roles of γδ T cells in the progression of HBV or HCV infection, including stages of acute infection, chronic infection, liver cirrhosis, and hepatocellular carcinoma. Finally, the functions and existing problems of γδ T cells in HBV or HCV infection are summarized. A better understanding of the function of γδ T cells during the progression of HBV and HCV infection will be helpful for the treatment of virus infection.

Identification of prognostic factors for γδT cell immunotherapy in patients with solid tumor

BACKGROUND AIMS

Activated γδT cells have been shown to exhibit cytotoxicity against tumor cells. However, the efficacy of γδT cell immunotherapy for a large number of patients with solid tumors remains unclear. In this study, we examined the efficacy of γδT cell immunotherapy using in vitro-activated γδT lymphocytes in combination with standard therapies in terms of the survival of patients with solid tumors, and determined prognostic factor for γδT cell immunotherapy.

METHODS

131 patients enrolled in this study received γδT cell immunotherapy with or without standard therapies. Their overall survival was analyzed by the Kaplan-Meier with log-rank test and Cox regression methods. Immunological analysis was performed by flow cytometry (FCM) before and after six cycles of γδT cell immunotherapy.

RESULTS

Multivariable analysis revealed that patients who showed stable disease (SD) and partial response (PR) to γδT cell immunotherapy showed better prognosis than those with a progressive disease (PD) (P = 0.0269, hazard ratio [HR], 0.410, 95% confidence interval [CI], 0.190-0.901). Furthermore, when immunological parameters were examined by FCM, the high Vγ9/γδT ratio (i.e., the high purity of the Vγ9 cells within the adoptively transferred γδT cells) before treatment was found to be a good prognostic factor for γδT cell immunotherapy (P = 0.0142, HR, 0.328, 95% CI, 0.125-0.801). No serious adverse events were reported during γδT cell immunotherapy.

CONCLUSION

Thus, γδT cell immunotherapy might extend the survival of patients with solid tumors.

Persistent gamma delta T-cell dysfunction in chronic HCV infection despite direct-acting antiviral therapy induced cure

Immune dysfunction is a hallmark of chronic HCV infection and viral clearance with direct antivirals recover some of these immune defects. TCRVγ9Vδ2 T-cell dysfunction in treated HCV patients however is not well studied and was the subject of this investigation. Peripheral blood cells from patients who had achieved sustained virologic response (SVR) or those who had relapsed after interferon-free therapy were phenotyped using flow cytometry. Functional potential of Vγ9Vδ2 T cells was tested by measuring proliferation in response to aminobisphosphonate zoledronic acid, and cytotoxicity against HepG2 hepatoma cell line. TCR sequencing was performed to analyse impact of HCV infection on Vδ2 T-cell repertoire. Vγ9Vδ2 cells from patients were activated and therapy resulted in reduction of CD38 expression on these cells in SVR group. Relapsed patients had Vδ2 cells with persistently activated and terminally differentiated cytotoxic phenotype (CD38⁺ CD45RA⁺ CD27^- CD107a⁺ ). Irrespective of outcome with therapy, majority of patients had persistently poor Vδ2 T-cell proliferative response to zoledronate along with lower expression of CD56, which identifies anti-tumour cytotoxic subset, relative to healthy controls. There was no association between the number of antigen reactive Vγ2-Jγ1.2 TCR rearrangements at baseline and levels of proliferation indicating nonresponse to zoledronate is not due to depletion of phosphoantigen responding chains. Thus, HCV infection results in circulating Vγ9Vδ2 T cells with a phenotype equipped for immediate effector function but poor cytokine response and expansion in response to antigen, a functional defect that may have implications for susceptibility for carcinogenesis despite HCV cure.

Tissue Adaptations of Memory and Tissue-Resident Gamma Delta T Cells

Epithelial and mucosal barriers are critical interfaces physically separating the body from the outside environment and are the tissues most exposed to microorganisms and potential inflammatory agents. The integrity of these tissues requires fine tuning of the local immune system to enable the efficient elimination of invasive pathogens while simultaneously preserving a beneficial relationship with commensal organisms and preventing autoimmunity. Although they only represent a small fraction of circulating and lymphoid T cells, γδ T cells form a substantial population at barrier sites and even outnumber conventional αβ T cells in some tissues. After their egress from the thymus, several γδ T cell subsets naturally establish residency in predetermined mucosal and epithelial locations, as exemplified by the restricted location of murine Vγ5⁺ and Vγ3Vδ1⁺ T cell subsets to the intestinal epithelium and epidermis, respectively. Because of their preferential location in barrier sites, γδ T cells are often directly or indirectly influenced by the microbiota or the pathogens that invade these sites. More recently, a growing body of studies have shown that γδ T cells form long-lived memory populations upon local inflammation or bacterial infection, some of which permanently populate the affected tissues after pathogen clearance or resolution of inflammation. Natural and induced resident γδ T cells have been implicated in many beneficial processes such as tissue homeostasis and pathogen control, but their presence may also exacerbate local inflammation under certain circumstances. Further understanding of the biology and role of these unconventional resident T cells in homeostasis and disease may shed light on potentially novel vaccines and therapies.

Obesity linking to hepatocellular carcinoma: A global view

Hepatocellular carcinoma (HCC) is the commonest primary liver cancer and the second leading cause of cancer death worldwide. Obesity is rapidly becoming pandemic and associated with increased carcinogenesis. In this review, we describe the obesity-related factors that influence the development of HCC. We provide evidence of strong links between neural regulation, endocrine and HCC in obesity. We discuss recent advances in our understanding of how adipose tissue alters hepatic metabolism and immune response in HCC development through inter-organ communication. Taken together, our review aims to provides a concise and up-to date summary about the connection between obesity and HCC, with emphasis on the opportunities for effective strategies in preventing the development of HCC in obese individuals.

CD163-positive tumor-associated macrophages and CD8-positive cytotoxic lymphocytes are powerful diagnostic markers for the therapeutic stratification of osteosarcoma patients: An immunohistochemical analysis of the biopsies fromthe French OS2006 phase 3 trial

The French phase 3 trial (OS 2006) testing zoledronic acid, an osteoclast inhibitor, with chemotherapy and surgery did not improve the outcome of patients with osteosarcoma (OS). To understand this unexpected result, the presence of infiltrating immune cells was investigated in 124 pre-therapeutic biopsies of patients enrolled in the trial. The percentage of CD68/CD163 tumor-infiltrating macrophages (TAMs), CD8⁺ lymphocytes, osteoclasts, and the PD1/PDL-1 checkpoint were assessed by immunohistochemistry. M1/M2 macrophage polarization was characterized by pSTAT1/CMAF staining. The expression of these biomarkers was correlated with clinical outcome. No statistical correlations were found with response to chemotherapy. High CD163 levels (>50% of cells per core; 43.8% of patients) were associated with CMAF nuclear expression and significantly correlated with better overall survival (p = 0.0025) and longer metastasis progression-free survival (MPFS, p = 0.0315) independently of metastatic status (p = 0.002). Only a trend was observed for patients with high CD68-positive cells (p = 0.0582). CD8⁺ staining was positive in >50% of cases with a median staining of 1%. Lower CD8⁺ levels were associated with metastatic disease at diagnosis and the presence of CD8-positive cells significantly correlated with improved overall survival in zoledronate-treated patients (p = 0.0415). PD1/PDL-1 staining was negative in >80% of cases and was not correlated with outcome. Finally, CD163-positive TAMs and CD8 positive cells are crucial prognostic biomarkers in OS, whereas PD1/PDL-1 checkpoint plays a minor role. For the first time, we described a correlation between CD8 positive cells and survival in zoledronate-treated patients. The immunohistochemical analysis of the microenvironment in biopsies may represent a novel tool for therapeutic stratification.