γδ T cells are increased in the peripheral blood of patients with gastric cancer

Identification of ferroptosis-related subtypes, characteristics of TME infiltration and development of prognostic models in gastric cancer

BACKGROUND

Ferroptosis is a distinct form of cell death characterized by unique morphology, biochemistry, and genetics, playing a crucial role in the initiation, progression, prognosis, and therapeutic strategies of tumors. However, the impact of ferroptosis-related genes (FRGs) on the tumor microenvironment (TME) remains unclear. This study may advance the existing knowledge of FRGs in gastric cancer, and push ahead with more effective prognostic assessment and the development of more effective immunotherapy approaches.

METHODS

FRGs were acquired from the FerrDb database and a consensus clustering technique was adopted to categorize patients with GC into groups in line with the expression profiles of 44 FRGs in order to further investigate the expression properties of these proteins. Assessment of the immune status, microsatellite instability (MSI) and cancer stem cell (CSC) index between the high- and low- risk groups to assess the proportion of TIICs in the TME, ssGSVA was adopted to detect the abundance of infiltrating immune cells from the low-risk and high-risk groups. Expression levels of eight ferroptosis-related genes of prognostic signature in GC tissues and adjacent normal tissues was detected by RT-PCR.

RESULTS

In the GC cohort, TP53 has the highest mutation frequency (44 %), and was shown to be highly linked with the expression levels of 11 FRGs. In accordance with the Kaplan-Meier curve, the overall survival time of patients with subtype A (Low FRG-score) discernibly exceeded that of patients with subtype B (High FRG-score).In addition, there is a significant difference in the infiltration of most immune cells between subtype A and subtype B, and some important immune checkpoints (CTLA4, PDCD1, CD274, LAG3, PDCD1LG2, and HAVCR2) have higher expression in cluster A. Finally, low FRG-scores were significantly associated with MSI-H status, while high FRG-scores were significantly associated with microsatellite stable status (MSS). FRG-score is negatively related to the cancer stem cell (CSC).

CONCLUSION

Low FRG-score, due to its high microsatellite instability (MSI-H), high mutational load and immune activation, indicates the possible advantage of OS. In addition, the FRG-score was closely related to the cancer stem cell (CSC) index and the sensitive degree of chemotherapeutic drug.

Expression patterns and immunological characterization of PANoptosis -related genes in gastric cancer

Background

Accumulative studies have demonstrated the close relationship between tumor immunity and pyroptosis, apoptosis, and necroptosis. However, the role of PANoptosis in gastric cancer (GC) is yet to be fully understood.

Methods

This research attempted to identify the expression patterns of PANoptosis regulators and the immune landscape in GC by integrating the GSE54129 and GSE65801 datasets. We analyzed GC specimens and established molecular clusters associated with PANoptosis-related genes (PRGs) and corresponding immune characteristics. The differentially expressed genes were determined with the WGCNA method. Afterward, we employed four machine learning algorithms (Random Forest, Support Vector Machine, Generalized linear Model, and eXtreme Gradient Boosting) to select the optimal model, which was validated using nomogram, calibration curve, decision curve analysis (DCA), and two validation cohorts. Additionally, this study discussed the relationship between infiltrating immune cells and variables in the selected model.

Results

This study identified dysregulated PRGs and differential immune activities between GC and normal samples, and further identified two PANoptosis-related molecular clusters in GC. These clusters demonstrated remarkable immunological heterogeneity, with Cluster1 exhibiting abundant immune infiltration. The Support Vector Machine signature was found to have the best discriminative ability, and a 5-gene-based SVM signature was established. This model showed excellent performance in the external validation cohorts, and the nomogram, calibration curve, and DCA indicated its reliability in predicting GC patterns. Further analysis confirmed that the 5 selected variables were remarkably related to infiltrating immune cells and immune-related pathways.

Conclusion

Taken together, this work demonstrates that the PANoptosis pattern has the potential as a stratification tool for patient risk assessment and a reflection of the immune microenvironment in GC.

Phenotypic characterization of human peripheral γδT-Cell subsets in glioblastoma

INTRODUCTION

The anti-tumoral contribution of γδT cells depends on their activation and differentiation into effectors. This depends on different molecules and membrane receptors, which conditions their physiology. We aimed to determine the phenotypic characteristics of γδT cells in glioblastoma (GBM) according to five layers of membrane receptors.

METHODS

Among ten GBM cases initially enrolled, five of them who had been confirmed by pathological examination and ten healthy controls underwent phenotyping of peripheral γδT cells by flow cytometry, using the following staining: αβTCR, γδTCR, CD3, CD4, CD8, CD16, CD25, CD27, CD28, CD45, CD45RA, CD56, NKG2D, CD272(BTLA) and CD279(PD-1).

RESULTS

Compared to controls, our results showed no significant change in the number of γδT cells. However, we noted a decrease of double-negative (CD4^- CD8^- ) Tγδ cells and an increase of naive γδT cells, a lack of CD25 expression, a decrease of the expression of CD279 and a remarkable, but not significant increase in the expression of the CD27 and CD28 costimulation markers. Among γδT cell subsets, the number of Vδ2 decreased in GBM and showed no significant difference in the expression of CD16, CD56 and NKG2D. In contrast, the number of Vδ1 increased in GBM with overexpression of CD16, CD56 and NKG2D.

CONCLUSION

Our results showed that γδT cells are prone to adopt a pro-inflammatory profile in the GBM's context, which suggests that they might be a potential tool to consider in T cell-based immunotherapy in GBM. However, this requires additional investigation on larger sample size. This article is protected by copyright. All rights reserved.

Human Peripheral Blood Gamma Delta T Cells: Report on a Series of Healthy Caucasian Portuguese Adults and Comprehensive Review of the Literature

Gamma delta T cells (Tc) are divided according to the type of Vδ and Vγ chains they express, with two major γδ Tc subsets being recognized in humans: Vδ2Vγ9 and Vδ1. Despite many studies in pathological conditions, only a few have quantified the γδ Tc subsets in healthy adults, and a comprehensive review of the factors influencing its representation in the blood is missing. Here we quantified the total γδ Tc and the Vδ2/Vγ9 and Vδ1 Tc subsets in the blood from 30 healthy, Caucasian, Portuguese adults, we characterized their immunophenotype by 8-color flow cytometry, focusing in a few relevant Tc markers (CD3/TCR-γδ, CD5, CD8), and costimulatory (CD28), cytotoxic (CD16) and adhesion (CD56) molecules, and we examined the impacts of age and gender. Additionally, we reviewed the literature on the influences of race/ethnicity, age, gender, special periods of life, past infections, diet, medications and concomitant diseases on γδ Tc and their subsets. Given the multitude of factors influencing the γδ Tc repertoire and immunophenotype and the high variation observed, caution should be taken in interpreting “abnormal” γδ Tc values and repertoire deviations, and the clinical significance of small populations of “phenotypically abnormal” γδ Tc in the blood.

Surface CD200 and CD200R antigens on lymphocytes in advanced gastric cancer: a new potential target for immunotherapy

INTRODUCTION

Gastric cancer (GC) is one of the leading causes of cancer death worldwide. The membrane glycoprotein CD200, widely expressed on multiple cells/tissues, uses a structurally similar receptor (CD200R), delivering immunoregulatory signals. There is evidence that CD200/CD200R signaling suppresses anti-tumor responses in different types of malignancies. Little is known about the CD200/CD200R pathway in GC. The aim of the study was to evaluate the frequencies of CD200+ and CD200R+ lymphocytes in patients with GC.

MATERIAL AND METHODS

Forty patients primarily diagnosed with GC and 20 healthy volunteers (control group) were enrolled. The viable peripheral blood lymphocytes underwent labeling with fluorochrome-conjugated monoclonal antibodies and were analyzed using a flow cytometer.

RESULTS

In the GC group, the percentages of T CD3+, CD3+/CD4+, and CD3+/CD8+ cells expressing CD200 antigen were higher than in the control group (p < 0.00013, p < 0.0004, and p < 0.0006, respectively). In the GC group, the frequencies of T CD3+, CD3+/CD4+ and CD3+/CD8+ cells expressing CD200R were lower than in the control group (p < 0.0009, p < 0.004, and p < 0.002, respectively). The percentage of B CD19+/CD200+ lymphocytes was higher in GC patients than in the control group (p < 0.00005). Lower frequency of B CD19+/CD200R+ cells was observed in GC patients compared to the control group (p < 0.0001). No differences in the frequencies of CD200+ and CD200R+ lymphocytes were found in relation to either UICC stage or histological grading of the tumors.

CONCLUSIONS

For GC pathogenesis, deregulation of the CD200/CD200R axis is important. High percentages of lymphocytes with CD200 expression may contribute to the continuous T cell activation and development of chronic inflammation and influence gastric carcinogenesis.

Tumor-infiltrating γδT cells predict prognosis and adjuvant chemotherapeutic benefit in patients with gastric cancer

Purpose : Tumor-infiltrating γδT cells (γδTILs) have different prognostic value and functions among various cancers. The aim of the present study was to evaluate the effect of γδTILs in gastric cancer. Patients and methods : A discovery set (n = 190) and a validation set (n = 273) were involved in this study. Patients with TNM II and III disease were used to predict response to 5-fluorouracil (5-FU)-based adjuvant chemotherapy (ACT) in both sets. γδTILs were defined as intense (γδT cells≥ 5/HPF) versus nonintense (γδT cells<5/HPF). Kaplan-Meier curve was plotted to analysis survival. Hazard ratio (HR) and 95%CI associated with γδTILs were evaluated by multivariable Cox models. Findings : The prognostic value of γδTILs in the discovery set (HR, 0.193; 95%CI, 0.097-0.383; P<0.001) was confirmed in the validation set (HR, 0.442; 95%CI, 0.251-0.779; P = 0.005) for overall survival (OS). Patients whose tumors with γδT cells≥ 5/HPF could benefit from ACT, with a reduced risk of compromised survival compared with those with γδT cells<5/HPF (HR, 0.086; 95%CI, 0.023-0.327; P<0.001 in discovery set; and HR, 0.077; 95%CI, 0.023-0.256; P<0.001 in validation set). Conclusion : The present study shows that intense γδT cells infiltration is an independent prognostic factor in patients with gastric cancer and is predictive of a survival benefit from adjuvant chemotherapy in patients with TNM II and III disease.

Adoptive Cellular Therapy (ACT) for Cancer Treatment

Adoptive cellular therapy (ACT) with various lymphocytes or antigen-presenting cells is one stone in the pillar of cancer immunotherapy, which relies on the tumor-specific T cell. The transfusion of bulk T-cell population into patients is an effective treatment for regression of cancer. In this chapter, we summarize the development of various strategies in ACT for cancer immunotherapy and discuss some of the latest progress and obstacles in technical, safety, and even regulatory aspects to translate these technologies to the clinic. ACT is becoming a potentially powerful approach to cancer treatment. Further experiments and clinical trials are needed to optimize this strategy.

Leukocyte populations and IL-6 in the tumor microenvironment of an orthotopic colorectal cancer model

Colorectal cancer (CRC) is a major health problem worldwide. It is often diagnosed late due to its asymptomatic nature. As with all cancers, an immune reaction is involved; however, in CRC, it is unknown if this immune response is favorable or unfavorable for disease progression. In this study, the immune response in mesenteric lymph nodes (MLNs) and Peyer's patches was investigated during development of CRC in an orthotopic mouse model. CRC was induced by injecting CT26 cells into the cecum wall of BALB/c mice. Flow cytometry was used to analyze leukocyte populations involved in tumor immunity in MLNs and Peyer's patches. Cryostat sections for immunohistochemistry were prepared from the caecum and colon from CRC-induced and sham-operated animals. Cytokines produced by mouse CT26 cell line were measuredin vitroandin vivo Significant increases in the number of CD8(+)/TCR(+)and CD49b(+)/TCR(-)(natural killer) cells were found in MLNs and Peyer's patches in the CRC group. In addition, γδT cells were present in the lamina propria of the colon tissues from sham-operated mice, but absent in the colon tissues from mice with CRC. Immunohistochemical analysis of tumorous tissues showed eosinophil, CD69(+)T cell, and CD11b(+)cell infiltration. Bothin vitroandin vivoCT26 tumor cells were interleukin (IL)-6 positive. In addition, tumor-infiltrating CD45(+)cells were also IL-6 positive. In summary, the kinetics of the immune response to CRC and the key effector lymphocytes that are implicated in tumor immunity are demonstrated. Furthermore, IL-6 is a key cytokine present within the tumor microenvironment.

Morphine and ketamine inhibit immune function of gastric cancer patients by increasing percentage of CD4(+)CD25(+)Foxp3(+) regulatory T cells in vitro

BACKGROUND

There is conflicting evidence regarding effects of anesthetic and analgesic drugs on immune function of cancer patients. This study was designed to observe changes of T cell subpopulations in the gastric cancer (GC) patients and to assess effects of morphine and ketamine on the CD4(+) T cells, CD8(+) T cells, and regulatory T cells (Tregs) populations obtained from the GC patients in vitro.

METHODS

The peripheral blood samples from 20 GC patients and 20 healthy volunteers were obtained. The peripheral blood mononuclear cells were isolated and incubated in a solution containing phorbol-myristate-acetate and ionomycin (2 μL/mL) in the presence or absence of morphine (50 ng/mL) or different-concentration ketamine (25, 50, and 100 μM). The CD4(+) T cells, CD8(+) T cells, and Tregs were determined using the flow cytometric assay.

RESULTS

The percentages of CD8(+) T cells were significantly decreased, but the ratio of CD4(+)/CD8(+) T cells and Tregs populations was significantly increased in the GC control group compared with the normal control group (P < 0.05). The ratio of CD4(+)/CD8(+) T cells was significantly increased in the groups M and K3 compared with the control group (P < 0.05) but was significantly decreased in the group K1 compared with the group K3. The percentage of Tregs was significantly increased in the groups M, K1, K2, and K3 compared with the control group. With the increased concentrations, ketamine increased the number of Tregs.

CONCLUSIONS

GC shifts the balance of CD4(+)/CD8(+) T cells toward CD4(+) T cells and increases the Tregs populations by inducing immune responses. Morphine increases the ratio of CD4(+)/CD8(+) T cells and Tregs populations. Ketamine affects the ratio of CD4(+)/CD8(+) T cells and Tregs populations in a dose-dependent model.

Quantitative peripheral blood perturbations of γδ T cells in human disease and their clinical implications

Human γδ T cells, which play innate and adaptive, protective as well as destructive, roles in the immune response, were discovered in 1986, but the clinical significance of alterations of the levels of these cells in the peripheral blood in human diseases has not been comprehensively reviewed. Here, we review patterns of easily measurable changes of this subset of T cells in peripheral blood from relevant publications in PubMed and their correlations with specific disease categories, specific diagnoses within disease categories, and prognostic outcomes. These collective data suggest that enumeration of γδ T cells and their subsets in the peripheral blood of patients could be a useful tool to evaluate diagnosis and prognosis in the clinical setting.

Phenotyping of peripheral blood mononuclear cells of patients with advanced heavily pre-treated adenocarcinoma of the stomach and gastro-esophageal junction

Immunotherapeutic approaches are emerging as promising new treatment options for patients with solid cancers. The host immune system in cancer patients is dysfunctional due to a number of reasons. The level of immunosuppression is variable at the time of diagnosis and depends on the particular cancer entity, stage, and prior anti-cancer therapies. For many cancer entities, the immune alterations of the respective patient population have not been further characterized even though a patient's immunophenotype may be prognostic for the course of the disease or predictive for clinical/biological response to immunotherapy. In this study, we used flow cytometry to determine the phenotype of peripheral blood mononuclear cells (PBMCs) from 30 patients with heavily pre-treated, advanced adenocarcinoma of the stomach and gastro-esophageal junction. The frequencies and activation status of relevant immune effector populations were determined in PBMCs and compared to those of healthy individuals. This report provides comprehensive immune phenotyping data of a patient population with a high medical need.