Clinical significance of the frequency of regulatory T cells in regional lymph node lymphocytes as a prognostic factor for non-small-cell lung cancer

Intranodal Injection of Immune Activator Demonstrates Antitumor Efficacy in an Adjuvant Approach

The tumor-draining lymph nodes (tdLN) are the initial site of metastases and are the prime site for generating robust antitumor responses. In this study, we explored the efficacy of a universal immune activator (ImmAct) targeted to the tdLN. This approach can be viewed as an attempt to turn a cold, unresponsive tdLN into a hot, responsive site. The adjuvant antitumor efficacy of our novel intranodal injection was evaluated in an aggressive metastatic mammary carcinoma murine model. The cancer cells were inoculated subcutaneously in the lower quadrant of the mouse to provoke the tdLN (inguinal lymph node). The study encompasses a range of methodologies, including in vivo and in vitro assays and high-dimensional flow cytometry analysis. Our findings demonstrated that intranodal administration of ImmAct following the dissection of the primary tumor led to improved tumor-free survival and minimized weight loss. ImmAct led to both local and systemic alterations in the cellular and humoral immunity. Additionally, after ImmAct treatment, non-responders showed a higher rate of exhausted CD8+ T cells compared to responders. Indeed, our innovative approach surpassed the gold standard surgery of sentinel lymph node excision. Overall, intranodal administration of ImmAct yielded a robust antitumor immune response, offering protection against micrometastases and relapse.

A novel iTreg-related signature for prognostic prediction in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is the most common subtype of lung cancer. Most patients are diagnosed at an advanced stage, therefore it is crucial to identify novel prognostic biomarkers for LUAD. As important regulatory cells, inducible regulatory T cells (iTregs) play a vital role in immune suppression and are important for the maintenance of immune homeostasis. This study explored the prognostic value and therapeutic effects of iTreg-related genes in LUAD. Data for LUAD patients, including immune infiltration data, RNA sequencing data, and clinical features, were acquired from The Cancer Genome Atlas, Gene Expression Omnibus, and Tumor Immune Single-cell Hub 2 databases. Immune-related subgroups with different infiltration patterns and iTreg-related genes were identified through univariate and multivariate Cox regression analyses and weighted correlation network analysis. Functional enrichment analyses were performed to explore the underlying mechanisms of iTreg-related genes. A prognostic risk signature was constructed using Cox regression analysis with the least absolute shrinkage and selection operator penalty. The ESTIMATE algorithm was applied to determine the immune status of LUAD patients. We applied the constructed signature to predict chemosensitivity and performed single-cell RNA sequencing analysis. The infiltration of iTregs was identified as an independent factor for predicting patient outcomes. We constructed a prognostic signature based on seven iTreg-related genes (GIMAP5, SLA, MS4A7, ZNF366, POU2AF1, MRPL12, and COL5A1), which was applied to subdivide patients into high- and low-risk subgroups. Our results revealed that patients in the iTreg-related low-risk subgroup had a better prognosis and possibly greater sensitivity to traditional chemotherapy. Our study provides a novel iTreg-related signature to elucidate the mechanisms underlying LUAD prognosis and promote individualized chemotherapy treatment.

The Role of CD4 T Cell Help in CD8 T Cell Differentiation and Function During Chronic Infection and Cancer

CD4 and CD8 T cells are key players in the immune response against both pathogenic infections and cancer. CD4 T cells provide help to CD8 T cells via multiple mechanisms, including licensing dendritic cells (DCs), co-stimulation, and cytokine production. During acute infection and vaccination, CD4 T cell help is important for the development of CD8 T cell memory. However, during chronic viral infection and cancer, CD4 helper T cells are critical for the sustained effector CD8 T cell response, through a variety of mechanisms. In this review, we focus on T cell responses in conditions of chronic Ag stimulation, such as chronic viral infection and cancer. In particular, we address the significant role of CD4 T cell help in promoting effector CD8 T cell responses, emerging techniques that can be utilized to further our understanding of how these interactions may take place in the context of tertiary lymphoid structures, and how this key information can be harnessed for therapeutic utility against cancer.

Host-Related Factors as Targetable Drivers of Immunotherapy Response in Non-Small Cell Lung Cancer Patients

Despite some significant therapeutic breakthroughs leading to immunotherapy, a high percentage of patients with non-small cell lung cancer (NSCLC) do not respond to treatment on relapse, thus experiencing poor prognosis and survival. The unsatisfying results could be related to the features of the tumor immune microenvironment and the dynamic interactions between a tumor and immune infiltrate. Host-tumor interactions strongly influence the course of disease and response to therapies. Thus, targeting host-associated factors by restoring their physiologic functions altered by the presence of a tumor represents a new therapeutic approach to control tumor development and progression. In NSCLC, the immunogenic tumor balance is shifted negatively toward immunosuppression due to the release of inhibitory factors as well as the presence of immunosuppressive cells. Among these cells, there are myeloid-derived suppressor cells, regulatory T cells that can generate a tumor-permissive milieu by reprogramming the cells of the hosts such as tumor-associated macrophages, tumor-associated neutrophils, natural killer cells, dendritic cells, and mast cells that acquire tumor-supporting phenotypes and functions. This review highlights the current knowledge of the involvement of host-related factors, including innate and adaptive immunity in orchestrating the tumor cell fate and the primary resistance mechanisms to immunotherapy in NSCLC. Finally, we discuss combinational therapeutic strategies targeting different aspects of the tumor immune microenvironment (TIME) to prime the host response. Further research dissecting the characteristics and dynamic interactions within the interface host-tumor is necessary to improve a patient fitness immune response and provide answers regarding the immunotherapy efficacy, with the aim to develop more successful treatments for NSCLC.

Distribution of Regulatory T-Cells and Other Phenotypes of T-Cells in Tumors and Regional Lymph Nodes of Colorectal Cancer Patients

BACKGROUND/AIM

Tumor microenvironments consist of many types of immune cells, in which regulatory T-cells (Tregs) are supposed to play important roles to suppress anti-tumor immunity. Regional lymph nodes are essential for antitumor immunity in colorectal cancer (CRC). In this study, we compared the diversity of phenotypes of T-cells in normal tissue and regional lymph nodes in order to determine the immunosuppressive mechanism of lymph node metastasis of CRC.

PATIENTS AND METHODS

Fifty patients were enrolled in this study, and paired samples (tumor tissue, normal tissue, and three regional lymph node samples and as well as non-regional lymph node samples) were obtained from each patient. In each paired-sample set, the proportions of different immune cell types and T-cells expressing immune checkpoint molecules were compared using flow cytometry.

RESULTS

Higher proportions of Tregs [7.58% (4.94%-13.87%) vs. 1.79% (0.03%-5.36%), p<0.001] and lower proportions of INFγ-producing CD4-positive T (iCD4+) cells [21.49% (12.08%-27.35%) vs. 26.55% (15.65%-37.63%), p<0.001] were observed in tumor tissue than in normal mucosa. Parts of regional lymph nodes nearest the tumor had a greater proportion of Tregs [5.86% (4.18%-7.69%)] and lower proportions of iCD4+ [5.94% (3.51%-9.04%)] and INFγ-producing CD8-positive T (iCD8+) cells [21.93% (14.92%-35.90%)] than distant parts of regional lymph nodes and non-regional lymph nodes. Both immune-suppressing molecules (CTLA-4 and PD-1) and immune-promoting molecules (OX-40 and ICOS) tended to be highly expressed in tumor tissue and local lymph nodes.

CONCLUSION

In patients with CRC, regional lymph nodes, especially the parts nearest the tumor, had a higher proportion of Tregs and other suppressive immunophenotypes of T-cells than those located more distantly.

Janus or Hydra: The Many Faces of T Helper Cells in the Human Tumour Microenvironment

CD4+ T helper (T_H) cells are key regulators in the tumour immune microenvironment (TIME), mediating the adaptive immunological response towards cancer, mainly through the activation of cytotoxic CD8+ T cells. After antigen recognition and proper co-stimulation, naïve T_H cells are activated, undergo clonal expansion, and release cytokines that will define the differentiation of a specific effector T_H cell subtype. These different subtypes have different functions, which can mediate both anti- and pro-tumour immunological responses. Here, we present the dual role of T_H cells restraining or promoting the tumour, the factors controlling their homing and differentiation in the TIME, their influence on immunotherapy, and their use as prognostic indicators.

Prognostic value of immune cells in the tumor microenvironment of early-stage lung cancer: a meta-analysis

BACKGROUND

Early-stage non-small cell lung cancer (NSCLC) patients carry significant risk of recurrence post-surgery. In-depth characterization of the immune tumor microenvironment (TME) can have prognostic value. This study aimed to evaluate the association of individual immune cell types in the TME with clinical outcomes in surgically resected, early-stage NSCLC.

METHODS

We performed a systematic literature search of the National Library of Medicine database through November 2019, investigating predefined biomarkers (CD3+ T cells, CD4+ T helper cells, CD8+ cytotoxic T cells, CD20+ B cells, CD56+ & CD57+ Natural Killer (NK) cells, CD68+ Tissue Associated Macrophages (TAMS), FoxP3+ T regulatory cells, and Mast Cells (MC)), and their association with survival following PRISMA guidelines.

RESULTS

Studies that adjusted for important clinical covariates (such as stage and age) showed that higher levels of CD8+ cytotoxic T cells were associated with improved OS (HR = 0.68; 95% CI, 0.50-0.93) and DFS (HR = 0.60; 95% CI, 0.41-0.87), while increased CD20+ B cells (HR = 0.16; 95% CI, 0.04-0.64) and CD 56/57+ NK cells (HR = 0.50; 95% CI, 0.26-0.95) were associated with improved OS; lung cancers with increased FoxP3+ T regulatory cells (HR = 2.22; 95% CI, 1.47-3.34) had worse OS.

CONCLUSIONS

Immune cell components of the TME have prognostic value in early-stage, surgically resected NSCLC, and may reveal which patients are more likely to need additional systemic treatment, including immunotherapy. Clinical covariates need to be considered when evaluating the prognostic value of immune cells in the TME.

Stereotactic Ablative Radiation Therapy for Pulmonary Recurrence-Based Oligometastatic Non-Small Cell Lung Cancer: Survival and Prognostic Value of Regulatory T Cells

PURPOSE

We evaluated survival of patients with pulmonary recurrence-based oligometastatic non-small cell lung cancer (NSCLC) whose lesions were all treated with stereotactic ablative radiation therapy (SABR) and the prognostic value of peripheral immune cells.

METHODS AND MATERIALS

In this prospective observational cohort study, we prospectively enrolled 63 patients with oligometastatic NSCLC, for whom all metastases were treated with SABR. Peripheral blood samples were collected 3 days before treatment began, and flow cytometry was used to identify proportions of regulatory T cells (Tregs; CD4+CD25+CD127^low), B cells, NK cells, γδT cells, CD8+CD28+ T cells, and CD8+CD28- T cells. Overall survival (OS) and progression-free survival (PFS) was estimated by the Kaplan-Meier method, and the potential prognostic value of clinicopathologic factors was evaluated by Cox proportional hazards regression.

RESULTS

At a median follow-up time of 19.1 months, estimated OS rates were 84.3% at 1 year, 63.4% at 2 years, and 44.0% at 3 years; corresponding PFS rates were 55.2%, 30.9%, and 25.7%. Estimated local control rates were 96.7% at 1 year and 92.7% at both 2 years and 3 years. Patients with high numbers of Tregs had poorer OS and PFS than did those with low numbers of Tregs (OS: 16.1 months vs not reached, P = .006; PFS: 11.0 vs 21.7 months, P = .013). Treg level was found to be an independent predictor of both OS and PFS in multivariate analyses (OS: hazard ratio 2.68, P = .038; PFS: hazard ratio 2.35, P = .011).

CONCLUSIONS

Our results revealed the independent prognostic value of Tregs in patients treated with SABR for pulmonary recurrence-based oligometastatic NSCLC. Additional treatments may be needed for patients with oligometastatic NSCLC and poor outcomes.

Tumor-draining lymph nodes demonstrate a suppressive immunophenotype in patients with non-small cell lung cancer assessed by endobronchial ultrasound-guided transbronchial needle aspiration: A pilot study

OBJECTIVES

Tumor draining lymph nodes (TDLN) are key sites of early immunoediting in patients with non-small cell lung cancer (NSCLC) and play an important role in generating anti-tumor immunity. Immune suppression in the tumor microenvironment has prognostic implications and may predict therapeutic response. T cell composition of draining lymph nodes may reflect an immunophenotype with similar prognostic potential which could be measured during standard-of-care bronchoscopic assessment. In this study, we compared the immunophenotype from different sites within individuals to primary tumor characteristics in patients with NSCLC to see whether there were tumor-regional differences in immunophenotype which could be evaluated from transbronchial needle aspirates.

MATERIALS AND METHODS

Twenty patients were enrolled in this study and had tissue (lymph node aspirates and/or peripheral blood) obtained during standard of care bronchoscopy with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for diagnosis or staging of known or suspected NSCLC. Aspirates and blood underwent flow-assisted cell sorting and a subset of sorted effector T cells underwent RNA quantitation to determine feasibility of this approach. Immunophenotypic patterns from twelve patients with paired data from tumor-draining and non-tumor draining lymph nodes (NDLN) were compared relative to one another and based on PD-L1 immunohistochemistry and primary tumor histology.

RESULTS

TDLN had significantly fewer CD4⁺ T cells (12.68% vs 27%, p = 0.002) and significantly more regulatory T cells (Treg, 12.03% vs 9.52%, p = 0.03) relative to paired NDLN suggesting tumor-regional immunosuppression. There were significantly more Treg in NDLN relative to paired PBMC (9.52% vs 5.6%, p = 0.016). Patients with PD-L1 expression ≥50% had significantly greater tumor-regional CD4⁺ T cell depletion compared to patients with PD-L1 expression <50% (-35.98% vs -1.89%, p = 0.0357; negative values represent absolute difference between paired TDLN and NDLN).

CONCLUSIONS

In patients with NSCLC, TDLN have a suppressive immunophenotype correlating with tumor PD-L1 status and can be assessed during routine EBUS-TBNA.

Increased frequency of regulatory T cells in the peripheral blood of patients with endometrioid adenocarcinoma

The aim of the present study was to investigate the frequency of cluster of differentiation (CD)4⁺CD25⁺CD127^- regulatory T cells (Tregs) in the peripheral blood mononuclear cells (PBMCs) of patients with endometrioid adenocarcinoma (EA). A total of 82 female patients with EA were recruited. The PBMCs were flow cytometrically analyzed to determine the percentage of CD4⁺CD25⁺CD127^- Tregs within the CD4⁺ T cell population. The associations between the prevalence of Tregs in PBMCs and defined clinical prognostic parameters were evaluated. To study the immunoregulatory capacity of Tregs, the level of specific cytokines were detected by ELISA, and the proliferation of cells was analyzed by incorporation of ³H-thymidine. It was revealed that Treg/CD4⁺ ratio in the peripheral blood of patients with EA was 4.89±1.42%, significantly higher than Treg/CD4⁺ ratio in healthy women. No correlation was observed between Treg frequency and stage, grade of differentiation, menopausal status or age. CD4⁺CD25⁺CD127^- Tregs secreted large amounts of IL-10 but not IFN-γ. The level of IL-10 secreted by Tregs from patients with EA and healthy controls was not significantly different. In addition, there was no significant difference in the suppressive activity of Tregs in patients with EA compared with that of the healthy controls. These findings demonstrate that the increased frequency of immunosuppressive Tregs in patients with EA may be responsible for immune tolerance in endometrial cancer.

Clinicopathological and prognostic significance of regulatory T cells in patients with non-small cell lung cancer: A systematic review with meta-analysis

The prognostic and clinicopathological value of regulatory T cells (Tregs) infiltration in patients with non-small cell lung cancer (NSCLC) remains undetermined. A comprehensive literature search of electronic databases (up to December 2015) was conducted. Relationship between Tregs infiltration and clinicopathological features, recurrence-free survival (RFS) and overall survival (OS) was investigated by synthesizing the qualified data. A total of 1303 NSCLC patients from 11 studies were included. The pooled hazard ratio (HR) for survival showed that high Tregs infiltration had no effect on RFS (HR = 2.03, 95% CI: 0.61–3.44, P = 0.708) and OS (HR = 1.20, 95% CI: 0.58–1.62, P = 0.981). High FoxP3⁺ Tregs infiltration was significantly associated with poor OS in NSCLC (HR = 3.88, 95% CI: 2.45–5.40, P = 0.000). Test methods, ethnicity and types of specimens had no effect on predicting prognosis of Tregs infiltration. While high Tregs infiltration was significantly correlated with smoking status [odds ratios (ORs) = 1.54, 95% CI: 1.15–2.08; P = 0.004], none of other clinicopathological characteristics such as gender, histological type, lymph node metastasis status, tumor size, vascular invasion, lymphatic invasion and pleural invasion were associated with Tregs infiltration. The present study demonstrated that high FoxP3⁺ Tregs infiltration was significantly associated with poor prognosis in NSCLC and smoking status.

Elevated Foxp3/CD8 Ratio in Lung Adenocarcinoma Metastatic Lymph Nodes Resected by Transcervical Extended Mediastinal Lymphadenectomy

A balance between tumor invasion and immune defence system is widely investigated. Objective. The aim of this study was to evaluate lymphocyte phenotype in lymph nodes (LNs) of patients with lung cancer in relation to the presence of metastases. Methods. We investigated 364 LNs resected by transcervical extended mediastinal lymphadenectomy (TEMLA) of 49 patients with squamous cell carcinoma (SCC) or adenocarcinoma (AD) with (A) and without metastases (B). Expression of CD4, CD8, CD25, CTLA-4, and Foxp3 was assessed by immunohistochemical staining. Results. We observed a strong nuclear staining for Foxp3 in lymphocytes and cancer cells and strong membranous/cytoplasmatic reaction for CD4 and CD8, but low for CD25 and CTLA-4. There were significantly higher proportions of CD8+ cells in AD (B) versus AD (A) LNs (80% versus 52.5%, p < 0.05). The Foxp3/CD8 ratio was higher in AD (A) versus AD (B) LNs (0.4 versus 0.25, p < 0.05). No significant differences in the cell markers expression in SCC LNs were found. Conclusion. Significant differences in lymphocyte phenotype in AD may indicate an exceptional biology of this type of lung cancer. TEMLA resected LNs may serve as valuable samples for evaluation of immune status in lung cancer patients.

Regulatory T cells as suppressors of anti-tumor immunity: Role of metabolism

Novel concepts in immunometabolism support the hypothesis that glucose consumption is also used to modulate anti-tumor immune responses, favoring growth and expansion of specific cellular subsets defined in the past as suppressor T cells and currently reborn as regulatory T (Treg) cells. During the 1920s, Otto Warburg and colleagues observed that tumors consumed high amounts of glucose compared to normal tissues, even in the presence of oxygen and completely functioning mitochondria. However, the role of the Warburg Effect is still not completely understood, particularly in the context of an ongoing anti-tumor immune response. Current experimental evidence suggests that tumor-derived metabolic restrictions can drive T cell hyporesponsiveness and immune tolerance. For example, several glycolytic enzymes, deregulated in cancer, contribute to tumor progression independently from their canonical metabolic activity. Indeed, they can control apoptosis, gene expression and activation of specific intracellular pathways, thus suggesting a direct link between metabolic switches and pro-tumorigenic transcriptional programs. Focus of this review is to define the specific metabolic pathways controlling Treg cell immunobiology in the context of anti-tumor immunity and tumor progression.

Prognostic value of circulating regulatory T cell subsets in untreated non-small cell lung cancer patients

The role of the different circulating regulatory T-cells (Treg) subsets, as well as their correlation with clinical outcome of non-small cell lung cancer (NSCLC) patients is poorly understood. Peripheral blood from 156 stage III/IV chemotherapy-naive NSCLC patients and 31 healthy donors (HD) was analyzed with flow cytometry for the presence and functionality of CD4⁺ Treg subsets (naive, effector and terminal effector). Their frequencies were correlated with the clinical outcome. All CD4⁺ Treg subsets exhibited highly suppressive activity by TGF-β and IL-10 production. The percentages of naive Treg were found elevated in NSCLC patients compared to HD and were associated with poor clinical outcome, whereas the percentage of terminal effector Treg was lower compared to HD and higher levels were correlated with improved clinical response. At baseline, normal levels of naive and effector Treg were associated with longer overall survival (OS) compared to high levels, while the high frequency of the terminal effector Treg was correlated with longer Progression-Free Survival and OS. It is demonstrated, for first time, that particular CD4⁺ Treg subtypes are elevated in NSCLC patients and their levels are associated to the clinical outcome. The blocking of their migration to the tumor site may be an effective therapeutic strategy.

Analysis of the prognostic role of an immune checkpoint score in resected non-small cell lung cancer patients

Tumors develop mechanisms to recruit tolerogenic immune cells and to induce the expression of molecules that act as immune checkpoints. This regulation of the immune microenvironment favors immune tolerance to the neoplastic cells. In this study, we have investigated the prognostic role of immune-checkpoint expression markers in a cohort of resectable non-small cell lung cancer (NSCLC) patients. RNA was isolated from fresh-frozen lung specimens (tumor and normal lung) (n = 178). RTqPCR was performed to analyze the relative expression of 20 immune-related genes that were normalized by the use of endogenous genes selected by GeNorm algorithm. Patients with higher expression levels of IL23A and LGALS2 presented better outcomes. In the clustering expression patterns, we observed that patients with higher expression of immunoregulatory genes had better survival rates. Additionally, these data were used to develop a gene expression score. Since CTLA4 and PD1 were associated with prognosis based on Cox regression analysis (Z-score > 1.5), a multivariate model including these two genes was created. Absolute regression coefficients from this analysis were used in order to calculate the immune-checkpoint score: (PD1×0.116) + (CTLA4×0.059) for each case. Kaplan-Meier survival analysis showed that patients with high immune-checkpoint score have longer overall survival (OS) [NR vs. 40.4 mo, p = 0.008] and longer relapse-free survival (RFS) [82.6 vs. 23 mo, p = 0.009]. Multivariate analysis in the entire cohort indicated that the immune-checkpoint score was an independent biomarker of prognosis for OS [HR: 0.308; 95% CI, 0.156-0.609; p = 0.001] and RFS [HR: 0.527; 95% CI, 0.298-0.933; p = 0.028] in early-stage NSCLC patients. In conclusion, this score provides relevant prognostic information for a better characterization of early stage NSCLS patients with strikingly different outcomes and who may be candidates for immune-based therapies.

Regulatory T cells and potential inmmunotherapeutic targets in lung cancer

Lung cancer and metastasis are two of the most lethal diseases globally and seldom have effective therapies. Immunotherapy is considered as one of the powerful alternatives. Regulatory T cells (Tregs) can suppress the activation of the immune system, maintain immune tolerance to self-antigens, and contribute to immunosuppression of antitumor immunity, which is critical for tumor immune evasion in epithelial malignancies, including lung cancer. The present review gives an overview of the biological functions and regulations of Tregs associated with the development of lung cancer and metastasis and explores the potentials of Treg-oriented therapeutic targets. Subsets and features of Tregs mainly include naturally occurring Tregs (nTregs) (CD4(+) nTregs and CD8(+) nTregs) and adaptive/induced Tregs (CD4(+) iTregs and CD8(+) iTregs). Tregs, especially in circulation or regional lymph nodes, play an important role in the progress and metastasis of lung cancer and are considered as therapeutic targets and biomarkers to predict the survival length and recurrence of lung cancer. Increasing understanding of Tregs' functional mechanisms will lead to a number of clinical trials on the discovery and development of Treg-oriented new therapies. Tregs play important roles in lung cancer and metastasis, and the understanding of Tregs becomes more critical for clinical applications and therapies. Thus, Tregs and associated factors can be potential therapeutic targets for lung cancer immunotherapy.

Expressions of CD8+TILs, PD-L1 and Foxp3+TILs in stage I NSCLC guiding adjuvant chemotherapy decisions

PURPOSE

Currently, adjuvant chemotherapy is recommended for patients with high risk stage I non-small cell lung cancer (NSCLC). However, identifying high risk patients remains a challenge. This study aims to identify the patient cohorts more likely to benefit from adjuvant chemotherapy based on the tumor micro-immune environment.

RESULTS

CD8+TILs significantly associated with disease-free survival (DFS) and overall survial (OS) (p=0.002; 0.040). Patients with high risk factors may also predict shorter DFS (P=0.056). When compared together, patients with high-CD8+TILs showed better DFS than patients with low-CD8+TILs, no matter their risk factors status. There's no correlation between PD-L1 expressions and survival. PD-L1 was highly expressed in men, squamous and well differentiated carcinoma. In addition, Foxp3+TILs alone didn't show any prognostic effects, but low-Foxp3/high-CD8+TILs were associated with prolonged DFS (p=0.031).

METHODS

A total of 126 patients with surgically resected stage I NSCLC were included to perform immunohistochemistry of CD8+ tumor infiltrating lymphocytes (TILs), programmed death ligand-1(PD-L1) and forkhead box P3 (Foxp3)+TILs.

CONCLUSION

CD8+TILs are effective prognostic predictors. Patients with surgically resected stage I NSCLC showing low CD8+TILs could be considered for adjuvant chemotherapy, even if they have no high risk features.

Preferential expansion of pro-inflammatory Tregs in human non-small cell lung cancer

OBJECTIVES

Lung cancer is the leading cause of cancer-related death in the USA. Regulatory T cells (Tregs) normally function to temper immune responses and decrease inflammation. Previous research has demonstrated different subsets of Tregs with contrasting anti- or pro-inflammatory properties. This study aimed to determine Treg subset distributions and characteristics present in non-small cell lung cancer (NSCLC) patients.

METHODS

Peripheral blood was collected from healthy controls (HC) and NSCLC patients preceding surgical resection, and mononuclear cells were isolated, stained, and analyzed by flow cytometry. Tregs were defined by expression of CD4 and CD25 and classified into CD45RA(+)Foxp3(int) (naïve, Fr. I) or CD45RA(-)Foxp3(hi) (activated Fr. II). Activated conventional T cells were CD4(+)CD45RA(-)Foxp3(int) (Fr. III).

RESULTS

Samples from 23 HC and 26 NSCLC patients were collected. Tregs isolated from patients with NSCLC were found to have enhanced suppressive function on naive T cells. Cancer patients had significantly increased frequencies of activated Tregs (fraction II: FrII), 17.5 versus 3.2% (P < 0.001). FrII Tregs demonstrated increased RORγt and IL17 expression and decreased IL10 expression compared to Tregs from HC, indicating pro-inflammatory characteristics.

CONCLUSIONS

This study demonstrates that a novel subset of Tregs with pro-inflammatory characteristics preferentially expand in NSCLC patients. This Treg subset appears identical to previously reported pro-inflammatory Tregs in human colon cancer patients and in mouse models of polyposis. We expect the pro-inflammatory Tregs in lung cancer to contribute to the immune pathogenesis of disease and propose that targeting this Treg subset may have protective benefits in NSCLC.

New Approaches in Immunotherapy for the Treatment of Lung Cancer

Despite the several advances in the last few years into treatment of advanced lung cancer, the 5-year survival remains extremely low. New therapeutic strategies are currently under investigation, and immunotherapy seems to offer a promising treatment alternative. In the last decade, therapeutic cancer vaccines in lung cancer have been rather disappointing, mainly due to the lack of efficient predictive biomarkers. A better refinement of the patient population that might respond to treatment might finally lead to a success story. For the first time, the immune checkpoint inhibitors are demonstrating sustained antitumor response and improved survival and they may be the first immunotherapeutics available for patients with lung cancer.