Immunophenotype of T Cells Expressing Programmed Death-1 and Cytotoxic T Cell Antigen-4 in Early Lung Cancer: Local vs. Systemic Immune Response

Flow Cytometric Analysis of Macrophages and Cytokines Profile in the Bronchoalveolar Lavage Fluid in Patients with Lung Cancer

Macrophages play an important role in the suppression and activation of immune anti-cancer response, but little is known about dominant macrophage phenotype in the lung cancer environment, evaluated by bronchoalveolar lavage fluid (BALF). The aim of this study was to characterize macrophages in BALF from a lung affected by cancer (cBALF) and a healthy lung (hBALF) of the same patient regarding their individual macrophage polarization and selected cytokines profile. A total of 36 patients with confirmed lung cancer were investigated. Macrophages markers: CD206 CD163 CD80 CD86 CD40 CD45, Arginase-1, and CD68 were evaluated by flow cytometry. Cytokines (IL-1 RA, IL-6, IL-10, TNF-α, IL-1β, IL-12, IL-23, and TGF-β) profile was analyzed. There was higher median proportion of macrophages in Cbalf than in Hbalf. The population of macrophages presented immunophenotype: Ccd68+bright CD206+bright CD163+bright CD80+ CD86+ CD40+bright CD45+ cArginase+. We observed some trends in the expression of the analyzed antigens in clBALF and hlBLAF. The highest concentrations of IL-1RA and IL-6 were in Cbalf and Hbalf supernatant. There were the correlations between pro- and anti-inflammatory cytokines. The findings showed that macrophages include a diverse and plastic group with the presence of different antigens and cytokines, and determining the target phenotype is a complex and variable process.

Immune-check blocking combination multiple cytokines shown curative potential in mice tumor model

OBJECTIVE

In order to ensure the stable transcription of target genes, we constructed a eukaryotic high expression vector carrying an immune-check inhibitor PD-1v and a variety of cytokines, and studied their effects on activating immune response to inhibit tumor growth.

METHODS

A novel eukaryotic expression plasmid vector named pT7AMPCE containing T7RNA polymerase, T7 promoter, internal ribosome entry site (IRES), and poly A tailing signal was constructed by T4 DNA ligase, on which homologous recombination was used to clone and construct the vector carrying PD-1v, IL-2/15, IL-12, GM-CSF, and GFP. In vitro transfection of CT26 cells was performed, and the protein expression of PD-1v, IL-12 and GM-CSF was detected by Western blot and ELISA after 48 h. Mice were subcutaneously inoculated with CT26-IRFP tumor cells in the rib abdomen, and the tumor tissues were injected with PD-1v, IL-2/15, IL-12, and GM-CSF recombinant plasmids for treatment during the experimental period. The efficacy of the treatment was evaluated by assay tumor size and survival time of tumor-bearing mice during the experiment. Expression levels of IFN-γ, TNF, IL-4, IL-2, and IL-5 in mouse blood were measured using the CBA method. Tumor tissues were extracted and immune cell infiltration in tumor tissues was detected by HE staining and the IHC method.

RESULTS

The recombinant plasmids carrying PD-1v, IL-2/15, IL-12, and GM-CSF were successfully constructed, and the Western blot and ELISA results showed that PD-1v, IL-12, and GM-CSF were expressed in the supernatant of CT26 cells 48 h after in vitro cell transfection. The combined application of PD-1v, IL-2/15, IL-12, and GM-CSF recombinant plasmids significantly inhibited tumor growth in mice, and the tumor growth rate was significantly lower than that in the blank control group and GFP plasmid control group (p < 0.05). Cytometric bead array data suggested that the combination of PD-1v and various cytokines can effectively activate immune cells. HE and IHC analysis revealed plenty of immune cell infiltrates in the tumor tissue, and a large proportion of tumor cells showed the necrotic phenotype in the combination treatment group.

CONCLUSION

The combination of immune check blockade and multiple cytokine therapy can significantly activate the body's immune response and inhibit tumor growth.

Comparing T Cell Subsets in Broncho-Alveolar Lavage (BAL) and Peripheral Blood in Patients with Advanced Lung Cancer

Background: Lung cancer (LC) tissue for immunological characterization is often scarce. We explored and compared T cell characteristics between broncho-alveolar lavage from tumor affected (t-BAL) and contralateral lung (cl-BAL), with matched peripheral blood (PB). Methods: BAL and PB were collected during bronchoscopy for diagnostic and/or therapeutic purposes in patients with monolateral primary lesion. Results: Of 33 patients undergoing BAL and PB sampling, 21 had histologically-confirmed LC. Most cases were locally-advanced or metastatic non-small cell LC. T cell characteristics were not significantly different in t-BAL vs. cl-BAL. Compared to PB, CD8 T cells in BAL presented features of immune activation and exhaustion (high PD-1, low IFN-g production). Accordingly, regulatory CD4 T cells were also higher in BAL vs. PB. When dichotomizing T cell density in t-BAL in high and low, we found that PD-L1 expression in LC was associated with T cell density in t-BAL. T-BAL with high T cell density had higher %IFN-g+CD8 T cells and lower %T-regs. Conclusion: In BAL from advanced LC patients, T cells present features of exhaustion. T cells in t-BAL could be the best surrogate of tumor-infiltrating T cell, and future studies should evaluate T cell phenotype and density as potential biomarkers for cancer immunotherapy outcome.

Effector Memory T Cells and CD45RO+ Regulatory T Cells in Metastatic vs. Non-Metastatic Lymph Nodes in Lung Cancer Patients

Lymphocytes play a leading role in regulation of the immune system in lung cancer patients. The recognition of T cells profile may help in prediction of effectiveness of anticancer immunotherapy. The aim of the study was to determine the dominant subpopulation of CD4+ and CD8+ lymphocytes in metastatic and non-metastatic lymph nodes (LNs) of lung cancer patients. LNs aspirates were obtained during EBUS/TBNA procedure and cells were analyzed by flow cytometry. We showed a higher percentage of CD4+ and CD8+ effector memory T cells in the metastatic than in the non-metastatic LNs (28.6 vs. 15.3% and 28.6 vs. 14.0%, p< 0.05). The proportion of CD45RO+ T regulatory cells (CD45RO+ Tregs) was higher in the metastatic LNs than in the non-metastatic ones (65.6 vs. 31%, p< 0.05). We reported the significant differences in T cell subsets depending on the lung cancer metastatic process. We observed that the effector memory T cells were predominant subpopulations in metastatic LNs. Lymphocyte profile in LNs is easy to evaluate by flow cytometry of EBUS/TBNA samples and may reflect the immune status in lung cancer.

Immunosuppressive properties of human PD-1 + , PDL-1 + and CD80 + dendritic cells from lymph nodes aspirates of lung cancer patients

Dendritic cells (DCs) play a pivotal role in the homeostasis of the immune system. The tumor microenvironment impairs the proper function of DCs. The immunomodulatory properties of DCs in lung cancer are of interest. In the present study, we analysed DCs subsets and immune cells with the expression of immunomodulatory molecules: PD-1 and PD-L1 and co-stimulatory molecule CD80 in metastatic, non-metastatic lymph nodes (LNs) and peripheral blood (PB). LNs aspirates were obtained during the EBUS/TBNA procedure of 29 patients with primary lung cancer. The cells were analyzed by flow cytometry. We reported a higher percentage of DCs in the metastatic than in the non-metastatic LNs and the PB (0.709% vs. 0.166% vs. 0.043%, p < 0.0001). The proportions of PD-1 + , PD-L1 + and CD80 + DCs were higher in the metastatic LNs than in the non-metastatic ones. A higher proportion of regulatory DCs (DCregs) was found in the metastatic ones than in the non-metastatic LNs (22.5% vs. 3.1%, p = 0.0189). We report that DCs cells show increased expression of PD-1, PD-L1 and CD80 molecules that can interact with T lymphocytes. It can be assumed that mature DCs infiltrating metastatic LNs can develop into DCregs, which are involved in the suppression of anti-tumor response.

Current challenges in targeting tumor desmoplasia to improve the efficacy of immunotherapy

Desmoplasia is crucial for the development, progression and treatment of immune-resistant malignancies. and treatment of immune-resistant malignancies. Targeting desmoplasia-related metabolic pathways appears to be an interesting approach to expand our stock of disposable anti-tumor agents.CXCL12/CXCR4 axis inhibition reduces fibrosis, alleviates immunosuppression and significantly enhances the efficacy of PD-1 immunotherapy. CD40L substitute therapy may increase the activity of T-cells, downregulate CD40+, prolong patients' survival and prevent cancer progression. Although FAPα antagonists used in preclinical models did not lead to permanent cure, an alleviation of immune-resistance, modification of desmoplasia and a decrease in angiogenesis were observed. Targeting DDR2 may enhance the effect of anti-PD-1 treatment in multiple neoplasm cell lines and has the ability to overcome the adaptation to BRAF-targeted therapy in melanoma. Reprogramming desmoplasia could potentially cooperate not only with present treatment, but also other potential therapeutic targets. We present the most promising metabolic pathways related to desmoplasia and discuss the emerging strategies to improve the efficacy of immunotherapy.

Evaluation of cytokines in the tumor microenvironment of lung cancer using bronchoalveolar lavage fluid analysis

INTRODUCTION

Lung cancer is the leading cause of death by cancer. In recent years, immunotherapy with checkpoint inhibitors (ICI) emerged as a promising new therapeutic approach. However, a deeper understanding of the immunologic responses adjacent to the tumor known as tumor microenvironment (TME) is needed. Our study investigated TME of lung cancer by analyzing cytokines in bronchoalveolar lavage fluid (BALF).

MATERIALS AND METHODS

Between January 2018 and June 2019, 119 patients were prospectively enrolled in this study. For each cancer patient, levels of 16 cytokines (fractalkine, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), and interleukins (IL): IL-1b, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, IL-13, IL-17A, and IL-23) were measured in BALF and serum and compared to healthy individuals and patients with other lung diseases.

RESULTS

There were several significant differences of cytokine levels of patients with lung cancer compared to healthy individuals. However, none of them remained in the multivariate analysis compared to other lung diseases in either BALF or serum. Furthermore, there were no significant differences between the groups in cell differentiation of either BALF or serum. Cytokine levels in BALF were generally near the lower detection limit and showed almost no correlation with their respective levels measured in serum of the same individual.

CONCLUSIONS

Cytokines in BALF and serum of lung cancer patients may indicate unspecific inflammation. BAL is not recommendable as a tool to investigate TME of lung cancer. Therefore, cytokines measured in BALF are probably not appropriate as predictors in patients treated with ICIs.

Lung Cancer Stem Cells-Origin, Diagnostic Techniques and Perspective for Therapies

Lung cancer remains one of the most aggressive solid tumors with an overall poor prognosis. Molecular studies carried out on lung tumors during treatment have shown the phenomenon of clonal evolution, thereby promoting the occurrence of a temporal heterogeneity of the tumor. Therefore, the biology of lung cancer is interesting. Cancer stem cells (CSCs) are involved in tumor initiation and metastasis. Aging is still the most important risk factor for lung cancer development. Spontaneously occurring mutations accumulate in normal stem cells or/and progenitor cells by human life resulting in the formation of CSCs. Deepening knowledge of these complex processes and improving early recognition and markers of predictive value are of utmost importance. In this paper, we discuss the CSC hypothesis with an emphasis on age-related changes that initiate carcinogenesis. We analyze the current literature in the field, describe our own experience in CSC investigation and discuss the technical challenges with special emphasis on liquid biopsy.

Identification of PD-1 ligands: PD-L1 and PD-L2 on macrophages in lung cancer milieu by flow cytometry

Background

The efficacy of immune checkpoint inhibitors (ICIs) remains unexpected and in some patients the resistance to anti-programmed death-1 (anti-PD-1) and anti-programmed death ligand 1 (anti-PD-L1) agents is observed. One of possible explanation may be PD-L2 activity. PD-1 ligands: PD-L1 and PD-L2 are present on cancer cells but also, not without significance, on alveolar macrophages (AMs) contributing to immune-suppression in the tumor microenvironment. The aim of this study was to analyse PD-L2, PD-L1 expression on AMs in bronchoalveolar lavage fluid (BALF) in relation to PD-1 positive T lymphocytes.

Methods

Seventeen patients with lung cancer were investigated. BALF cells from the lung with cancer (clBALF) and from the opposite “healthy” lung (hlBALF) and peripheral blood (PB) lymphocytes were investigated. Flow cytometry method was used.

Results

We found that 100% of CD68+ AMs from the clBALF were PD-L1 and PD-L2-positive. Unexpectedly, fluorescence minus one (FMO) PD-L1 and PD-L2 stained controls and isotype controls also showed strong autofluorescence. The hlBALF AMs exhibited a similar PD-L1 and PD-L2 autofluorescence. The median proportion of PD-1+ T lymphocytes was higher in the clBALF than the hlBALF and PB (28.9 vs. 23.4% vs. 15.6%, P=0.0281).

Conclusions

We discussed the opportunities of exploring the PD-1-PD-L1/PD-L2 pathway in the lung cancer environment, which may help to find new potential biomarkers for immunotherapy. We concluded that precise identification by flow cytometry of macrophages in the BALF is possible, but our study showed that the autofluorescence of macrophages did not allow to assess a real expression of PD-L2 as well as PD-L1 on AMs.

The Search for an Interesting Partner to Combine with PD-L1 Blockade in Mesothelioma: Focus on TIM-3 and LAG-3

Malignant pleural mesothelioma (MPM) is an aggressive cancer that is causally associated with previous asbestos exposure in most afflicted patients. The prognosis of patients remains dismal, with a median overall survival of only 9-12 months, due to the limited effectiveness of any conventional anti-cancer treatment. New therapeutic strategies are needed to complement the limited armamentarium against MPM. We decided to focus on the combination of different immune checkpoint (IC) blocking antibodies (Abs). Programmed death-1 (PD-1), programmed death ligand-1 (PD-L1), T-cell immunoglobulin mucin-3 (TIM-3), and lymphocyte activation gene-3 (LAG-3) blocking Abs were tested as monotherapies, and as part of a combination strategy with a second IC inhibitor. We investigated their effect in vitro by examining the changes in the immune-related cytokine secretion profile of supernatant collected from treated allogeneic MPM-peripheral blood mononuclear cell (PBMC) co-cultures. Based on our in vitro results of cytokine secretion, and flow cytometry data that showed a significant upregulation of PD-L1 on PBMC after co-culture, we chose to further investigate the combinations of anti PD-L1 + anti TIM-3 versus anti PD-L1 + anti LAG-3 therapies in vivo in the AB1-HA BALB/cJ mesothelioma mouse model. PD-L1 monotherapy, as well as its combination with LAG-3 blockade, resulted in in-vivo delayed tumor growth and significant survival benefit.

Impact of PD-1 gene polymorphism and its interaction with tea drinking on susceptibility to tuberculosis

The aim of this study was to explore the impact of polymorphism of PD-1 gene and its interaction with tea drinking on susceptibility to tuberculosis (TB). A total of 503 patients with TB and 494 controls were enrolled in this case–control study. Three single-nucleotide polymorphisms of PD-1 (rs7568402, rs2227982 and rs36084323) were genotyped and unconditional logistic regression analysis was used to identify the association between PD-1 polymorphism and TB, while marginal structural linear odds models were used to estimate the interactions. Genotypes GA (OR 1.434), AA (OR 1.891) and GA + AA (OR 1.493) at rs7568402 were more prevalent in the TB patients than in the controls (P < 0.05). The relative excess risk of interaction (RERI) between rs7568402 of PD-1 genes and tea drinking was −0.3856 (95% confidence interval −0.7920 to −0.0209, P < 0.05), which showed a negative interaction. However, the RERIs between tea drinking and both rs2227982 and rs36084323 of PD-1 genes were not statistically significant. Our data demonstrate that rs7568402 of PD-1 genes was associated with susceptibility to TB, and there was a significant negative interaction between rs7568402 and tea drinking. Therefore, preventive measures through promoting the consumption of tea should be emphasised in the high-risk populations.

Immune Modulation in Lung Cancer: Current Concepts and Future Strategies

Cancer immunotherapy represents the most dynamic field of biomedical research currently, with thoracic immuno-oncology as a forerunner. PD-(L)1 inhibitors are already part of standard first-line treatment for both non-small-cell and small-cell lung cancer, while unprecedented 5-year survival rates of 15-25% have been achieved in pretreated patients with metastatic disease. Evolving strategies are mainly aiming for improvement of T-cell function, increase of immune activation in the tumor microenvironment (TME), and supply of tumor-reactive lymphocytes. Several novel therapeutics have demonstrated preclinical efficacy and are increasingly used in rational combinations within clinical trials. Two overarching trends dominate: extension of immunotherapy to earlier disease stages, mainly as neoadjuvant treatment, and a shift of focus towards multivalent, individualized, mutatome-based antigen-specific modalities, mainly adoptive cell therapies and cancer vaccines. The former ensures ample availability of treated and untreated patient samples, the latter facilitates deeper mechanistic insights, and both in combination build an overwhelming force that is accelerating progress and driving the greatest revolution cancer medicine has seen so far. Today, immune modulation represents the most potent therapeutic modality in oncology, the most important topic in clinical and translational cancer research, and arguably our greatest, meanwhile justified hope for achieving cure of pulmonary neoplasms and other malignancies in the next future.

Programmed Cell Death Ligand (PD-L)-1 Contributes to the Regulation of CD4+ T Effector and Regulatory T Cells in Cutaneous Leishmaniasis

Cutaneous Leishmaniasis (CL) affects up to one million people every year and treatments are costly and toxic. The regulation of the host immune response is complex and the knowledge of how CD4⁺ T cells are activated and maintained during Leishmania infection is still limited. Current therapies aim to target programmed cell death (PD)-1 and programmed cell death ligand (PD-L)-1 in order to boost T cell activity. However, the role of the PD-1/PD-L1 axis during Leishmania infection is still unclear. In this study, we found that patients with active and post-treatment CL displayed different subsets of CD4⁺PD-1⁺ T cells. Accordingly, L. major-infected mice upregulated PD-1 on activated CD4⁺ T effector cells and PD-L1 on resident macrophages and infiltrating monocytes at the site of infection. L. major-infected Pdl1^−/− mice expressed lower levels of MHCII and higher levels of CD206 on macrophages and monocytes and, more importantly, the lack of PD-L1 contributed to a reduced frequency of CD4⁺Ly6C^hi T effector cells and an increase of CD4⁺Foxp3⁺ regulatory T cells at the site of infection and in draining lymph nodes. Additionally, the lack of PD-L1 was associated with lower production of IL-27 by infiltrating monocytes and lower levels of the Th1 cytokines IFN-γ and TNF-α produced by CD4⁺ T effector cells. Pdl1^−/− mice initially exhibited larger lesions despite having a similar parasite load. Our results describe for the first time how the interruption of the PD-1/PD-L1 axis influences the immune response against CL and suggests that this axis regulates the balance between CD4⁺Ly6C^hi T effector cells and CD4⁺Foxp3⁺ regulatory T cells.

The relevance of bronchoalveolar lavage fluid analysis for lung cancer patients

Introduction: Lung cancer is a serious malignant disease with poor prognosis. The methods for improving early recognition and markers of predictive value are widely investigated. Bronchoalveolar lavage (BAL) is a valuable method of respiratory tract investigation. Currently, BAL is rarely used for tumor diagnosis, but for ruling out differential diagnosis, due to its poor sensitivity. The new indication for BAL fluid analysis is evaluation of local immune reaction in lung cancer patients and description of tumor microenvironment (TME). A literature search was performed in bibliography bases from the time of the introduction of BAL in the diagnosis of lung diseases. We analyzed our prior original studies with the bibliography.Area covered: The usefulness of BAL in the diagnosis of peripheral spread of malignant diseases and in the evaluation of TME in lung cancer, as well as a role of BAL in the diagnosis of checkpoint inhibitor pneumonitis is presented. Commentary concerning methodology of BALF analysis in lung cancer is included.Expert opinion: It seems that in the near future BAL will find an important place in the evaluation of lung cancer TME in two aspects. The first could be characteristic of immune reaction by analysis of immune cells and mediators and the second cancer molecular characteristic by free DNA and exosomes analysis.

New Frontiers for Molecular Pathology

Lung cancer remains a serious oncological problem worldwide. The delayed diagnosis and a prevalence of advanced stages in up to 70% of cases at recognition are still observed. Thanks to targeted therapies and immunotherapy a significant progress in achieving prolonged survival in some lung cancer patients is reported. A precise histopathological diagnosis, especially the recognition of adenocarcinoma, and a progress in the methods of clinical staging underlie the proper qualification of patients for a tailored therapy. The deep molecular characteristics of lung cancer in liquid biopsy, for example blood, bronchoalveolar lavage fluid (BALF), cell suspension from needle aspirates, are currently available. The molecular characteristic has recently been extended with molecular aberrations of BRAF, KRAS, MET, ERBB2, RET, NTRK next to the well-known EGFR mutations and ALK, ROS-1 relocation. The present paper discusses the usefulness of adequate pathological methods and molecular testing for the identification of a broad spectrum of predictive biomarkers for a molecular-directed lung cancer therapy. Immunotherapy with immune checkpoint inhibitors (ICIs) is approved in the first line therapy of advanced non-small-cell lung cancer. To date only PD-L1 expression on tumor cells has been found to be a marker of response to ICIs. The efficacy of ICIs as well as the susceptibility to immune-related adverse events are highly individual, so immune biomarkers are widely investigated. The candidates for predictive factors for ICIs immunotherapy include cancer cell antigenicity, presence of regulatory/suppressory molecules on cancer cells, cancer stem cells or on exosomes, and, on the other hand, an immune status of the patient. Cancers with high immune infiltration in the tumor milieu, referred to as “hot” tumors, seem to ensure a better response to ICIs than the “cold” ones. BALF analysis may replace cancer tissue examination, which is of limited access in advanced stages, for the recognition of the nature of immune response in the tumor environment. Tumor mutational burden (TMB) was shown to correlate with a good response to ICIs, especially when combined with other anticancer therapies. The present paper demonstrates the results of recent studies on lung cancer characteristics which bring us closer to the definition of useful prognostic/predictive factors.