Impaired STAT phosphorylation in T cells from melanoma patients in response to IL-2: association with clinical stage

pSTAT5 is associated with improved survival in patients with thick or ulcerated primary cutaneous melanoma

Identifying prognostic biomarkers to predict clinical outcomes in stage I and II cutaneous melanomas could guide the clinical application of adjuvant and neoadjuvant therapies. We aimed to investigate the prognostic value of phosphorylated signal transducer and activator of transcription 5 (pSTAT5) as a biomarker in early-stage melanoma. This study evaluated all initially staged Ib and II melanoma patients undergoing sentinel node biopsy at a tertiary centre in Brisbane, Australia between 1994 and 2007, with survival data collected from the Queensland Cancer Registry. Primary melanoma tissue from 189 patients was analysed for pSTAT5 level through immunohistochemistry. Cox regression modelling, with adjustment for sex, age, ulceration, anatomical location, and Breslow depth, was applied to determine the association between pSTAT5 detection and melanoma-specific survival. Median duration of follow-up was 7.4 years. High pSTAT5 detection was associated with ulceration and increased tumour thickness. However, multivariate analysis indicated that high pSTAT5 detection was associated with improved melanoma-specific survival (hazard ratio: 0.15, 95% confidence interval: 0.03-0.67) as compared to low pSTAT5 detection. This association persisted when pSTAT5 detection was limited to immune infiltrate or the vasculature, as well as when sentinel node positivity was accounted for. In this cohort, staining for high-pSTAT5 tumours identified a subset of melanoma patients with increased survival outcomes as compared to low-pSTAT5 tumours, despite the former having higher-risk clinicopathological characteristics at diagnosis. pSTAT5 is likely an indicator of local immune activation, and its detection could represent a useful tool to stratify the risk of melanoma progression.

Determination of hypoxia signature to predict prognosis and the tumor immune microenvironment in melanoma

Melanoma is one of the highly malignant skin tumors, the incidence and death of which continue to increase. The hypoxic microenvironment drives tumor growth, progression, and heterogeneity; it also triggers a cascade of immunosuppressive responses and affects the levels of T cells, macrophages, and natural killer cells. Here, we aim to develop a hypoxia-based gene signature for prognosis evaluation and help evaluate the status of hypoxia and the immune microenvironment in melanoma. Based on the data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database, we performed integrated bioinformatics to analyze the hypoxia-related genes. Using Lasso Cox regression, a hypoxia model was constructed. The receiver operating characteristic and the Kaplan-Meier curve were used to evaluate the predictive capacity of the model. With the CIBERSORT algorithm, the abundance of 22 immune cells in the melanoma microenvironment was analyzed. A total of 20 hypoxia-related genes were significantly related to prognosis in the log-rank test. Lasso regression showed that FBP1, SDC3, FOXO3, IGFBP1, S100A4, EGFR, ISG20, CP, PPARGC1A, KIF5A, and DPYSL4 displayed the best features. Based on these genes, a hypoxia model was established, and the area under the curve for the model was 0.734. Furthermore, the hypoxia score was identified as an independent prognostic factor. Besides, the hypoxia score could also predict the immune microenvironment in melanoma. Down-regulated activated CD4 memory T cells, CD8 T cells, and M1-like macrophages, and up-regulated Tregs were observed in patients with a high hypoxia score. The hypoxia-related genes were identified, and the hypoxia score was found to be a prognostic factor for overall survival and a predictor for the immune microenvironment. Our findings provide new ideas for evaluation and require further validation in clinical practice.

Exploration of the Immune-Related Signatures and Immune Infiltration Analysis in Melanoma

In the present study, we aimed to investigate immune-related signatures and immune infiltration in melanoma. The transcriptome profiling and clinical data of melanoma were downloaded from The Cancer Genome Atlas database, and their matched normal samples were obtained from the Genotype-Tissue Expression database. After merging the genome expression data using Perl, the limma package was used for data normalization. We screened the differentially expressed genes (DEGs) and obtained immune signatures associated with melanoma by an immune-related signature list from the InnateDB database. Univariate Cox regression analysis was used to identify potential prognostic immune genes, and LASSO analysis was used to identify the hub genes. Next, based on the results of multivariate Cox regression analysis, we constructed a risk model for melanoma. We investigated the correlation between risk score and clinical characteristics and overall survival (OS) of patients. Based on the TIMER database, the association between selected immune signatures and immune cell distribution was evaluated. Next, the Wilcoxon rank-sum test was performed using CIBERSORT, which confirmed the differential distribution of immune-infiltrating cells between different risk groups. We obtained a list of 91 differentially expressed immune-related signatures. Functional enrichment analysis indicated that these immune-related DEGs participated in several areas of immune-related crosstalk, including cytokine-cytokine receptor interactions, JAK-STAT signaling pathway, chemokine signaling pathway, and Th17 cell differentiation pathway. A risk model was established based on multivariate Cox analysis results, and Kaplan-Meier analysis was performed. The Kruskal-Wallis test suggested that a high risk score indicated a poorer OS and correlated with higher American Joint Committee on Cancer-TNM (AJCC-TNM) stages and advanced pathological stages (P < 0.01). Furthermore, the association between hub immune signatures and immune cell distribution was evaluated in specific tumor samples. The Wilcoxon rank-sum test was used to estimate immune infiltration density in the two groups, and results showed that the high-risk group exhibited a lower infiltration density, and the dominant immune cells included M0 macrophages (P = 0.023) and activated mast cells (P = 0.005).

Modulation of IL-6/STAT3 signaling axis in CD4+FOXP3- T cells represents a potential antitumor mechanism of azacitidine

CD4+ T cells orchestrate immune responses and are actively engaged in shaping tumor immunity. Signal transducer and activator of transcription (STAT) signaling controls the epigenetic tuning of CD4+ T-cell differentiation and polarization, and perturbed STAT signaling networks in CD4+ T cells subvert antitumor immunity in malignancies. Azacitidine (AZA), the mainstay therapy for high-risk myelodysplastic syndromes (HR-MDS), affects CD4+ T-cell polarization and function, but whether this contributes to AZA efficacy is currently unknown. By using functional proteomic, transcriptomic, and mutational analyses in 73 HR-MDS patients undergoing AZA therapy, we demonstrate that responding patients exhibited a coordinated CD4+ T-cell immune response and downregulated the inflammatory cytokine signaling pathways in CD4+ T cells after AZA, in contrast to nonresponders who upregulated the same pathways. We further observed an AZA-mediated downregulation of intereukin-6 (IL-6)-induced STAT3 phosphorylation in CD4+FOXP3- conventional T cells (Tcons) that correlated independently with better response and survival, whereas it was also not associated with the mutation number and profile of the patients. The AZA-induced downregulation of IL-6/STAT3 axis in Tcons restored the STAT signaling architecture in CD4+ T-cell subsets, whereas STAT signaling networks remained disorganized in patients who upregulated IL-6/STAT3 activity in Tcons. Given the pivotal role of CD4+ T cells in adaptive immunity, our findings suggest that the downregulation of the IL-6/STAT3 pathway in Tcons potentially constitutes a previously unrecognized immune-mediated mechanism of action of AZA and sets the scene for developing rational strategies of AZA combinations with IL-6/STAT3 axis inhibitors.

Role of CD25 expression on prognosis of acute myeloid leukemia: A literature review and meta-analysis

The gene expression for interleukin-2 receptor subunit alpha (CD25/IL2RA) is frequently altered in adults with acute myeloid leukemia (AML). Increasing evidence indicates that the elevated expression of CD25 may be correlated with poor survival for AML patients. Thus, we performed this meta-analysis to further evaluate the prognostic value of elevated CD25 in AML. Eligible studies were gathered by searching on PubMed, Web of Science, and Embase. Using the R language 3.6.0 software, Pooled hazard ratios (HRs) with their corresponding 95% confidence intervals (CIs) of overall survival (OS) and disease-free survival (DFS)/relapse-free survival (RFS)/event-free survival (EFS) for total and subgroup analyses were calculated to investigate the association of elevated CD25 and outcomes of AML patients. Ten studies with a total of 1640 participants were enrolled in this meta-analysis. Pooled HRs suggested that overexpression of CD25 predicted poor outcomes on both OS (HR = 2.27, 95%CI 1.95–2.64) and DFS/RFS/EFS (HR = 1.77, 95%CI 1.44–2.17) in overall population. Subgroup analyses stratified by ethnicity, AML subtype, cut-off value, statistical methodologies and detection method draw similar results. Our meta-analysis indicates that elevated CD25 expression is a poor prognostic factor for AML patients. Considering limited number of samples, further relevant studies are warranted.

A Novel Type of Blood Biomarker: Distinct Changes of Cytokine-Induced STAT Phosphorylation in Blood T Cells Between Colorectal Cancer Patients and Healthy Individuals

Background: Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. Although early diagnosis and treatment is the most successful strategy for improving patient survival, feasible and sensitive blood biomarkers for CRC screening remain elusive. Methods: Sixty-five CRC patients and thirty-three healthy individuals were enrolled. Peripheral blood (PB) and tumor tissues from CRC patients, and PB from healthy individuals were subjected to immunophenotyping and phospho-flow analysis of cytokine-induced phosphorylated STAT (CIPS). Logistic regression was used as a classifier that separates CRC patients from healthy individuals. Results: The proportion of regulatory T cells was increased in PB from CRC patients compared to PB from healthy individuals (p < 0.05). Interestingly, peripheral T cells share several cytokine-induced phosphorylated STAT (CIPS) signatures with T cells from CRC tumor-sites. Additionally, a classifier was made using two signatures distinct between T cells from CRC patients and T cells from healthy individuals. The AUCs (area under curves) of the classifier were 0.88 in initial cohort and 0.94 in the additional validation cohort. Overall AUC was 0.94 with sensitivity of 91% and specificity of 88%. Conclusion: This study highlights that immune cell signatures in peripheral blood could offer a new type of biomarker for CRC screening.

Emergence of NK Cell Hyporesponsiveness after Two IL-15 Stimulation Cycles

IL-15 is a cytokine playing a crucial role in the function of immune cells, including NK and CD8 T cells. In this study, we demonstrated that in vivo, in mice, IL-15-prestimulated NK cells were no longer able to respond to a second cycle of IL-15 stimulation. This was illustrated by defects in cell maturation, proliferation, and activation, seemingly linked to the environment surrounding NK cells but not related to the presence of CD4 regulatory T cells, TGF-β, or IL-10. Moreover, NK cells from immunodeficient mice could respond to two cycles of IL-15 stimulation, whereas an adoptive transfer of CD44⁺CD8⁺ cells impaired their responsiveness to the second cycle. Conversely, in immunocompetent mice, NK cell responsiveness to a second IL-15 stimulation was restored by the depletion of CD8⁺ cells. These biological findings refine our understanding of the complex mode of action of NK cells in vivo, and they should be taken into consideration for IL-15-based therapy.

Different Lipid Regulation in Ovarian Cancer: Inhibition of the Immune System

Lipid metabolism is altered in several cancer settings leading to different ratios of intermediates. Ovarian cancer is the most lethal gynecological malignancy. Cancer cells disperse in the abdominal space and ascites occurs. T cells obtained from ascites are unable to proliferate after an antigenic stimulus. The proliferation of ascites-derived T cells can be restored after culturing the cells for ten days in normal culture medium. No pathway aberrancies were detected. The acellular fraction of ascites can inhibit the proliferation of autologous as well as allogeneic peripheral blood lymphocytes, indicating the presence of soluble factors that interfere with T cell functionality. Therefore, we analyzed 109 lipid mediators and found differentially regulated lipids in suppressive ascitic fluid compared to normal abdominal fluid. Our study indicates the presence of lipid intermediates in ascites of ovarian cancer patients, which coincidences with T cell dysfunctionality. Since the immune system in the abdominal cavity is compromised, this may explain the high seeding efficiency of disseminated tumor cells. Further research is needed to fully understand the correlation between the various lipids and T cell proliferation, which could lead to new treatment options.

Defective STAT1 activation associated with impaired IFN-γ production in NK and T lymphocytes from metastatic melanoma patients treated with IL-2

High dose (HD) IL-2 therapy has been used for almost two decades as an immunotherapy for metastatic melanoma. IL-2 promotes the proliferation and effector function of T and NK cells through the tyrosine phosphorylation and activation of signal transducer and activator of transcription factors (STAT), especially STAT5. However, whether any defects in STAT activation exist in T and NK lymphocytes from melanoma patients are under debate. Here, we measured the extent of HD IL-2-induced phosphorylation of STAT5 and STAT1 in lymphocyte subsets from metastatic melanoma patients and healthy controls at a single cell level using flow cytometry. We found no defects in IL-2-induced STAT5 phosphorylation and induction of proliferation in T and NK cell subsets in vitro. This was confirmed by measuring ex vivo STAT5 activation in whole blood collected from patients during their first bolus HD IL-2 infusion. IL-2 also induced STAT1 phosphorylation via IFN-γ receptors in T and NK cell subsets through the release of IFN-γ by CD56^hi and CD56^lo NK cells. Further analysis revealed that melanoma patients had a sub-optimal STAT1 activation response linked to lower IL-2-induced IFN-γ secretion in both CD56^hi and CD56^low NK cell subsets. STAT1 activation in response to IL-2 also showed an age-related decline in melanoma patients not linked to tumor burden indicating a premature loss of NK cell function. Taken together, these findings indicate that, although STAT5 activation is normal in metastatic melanoma patients in response to IL-2, indirect STAT1 activation is defective owing to deficiencies in the NK cell response to IL-2.

Attenuated IL-2R signaling in CD4 memory T cells of T1D subjects is intrinsic and dependent on activation state

The IL-2/IL-2R pathway is implicated in type 1 diabetes (T1D). While its role in regulatory T cell (Treg) biology is well characterized, mechanisms that influence IL-2 responses in effector T cells (Teff) are less well understood. We compared IL-2 responses in 95 healthy control and 98 T1D subjects. In T1D, low IL-2 responsiveness was most pronounced in memory Teff. Unlike Treg, CD25 expression did not influence the Teff responses. Reduced IL-2 responses in memory Teff were not rescued by resting, remained lower after activation and proliferation, and were absent in type 2 diabetes. Comparing basal IL-2 responses in resting versus activated cells, memory Teff displayed lower, but more sustained, responses to IL-2 overtime. These results suggest that T1D-associated defects in the Teff compartment are due to intrinsic factors related to activation. Evaluation of both Teff and Treg IL-2R signaling defects in T1D subjects may inform selection of therapies.

Differential intratumoral distributions of CD8 and CD163 immune cells as prognostic biomarkers in breast cancer

Background

Tumor immune cell infiltrates are essential in hindering cancer progression and may complement the TNM classification. CD8+ and CD163+ cells have prognostic impact in breast cancer but their spatial heterogeneity has not been extensively explored in this type of cancer. Here, their potential as prognostic biomarkers was evaluated, depending on their combined densities in the tumor center (TC) and the tumor invasive margin (IM).

Methods

CD8+ and CD163+ cells were quantified by immunohistochemistry of formalin-fixed, paraffin-embedded (FFPE) tumor tissue samples from a cohort totaling 162 patients with histologically-confirmed primary invasive non-metastatic ductal breast cancer diagnosed between 2000 and 2015. Clinical follow-up (median 6.9 years) was available for 97 of these patients.

Results

Differential densities of CD8+ and CD163+ cells in the combined TC and IM compartments (i.e., high(H)/low(L), respectively for CD8+ cells and the reverse L/H combination for CD163+ cells) were found to have significant prognostic value for survival, and allowed better patient stratification than TNM stage, tumor size, lymph node invasion and histological grade. The combined evaluation of CD8+ and CD163+ cell densities jointly in TC and IM further improves prediction of clinical outcomes based on disease-free and overall survival. Patients having the favorable immune signatures had favorable clinical outcomes despite poor clinicopathological parameters.

Conclusions

Given the important roles of CD8+ and CD163+ cells in regulating opposing immune circuits, adding an assessment of their differential densities to the prognostic biomarker armamentarium in breast cancer would be valuable. Larger validation studies are necessary to confirm these findings.

Trial registrations

Study code: IRB-ID 6079/448/10-6-13

Date of approval: 10/06/2013

Retrospective study (2000–2010)

First patient prospectively enrolled 14/2/2014

Electronic supplementary material

The online version of this article (doi:10.1186/s40425-017-0240-7) contains supplementary material, which is available to authorized users.

Cytokine responsiveness of CD8(+) T cells is a reproducible biomarker for the clinical efficacy of dendritic cell vaccination in glioblastoma patients

Background

Immunotherapeutic approaches, such as dendritic cell (DC) vaccination, have emerged as promising strategies in the treatment of glioblastoma. Despite their promise, however, the absence of objective biomarkers and/or immunological monitoring techniques to assess the clinical efficacy of immunotherapy still remains a primary limitation. To address this, we sought to identify a functional biomarker for anti-tumor immune responsiveness associated with extended survival in glioblastoma patients undergoing DC vaccination.

Methods

28 patients were enrolled and treated in two different Phase 1 DC vaccination clinical trials at UCLA. To assess the anti-tumor immune response elicited by therapy, we studied the functional responsiveness of pre- and post-vaccination peripheral blood lymphocytes (PBLs) to the immunostimulatory cytokines interferon-gamma (IFN-γ) and interleukin-2 (IL-2) in 21 of these patients for whom we had adequate material. Immune responsiveness was quantified by measuring downstream phosphorylation events of the transcription factors, STAT-1 and STAT-5, via phospho-specific flow cytometry.

Results

DC vaccination induced a significant decrease in the half-maximal concentration (EC-50) of IL-2 required to upregulate pSTAT-5 specifically in CD3⁺CD8⁺ T lymphocytes (p < 0.045). Extended survival was also associated with an increased per cell phosphorylation of STAT-5 in cytotoxic T-cells following IL-2 stimulation when the median post/pre pSTAT-5 ratio was used to dichotomize the patients (p = 0.0015, log-rank survival; hazard ratio = 0.1834, p = 0.018). Patients whose survival was longer than two years had a significantly greater pSTAT-5 ratio (p = 0.015), but, contrary to our expectations, a significantly lower pSTAT-1 ratio (p = 0.038).

Conclusions

Our results suggest that monitoring the pSTAT signaling changes in PBL may provide a functional immune monitoring measure predictive of clinical efficacy in DC-vaccinated patients.

Melanoma NOS1 expression promotes dysfunctional IFN signaling

In multiple forms of cancer, constitutive activation of type I IFN signaling is a critical consequence of immune surveillance against cancer; however, PBMCs isolated from cancer patients exhibit depressed STAT1 phosphorylation in response to IFN-α, suggesting IFN signaling dysfunction. Here, we demonstrated in a coculture system that melanoma cells differentially impairs the IFN-α response in PBMCs and that the inhibitory potential of a particular melanoma cell correlates with NOS1 expression. Comparison of gene transcription and array comparative genomic hybridization (aCGH) between melanoma cells from different patients indicated that suppression of IFN-α signaling correlates with an amplification of the NOS1 locus within segment 12q22-24. Evaluation of NOS1 levels in melanomas and IFN responsiveness of purified PBMCs from patients indicated a negative correlation between NOS1 expression in melanomas and the responsiveness of PBMCs to IFN-α. Furthermore, in an explorative study, NOS1 expression in melanoma metastases was negatively associated with patient response to adoptive T cell therapy. This study provides a link between cancer cell phenotype and IFN signal dysfunction in circulating immune cells.

Early in vivo signaling profiles in MUC1-specific CD4+ T cells responding to two different MUC1-targeting vaccines in two different microenvironments

Vaccines are beginning to be explored for as measures to prevent cancer. Since determining the efficacy of vaccines by evaluating disease outcome requires a long time, there is an urgent need for early predictive biomarkers. To this end, immunological endpoints that can be assessed weeks or months post-vaccination are currently being evaluated. However, when multiple vaccines are available, waiting for the development of humoral and cellular immunity could still cause delays, whereas early assessments would allow for a timely shift to more effective prevention modalities. Applying the phospho-flow technique to primary T cells, we examined the phosphorylation status of various proteins that shape the activation, proliferation, and differentiation of mucin 1 (MUC1)-specific CD4+ T cells within the first 24 hours post-immunization. It is known that a vaccine composed of a MUC1-derived peptide loaded on dendritic cells is more effective in eliciting T-cell responses than a vaccine including the same peptide plus an adjuvant. Both these vaccines stimulate T cells more effectively in wild-type (WT) than in MUC1-transgenic mice. We examined if the signaling events downstream of the TCR or linked to various proliferative and survival pathways, monitored in two different hosts as early as 3, 6, 12 and 24 hours post-immunization, could predict the differential potential of these two MUC1-targeting vaccines. The signaling signatures that we obtained primarily reflect differences between the vaccines rather than between the hosts. We demonstrate the feasibility of using a phospho-flow-based approach to evaluate the potential of a given vaccine to elicit a desired immune response.

NFATc2 is a potential therapeutic target in human melanoma

The identification of intracellular signaling pathways that promote cell proliferation and resistance to cell death may lead to the development of improved treatment for advanced melanoma. Here we show that the calcineurin/nuclear factor of activated T cells c2 (NFATc2) pathway has an antiapoptotic role in melanoma cells. Expression of NFATc2 was constitutive in vitro and in vivo in human melanoma, and cyclosporin A (CsA) treatment of melanoma cells led to downmodulation of NFATc2. Inhibition of the calcineurin/NFAT pathway by CsA, or by NFATc2 silencing, led to modulation of cell cycle inhibitors and apoptosis-related proteins such as Apollon, and promoted caspase-dependent apoptosis of neoplastic cells. Calcineurin/NFATc2 targeting significantly enhanced melanoma cell death induced by antitumor agents, such as MEK- or BRAF(V600E)-specific inhibitors, and tumor necrosis factor-related apoptosis-inducing ligand, which trigger the intrinsic or extrinsic pathway of apoptosis, respectively. These findings identify NFATc2 as a potential therapeutic target in melanoma.

Reflections upon human cancer immune responsiveness to T cell-based therapy

Immune-mediated rejection of human cancer is a relatively rare but well-documented phenomenon. Its rate of occurrence progressively increases from the occasional observation of spontaneous regressions to the high rate of complete remissions observed in response to effective treatments. For two decades, our group has focused its interest in understanding this phenomenon by studying humans following an inductive approach. Sticking to a sequential logic, we dissected the phenomenon by studying to the best of our capability both peripheral and tumor samples and reached the conclusion that immune-mediated cancer rejection is a facet of autoimmunity where the target tissue is the cancer itself. As we are currently defining the strategy to effectively identify the mechanisms leading in individual patients to rejection of their own tumors, we considered useful to summarize the thought process that guided us to our own interpretation of the mechanisms of immune responsiveness.

Role of Apollon in human melanoma resistance to antitumor agents that activate the intrinsic or the extrinsic apoptosis pathways

PURPOSE

To assess the role of Apollon in melanoma resistance to intrinsic and extrinsic pathways of apoptosis and to identify strategies to reduce its expression.

EXPERIMENTAL DESIGN

Apollon expression was assessed in melanoma cells in vitro and in vivo. Apollon modulation and melanoma apoptosis were evaluated by Western blot and/or flow cytometry in response to cytotoxic drugs, mitogen-activated protein/extracellular signal-regulated kinase (MEK)-, BRAF(V600E)-, and mTOR-specific inhibitors, TRAIL and anti-HLA class II monoclonal antibodies (mAb). Mitochondrial depolarization, caspase activation, apoptosis assays, and gene expression profiling were used to test effects of Apollon silencing, by siRNA, on melanoma response to antitumor agents.

RESULTS

Apollon was constitutively expressed by melanoma cells, in vitro and in vivo, and at higher levels than in benign melanocytic lesions. Melanoma apoptosis correlated significantly with Apollon protein downmodulation in response to cytotoxic drugs, MEK, or BRAF(V600E)-specific inhibitors. Combinatorial treatment with MEK and mTOR inhibitors and HLA class II ligation, by a specific mAb, promoted Apollon downmodulation and enhanced melanoma apoptosis. Apollon downmodulation induced by antitumor agents was caspase independent, but proteasome dependent. Knockdown of Apollon, by siRNA, triggered apoptosis and/or significantly enhanced melanoma cell death in response to cytotoxic drugs, MEK- and BRAF(V600E)-specific inhibitors, and soluble or membrane-bound TRAIL. Apollon silencing promoted mitochondrial depolarization and caspase-2, caspase-8, caspase-9, and caspase-3 activation in response to different antitumor agents and altered the profile of genes modulated by MEK or BRAF(V600E)-specific inhibitors.

CONCLUSIONS

Targeting of Apollon may significantly improve melanoma cell death in response to antitumor agents that trigger the intrinsic or the extrinsic apoptosis pathways.

JAK3, STAT3 and CD3-zeta signaling proteins status in regard to the lymphocytes function in patients with ovarian cancer

Several groups of author have published that, in most cases of carcinoma, circulating lymphocytes are unable to carry out immune functions successfully. A molecular mechanism responsible for T lymphocytes defective reactivity in cancer patients is not completely defined. We evaluated whether the impaired function of peripheral blood lymphocytes (PBLs) from ovarian cancer patients could be associated with signaling elements such as JAK3, STAT3 and CD3-zeta chain. The study addressed to the simultaneous expression and phosphorylation status of mentioned molecules evaluation in regard to lymphocyte function in patients with advanced ovarian cancer has not yet been demonstrated by others. We found that PBLs of cancer patients showed lower JAK3, CD3-zeta molecules expression levels, as well as lower STAT3 and CD3-zeta phosphorylation levels than cells of control. The lower proliferative response and IL-2 production capacity of cancer patients PBLs in comparison with that of the control group cells were the functional consequences of reported in this study signaling abnormalities.

An immunologic portrait of cancer

The advent of high-throughput technology challenges the traditional histopathological classification of cancer, and proposes new taxonomies derived from global transcriptional patterns. Although most of these molecular re-classifications did not endure the test of time, they provided bulk of new information that can reframe our understanding of human cancer biology. Here, we focus on an immunologic interpretation of cancer that segregates oncogenic processes independent from their tissue derivation into at least two categories of which one bears the footprints of immune activation. Several observations describe a cancer phenotype where the expression of interferon stimulated genes and immune effector mechanisms reflect patterns commonly observed during the inflammatory response against pathogens, which leads to elimination of infected cells. As these signatures are observed in growing cancers, they are not sufficient to entirely clear the organism of neoplastic cells but they sustain, as in chronic infections, a self-perpetuating inflammatory process. Yet, several studies determined an association between this inflammatory status and a favorable natural history of the disease or a better responsiveness to cancer immune therapy. Moreover, these signatures overlap with those observed during immune-mediated cancer rejection and, more broadly, immune-mediated tissue-specific destruction in other immune pathologies. Thus, a discussion concerning this cancer phenotype is warranted as it remains unknown why it occurs in immune competent hosts. It also remains uncertain whether a genetically determined response of the host to its own cancer, the genetic makeup of the neoplastic process or a combination of both drives the inflammatory process. Here we reflect on commonalities and discrepancies among studies and on the genetic or somatic conditions that may cause this schism in cancer behavior.

Vaccination-induced functional competence of circulating human tumor-specific CD8 T-cells

T-cells specific for foreign (e.g., viral) antigens can give rise to strong protective immune responses, whereas self/tumor antigen-specific T-cells are thought to be less powerful. However, synthetic T-cell vaccines composed of Melan-A/MART-1 peptide, CpG and IFA can induce high frequencies of tumor-specific CD8 T-cells in PBMC of melanoma patients. Here we analyzed the functionality of these T-cells directly ex vivo, by multiparameter flow cytometry. The production of multiple cytokines (IFNγ, TNFα, IL-2) and upregulation of LAMP-1 (CD107a) by tumor (Melan-A/MART-1) specific T-cells was comparable to virus (EBV-BMLF1) specific CD8 T-cells. Furthermore, phosphorylation of STAT1, STAT5 and ERK1/2, and expression of CD3 zeta chain were similar in tumor- and virus-specific T-cells, demonstrating functional signaling pathways. Interestingly, high frequencies of functionally competent T-cells were induced irrespective of patient's age or gender. Finally, CD8 T-cell function correlated with disease-free survival. However, this result is preliminary since the study was a Phase I clinical trial. We conclude that human tumor-specific CD8 T-cells can reach functional competence in vivo, encouraging further development and Phase III trials assessing the clinical efficacy of robust vaccination strategies.

Immune-related biomarkers for diagnosis/prognosis and therapy monitoring of cutaneous melanoma

Skin melanoma, a life-threatening disease, has a recently reported worldwide increase in incidence, despite primary prevention. Skin melanoma statistics emphasize the need for finding markers related to the immune response of the host. The mechanisms that are able to over-power the local immune surveillance comprise molecules that can be valuable markers for diagnosis and prognosis. This article summarizes the immune markers that can monitor the disease stage and evaluate the efficacy of therapeutic interventions. Recent data regarding immunotherapy are presented in the context of tumor escape from immune surveillance and the immune molecules that are both targets and a means of monitoring. Perspectives for developing immune interventions for skin melanoma management and the position of tissue or soluble immune markers as a diagnostic/prognostic panel are evaluated. State-of-the-art technology is emphasized for developing immune molecular signatures for a complex characterization of the patient's immunological status.

Tumor-reactive CD8+ early effector T cells identified at tumor site in primary and metastatic melanoma

CD8(+) T cells at the earliest stage of effector generation have not been identified at tumor site of melanoma patients. Such early effectors, if present, should be characterized by a specific phenotype, distinct from that expressed at later stages of the antigen-induced differentiation program, by short-lived effector cells, memory precursors, and terminal effectors. Here, we show that neoplastic tissues from primary and metastatic lesions of melanoma patients contain a subset of CD8(+) T cells expressing FOXP3. CD8(+) FOXP3(+) CD25(+) T lymphocytes were found in tumor-invaded lymph nodes (TILN), s.c. metastases, and advanced primary lesions. Their frequency was significantly higher in TILN compared with tumor-free lymph nodes or with peripheral blood and in primary tumors compared with TILN. CD8(+) FOXP3(+) T cells did not express markers of regulatory [CTLA-4, CCL4, interleukin-10 (IL-10), transforming growth factor-β1], exhausted (PD-1), or senescent (CD57) CD8(+) T lymphocytes. Instead, this subset showed an antigen-experienced "EM1" phenotype (CCR7(-) CD45RA(-) CD28(+) CD27(+)) and exhibited a CD127(-), KLRG1(-), HLA-DR(+), CD38(+), T-bet(+), perforin(+) "early effector" profile predicted by current models. CD8(+) FOXP3(+) T cells produced IFN-γ on short in vitro activation, recognized autologous tumor by CD107a mobilization, and expressed Ki-67 on ex vivo analysis. In response to autologous tumor plus IL-2/IL-15, the CD8(+) FOXP3(+) T cells proliferated promptly and showed competence for differentiation (downregulation of CD27 and upregulation of T-bet). These results suggest development of early phases of antitumor immunity even in advanced melanoma. Moreover, the CD8(+) FOXP3(+) "early effector" subset may be an invaluable tool for monitoring immunity at tumor site.

Development and application of 'phosphoflow' as a tool for immunomonitoring

Flow cytometry has revolutionized our ability to monitor immune responses by allowing us to simultaneously track a variety of cell surface and intracellular markers in discrete cell subsets in a highly sensitive and reproducible manner. This is especially critical in this new era of vaccinology trying to tackle the growing problems of chronic viral infections and cancer that not only evade host immune responses, but can negatively manipulate vaccine-induced immune responses. Thus, understanding how lymphocyte signaling is altered under normal and pathological conditions has become more critical. Over the last decade, a new flow cytometry technology called 'phosphoflow' (also sometimes called 'phosflow'), is rapidly developing for tracking multiple intracellular signaling molecules in the immune system at a single-cell level. Antibodies and reagents for tracking both tyrosine-phosphorylated and serine/threonine-phosphorylated signaling intermediaries in key immune signaling pathways have been developed, and phosphoflow is now starting to be applied to a wide variety of both preclinical and clinical studies on lymphocyte responses, as well as the functioning of cancer cells and virally infected cells. Here, we review the development of phosphoflow technology, its modern applications in the field of immunomonitoring and its current limitations. We then provide a perspective on the future of phosphoflow and a vision of how it can be applied to emerging critical questions in human vaccinology and public health.