Long‐term prognostic significance of interleukin‐17‐producing T cells in patients with non‐small cell lung cancer

The presence of interleukin (IL)‐17‐producing T cells has recently been reported in non‐small cell lung cancer (NSCLC) patients. However, the long‐term prognostic significance of these populations in NSCLC patients remains unknown. In the present study, we collected peripheral blood from 82 NSCLC patients and 22 normal healthy donors (NC). Percentages of IL‐17‐producing CD4⁺T (Th17), CD8⁺T (Tc17) and γδT cells (γδT17) were measured to determine their association with clinical outcomes and overall survival (OS) in NSCLC. All NSCLC patients were followed up until July 2018. Median follow‐up time was 13.5 months (range 1‐87 months). The 3‐ and 5‐year survival rate was 27% and 19.6%, respectively. We found that Th17 cells and γδT17 cells were significantly increased, whereas Tc17 cells were markedly decreased in patients with NSCLC compared with those in NC. In addition, Th17 cells were significantly positively associated with T helper type 1 cells (Th1), whereas γδT17 cells were significantly negatively associated with γδT ⁺ interferon (IFN)‐γ⁺ cells. High percentages of peripheral Tc17 cells were significantly associated with favorable 5‐year OS (P = .025), especially in patients with early TNM stage (P = .016). Furthermore, high percentages of peripheral Th17 cells were positively associated with favorable 5‐year OS in patients with late TNM stage (P = .002). However, no significant association was observed between γδT17 cells and OS, regardless of the TNM stage. In conclusion, our findings suggest that enhanced Th17 and reduced Tc17 cells in the peripheral blood could be a significant predictor of a favorable prognosis for NSCLC patients.     

Absolute monocyte count predicts overall survival in mantle cell lymphomas: correlation with tumour‐associated macrophages

Mantle cell lymphoma (MCL) is characterized by a variable clinical course in which patients can experience indolent disease or frequent relapses despite a good initial response to conventional therapy. Risk stratification of MCL is most frequently performed using the MCL International Prognostic Index (MIPI). Recent studies indicate that the peripheral blood absolute monocyte count (AMC) and tumour‐associated macrophages may reflect the state of the tumour microenvironment in lymphomas. The significance of AMC and tumour‐associated macrophages in the clinical course of MCL is unknown. The prognostic impact of the AMC, of CD68 expression and of CD163 expression was retrospectively examined in 103 MCL samples using the receiver operating characteristic curved. Patients with an AMC ≥ 375 cells/μL at diagnosis were more likely to present with advanced‐stage disease (p = 0.026), leukocytosis (p < 0.001), lymphocytosis (p = 0.01) and granulocytosis (p = 0.003). On univariate analysis, a high AMC (≥375 cells/μL) correlated with poorer overall survival (OS) (p = 0.01). Neither CD68 nor CD163 expression was significantly associated with either OS or event‐free survival. Multivariate analysis showed that a high AMC was a prognostic factor for OS, independent of the MIPI [hazards ratio (HR), 1.811; 95% confidence interval, 1.018–3.223; p = 0.043]. This study demonstrates that the AMC at the time of diagnosis is an independent prognostic factor for OS in MCL, which suggests the possibility that AMC may be used in addition to the MIPI to predict outcome in patients with MCL. Copyright © 2013 John Wiley & Sons, Ltd.     

Alterations of T‐cell surface markers in older women with persistent human papillomavirus infection

We previously reported decreased lymphocyte proliferative responses among older women with persistent human papillomavirus (HPV) infection. To characterize the phenotype of peripheral lymphocytes associated with persistent HPV infection, we evaluated the expression of different cell surface markers in peripheral blood mononuclear cells (PBMCs) from a case–control study within a 10,049 woman population‐based cohort study in Guanacaste, Costa Rica. Women in the cohort aged 46–74 and with HPV results at their 5th year anniversary visit were considered, and all women (n = 87) with persistent HPV infections, all women (n = 196) with transient HPV infections and a random sample of HPV DNA‐negative women (n = 261) frequency‐matched to cases on age were selected for this study. A median of 3 years after the case–control matching visit, cervical cells were collected for liquid‐based cytology and repeat HPV DNA genotyping. Blood was obtained from which PBMCs were extracted and cryopreserved for immunological phenotyping via flow cytometry. Significant increases in risk of HPV persistence were observed for 3 marker subsets indicative of immune cell activation/differentiation. Relative risk estimates were 5.4 (95% CI = 2.2–13.3) for CD69⁺CD4⁺, 2.6 (95% CI = 1.2–5.9) for HLADR⁺CD3⁺CD4⁺ and 2.3 (95% CI = 1.1–4.7) for CD45RO⁺CD27^?CD8⁺. A significant decrease in HPV persistence was observed for a subset marker indicative of an immature, undifferentiated memory state CD45RO⁺CD27⁺CD4⁺ (OR = 0.36; 95% CI = 0.17–0.76). Adjustment for these markers only partially explained the previously reported association between decreased lymphoproliferative responses and persistent HPV infection. Whether phenotypic alterations observed predispose to HPV persistence or result from it should be the focus of future studies.     

Reappraisal of nodal Epstein‐Barr Virus‐negative cytotoxic T‐cell lymphoma: Identification of indolent CD5+ diseases

Nodal cytotoxic molecule (CM)‐positive peripheral T‐cell lymphoma (CTL) has recently been recognized as a clinicopathologically distinct disease. To further characterize this disease, here we compared 58 patients with Epstein‐Barr virus (EBV)‐negative CTL to 48 patients with EBV‐positive CTL. The two groups did not differ in histopathology, T‐cell receptor (TCR) expression or rearrangement incidences, or survival curves. However, patients with EBV‐negative CTL less frequently showed hepatic involvement (P = .007), B symptoms (P = .020), hemophagocytosis (P = .024), and detectable CD4 (P = .002) and CD5 (P = .009). Univariate and multivariate analyses identified three factors that independently predicted favorable survival, onset age <60 years (P = .002), CD5 expression (P = .002), and mixed morphology (P = .013), TCRαβ was not an independent predictor (P = .30), but was strongly linked with long survivorship among patients younger than 60 years old. A prognostic model incorporating these factors worked well for prognostic delineation, independently of the International Prognostic Index (P = .007 vs P = .082) and Prognostic Index for PTCL (P = .020 vs P = .15). Moreover, this constellation of findings indicated two nodal indolent diseases: CD5⁺TCRαβ (n = 13), and CD5⁺ NK‐cell type lacking TCR expression or clonal TCRγ rearrangement (n = 4). The survival curves for these two groups were significantly superior to others (n = 29, P < .001). These diseases appear to be unique in their indolent clinical behavior, and should be managed differently from other diseases.     

Dynamic changes in immune cell profile in head and neck squamous cell carcinoma: Immunomodulatory effects of chemotherapy

Tumor cells have evolved sophisticated means of escape from the host immune system. To date, several important immunological phenomena have been revealed in peripheral blood as well as within tumors. In the present study, we first investigated the proportion and activation status of peripheral immune regulatory cells and CD8⁺ T‐cell subsets in patients with head and neck squamous cell carcinoma (HNSCC) using a multicolor flow cytometer, and then evaluated how therapy with docetaxel, cisplatin, and 5‐fluorouracil modulated the immune cell profile in peripheral blood. The proportion of naïve T cells was lower and that of effector memory T cells (T_EM) was higher in HNSCC patients than in healthy donors. Moreover, the proportions of activated T_EM cells and effector T cells (T_EFF) were dramatically increased in patients with advanced stage disease. The proportion of regulatory T cells and CD14⁺HLA‐DR^? myeloid‐derived suppressor cells was elevated in HNSCC patients. Of note, after therapy, in addition to the transient reduction in immune regulatory cells, decreases in central memory T cells and increases in T_EFF cells were observed among CD8⁺ T‐cell subsets, suggesting differentiation from central memory T cells into T_EFF cells. Our results suggested that, despite the immunosuppressive status in HNSCC patients, tumor‐specific immune responses mediated by CD8⁺ T cells might be induced and maintained. Moreover, chemotherapy can trigger not only a transient reduction in immune regulatory cells but also further activation of CD8⁺ T cells.     

'Normal counterparts' of nodal peripheral T-cell lymphoma

Peripheral T‐cell lymphomas (PTCL) have been difficult to classify. A homogeneous principle of classification is still lacking, partly because lymph node compartments containing functionally distinct T‐cell subsets have not been identified. A correlation to differentiated T‐cell subsets, as CD4⁺ or CD8⁺ cells as well as cytotoxic populations has not revealed clinically meaningful entities. Upon antigen encounter, mature T‐cells pass through distinct stages characterized by their surface molecule expression. Naïve T‐cells are CD45RA⁺/CD45R0^?/CD27⁺/CCR7⁺, however, after antigen contact CD45RA expression is replaced by CD45R0. They differentiate to central memory cells, which retain CD27 and CCR7, or to effector‐memory cells, which loose expression of both molecules depending on the strength of the antigen interaction. Immunohistological analysis of PTCL showed an effector or effector‐memory cell phenotype (CD45RA^?/CD45R0⁺/CD27^?) for both angioimmunoblastic T‐cell lymphoma (AILT) and anaplastic large cell lymphoma (ALCL), but different cytotoxic and activation markers expressed by these tumours. A subset of CD4⁺ PTCL‐not otherwise specified (PTCL‐NOS) may correspond to a central memory cell phenotype (CD45RA^?/CD45R0⁺/CD27⁺). Thus, a correlation of PTCL to stages of differentiation, rather than to the direction of differentiation, may reveal homogeneous categories. A comparison between the lymphomas and their normal counterparts maycontribute to the understanding of the underlying transformation mechanisms. Copyright © 2006 John Wiley & Sons, Ltd.     

The relationships between serum cytokine levels and tumor infiltrating immune cells and their clinical significance in colorectal cancer

Increased inflammatory cell infiltration correlates to improved survival in colorectal cancer (CRC). Development and progression of CRC is associated with alterations in serum cytokine levels but their significance is not well defined. In this study, we investigated the relationships between the serum levels of 13 cytokines and the densities of eight types of tumor infiltrating inflammatory cells and their impact on disease‐free survival (DFS), cancer‐specific survival (CSS) and overall survival (OS) in a prospectively recruited group of 147 CRC patients. There were strong positive correlations between the serum concentrations of different cytokines, as well as between the different types of tumor infiltrating immune cells, whereas the associations between serum cytokines and tumor infiltrating immune cells were generally weak. High serum IL‐12 levels associated with increased densities of peritumoral CD8⁺ T cells, intraepithelial CD3⁺ T cells and intratumoral neutrophils, while high serum CCL4 levels associated with increased densities of peritumoral CD68⁺ cells. In multivariate survival models, increased infiltration of intraepithelial CD3⁺ T cells and increased serum CCL4 associated with improved DFS, whereas higher intratumoral CD83⁺ dendritic cell density and increased serum interferon gamma levels associated with improved CSS and OS. Also high density of peritumoral CD3⁺ T cells associated with improved CSS. In conclusion, serum cytokines and tumor infiltrating immune cells in CRC represent entities with high intragroup correlations but relatively weak intergroup correlations. The results suggest that tumor infiltrating CD3⁺ T cells, CD83⁺ dendritic cells, serum CCL4 and serum interferon gamma represent relevant markers of disease outcome.     

Prognostic value of tumor-infiltrating lymphocytes differs depending on histological type and smoking habit in completely resected non-small-cell lung cancer

BackgroundT-cell infiltration in tumors has been used as a prognostic tool in non-small-cell lung cancer (NSCLC). However, the influence of smoking habit and histological type on tumor-infiltrating lymphocytes (TILs) in NSCLC remains unclear.Patients and methodsWe evaluated the prognostic significance of TILs (CD4⁺, CD8⁺, CD20⁺, and FOXP3⁺) according to histological type and smoking habit using automatic immunohistochemical staining and cell counting in 218 patients with NSCLC.ResultsIn multivariate survival analyses of clinical, pathological, and immunological factors, a high ratio of FOXP3⁺ to CD4⁺ T cells (FOXP3/CD4) [hazard ratio (HR): 4.46, P < 0.01 for overall survival (OS); HR: 1.96, P < 0.05 for recurrence-free survival (RFS)] and a low accumulation of CD20⁺ B cells (HR: 2.45, P = 0.09 for OS; HR: 2.86, P < 0.01 for RFS) were identified as worse prognostic factors in patients with adenocarcinoma (AD). In non-AD, a low number of CD8⁺ T cells were correlated with an unfavorable outcome (HR: 7.69, P < 0.01 for OS; HR: 3.57, P < 0.02 for RFS). Regarding smoking habit in AD, a high FOXP3/CD4 ratio was poorly prognostic with a smoking history (HR: 5.21, P < 0.01 for OS; HR: 2.38, P < 0.03 for RFS), whereas a low accumulation of CD20⁺ B cells (HR: 4.54, P = 0.03 for OS; HR: 2.94, P < 0.01 for RFS) was confirmed as an unfavorable factor in non-smokers with AD.ConclusionsA low number of CD8⁺ T cells in non-AD, a high FOXP3/CD4 ratio in smokers with AD, and a low number of CD20⁺ B cells in non-smokers with AD were identified as independent unfavorable prognostic factors in resected NSCLC. Evaluating the influence of histological type and smoking habit on the immunological environment may lead to the establishment of immunological diagnosis and appropriate individualized immunotherapy for NSCLC.     

Identification of NY‐BR‐1‐specific CD4+ T cell epitopes using HLA‐transgenic mice

Breast cancer represents the second most common cancer type worldwide and has remained the leading cause of cancer‐related deaths among women. The differentiation antigen NY‐BR‐1 appears overexpressed in invasive mammary carcinomas compared to healthy breast tissue, thus representing a promising target antigen for T cell based tumor immunotherapy approaches. Since efficient immune attack of tumors depends on the activity of tumor antigen‐specific CD4⁺ effector T cells, NY‐BR‐1 was screened for the presence of HLA‐restricted CD4⁺ T cell epitopes that could be included in immunological treatment approaches. Upon NY‐BR‐1‐specific DNA immunization of HLA‐transgenic mice and functional ex vivo analysis, a panel of NY‐BR‐1‐derived library peptides was determined that specifically stimulated IFNγ secretion among splenocytes of immunized mice. Following in silico analyses, four candidate epitopes were determined which were successfully used for peptide immunization to establish NY‐BR‐1‐specific, HLA‐DRB1*0301– or HLA‐DRB1*0401‐restricted CD4⁺ T cell lines from splenocytes of peptide immunized HLA‐transgenic mice. Notably, all four CD4⁺ T cell lines recognized human HLA‐DR‐matched dendritic cells (DC) pulsed with lysates of NY‐BR‐1 expressing human tumor cells, demonstrating natural processing of these epitopes also within the human system. Finally, CD4⁺ T cells specific for all four CD4⁺ T cell epitopes were detectable among PBMC of breast cancer patients, showing that CD4⁺ T cell responses against the new epitopes are not deleted nor inactivated by self‐tolerance mechanisms. Our results present the first NY‐BR‐1‐specific HLA‐DRB1*0301– and HLA‐DRB1*0401‐restricted T cell epitopes that could be exploited for therapeutic intervention against breast cancer.     

Peripheral blood sCD3− CD4+ T cells: a useful diagnostic tool in angioimmunoblastic T cell lymphoma

Angioimmunoblastic T cell lymphoma (AITL) belongs to the subgroup of mature T cell lymphomas according to the World Health Organization and is one of the common T cell lymphomas in Western countries. Particularly in cases in which histological confirmation cannot be easily achieved, immunophenotyping of peripheral blood can give important information for the differential diagnosis of AITL. sCD3^? CD4⁺ T cells are a typical feature of AILT in flow cytometry of peripheral blood. In this retrospective study, the diagnostic value of flow cytometry for the diagnosis ‘AITL’ was assessed by comparing the frequency of sCD3^? CD4⁺ T cells in leukemic AITL patients and in patients with other leukemic CD4⁺ T cell lymphomas. Immunophenotyping of peripheral blood by flow cytometry was performed in a lymphocyte gate using fluorochrome‐labelled antibodies against CD3, CD2, CD4, CD5, CD7, CD8, CD10, CD14, CD16, CD19, CD56, CD57 and T cell receptor. In 17/17 leukemic AITL patients, a small but distinct population of sCD3^? CD4⁺ T cells was detected (mean percentage of sCD3^? CD4⁺ T cells in the lymphocyte gate: 11.9 ± 15.4%, range 0.1–51.8%). In contrast, sCD3^? CD4⁺ T cells were found in only 1/40 patients with other leukemic CD4⁺ T cell lymphomas (one patient with mycosis fungoides). sCD3^? CD4⁺ T cells have a high positive predictive value (94%) for the diagnosis ‘AITL’. Flow cytometry is particularly useful in the differential diagnosis of AITL, even if the aberrant T cell population has a very low frequency. Further biological characterization of this subfraction of lymphoma cells is warranted. Copyright © 2013 John Wiley & Sons, Ltd.     

Predictive clinical outcome of the intratumoral CD66b-positive neutrophil-to-CD8-positive T-cell ratio in patients with resectable nonsmall cell lung cancer

BACKGROUND:

The role of the interaction between tumor cells and inflammatory cells in nonsmall cell lung carcinoma (NSCLC) is unclear. In this study, the authors assessed the prognostic impact of intratumoral cluster of differentiation 66b (carcinoembryonic antigen‐related cell adhesion molecule 8 [CD66b])‐positive neutrophils and of the intratumoral CD66b‐positive neutrophil‐to‐cluster of differentiation 8 (cell surface antigen T8 [CD8])‐positive lymphocytes (the CD66b‐positive neutrophil‐to‐CD8‐positive lymphocyte ratio [iNTR]) in patients with resectable NSCLC.

METHODS:

Expression levels of CD66b and CD8 were evaluated by immunohistochemistry on tissue microarrays consisting of 632 NSCLC specimens from patients who underwent curative surgery. The relation between clinicopathologic variables and patient outcome was assessed.

RESULTS:

Intratumoral CD66b‐positive neutrophils were elevated in 318 patients (50%). In univariate analysis, an increase in CD66b‐positive cells was associated with a high cumulative incidence of relapse (CIR) (median CIR, 51 months for low CD66b‐positive cell density; 36 months for high CD66b‐positive cell density; P = .002) and trended toward worse overall survival (OS) (median OS, 57 months for low CD66b‐positive cell density; 54 months for high CD66b‐positive cell density; P = .088). The iNTR was elevated in 190 patients (30%). An increased iNTR was strongly associated with both a high CIR (median CIR: 43 months for an iNTR ≤1; 34 months for an iNTR >1; P < .0001) and poor OS (median OS: 60 months for an iNTR ≤1; 46 months for an iNTR >1; P < .0001). In multivariate analysis, independent prognostic factors for a higher CIR were high iNTR (hazard ratio [HR], 0.71; 95% confidence interval [CI], 0.56‐0.90; P = .005) and tumor stage >I, (HR, 0.39; 95% CI, 0.30‐0.52; P < .0001). Independent prognostic factors for worse OS were a high iNTR (HR, 0.70; 95% CI, 0.54‐0.91; P = .007) and tumor stage >I (HR, 0.35; 95% CI, 0.26‐0.47; P < .0001).

CONCLUSIONS:

The current results indicated that the iNTR is a novel, independent prognostic factor for a high rate of disease recurrence and poor OS in patients with resectable NSCLC. Cancer 2011;. © 2011 American Cancer Society.     

Targeting high‐grade B cell lymphoma with CD19‐specific T cells

Adoptive T cell therapy is an important additional treatment option for malignant diseases resistant to chemotherapy. Using a murine high‐grade B cell lymphoma model, we have addressed the question whether the B cell differentiation antigen CD19 can act as rejection antigen. CD19^?/? mice inoculated with CD19⁺ B cell lymphoma cells showed higher survival rates than WT mice and were protected against additional tumor challenge. T cell depletion prior to tumor transfer completely abolished the protective response. By heterotypic vaccination of CD19^?/? mice against murine CD19, survival after tumor challenge was significantly increased. To define protective epitopes within the CD19 molecule, T cells collected from mice that had survived the tumor transfer were analyzed for IFNγ secretion in response to CD19‐derived peptides. The majority of mice exhibited a CD4⁺ T cell response to CD19 peptide 27, which was the most dominant epitope after CD19 vaccination. A peptide 27‐specific CD4⁺ T cell line protected CD19^?/? mice against challenge with CD19⁺ lymphoma and also cured a significant proportion of WT mice from recurrent disease in a model of minimal residual disease after chemotherapy. In conclusion, our data highlight CD19‐specific CD4⁺ T cells for adoptive T cell therapy of B cell lymphomas.     

Immunophenotypic profile and clinical characteristics in patients with advanced stage mantle cell lymphoma

The objective of this study was to evaluate immunophenotypic profile along with clinical follow-up in patients with advanced stage mantle cell lymphoma (MCL), and their possible influence on overall survival (OS). Bone marrow (BM) cell and/or peripheral blood mononuclear cell flow cytometric analyses of the following antigens were performed: HLA–DR, CD19, CD20, CD22, CD23, CD25, CD10, SmIg, kappa, lambda, CD79b, CD38, FMC7, CD3, CD2, and CD5. There were 14 patients in IV CS, and 26 patients in CS V. All patients were treated with CHOP. Immunological markers showed a typical phenotype (CD5+ CD23-, Cyclin D1) in all cases. Pathohystological type of BM infiltration was predominantly diffuse (72.5%), and in remainder of patients, nodular. Comparison of patients with leukemic phase of MCL with CSIV (BM), has shown significantly higher expression of CD19, CD20, and CD23, followed by permanently negative expression of CD23. Patients with blastic variant of MCL had higher expression of CD23, compared to typical MCL (P < 0.001). Median OS was 20 months, and there were no significant OS-differences between CS IV and leukemic phase patients. Survival analyses showed that negative prognostic influence had high IPI (P < 0.01), presence of extranodal localization (P < 0.01), and diffuse type of BM involvement (P < 0.01). Using Cox regression according to OS, IPI had independent prognostic value (P < 0.001). Our results demonstrated that in the advanced MCL patients the most powerful prognostic factor was IPI, while extranodal localization and type of BM infiltration were of a limited value.     

Synergistic effects of CTLA‐4 blockade with tremelimumab and elimination of regulatory T lymphocytes in vitro and in vivo

Anti‐CTLA‐4 monoclonal antibodies (mAb) that block the interaction of CTLA‐4 with CD80 and CD86 such as tremelimumab and ipilimumab are currently being tested in the clinic for cancer treatment exploiting their properties to de‐repress tumor‐specific cellular immunity. Addition of the fully human anti‐CTLA‐4 (tremelimumab) to cultures of human T cells with allogenic dendritic cells (DCs) did not increase proliferation. Magnetic bead‐mediated elimination of CD4⁺ CD25⁺ regulatory T cells (T_reg) before setting up those alloreactive cultures also largely failed to increase primary proliferation. In contrast, predepletion of CD4⁺ CD25⁺ T_reg and culture in the presence of tremelimumab synergistically resulted in increased proliferation and DC:T‐cell aggregation. These effects were much more prominent in CD4 than in CD8 T cells. The synergy mechanism can be traced to enhanced CTLA‐4 expression in effector cells as a result of T_reg elimination, thereby offering more targets to the blocking antibody. Human T cells and allogenic DCs (derived both from healthy donors and advanced cancer patients) were coinjected in the peritoneum of Rag2^?/? IL‐2Rγ^?/? mice. In these conditions, tremelimumab injected intravenously did not significantly enhance alloreactive proliferation unless T_reg cells had been predepleted. Synergistic effects in vivo were again largely restricted to the CD4 T‐cell compartment. In addition, T_reg depletion and CTLA‐4 blockade synergistically enhanced specific cytotoxicity raised in culture against autologous EBV‐transformed cell lines. Taken together, these experiments indicate that tremelimumab therapy may benefit from previous or concomitant T_reg depletion.     

Intratumoral T cell subset ratios and Fas ligand expression on brain tumor endothelium

Summary Introduction: T cell presence in TIL, and the ratio of CD8⁺ and CD4⁺ T cell subsets in particular, can correlate with tumor prognosis in some tumors, although the significance of such infiltration into glioma is controversial. However, gliomas represent a lower extreme in their extent of T cell infiltration, and are thus useful in assessing factors that can decrease T cell presence within tumor tissue. Fas ligand, a pro-apoptotic cell surface protein, may play a key role in reduction of T cells in tumor tissue. Objective: To assess the level of FasL expression on brain tumor endothelium and to correlate this with relative levels of CD4⁺ and CD8⁺ T cell subsets in TIL from brain tumors. Methods: CD3⁺, CD4⁺, and CD8⁺ cells were quantified in fresh TIL by flow cytometry. Paraffin embedded sections of tumors, including meningiomas and gliomas as well as extracranial malignancies, underwent immunohistochemical staining for FasL and Von-Willebrand’s factor (Factor VIII) to determine expression levels of endothelial FasL. Results: FasL expression was high in aggressive intracranial malignancies compared to more indolent neoplasms, and correlated inversely with CD8⁺/CD4⁺ TIL ratios in all tumor classes combined (ANOVA,p<0.05). Conclusion: Low levels of T cells within TIL, as well as low CD8⁺/CD4⁺ TIL ratios appear to be a property of parenchymal tumor presence. Together with the inverse correlation seen between FasL expression and CD8⁺/CD4⁺ TIL ratios, the high levels of endothelial FasL expression in gliomas suggests that FasL decreases T cell presence in brain tumors in a subset-selective manner, thus contributing to glioma immune privilege.     

NY‐CO‐58/KIF2C is overexpressed in a variety of solid tumors and induces frequent T cell responses in patients with colorectal cancer

NY‐CO‐58/KIF2C has been identified as a tumor antigen by screening antibody responses in patients with colorectal cancer. However, expression had not consequently been examined, and nothing was known about its ability to induce spontaneous T cell responses, which have been suggested to play a role in the development of colorectal cancer. We analyzed 5 colorectal cancer cell lines, and tumor samples and adjacent healthy tissues from 176 patients with epithelial cancers for the expression of NY‐CO‐58/KIF2C by RT‐PCR and Western Blot. T cell responses of 43 colorectal cancer patients and 35 healthy donors were evaluated by ELISpot following stimulation with 30mer peptides or full‐length protein. All cell lines and tumor samples from colorectal cancer patients expressed NY‐CO‐58/KIF2C on the protein and RNA level, and expression levels correlated strongly with Ki‐67 expression (r = 0.69; p = 0.0003). Investigating NY‐CO‐58/KIF2C‐specific T cell responses, CD8⁺ T cells directed against 1 or more peptides were found in less than 10% of patients, whereas specific CD4⁺ T cells were detected in close to 50% of patients. These T cells were of high avidity, recognized the naturally processed antigen and secreted IFN‐γ and TNF‐α. Depletion of CD4⁺CD25⁺ T cells before stimulation significantly increased the intensity of the preexisting response. NY‐CO‐58/KIF2C is significantly overexpressed in colorectal and other epithelial cancers and expression levels correlate with the proliferative activity of the tumor. Importantly, NY‐CO‐58/KIF2C was able to induce spontaneous CD4⁺ T cell responses of the Th1‐type, which were tightly controlled by peripheral T regulatory cells.     

Overexpression of hypoxia‐inducible factor 1 alpha impacts FoxP3 levels in mycosis fungoides—Cutaneous T‐cell lymphoma: Clinical implications

Mycosis fungoides (MF) is the most common variant of primary cutaneous T‐cell lymphoma, and decreased forkhead box P3 (FoxP3) expression has been reported in MF late stages. Hypoxia‐inducible factor 1 alpha (HIF‐1α) may regulate FoxP3 expression; however, it is unknown whether HIF‐1α is expressed in the CD4⁺ T cells of MF patients and how it could affect the expression of FoxP3. Therefore, we evaluated the expression of HIF‐1α and FoxP3 in CD4⁺ T cells obtained from the skin lesions of MF patients. We found increased cell proliferation and an increase in CD4⁺ T cells with an aberrant phenotype among early stage MF patients. HIF‐1α was overexpressed in these CD4⁺ T cells. In addition, we found a decrease in the percentage of FoxP3⁺ cells both in the skin of MF patients, when compared with control skin samples, and with disease progression. In addition, a negative correlation was established between HIF‐1α and FoxP3 expression. Skin HIF‐1α expression in MF patients correlated with the extent of the affected area and increased with the disease progression. Finally, we showed that ex vivo inhibition of HIF‐1α degradation increases the percentage of FoxP3⁺ T cells in skin lesions. Our results suggest that overexpression of HIF‐1α affects the levels of FoxP3 in MF patients, which could have relevant implications in terms of disease outcome.     

Silent NK/T cell reactions to dasatinib during sustained deep molecular response before cessation are associated with longer treatment‐free remission

This study presents the final report of the multicenter, prospective tyrosine kinase inhibitor discontinuation study, D‐STOP, after a 3‐year follow‐up of 54 patients with chronic CML who discontinued dasatinib after a sustained deep molecular response (DMR) for ≥2 years with dasatinib treatment. Estimated treatment‐free remission (TFR) rates at 12 and 36 months were 63.0% [95% confidence interval (CI): 48.7‐74.3] and 59.3% (95% CI: 45.0‐71.0), respectively. CD3^?CD56⁺ NK, CD16⁺CD56⁺ NK, and CD57⁺CD56⁺ NK large granular lymphocyte (NK‐LGL), CD8⁺CD4^– cytotoxic T cell, and CD57⁺CD3⁺ T‐LGL cell numbers were relatively elevated throughout the 24‐month consolidation only in failed patients who molecularly relapsed within 12 months. In successful patients, these subsets elevated transiently after 12 months, but returned to basal levels after 24‐month consolidation. Therefore, smaller changes in NK/T, particularly the NK subset throughout consolidation, reflected higher TFR rates. TFR rates of those patients exhibiting elevation in CD3^?CD56⁺ NK >376 cells/μL, CD16⁺CD56⁺ NK > 241 cells/μL, or CD57⁺CD56⁺ NK‐LGL >242 cells/μL during consolidation compared with others were 26.7% (8.3%‐49.6%) vs 78.3% (55.4%‐90.3%), HR 0.032 (0.0027‐0.38; P = .0064), 31.2% (11.4%‐53.6%) vs 85.0% (60.4%‐94.9%), HR 0.039 (0.0031‐0.48; P = .011), or 36.8% (16.5%‐57.5%) vs 77.3% (53.7%‐89.8%), HR 0.21 (0.065‐0.69; P = .010), respectively. Therefore, silent responses of T/NK subsets to dasatinib throughout consolidation were significant for longer TFR. Elevated NK/T, particularly NK lymphocytes responsive to dasatinib, may be immunologically insufficient to maintain TFR. Their decline, subsequently replaced by altered lymphocyte population with less response to dasatinib during sustained DMR, might be immunologically significant. (D‐STOP, NCT01627132).     

Specific blockade CD73 alters the “exhausted” phenotype of T cells in head and neck squamous cell carcinoma

The adenosine‐induced immunosuppression hampers the immune response toward tumor cells and facilitates the tumor cells to evade immunosurveillance. CD73, an ecto‐5‐nucleotidase, is the ectoenzyme dephosphorylating extracellular AMP to adenosine. Here, using immunocompetent transgenic head and neck squamous cell carcinoma (HNSCC) mouse model, immune profiling showed high expression of CD73 on CD4⁺ and CD8⁺ T cells was associated with an “exhausted” phenotype. Further, treatment with anti‐CD73 monoclonal antibody (mAb) significantly blunted the tumor growth in the mouse model, and the blockade of CD73 reversed the “exhausted” phenotype of CD4⁺ and CD8⁺ T cells through downregulation of total expression of PD‐1 and CTLA‐4 on T cells. Whereas the population of CD4⁺CD73^hi/CD8⁺CD73^hi T cells expressed higher CTLA‐4 and PD‐1 as compared to untreated controls. In addition, the human tissue microarrays showed the expression of CD73 is upregulated on tumor infiltrating immune cells in patients with primary HNSCC. Moreover, CD73 expression is an independent prognostic factor for poor outcome in our cohort of HNSCC patients. Altogether, these findings highlight the immunoregulatory role of CD73 in the development of HNSCC and we propose that CD73 may prove to be a promising immunotherapeutic target for the treatment of HNSCC.     

Sorafenib reduces the percentage of tumour infiltrating regulatory T cells in renal cell carcinoma patients

Tyrosine kinase inhibitors (TKIs) as sorafenib are known to reduce the number of immunosuppressive regulatory T cells (Tregs) in the peripheral blood and thereby shifting the immune balance to a more stimulating setting. The effect of sorafenib on intratumoural Tregs is unclear but important for future combinations of TKIs and immunotherapy. We, therefore, evaluated the accumulation of regulatory T cells (Tregs, defined as, CD4⁺FoxP3⁺CD25^highCD127^low‐cells) in blood, ascites, metastases and primary tumours of patients with renal cell carcinoma (RCC), and we explored the effect of neoadjuvant treatment with sorafenib 400 mg bid on intratumoural Tregs in 11 patients with RCC in comparison to 15 nontreated RCC patients. We found that immunosuppressive Tregs specifically accumulate in primary tumour, metastases and ascites of RCC‐patients. Tumour infiltrating Tregs were functional. Neoadjuvant sorafenib treatment significantly reduced the percentage of tumour‐infiltrating Tregs (mean 17.3% vs. 28.1%, p = 0.046). Diminished Treg accumulation at the tumour site adds to explain the clinical effectiveness of sorafenib treatment. This observation may have important implications for the use of sorafenib in combination with immunotherapy in patients with RCC, since the depletion of Tregs has been associated with enhanced responses on vaccine mediated immunotherapy.