Christine Menetrier-Caux

Regulatory T Cells Recruited through CCL22/CCR4 Are Selectively Activated in Lymphoid Infiltrates Surrounding Primary Breast Tumors and Lead to an Adverse Clinical Outcome

Immunohistochemical analysis of FOXP3 in primary breast tumors showed that a high number of tumor-infiltrating regulatory T cells (Ti-Treg) within lymphoid infiltrates surrounding the tumor was predictive of relapse and death, in contrast to those present within the tumor bed. Ex vivo analysis showed that these tumor-infiltrating FOXP3(+) T cells are typical Treg based on their CD4(+)CD25(high)CD127(low)FOXP3(+) phenotype, their anergic state on in vitro stimulation, and their suppressive functions. These Ti-Treg could be selectively recruited through CCR4 as illustrated by (a) selective blood Treg CCR4 expression and migration to CCR4 ligands, (b) CCR4 down-regulation on Ti-Treg, and (c) correlation between Ti-Treg in lymphoid infiltrates and intratumoral CCL22 expression. Importantly, in contrast to other T cells, Ti-Treg are selectively activated locally and proliferate in situ, showing T-cell receptor engagement and suggesting specific recognition of tumor-associated antigens (TAA). Immunohistochemical stainings for ICOS, Ki67, and DC-LAMP show that Ti-Treg were close to mature DC-LAMP(+) dendritic cells (DC) in lymphoid infiltrates but not in tumor bed and were activated and proliferating. Furthermore, proximity between Ti-Treg, CD3(+), and CD8(+) T cells was documented within lymphoid infiltrates. Altogether, these results show that Treg are selectively recruited within lymphoid infiltrates and activated by mature DC likely through TAA presentation, resulting in the prevention of effector T-cell activation, immune escape, and ultimately tumor progression. This study sheds new light on Treg physiology and validates CCR4/CCL22 and ICOS as therapeutic targets in breast tumors, which represent a major health problem.

Role of interleukin-6 in the paraneoplastic inflammatory syndrome associated with renal-cell carcinoma

We investigated the possible causative role of interleukin 6 (IL‐6) in the paraneoplastic inflammatory syndrome and in paraneoplastic cholestasis (Stauffer syndrome) associated with renal‐cell carcinoma in a series of 119 patients with metastases. IL‐6 levels were found significantly higher in patients with paraneoplastic fever and weight loss. Patients with detectable serum IL‐6 (n = 90, 76%) had significantly higher serum CRP, haptoglobin, and serum alkaline‐phosphatase and gammaglutamyl‐transferase levels. Platelets, polymorphonuclear neutrophil (PMN) and monocyte counts were also significantly higher in patients with detectable serum IL‐6; in contrast, hemoglobin levels were significantly lower in patients with serum IL‐6 over 80 pg/ml. Three of these patients were included in a phase‐II trial of an anti‐IL‐6 monoclonal antibody given daily during 21 days. Reductions of CRP, haptoglobin and serum alkalin phosphatases were observed in all 3 patients during anti‐IL‐6 administration, with a subsequent increase up to or above pre‐treatment levels after the end of anti‐IL‐6. Decrease of platelets, PMN and monocyte counts were also observed in the 3 patients during anti‐IL‐6 administration, with a normalization of cell counts in a patient with increased platelets, PMN and monocyte counts. Hemoglobin concentration, serum albumin concentration and lymphocyte counts remained stable in the 3 patients during and after anti‐IL‐6 administration. Serum IL‐6, as evaluated by IRMA, decreased in the 3 patients during anti‐IL‐6 administration, but increased above pre‐treatment levels after the end of anti‐IL‐6 administration. These results demonstrate that IL‐6 is involved in the physiopathology of paraneoplastic syndromes observed in patients with metastatic renal‐cell carcinoma, in particular CRP and haptoglobin increase, paraneoplastic cholestasis, also paraneoplastic thrombocytosis, neutrophilia and monocytosis. Int. J. Cancer 72:424–430, 1997.

Interleukin-6, Interleukin-10, and Vascular Endothelial Growth Factor in Metastatic Renal Cell Carcinoma: Prognostic Value of Interleukin-6—From the Groupe Français d'Immunothérapie

PURPOSE Few clinical prognostic factors have been identified for patients with metastatic renal cell carcinoma (MRCC), and no biomarker is known in this disease. Several endogenous cytokines have demonstrated interesting and significant correlations with survival in these patients. Our objective was to analyze the prognostic value of circulating vascular endothelial growth factor (VEGF), interleukin-10 (IL-10), and interleukin-6 (IL-6). PATIENTS AND METHODS Serum levels of IL-6, IL-10, and VEGF were measured in patients with MRCC. Their prognostic value for response to treatment and progression-free and overall survival was evaluated. Pretreatment samples were obtained from 138 patients of a large randomized multicentric trial. Endogenous cytokine levels were determined using immunoassays. Univariate and multivariate analyses were performed to evaluate the prognostic value of each factor further controlled by an internal validation test. Threshold values for serum IL-6 and VEGF were determined using the quartile method. RESULTS Serum IL-6 was detectable in 70% of the patients. IL-10 and VEGF were elevated in 8% and 71% of the patients, respectively. None of these circulating factors was correlated with response to treatment. IL-10 was not significantly correlated with progression-free or overall survival. Despite significant correlation with survival, VEGF was not an independent prognostic factor in the multivariate analysis. Finally, IL-6 was significantly correlated with progression-free survival and overall survival, and has prognostic value for overall survival. CONCLUSION Circulating IL-6 level appears to be an important independent prognostic factor in patients with MRCC; if confirmed in further studies, it could be considered for treatment decisions in these patients.

Early detection of tumor cells by innate immune cells leads to T(reg) recruitment through CCL22 production by tumor cells.

In breast carcinomas, patient survival seems to be negatively affected by the recruitment of regulatory T cells (T(reg)) within lymphoid aggregates by CCL22. However, the mechanisms underpinning this process, which may be of broader significance in solid tumors, have yet to be described. In this study, we determined how CCL22 production is controlled in tumor cells. In human breast carcinoma cell lines, CCL22 was secreted at low basal levels that were strongly increased in response to inflammatory signals [TNF-α, IFN-γ, and interleukin (IL)-1β], contrasting with CCL17. Primary breast tumors and CD45(+) infiltrating immune cells appeared to cooperate in driving CCL22 secretion, as shown clearly in cocultures of breast tumor cell lines and peripheral blood mononuclear cells (PBMC) or their supernatants. We determined that monocyte-derived IL-1β and TNF-α are key players as monocyte depletion or neutralization of these cytokines attenuated secretion of CCL22. However, when purified monocytes were used, exogenous human IFN-γ was also required to generate this response suggesting a role for IFN-γ-producing cells within PBMCs. In this setting, we found that human IFN-γ could be replaced by the addition of (i) IL-2 or K562-activated natural killer (NK) cells or (ii) resting NK cells in the presence of anti-MHC class I antibody. Taken together, our results show a dialogue between NK and tumor cells leading to IFN-γ secretion, which in turn associates with monocyte-derived IL-1β and TNF-α to drive production of CCL22 by tumor cells and subsequent recruitment of T(reg). As one validation of this conclusion in primary breast tumors, we showed that NK cells and macrophages tend to colocalize within tumors. In summary, our findings suggest that at early times during tumorigenesis, the detection of tumor cells by innate effectors (monocytes and NK cells) imposes a selection for CCL22 secretion that recruits T(reg) to evade this early antitumor immune response.

Cell proliferation and survival induced by Toll-like receptors is antagonized by type I IFNs

TRIF is an adaptor protein associated with the signaling by Toll-like receptor (TLR)3 and TLR4 for the induction of type I IFNs. Here, we demonstrate a mechanism by which TLR signaling controls cell proliferation and survival. We show that TLR3 and TLR4 can induce cell cycle entry via TRIF, which targets the cell cycle inhibitor p27kip1 for relocalization, phosphorylation by cyclin/cdk complexes, and proteasome degradation. These events are antagonized by type I IFN induced by the TRIF pathway. Furthermore, in human dendritic cells treated with TLR3, TLR4, or TLR5 ligands, we demonstrate that IFN signaling modulates p27kip1 degradation and apoptosis, identifying an immunoregulatory “switching” function of type I IFNs. These findings reveal a previously uncharacterized function of TLR signaling in cell proliferation and survival.

Targeting regulatory T cells

Cancers express tumor-associated antigens that should elicit immune response to antagonize the tumor growth, but spontaneous immune rejection of established cancer is rare, suggesting an immunosuppressive environment hindering host antitumor immunity. Among the specific and active tumor-mediated mechanisms, CD4+CD25high T regulatory cells (Treg) are important mediators of active immune evasion in cancer. In this review, we will discuss Treg subpopulations and the mechanisms of their suppressive functions. Treg depletion improves endogenous antitumor immunity and the efficacy of active immunotherapy in animal models for cancer, suggesting that inhibiting Treg function could also improve the limited successes of human cancer immunotherapy. We will also discuss specific strategies for devising effective cancer immunotherapy targeting Treg.

Lymphopenia combined with low TCR diversity (divpenia) predicts poor overall survival in metastatic breast cancer patients.

Lymphopenia (< 1Giga/L) detected before initiation of chemotherapy is a predictive factor for death in metastatic solid tumors. Combinatorial T cell repertoire (TCR) diversity was investigated and tested either alone or in combination with lymphopenia as a prognostic factor at diagnosis for overall survival (OS) in metastatic breast cancer (MBC) patients. The combinatorial TCR diversity was measured by semi quantitative multi-N-plex PCR on blood samples before the initiation of the first line chemotherapy in a development (n = 66) and validation (n = 67) MBC patient cohorts. A prognostic score, combining lymphocyte count and TCR diversity was evaluated. Univariate and multivariate analyses of prognostic factors for OS were performed in both cohorts. Lymphopenia and severe restriction of TCR diversity called “divpenia” (diversity ≤ 33%) were independently associated with shorter OS. Lympho-divpenia combining lymphopenia and severe divpenia accurately identified patients with poor OS in both cohorts (7.6 and 10.6 vs 24.5 and 22.9 mo). In multivariate analysis including other prognostic clinical factors, lympho-divpenia was found to be an independent prognostic factor in the pooled cohort (p = 0.005) along with lack of HER2 and hormonal receptors expression (p = 0.011) and anemia (p = 0.009). Lympho-divpenia is a novel prognostic factor that will be used to improve quality of MBC patients’ medical care.

Cytokines pattern after surgical radiofrequency ablation of liver colorectal metastases.

AIMS The aim of this study was to evaluate the serum pattern of cytokines evolution after surgical radiofrequency ablation (SRFA) of colorectal metastases. METHODS Metastases of ten non consecutive patients were destroyed by radiofrequency ablation without concomitant resection after a complete surgical procedure including a laparotomy, a peritoneal examination, liver mobilisation and liver ultrasound. Serum levels of IL-6, TNFalpha, HGF, VEGF, bFGF, TGFbeta1 and CRP were assessed by ELISA assays at different time points. RESULTS TNFalpha and bFGF remained undetectable. IL-6 peaked at 3 hours and remained elevated during the entire study period. HGF increased by three-fold by Day 1 then decreased until Day 7 where it was still twice its baseline level. VEGF level increased from Day 5 onward. TGFbeta1 did not show significant variations. CRP was increased throughout the study. CONCLUSIONS In contrast with cryotherapy, SRFA does not lead to high serum TNFalpha suggesting a better tolerance. Nevertheless high IL-6, HGF and VEGF serum levels are characteristic of a general inflammatory stress which should be taken into account.

Serum cytokines in follicular lymphoma. Correlation of TGF-β and VEGF with survival

The prognosis of follicular lymphoma could vary with the tumor immune microenvironment. We evaluated the prognostic value of serum levels of ten cytokines. Our study cohort included 60 follicular lymphoma patients and 20 controls. Serum was available at diagnosis in 31 patients, at first relapse in 18, and complete remission in 11. Bioplex technology was used for determination of nine cytokines [interleukin (IL)-1Ra, IL-6, IL-7, IL-10, IL-13, tumor necrosis factor alpha (TNF-α), vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and basic fibroblast growth factor (b-FGF)]. Transforming growth factor beta (TGF-β) was measured by sandwich enzyme-linked immunosorbent assay. IL-1Ra, IL-6, IL-7, IL-10, IL-13, TNF-α, VEGF, and PDGF levels were found increased in follicular lymphoma patients compared to controls. Multivariate analysis identified early stage and high TGF-β levels as independent predictors of overall survival associated with improved outcome. High lactate dehydrogenase and VEGF levels were independently associated with poorer progression-free survival. These results show the prognostic value of TGF-β and VEGF in follicular lymphoma and suggest their contribution to tumor microenvironment alterations.

Disequilibrium of BMP2 Levels in the Breast Stem Cell Niche Launches Epithelial Transformation by Overamplifying BMPR1B Cell Response

Summary Understanding the mechanisms of cancer initiation will help to prevent and manage the disease. At present, the role of the breast microenvironment in transformation remains unknown. As BMP2 and BMP4 are important regulators of stem cells and their niches in many tissues, we investigated their function in early phases of breast cancer. BMP2 production by tumor microenvironment appeared to be specifically upregulated in luminal tumors. Chronic exposure of immature human mammary epithelial cells to high BMP2 levels initiated transformation toward a luminal tumor-like phenotype, mediated by the receptor BMPR1B. Under physiological conditions, BMP2 controlled the maintenance and differentiation of early luminal progenitors, while BMP4 acted on stem cells/myoepithelial progenitors. Our data also suggest that microenvironment-induced overexpression of BMP2 may result from carcinogenic exposure. We reveal a role for BMP2 and the breast microenvironment in the initiation of stem cell transformation, thus providing insight into the etiology of luminal breast cancer.