High-dose (HD) IL-2 therapy in patients with

Purpose: Cytotoxic lymphocytes interact with human tumor cells via the activating immunoreceptor NKG2D, recognizing a variety of stress-associated MIC and ULBP surface molecules. However, tumors can escape from this immunosurveillance by shedding NKG2D ligands (NKG2DL), rendering the soluble products detectable in patients' sera. Experimental Design: To elucidate the clinical significance of NKG2DL diversity, we studied their expression on melanoma tissues and their presence as soluble molecules in sera from >200 melanoma patients and compared the latter with the well-established serum marker S100B. Results: Immunohistochemistry revealed a heterogeneous expression of MIC and ULBP2 molecules between and within melanoma metastases. Compared with MIC, ULBP2 was less frequently expressed. Accordingly, elevated levels of soluble ULBP2 (sULBP2) were detected in sera of melanoma patients less frequently than elevated levels of soluble MICA (sMICA), although both soluble NKG2DL (sNKG2DL) were significantly increased compared with sera of healthy controls (P < 0.0001). Strikingly, elevated concentrations of sULBP2, but not of sMICA, were strongly associated with disease progression (P < 0.0001) and tumor load (P = 0.0003). Elevated serum levels of either sNKG2DL correlated with reduced overall survival, albeit considerably stronger for sULBP2 (P < 0.0001) than for sMICA (P = 0.011). In early-stage (I-III) melanoma patients, only sULBP2 (P < 0.0001) but neither sMICA nor S100B revealed prognostic significance. Multivariate analysis identified sULBP2 (P = 0.0015) and S100B (P = 0.013) but not sMICA as independent predictors of prognosis. Conclusion: Our data reveal marked differences in the clinical significance of individual sNKG2DL. Only sULBP2 is an independent predictor of prognosis, the significance of which is superior to the well-established and widely used melanoma serum marker S100B. (Clin Cancer Res 2009;15(16):5208-15) Genetic and epigenetic alterations are hallmarks of cancer.These modifications, on the one hand, are a prerequisite for cancer development and progression but, on the other hand, expose tumor cells as altered self to the immune system. Genetic alterations can initiate an intrinsic DNA damage response that in turn induces the expression of surface ligands binding to the activating immunoreceptor NKG2D (1). NKG2D is expressed on innate, innate-like, and adaptive immune effectors such as natural killer (NK) cells, γδ cells, and αβ T cells, respectively. Whereas NKG2D engagement directly activates NK cells, in T cells it delivers costimulatory signals modulating T-cell receptor-mediated activation (2-4). Studies in different

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Treatment options are limited in well differentiated (WD) and dedifferentiated (DD) retroperitoneal liposarcoma. We sought to study the intratumoral adaptive immune response and explore the potential feasibility of immunotherapy in this disease. Tumor-infiltrating lymphocytes (TILs) were isolated from fresh surgical specimens and analyzed by flow cytometry for surface marker expression. Previously reported immune cell aggregates known as tertiary lymphoid structures (TLS) were further characterized by immunohistochemistry. In all fresh tumors, TILs were found. The majority of TILs were CD4 T cells; however cytotoxic CD8 T cells were also seen (average: 20% of CD3 T cells). Among CD8 T cells, 65% expressed the immune checkpoint molecule PD-1. Intratumoral TLS may be sites of antigen presentation as DC-LAMP positive, mature dendritic cells were found juxtaposed next to CD4 T cells. Clinicopathologic correlation, however, demonstrated that presence of TLS was associated with worse recurrence-free survival in WD disease and worse overall survival in DD disease. Our data suggest that an adaptive immune response is present in WD/DD retroperitoneal liposarcoma but may be hindered by TLS, among other possible microenvironmental factors; further investigation is needed. Immunotherapy, including immune checkpoint blockade, should be evaluated as a treatment option in this disease.

Clinical responses to high-dose IL2 therapy are limited due to selective expansion of CD4CD25Foxp3 T-regulatory cells (Treg), especially ICOS Tregs, rather than natural killer (NK) cells and effector T cells. These ICOS Tregs are highly suppressive and constitutively express high levels of IL2Rα (CD25) and CD39. Here, we characterized the effect of a mutant form of IL2 (F42K), which preferentially binds to the lower affinity IL2Rβγ with reduced binding to CD25, on Tregs, effector NK cells, and T-cell subsets. Unlike wild-type (WT) IL2, F42K did not efficiently induce the expansion of highly suppressive ICOS Tregs in peripheral blood mononuclear cells (PBMC) from healthy controls and melanoma patients. Instead, it promoted the expansion of CD16CD56 NK cells and CD56CD16 NK cell subsets in both short- and long-term cultures, with enhanced Bcl-2 expression. Stimulation of PBMCs with F42K induced expression of more NK cell activation molecules, such as NKp30, NKp44, DNAM-1, NKG2D, 4-1BB/CD137, and Tim-3, than WT IL2. F42K induced greater upregulation of TRAIL, and NK-mediated cytolytic activity was increased against both autologous and HLA-mismatched melanoma cells compared with WT IL2. Gene expression analysis revealed distinct gene expression profiles stimulated by F42K, WT IL2, and IL15. F42K therapy in vivo also induced a dramatic reduction in the expansion of ICOS Tregs, promoted NK cell expansion, and inhibited melanoma tumor growth more efficiently than WT IL2 and more effectively than anti-CTLA-4. Our findings suggest that F42K could be a potential substitute for WT IL2 as a cytokine therapy for cancer. Cancer Immunol Res; 4(11); 983-94. ©2016 AACR.

Cancer immunotherapy has become an important area for the future development of cancer therapy; this includes T-cell-based therapies that involve adoptive transfer of autologous T cells derived from the tumors or peripheral blood of cancer patients, vaccines, oncolytic virus therapy, and immunomodulatory antibodies and ligands. Here, we summarize the current approaches and clinical data in the field of adoptive T-cell transfer therapy using tumor-infiltrating lymphocytes (TILs) for metastatic melanoma. We also discuss current knowledge on the mechanism of transferred TILs in mediating tumor regression and the growing need for and recent advances in the identification of predictive biomarkers to better select patients for TIL therapy. The current technical limitations of current TIL expansion methods for out-scaling are discussed as well as how these are being addressed in order to further "industrialize" this form of cell therapy. Lastly, how TIL adoptive transfer can be incorporated into the current melanoma treatment continuum, especially as combination therapy with other immunomodulators and targeted drugs, is discussed.

SUMMARYLiposarcomas are soft tissue sarcomas of adipocyte origin. We describe a case of a dedifferentiated retroperitoneal liposarcoma with an unusual presentation on recurrence as a large, multicystic tumour. The patient was a 72-year-old woman who had undergone multiple treatments including two prior resections. For her most recent locoregional disease recurrence, the patient was offered surgical debulking for symptom palliation. At this operation, performed after two cycles of chemotherapy, the tumour cyst fluid was analysed and found to have a predominance of immune cells with no identifiable malignant cells. This case and the results of our tumour cyst fluid analysis raise several interesting considerations for the management of this unique situation in a rare disease. BACKGROUND

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 CD56hi and CD56lo 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 CD56hi and CD56low 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.