RESUMEN
Sarcomas are rare and heterogeneous malignancies that are difficult to treat. Approximately 50% of patients diagnosed with sarcoma develop metastatic disease with so far very limited treatment options. The transmembrane protein B7-H3 reportedly is expressed in various malignancies, including different sarcoma subtypes. In several cancer entities B7-H3 expression is associated with poor prognosis. In turn, B7-H3 is considered a promising target for immunotherapeutic approaches. We here report on the preclinical characterization of a B7-H3xCD3 bispecific antibody in an IgG-based format, termed CC-3, for treatment of different sarcoma subtypes. We found B7-H3 to be expressed on all sarcoma cells tested and expression on sarcoma patients correlated with decreased progression-free and overall survival. CC-3 was found to elicit robust T cell responses against multiple sarcoma subtypes, resulting in significant activation, release of cytokines and effector molecules. In addition, CC-3 promoted T cell proliferation and differentiation, resulting in the generation of memory T cell subsets. Finally, CC-3 induced potent target cell lysis in a target cell restricted manner. Based on these results, a clinical trial evaluating CC-3 in soft tissue sarcoma is currently in preparation.
Asunto(s)
Anticuerpos Biespecíficos , Antígenos B7 , Sarcoma , Humanos , Anticuerpos Biespecíficos/farmacología , Anticuerpos Biespecíficos/uso terapéutico , Sarcoma/inmunología , Sarcoma/tratamiento farmacológico , Antígenos B7/inmunología , Antígenos B7/metabolismo , Linfocitos T/inmunología , Linfocitos T/metabolismo , Línea Celular Tumoral , Neoplasias Óseas/inmunología , Neoplasias Óseas/patología , Femenino , Masculino , Animales , Activación de Linfocitos/inmunología , Persona de Mediana Edad , Complejo CD3/inmunología , Anciano , Proliferación Celular , AdultoRESUMEN
Ligands of the natural killer group 2D (NKG2DL) family are expressed on malignant cells and are usually absent from healthy tissues. Recognition of NKG2DLs such as MICA/B and ULBP1-3 by the activating immunoreceptor NKG2D, expressed by NK and cytotoxic T cells, stimulates anti-tumor immunity in breast cancer. Upregulation of membrane-bound NKG2DLs in breast cancer has been demonstrated by immunohistochemistry. Tumor cells release NKG2DLs via proteolytic cleavage as soluble (s)NKG2DLs, which allows for effective immune escape and is associated with poor prognosis. In this study, we collected serum from 140 breast cancer (BC) and 20 ductal carcinoma in situ (DCIS) patients at the time of initial diagnosis and 20 healthy volunteers (HVs). Serum levels of sNKG2DLs were quantified through the use of ELISA and correlated with clinical data. The analyzed sNKG2DLs were low to absent in HVs and significantly higher in BC patients. For some of the ligands analyzed, higher sNKG2DLs serum levels were associated with the classification of malignant tumor (TNM) stage and grading. Low sMICA serum levels were associated with significantly longer progression-free (PFS) and overall survival (OS). In conclusion, we provide the first insights into sNKG2DLs in BC patients and suggest their potential role in tumor immune escape in breast cancer. Furthermore, our observations suggest that serum sMICA levels may serve as a prognostic parameter in the patients analyzed in this study.
Asunto(s)
Neoplasias de la Mama , Carcinoma Intraductal no Infiltrante , Humanos , Femenino , Investigadores , Ensayo de Inmunoadsorción Enzimática , Estado de SaludRESUMEN
Although checkpoint inhibitors (CPI) have recently extended the treatment options and improved clinical response of advanced stage head and neck squamous cell carcinoma (HNSCC), treatment success remains unpredictable. Programmed cell death ligand1 (PDL1) is a key player in immunotherapy. Tumor cells, and exosomes derived therefrom, are carriers of PDL1 and efficiently suppress immune responses. The aim of the present study was to analyze the influence of established therapies on PDL1 expression of HNSCC cell lines and their exosomes. The HNSCC cell lines, UMSCC11B, UMSCC14C and UMSCC22C were treated with fractionated radiotherapy (RT; 5x2 Gy), cisplatin (CT) and cetuximab (Cetux) as monotherapy, or combined therapy, chemoradiotherapy (CRT; RT and CT) or radioimmunotherapy (RT and Cetux). The expression of PDL1 and phosphorylated (p)ERK1/2 as a mediator of radioresistance were assessed using western blotting, immunohistochemistry and an ex vivo vital tissue culture model. Additionally, exosomes were isolated from concentrated supernatants of the (un)treated HNSCC cell lines by size exclusion chromatography. Exosomal protein expression levels of PDL1 were detected using western blotting and semiquantitative levels were calculated. The functional impact of exosomes from the (un)treated HNSCC cell lines on the proliferation (MTS assay) and apoptosis (Caspase 3/7 assay) of the untreated HNSCC cell lines were measured and compared. The HNSCC cell lines UMSCC11B and UMSCC22B showed strong expression of pERK1/2 and PDL1, respectively. RT upregulated the PDL1 expression in UMSCC11B and UMSCC14C and in exosomes from all three cell lines. CT alone induced PDL1 expression in all cell lines. CRT induced the expression of PDL1 in all HNSCC cell lines and exosomes from UMSCC14C and UMSCC22B. The data indicated a potential coregulation of PDL1 and activated ERK1/2, most evident in UMSCC14C. Exosomes from irradiated UMSCC14C cells protected the unirradiated cells from apoptosis by Caspase 3/7 downregulation. The present study suggested a tumor cellmediated regulation of PDL1 upon platinumbased CRT in HNSCC and in exosomes. A coregulation of PDL1 and MAPK signaling response was hypothesized.