1,218 research outputs found

    STAT1 contributes to HLA class I upregulation and CTL reactivity after anti-EGFR mAb cetuximab therapy in head and neck cancer patients

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    Squamous cell carcinoma of head and neck (HNSCC) cells express low HLA class I and antigen processing machinery (APM) components, such as transporter TAP-1/2, which is associated with the reduced sensitivity to cytotoxic T lymphocyte (CTL) mediated lysis. Epidermal growth factor receptor (EGFR) is overexpressed in HNSCC and is associated with the poor prognosis. FDA approved anti-EGFR blockade mAb cetuximab inhibits HNSCC proliferation, and induces EGFR-specific CTL. However, the molecular mechanism(s) underlying the EGFR-specific CTL recognition of HNSCC in the therapeutic efficacy of anti-EGFR mAb is still emerging. We show that cetuximab or EGFR knockdown enhanced expression of HLA class I antigens, which is associated with the EGFR expression level on HNSCC. These findings were validated in a prospective trial of neoadjuvant cetuximab therapy. Interestingly, upregulation of HLA-B/C alleles were more pronounced than HLA-A alleles after cetuximab or EGFR knockdown treatment. EGFR signaling blockade or EGFR depletion also enhanced IFN gamma receptor (IFNAR) on HNSCC and augmented induction of HLA class I and TAP-1/2 caused by IFN gamma treatment. Cetuximab or EGFR knockdown enhanced the level of HLA class I, STAT-1, TAP-1/2 in a STAT-1+/+ cell line but not in STAT-1-/- cell line, documenting the STAT-1 dependence of this effect. We also found that Src homology domain-containing phosphatase 2 (SHP-2), which is downstream of EGFR and also overexpressed in SCCHN, can suppress the immunostimulatory effect of cetuximab treatment on HLA class I/STAT-1 upregulation, and dual targeting of EGFR and SHP-2 co-operates in the most efficient reversal of immune escape phenotype. In addition, cetuximab-based EGFR inhibition and SHP-2 depletion enhanced the recognition of HNSCC cells by EGFR 853-861 specific CTL, and enhanced surface presentation of non-EGFR TA, such as MAGE-3 271-279 , indicating that a broad tumor antigen repertoire is processed and presented by HLA/APM upregulation. These findings elucidate a novel immune escape mechanism associated with EGFR signaling through STAT1 suppression and the reversal with cetuximab, which may provide additional targets for on-going mAb-based immunotherapy

    The role of nailfold videocapillaroscopy in Raynaud's phenomenon monitoring and early diagnosis of systemic sclerosis

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    Several connective tissue diseases, in particular systemic sclerosis (SSc), have Raynaud's phenomenon (RP) as their first clinical manifestation. Primary RP represents a benign condition often observed in otherwise healthy subjects, especially women: it is due to an exaggerated response to the physiological cold-induced vasospasm, whereas the secondary form of RP is typically associated with connective tissue diseases, especially SSc. Nailfold videocapillaroscopy (NVC), particulary after the recent technological advances, is a safe and reliable method to observe the microvascular structure and its early changes, especially during the transition from primary to secondary RP. In case of SSc, by considering validated patterns and scoring systems, NVC is the main tool that rheumatologists can rely on, besides the presence of specific auto-antibodies, to perform a very early diagnosis of the disease. This implies the possibility of early treatment of SSc, with an eye of predicting and preventing its major clinical complications

    Canine Melanoma Immunology and Immunotherapy: Relevance of Translational Research

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    In veterinary oncology, canine melanoma is still a fatal disease for which innovative and long-lasting curative treatments are urgently required. Considering the similarities between canine and human melanoma and the clinical revolution that immunotherapy has instigated in the treatment of human melanoma patients, special attention must be paid to advancements in tumor immunology research in the veterinary field. Herein, we aim to discuss the most relevant knowledge on the immune landscape of canine melanoma and the most promising immunotherapeutic approaches under investigation. Particular attention will be dedicated to anti-cancer vaccination, and, especially, to the encouraging clinical results that we have obtained with DNA vaccines directed against chondroitin sulfate proteoglycan 4 (CSPG4), which is an appealing tumor-associated antigen with a key oncogenic role in both canine and human melanoma. In parallel with advances in therapeutic options, progress in the identification of easily accessible biomarkers to improve the diagnosis and the prognosis of melanoma should be sought, with circulating small extracellular vesicles emerging as strategically relevant players. Translational advances in melanoma management, whether achieved in the human or veterinary fields, may drive improvements with mutual clinical benefits for both human and canine patients; this is where the strength of comparative oncology lies
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