27 research outputs found

    Chemokine-mediated distribution of dendritic cell subsets in renal cell carcinoma

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    <p>Abstract</p> <p>Background</p> <p>Renal cell carcinoma (RCC) represents one of the most immunoresponsive cancers. Antigen-specific vaccination with dendritic cells (DCs) in patients with metastatic RCC has been shown to induce cytotoxic T-cell responses associated with objective clinical responses. Thus, clinical trials utilizing DCs for immunotherapy of advanced RCCs appear to be promising; however, detailed analyses concerning the distribution and function of DC subsets in RCCs are lacking.</p> <p>Methods</p> <p>We characterized the distribution of the different immature and mature myeloid DC subsets in RCC tumour tissue and the corresponding normal kidney tissues. In further analyses, the expression of various chemokines and chemokine receptors controlling the migration of DC subsets was investigated.</p> <p>Results</p> <p>The highest numbers of immature CD1a+ DCs were found within RCC tumour tissue. In contrast, the accumulation of mature CD83+/DC-LAMP+ DCs were restricted to the invasive margin of the RCCs. The mature DCs formed clusters with proliferating T-cells. Furthermore, a close association was observed between MIP-3α-producing tumour cells and immature CCR6+ DC recruitment to the tumour bed. Conversely, MIP-3ÎČ and SLC expression was only detected at the tumour border, where CCR7-expressing T-cells and mature DCs formed clusters.</p> <p>Conclusion</p> <p>Increased numbers of immature DCs were observed within the tumour tissue of RCCs, whereas mature DCs were found in increased numbers at the tumour margin. Our results strongly implicate that the distribution of DC subsets is controlled by local lymphoid chemokine expression. Thus, increased expression of MIP-3α favours recruitment of immature DCs to the tumour bed, whereas <it>de novo </it>local expression of SLC and MIP-3ÎČ induces accumulation of mature DCs at the tumour margin forming clusters with proliferating T-cells reflecting a local anti-tumour immune response.</p

    Dendritic Cell Based Tumor Vaccination in Prostate and Renal Cell Cancer: A Systematic Review and Meta-Analysis

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    BACKGROUND: More than 200 clinical trials have been performed using dendritic cells (DC) as cellular adjuvants in cancer. Yet the key question whether there is a link between immune and clinical response remains unanswered. Prostate and renal cell cancer (RCC) have been extensively studied for DC-based immunotherapeutic interventions and were therefore chosen to address the above question by means of a systematic review and meta-analysis. METHODOLOGY/PRINCIPAL FINDINGS: Data was obtained after a systematic literature search from clinical trials that enrolled at least 6 patients. Individual patient data meta-analysis was performed by means of conditional logistic regression grouped by study. Twenty nine trials involving a total of 906 patients were identified in prostate cancer (17) and RCC (12). Objective response rates were 7.7% in prostate cancer and 12.7% in RCC. The combined percentages of objective responses and stable diseases (SD) amounted to a clinical benefit rate (CBR) of 54% in prostate cancer and 48% in RCC. Meta-analysis of individual patient data (n = 403) revealed the cellular immune response to have a significant influence on CBR, both in prostate cancer (OR 10.6, 95% CI 2.5-44.1) and in RCC (OR 8.4, 95% CI 1.3-53.0). Furthermore, DC dose was found to have a significant influence on CBR in both entities. Finally, for the larger cohort of prostate cancer patients, an influence of DC maturity and DC subtype (density enriched versus monocyte derived DC) as well as access to draining lymph nodes on clinical outcome could be demonstrated. CONCLUSIONS/SIGNIFICANCE: As a 'proof of principle' a statistically significant effect of DC-mediated cellular immune response and of DC dose on CBR could be demonstrated. Further findings concerning vaccine composition, quality control, and the effect of DC maturation status are relevant for the immunological development of DC-based vaccines

    Successful Combination of Sunitinib and Girentuximab in Two Renal Cell Carcinoma Animal Models: A Rationale for Combination Treatment of Patients with Advanced RCC

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    Anti-angiogenic treatment with tyrosine kinase inhibitors (TKI) has lead to an impressive increase in progression-free survival for patients with metastatic RCC (mRCC), but mRCC remains largely incurable. We combined sunitinib, targeting the endothelial cells with Girentuximab (monoclonal antibody cG250, recognizing carbonic anhydrase IX (CAIX) targeting the tumor cells to study the effect of sunitinib on the biodistribution of Girentuximab because combination of modalities targeting tumor vasculature and tumor cells might result in improved effect. Nude mice with human RCC xenografts (NU12, SK-RC-52) were treated orally with 0.8 mg/day sunitinib, or vehicle for 7 to 14 days. Three days before start or cessation of treatment mice were injected i.v. with 0.4 MBq/5 ÎŒg 111In-Girentuximab followed by biodistribution studies. Immunohistochemical analyses were performed to study the tumor vasculature and CAIX expression and to confirm Girentuximab uptake. NU12 appeared to represent a sunitinib sensitive tumor: sunitinib treatment resulted in extensive necrosis and decreased microvessel density (MVD). Accumulation of Girentuximab was significantly decreased when sunitinib treatment preceded the antibody injection but remained unchanged when sunitinib followed Girentuximab injection. Cessation of therapy led to a rapid neovascularization, reminiscent of a tumor flare. SK-RC-52 appeared to represent a sunitinib-resistant tumor: (central) tumor necrosis was minimal and MVD was not affected. Sunitinib treatment resulted in increased Girentuximab uptake, regardless of the sequence of treatment. These data indicate that sunitinib can be combined with Girentuximab. Since these two modalities have different modes of action, this combination might lead to enhanced therapeutic efficacy

    Targeted therapy of renal cell carcinoma: synergistic activity of cG250-TNF and IFNg

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    Immunotherapeutic targeting of G250/Carbonic anhydrase IX (CA-IX) represents a promising strategy for treatment of renal cell carcinoma (RCC). The well characterized human-mouse chimeric G250 (cG250) antibody has been shown in human studies to specifically enrich in CA-IX positive tumors and was chosen as a carrier for site specific delivery of TNF in form of our IgG-TNF-fusion protein (cG250-TNF) to RCC xenografts. Genetically engineered TNF constructs were designed as CH2/CH3 truncated cG250-TNF fusion proteins and eucariotic expression was optimized under serum-free conditions. In-vitro characterization of cG250-TNF comprised biochemical analysis and bioactivity assays, alone and in combination with Interferon-gamma (IFNgamma). Biodistribution data on radiolabeled [(125)J] cG250-TNF and antitumor activity of cG250-TNF, alone and in combination with IFNgamma, were measured on RCC xenografts in BALB/c nu/nu mice. Combined administration of cG250-TNF and IFNgamma caused synergistic biological effects that represent key mechanisms displaying antitumor responses. Biodistribution studies demonstrated specific accumulation and retention of cG250-TNF at CA-IX-positive RCC resulting in growth inhibition of RCC and improved progression free survival and overall survival. Antitumor activity induced by targeted TNF-based constructs could be enhanced by coadministration of low doses of nontargeted IFNgamma without significant increase in side effects. Administration of cG250-TNF and IFNgamma resulted in significant synergistic tumoricidal activity. Considering the poor outcome of renal cancer patients with advanced disease, cG250-TNF-based immunotherapeutic approaches warrant clinical evaluation

    Molecular cloning and immunogenicity of renal cell carcinoma-associated antigen G250

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    The molecular cloning of the cDNA and gene encoding the renal cell carcinoma (RCC)-associated protein G250 is described. This protein is one of the best markers for clear cell RCC: all clear-cell RCC express this protein, whereas no expression can be detected in normal kidney and most other normal tissue. Antibody studies have indicated that this molecule might serve as a therapeutic target. In view of the induction/up-regulation of G250 antigen in RCC, its restricted tissue expression and its possible role in therapy, we set out to molecularly define the G250 antigen, which we identified as a transmembrane protein identical to the tumor-associated antigen MN/CAIX. We determined, by FISH analysis, that the G250/MN/CAIX gene is located on chromosome 9p12-13. In view of the relative immunogenicity of RCC, we investigated whether the G250 antigen can be recognized by TIL derived from RCC patients. The initial characterization of 18 different TIL cultures suggests that anti-G250 reactivity is rare. (C) 2000 Wiley-Liss, Inc
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