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Reyes D.,University of Chile | Salazar L.,University of Chile | Espinoza E.,University of Chile | Pereda C.,University of Chile | And 7 more authors.
British Journal of Cancer | Year: 2013

Background:Recently, we produced a tumour antigen-presenting cells (TAPCells) vaccine using a melanoma cell lysate, called TRIMEL, as an antigen source and an activation factor. Tumour antigen-presenting cells induced immunological responses and increased melanoma patient survival. Herein, we investigated the effect of TAPCells loaded with prostate cancer cell lysates (PCCL) as an antigen source, and TRIMEL as a dendritic cell (DC) activation factor; which were co-injected with the Concholepas concholepas haemocyanin (CCH) as an adjuvant on castration-resistant prostate cancer (CRPC) patients.Methods:The lysate mix capacity, for inducing T-cell activation, was analysed by flow cytometry and Elispot. Delayed-type hypersensitivity (DTH) reaction against PCCL, frequency of CD8 + memory T cells (Tm) in blood and prostate-specific antigen (PSA) levels in serum were measured in treated patients.Results:The lysate mix induced functional mature DCs that were capable of activating PCCL-specific T cells. No relevant adverse reactions were observed. Six out of 14 patients showed a significant decrease in levels of PSA. DTH + patients showed a prolonged PSA doubling-time after treatment. Expansion of functional central and effector CD8 + Tm were detected.Conclusion:Treatment of CRPC patients with lysate-loaded TAPCells and CCH as an adjuvant is safe: generating biochemical and memory immune responses. However, the limited number of cases requires confirmation in a phase II clinical trial. © 2013 Cancer Research UK. Source

Manubens A.,Fundacion Ciencia y Tecnologia para el Desarrollo | Manubens A.,Biosonda Corporation | Salazar F.,Fundacion Ciencia y Tecnologia para el Desarrollo | Haussmann D.,Austral University of Chile | And 7 more authors.
Cell and Tissue Research | Year: 2010

Hemocyanins are copper-containing glycoproteins in some molluscs and arthropods, and their bestknown function is O2 transport. We studied the site of their biosynthesis in the gastropod Concholepas concholepas by using immunological and molecular genetic approaches. We performed immunohistochemical staining of various organs, including the mantle, branchia, and hepatopancreas, and detected C. concholepas hemocyanin (CCH) molecules in circulating and tissue-associated hemocytes by electron microscopy. To characterize the hemocytes, we purified them from hemolymph. We identified three types of granular cells. The most abundant type was a phagocytelike cell with small cytoplasmic granules. The second type contained large electron-dense granules. The third type had vacuoles containing hemocyanin molecules suggesting that synthesis or catabolism occurred inside these cells. Our failure to detect cch-mRNA in hemocytes by reverse transcription with the polymerase chain reaction (RT-PCR) led us to propose that hemocytes instead played a role in CCH metabolism. This hypothesis was supported by colloidal gold staining showing hemocyanin molecules in electron-dense granules inside hemocytes. RT-PCR analysis, complemented by in situ hybridization analyses with single-stranded antisense RNAs as specific probes, demonstrated the presence of cch-mRNA in the hepatopancreas; this was consistent with the specific hybridization signal and confirmed the hepatopancreas as the site of CCH synthesis. Finally, we investigated the possibility that CCH catabolism in hemocytes was involved in the host immune response and in the generation of secondary metabolites such as antimicrobial peptides and phenoloxidase. © Springer-Verlag 2010. Source

del Campo M.,Fundacion Ciencia y Tecnologia para el Desarrollo | del Campo M.,University of Chile | Arancibia S.,Fundacion Ciencia y Tecnologia para el Desarrollo | Arancibia S.,University of Chile | And 12 more authors.
Revista Medica de Chile | Year: 2011

Hemocyanins, the giant oxygen transporter glycoproteins of diverse mollusks, are xenogenic to the mammalian immune system and they display a remarkable immunogenicity. Therefore they are ideal non-specific immunostimulants to treat some types of cancer. They are used as an alternative therapy for superficial urinary bladder cancer (SBC), that has been traditionally treated with Bacillus Calmette-Guèrin (BCG). In contrast to BCG, hemocyanins do not cause side-effects, making them ideal for long-term repetitive treatments. Hemocyanins have also been exploited as carriers to develop antibodies against hapten molecules and peptides, as carrier-adjuvants for cutting-edge vaccines against cancer, drug addiction, and infectious diseases and in the diagnosis of parasitic diseases, such as Schistosomiasis. The hemocyanin from Megathura crenulata, also known as keyhole limpet hemocyanin (KLH), has been used for over thirty years for the purposes described above. More recently, hemocyanin from the Chilean mollusk Concholepas concholepas (CCH) has proved to be a reliable alternative to KLH, either as carrier protein, and as a likely alternative for the immunotherapy of SBC. Despite KLH and CCH differ significantly in their origin and structure, we have demonstrated that both hemocyanins stimulate the immune system of mammals in a similar way by inducing a potent Th1-polarized cellular and humoral response. Source

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