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Tumor-specific Antigens (tumor-specific + antigen)
Selected AbstractsThymus-leukemia antigen (TL) as a major histocompatibility complex (MHC) class Ib molecule and tumor-specific antigenCANCER SCIENCE, Issue 6 2004Kunio Tsujimura Mouse thymus-leukemia antigens (TL) belong to the family of major histocompatibility complex (MHC) class Ib antigens and have a unique mode of expression, i.e., in contrast to other MHC class Ib or la antigens, they are found restricted to the intestines in all mouse strains, but also in the thymus of certain strains (TL+ strains). Nevertheless, a proportion of T lymphomas/leukemias in strains that do not express TL in the thymus (TL, strains) feature TL as a tumor antigen. TL was originally defined serologically, but subsequently we have succeeded in generating T cell receptor (TCR) ,, and ,, cytotoxic T lymphocytes (CTL) recognizing TL. By use of TL tetramers free from peptides and transfectants expressing various TL/H-2 chimeric molecules, we have been able to show that TL-specific CTL recognize the ,1 /,2 domain of TL without any additional antigen molecules. We previously reported that one of TL's functions in the thymus is positive selection of TCR,, CTL. Recent studies with TL tetramers revealed that they can bind to normal intestinal intraepithelial lymphocytes (ilEL) and thymocytes in a CD8-dependent, but TCR/CD3-independent manner, while their binding to TL-specific CTL is TCR/CD3-and CDS-dependent. The possible significance of these findings in relation to the roles of TL in the intestines is discussed. We have long been interested in TL as a model tumor antigen which shares characteristics with human differentiation tumor antigens, and we have demonstrated that growth of TL+ lymphoma cells in vivo is suppressed by immunization with TL+ skin or dendritic cells (DC) from TL transgenic mice. In addition, anti-tumor effects against TL+ T lymphomas were obtained by adoptive transfer of TL tetramer strongly-positive TL-specific CTLs. [source] Phage display particles expressing tumor-specific antigens induce preventive and therapeutic anti-tumor immunity in murine p815 modelINTERNATIONAL JOURNAL OF CANCER, Issue 5 2002Yuzhang Wu Abstract The efficacy of phage display particles expressing tumor antigen P1A35-43 in inducing protective and therapeutic anti-tumor immune responses were studied. A protective immune response against a lethal progressive P815 mastocytoma tumor cell challenge was established after subcutaneous injection of phage display particles. Furthermore, the vaccine suppressed growth of pre-existing tumors. Immunization with the hybrid phage particles elicited P1A35,43 specific CTL responses and a Th1-dominated immune response with phage particle-specific secretion of IFN-, but not IL-4. Our results indicate that phage display particles might be a useful vaccine form for tumor-associated antigen epitopes in tumor immunotherapy. © 2002 Wiley-Liss, Inc. [source] Expression of intercellular adhesion molecule (ICAM)-1 or ICAM-2 is critical in determining sensitivity of pancreatic cancer cells to cytolysis by human ,,-T cells: Implications in the design of ,,-T-cell-based immunotherapies for pancreatic cancerJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 5 2009Zhiyong Liu Abstract Background and Aims:, ,,-T cells can recognize and kill malignant cells, particularly those of epithelial origin, through mechanisms which do not require the recognition of tumor-specific antigens (innate immune response). This natural ability of ,,-T cells to kill tumor cells in a tumor antigen-independent manner provides a strong rationale for developing clinical trials designed to exploit the innate antitumor properties of ,,-T cells. Methods:,In vitro studies were carried out to asses the sensitivity of pancreatic cancer cells (MIA PaCa2, BxPC-3, PANC-1) to killing by ex vivo expanded human ,,-T cells. Results:, The capacity of ,,-T cells to bind to as well as to kill pancreatic cancer cells correlated with the degree of surface expression of key intercellular adhesion molecules (ICAM) present on pancreatic cancer cells. Moreover, pancreatic cancer cells expressing neither ICAM-1 nor ICAM-2 were bound poorly by ,,-T cells and were found to be resistant to ,,-T-cell killing. However, upon transfection of resistant cells with ICAM-1 or ICAM-2, ,,-T cells were then able to bind to and subsequently kill these cells. Conclusion:,In vitro, the expression of ICAM-1 or ICAM-2 on human pancreatic cancer cells is critically important in determining the extent to which these cells are sensitive to killing by human ,,-T cells. Accordingly, in ongoing and future clinical studies using ,,-T cells for the treatment of a variety of epithelial-derived solid tumors,including pancreatic cancer,interventions intended to modulate ICAM expression on tumor cells may become important adjuncts to ,,-T-cell-based immunotherapies. [source] Vaccinations With Dendritic Cells Primed With Apoptotic Tumor Cells Can Elicit Preventive Antitumor Immunity in a Poorly Immunogenic Animal Model of Squamous Cell CarcinomaTHE LARYNGOSCOPE, Issue 9 2007Han-Sin Jeong MD Abstract Background: Dendritic cells (DCs) can effectively mediate the prevention and regression of a variety of solid tumors. However, not much has been determined about their efficacy for the prevention of squamous cell carcinoma (SCC), partly because there are no known tumor-specific antigens or low immunogenicity for this tumor. The authors aimed to determine the preventive effect of DC-based immunotherapy in a SCC animal model. Methods: Bone marrow derived DCs of C3H/He mice were pulsed with ultraviolet,B-irradiated apoptotic SCCVII cells, which are known as a poorly immunogenic SCC cell line. After the animals were vaccinated with these DCs, a tumorigenic dosage of SCCVII cells was subcutaneously injected and the tumor growth assessed. Results: Animals pretreated with apoptotic SCCVII cell-pulsed DCs showed tumor extinction within 2 weeks after forming a small tumor, or there was no tumor formation at all, as seen in 81% of the mice; in the remaining 19% of the mice, tumor growth was significantly retarded compared with the control groups (P = .0029). The SCCVII cell-specific T-cell response was observed in the immunized mice. Conclusion: The adoptive transfer of DCs primed with apoptotic tumor cells can hopefully serve as an effective preventive vaccine, even in poorly immunogenic SCC. [source] | ||||||||||