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Objective@#To evaluate the inhibitory effect of tumor vaccines in colon carcinoma model mice.@*Methods@# Mouse bone marrow⁃derived dendritic cells（BMDCs）were stimulated by using CpG β⁃glucan nanoparticles（CNP）in vitro. The BMDCs were divided into PBS group，NP group（without CpG nanoparticles），Lysate group（MC38 cell lysate）and CpG group（CpG1826），which were determined for the expression of marker molecules on the surface by flow cytometry and for the contents of interleukin⁃6（IL⁃6）and IL⁃12p40 in the culture supernatant by ELISA. The tumor lysate nano⁃vaccine was pre⁃ pared by mixing 50 mg／mL tumor lysate（MC38 cell lysate）with 200 mg／mL CNP in a volume ratio of 1∶1，with which mice were subcutaneously immunized as Vaccine group. Vaccine group，PBS group，CNP group and Lysate group were im⁃ munized once a week，for three times in total. Mice were subcutaneously inoculated with MC38 cells，2 × 105 cells for each， in the right lower limb 1 h after the last immunization，and measured for tumor volume once every three days to plot the tumor growth curve. The ratios of CD3+ CD4+ T and CD3+ CD8+ T cells in the blood were analyzed by flow cytometry and the levels of tumor necrosis factor⁃α（TNF⁃α）and interferon γ（IFNγ）in the blood and spleen of mice were determined by ELISA.@*Results@# CNP effectively increased the expression of CD11c+ CD80+，CD11c+ CD86+，CD11c+ MHC⁃Ⅱ+ and the secretion of IL⁃6 and IL⁃12p40 in BMDCs in vitro，which were significantly higher than those in other 4 groups（t = 4. 3 ~ 46. 2，each P < 0. 05）. Compared with that of the other three groups，the tumor volume of mice in Vaccine group decreased significantly（t =2.6~3.4，eachP <0. 05）；TherewasnosignificantdifferenceinCD3+ CD8+ TandCD3+ CD8+ Tcellratios（t = 0.5~ 1. 9，each P > 0. 05）；The content of IFNγ in blood increased significantly（t = 3. 8 ~ 4. 6，P < 0. 05），while thatof TNF⁃α showed no significant difference（t = 0. 4 ~ 2. 0，each P > 0. 05）；However，the contents of IFN γ and TNF⁃α in spleen increased significantly（t = 6. 3 ~ 13. 0，each P < 0. 001）.@*Conclusion@#The prepared nano⁃vaccine of tumor lysate improvedtheimmune level in mice and effectively inhibited the growth of colon carcinoma.
ABSTRACT
PURPOSE: Vaccine strategies utilizing dendritic cells (DCs) to elicit anti-tumor immunity are the subject of intense research. Although we have shown that DCs pulsed with heat-treated tumor lysate (HTL) induced more potent anti-tumor immunity than DCs pulsed with conventional tumor lysate (TL), the underlying molecular mechanism is unclear. In order to explore the molecular basis of this approach and to identify potential antigenic peptides from pancreatic cancer, we analyzed and compared the major histocompatibility complex (MHC) ligands derived from TL- and HTL-pulsed dendritic cells by mass spectrophotometry. MATERIALS AND METHODS: Human monocyte-derived dendritic cells were pulsed with TL or HTL prior to maturation induction. To delineate differences of MHC-bound peptide repertoire eluted from DCs pulsed with TL or HTL, nanoflow liquid chromatography-electrospray ionization-tandem mass spectrometry (nLC-ESI-MS-MS) was employed. RESULTS: HTL, but not TL, significantly induced DC function, assessed by phenotypic maturation, allostimulation capacity and IFN-gamma secretion by stimulated allogeneic T cells. DCs pulsed with TL or HTL displayed pancreas or pancreatic cancer-related peptides in context of MHC class I and II molecules. Some of the identified peptides had not been previously reported as expressed in pancreatic cancer or cancer of other tissue types. CONCLUSION: Our partial lists of MHC-associated peptides revealed the differences between peptide profiles eluted from HTL-and TL-loaded DCs, implying that induced heat shock proteins in HTL chaperone tumor-derived peptides enhanced their delivery to DCs and promoted cross-presentation by DC. These findings may aid in identifying novel tumor antigens or biomarkers and in designing future vaccination strategies.
Subject(s)
Humans , Antigens, Neoplasm/immunology , Cell Line, Tumor , Dendritic Cells/immunology , Pancreatic Neoplasms/immunologyABSTRACT
Objective:This work aims to use the characteristics of dendritic cells (DCs) pulsed with recombinant human HSP70, which can present and process tumor antigens, to enhance the killing activity of cytotoxic t lymphocytes (CTLs) against breast neoplasms. Methods:Autologous DCs were isolated from peripheral blood mononuclear cells and then stimulated in vitro with granulocyte macrophage-colony stimulating factor and interleukin-4. The DCs were loaded with A549 tumor cell freeze-thaw lysate, and rhHSP70 was added as an immune adjuvant. The specific groups were subjected to tumor-specific cytotoxic assay, enzyme-linked immunosorbent assay, and fluores-cence-activated cell sorting. Results:DCs pulsed with A549 tumor cell lysate enhanced the growth expansion of CTLs, upregulated CD40 and CD80 populations in CTLs, and augmented Th1 cytokines. In addition, the cytotoxicity of specific CTLs against A549 was highly enhanced. The above indications became more obvious after the addition of rhHSP70. Conclusion:DCs pulsed with freeze-thaw cell lysates derived from breast cancer can enhance growth expansion of lymphocytes. They may serve as an effective tumor antigen to stimulate the proliferation of specific CTLs, which are very effective in activating specific T-cell responses against breast cancer cells in vitro. The improved anti-tumor immunity response by DC-based vaccines may be related to the maturation of the DCs promoted by rhHSP70.
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Objective To make use of the characteristics of presenting and processing tumor antigen of dendritic cells to enhance killing capability of CTLs against autologous renal cell carcinoma. Methods Autologous dendritic cells were obtained by culturing bone marrow cell from patient with RCC in the presence of granulocyte macrophage colony stimulating factor(GM CSF) and IL 4. Dendritic cells were loaded with tumor cell lysate and co cultured with autologous PBMCs from patient to induce generation of tumor specific cytotoxic T cells(CTL). Killing activity and cytokine release of the CTL and the population of CTL were measured by cytotoxic assay and ELISA and FACS analyses. Results Immune response of DC Tuly induced CTL was demonstrated by the following facts:(1)the growth expansion of CTL enhanced 43 folds on day 16;(2)up regulation of the CD3 + and CD8 + population in CTL;(3)the cytotoxicity of specific CTL against autologous RCC was highly enhanced as compared with allogenic RCC and heterogenous tumor( P
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Objective:To make use of the characteristics of presenting and processing tumor antigen of dendritic cell to enhance generation of isotypical but xenogenous T lymphocyte.Methods:Autologous dendritic cells were obtained by culturing peripheral blood monocyte of patients with cervical cancer in the presence of granulocyte-macrophage colony stimulating factor(GM-CSF) and interleukin-4(IL-4).Dendritic cells were loaded with tumor cell lysate and co-cultured with heterogenous PBMCs from patients to induce generation of tumor specific cytotoxic T cell.The generation rate was measured by MTT.Results:Tumor lysate-loaded DC which was isolated from peripheral blood monocyte of patients with cervical cancer could induce the generation of isotypical but xenogenous T lymphcyte.There was no significant difference between tumor tissue lysate and tumor cell strain lysate(P
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AIM: To prepare the efficient tumor-DC vaccines, dendritic cells(DC) derived from 6-8 weeks Balb/c mice bone marrow progenitor cells were pulsed by apoptotic SP2/0 tumor cells and induced maturation by SP2/0 tumor lysates supernatants. Then SP2/0 tumor burdening Balb/c mice were immunized by the tumor-DC vaccines to observe the therapeutic effects in vivo .METHODS: Immature DC were derived by recombinant murine GM-CSF and IL-4, then were pulsed by SP2/0 apoptotic cells. Tumor-DC vaccines were stimulated by LPS and SP2/0 tumor lysates supernatants prepared by four cycles repetitive freezing and thawing, respectively. -thymidine incorporation test and standard 4h [ 51 Cr] release assay were used to detect the proliferation and activation of cytotoxic T lymphocytes (CTL) stimulated by DC in vitro . (4-5)?10 5 DC were immunized in the right inguen of SP2/0 tumor burdening Balb/c mice and most mice received three cycles immunization every two weeks. Changes of the tumor and mice life-spans were recorded. RESULTS: In vitro proliferation and activation of CTL induced by the tumor-DC vaccines of tumor lysates supernatants or LPS stimulation group were more powerful than other groups ( P