共查询到5条相似文献,搜索用时 0 毫秒
1.
Karagiannis SN Bracher MG Beavil RL Beavil AJ Hunt J McCloskey N Thompson RG East N Burke F Sutton BJ Dombrowicz D Balkwill FR Gould HJ 《Cancer immunology, immunotherapy : CII》2008,57(2):247-263
Antibodies directed against tumor-associated antigens are emerging as effective treatments for a number of cancers, although
the mechanism(s) of action for some are unclear and still under investigation. We have previously examined a chimeric IgE
antibody (MOv18 IgE), against the ovarian tumor-specific antigen, folate binding protein (FBP), and showed that it can direct
human PBMC to kill ovarian cancer cells. We have developed a three-color flow cytometric assay to investigate the mechanism
by which IgE receptors on U937 monocytes target and kill ovarian tumor cells. U937 monocytes express three IgE receptors,
the high-affinity receptor, FcεRI, the low-affinity receptor, CD23, and galectin-3, and mediate tumor cell killing in vitro
by two mechanisms, cytotoxicity, and phagocytosis. Our results suggest that CD23 mediates phagocytosis, which is enhanced
by upregulation of CD23 on U937 cells with IL-4, whereas FcεRI mediates cytotoxicity. We show that effector : tumor cell bridging
is associated with both activities. Galectin-3 does not appear to be involved in tumor cell killing. U937 cells and IgE exerted
ovarian tumor cell killing in vivo in our xenograft model in nude mice. Harnessing IgE receptors to target tumor cells suggests
the potential of tumor-specific IgE antibodies to activate effector cells in immunotherapy of ovarian cancer.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
2.
3.
Blocking the dengue virus 2 infections on BHK-21 cells with purified recombinant dengue virus 2 E protein expressed in Escherichia coli 总被引:2,自引:0,他引:2
Dengue viruses (DVs) are mosquito-borne infectious pathogens. They have become an expanding public health problem in the tropics and subtropics. The dengue envelope (E) protein is one of the viral structure proteins responsible mainly for the virus attachment and entry onto host cells. It is also the major immunogen for virus neutralization. In this study, we have constructed a recombinant plasmid expressing a truncated E protein of DV-2 virus PL046 strain. The C-terminal hydrophobic domain of the E protein was removed and replaced with the sequence of S peptide to facilitate expression and purification. When expressed in Escherichia coli, the recombinant E proteins were found to be in the form of aggregated state. Through denaturation and dialysis processes, the receptor-interacting function of the purified recombinant E proteins was maintained, which was demonstrated by its ability to inhibit the DV-2 plaque-forming efficiency on mammalian BHK-21 host cells. 相似文献
4.
The C5a anaphylatoxin protein plays a central role in inflammation associated with complement activation. This protein is commonly regarded as one of the most potent inducers of the inflammatory response and a C5a peptide agonist was used as a molecular adjuvant. However, the full length C5a protein has not been tested as a potential tumor therapy. In this report, we describe the creation of a mini-gene construct that directs C5a expression to any cell of interest. Functional expression could be demonstrated in the murine mammary sarcoma, EMT6. When C5a expressing cells were injected into syngeneic mice, most C5a-expressing clones had significantly reduced tumor growth. Further characterization of a clone expressing low levels of C5a demonstrated that one-third of mice injected with this line had complete tumor regression. The mice whose tumors regressed were immune to subsequent challenge with unmodified EMT6 cells, suggesting that a component of the innate immune response can be used to augment adaptive immunity. Cellular analyses demonstrated that a significant difference in actual tumor cell number could be detected as early as day 10. A block in cell cycle progression was evident at all time points and high levels of apoptosis were observed early in the regression event. These data demonstrate that the complement protein C5a can play a significant protective role in tumor immunity. 相似文献
5.
Mehdy Elahi S Bergeron J Nagy E Talbot BG Harpin S Shen SH Elazhary Y 《FEMS microbiology letters》1999,171(2):107-114
A recombinant fowlpox virus (rFPV/E2) expressing the E2 protein of bovine viral diarrhea virus (BVDV) was constructed and characterized. Mice were immunized with recombinant virus and both humoral and cellular immune responses were studied. rFPV/E2 induced BVDV-specific antibodies which were detected by ELISA. In addition, mouse sera were shown to neutralize BVDV. A cytokine ELISA assay revealed that mice vaccinated with rFPV/E2 induced 7-fold more interferon-gamma than parental fowlpox virus. 相似文献