[Induction of antitumor immune response by NK-cell-sensitive target cells transfected by B7-1 gene].
OBJECTIVE
To investigate whether the expression of B7-1 is involved in NK cell activation.


METHODS
B7-1 gene was transfected into K562 cell line (a sensitive target cell of NK cell, without MHC class I expression) by electropolation. Specific cytotoxicity of NK cells to B7+K562 cell was assayed by 4-h Cr release assay. The proliferation of NK cells induced by B7+K562 cell was analysed by Flow Cytometry. Expansion of NK cells and cloning of NK cells were performed by mixed lymphocyte-tumor cultures and limiting dilution analysis. Production of TNF-A, GM-CSF and IFN-A was detected by ELISA tests.


RESULTS
The cytotoxicity of NK cells to B7+K562 cell could be induced and that the number of NK cells could be increased by stimulation with B7+K562 cells, in particular, further enhanced with biotherapeutic agent such as OK432 and IL-2. Also, NK cell clones were established. Cytokines such as TNF- A, INF- A and GM-CSF were detected in the supernatant produced by NK cell clones. In addition, culture of lymphocytes in the presence of supernatant produced by NK cell clones and tumor antigens resulted in an increased autologous tumor killing(ATK).


CONCLUSIONS
These findings suggest that K562 cells transfected by B7-1 gene may elicit a series of antitumor immunity and these cells may be used for further development of therapeutic tumor vaccine.
Department of Obstetrics and Gynecology, The Second Affiliated Hospital, West China University of Medical Sciences, Chengdu, Sichuan, 610041 P. R. China. Yuquawei@mail.sc.cninfo.net
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Zhao
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Wei
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Kariya
D018122:B7-1 Antigen / Q000235:genetics*; D002460:Cell Line; D016207:Cytokines / Q000096:biosynthesis; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D009369:Neoplasms / Q000276:immunology*; D014162:Transfection
D018122:B7-1 Antigen; D016207:Cytokines