Abstract
Background: Adoptive immunotherapy using natural killer (NK) cells from cancer patients yielded only modest success. Whether Herceptin® and OK432-activated NK cells (NK cells obtained by stimulating peripheral blood mononuclear cells with OK432 and interleukin-2) improve the outcome of adoptive immunotherapy against HER-2/neu positive tumor cells via antibody-dependent cellular cytotoxicity, was examined in vitro. Materials and Methods: A 51Cr release assay was performed to assess cytotoxicity. OK432-activated NK cells and lymphokine-activated killer (LAK) cells from healthy donors and cancer patients were used as effectors. Three cell lines expressing different amounts of HER-2/neu served as targets. Results: In the case of effectors from patients, OK432-activated NK cells showed higher cytotoxicity than that of LAK cells, and the cytotoxicity of OK432-activated NK cells against the SK-BR-3 cell line (over-expressing HER-2/neu) was increased by Herceptin®. Conclusion: Combination of Herceptin® and OK432-activeted NK cells may improve the efficacy of the treatment for HER-2/neu-positive malignancy.
Footnotes
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Abbreviations: ADCC, antibody-dependent cellular cytotoxicity; NK, natural killer cells; LAK, lymphokine-activated killer; PBMCs, peripheral blood mononuclear cells; MFI, mean fluorescence intensity; Th1, helper T-cell 1; Th2, helper T-cell 2.
- Received June 7, 2006.
- Accepted September 11, 2006.
- Copyright© 2006 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved