AIM:To induce efficient expansion of natural killer(NK)cells from peripheral blood mononuclear cells(PBMCs)using a culture of anchorage-dependent Wilms tumor celllines,and to provide a reliable supply for adoptiveimmunotherapy of hepatocellular carcinoma.METHODS:Culture expansion of NK cells was achieved usingPBMCs cultured with Wilms tumor cells.Cytotoxicity wasmeasured using a standard ~(51)Cr release assay and crystal violetstaining technique.The proportions of CD3+,CD4+,CD8+,CD16+,and CD56+ cells were determined by flow cytometry.RESULTS:After PBMCs from healthy donors andhepatocellular carcinoma(HCC)were cultured withirradiated HFWT cells for 10-21 d,CD56+ CD16+ cellsshared more than 50% of the cell population,and morethan 80% of fresh HFVVT cells were killed at an effector/target ratio of 2 over 24 h.NK-enriched lymphocytepopulation from HCC patients killed HCC-1 and 2 cells withsensitivities comparable to fresh TKB-17RGB cells.HCC cellsproliferated 196-fold with the irradiated HFWT cells at18 d.Stimulation by HFVVT cells required intimate cell-cellinteraction with PBMC.However,neither the soluble factorsreleased from HFWT cells nor the fixed HFWT cells wereeffective for NK expansion.The lymphocytes expanded withIL-2 killed fresh HFWT target cells more effectively thanthe lymphocytes expanded with the 4-cytokine cocktail(IL-1 β,IL-2,IL-4 and IL-6).IL-2 was the sole cytokinerequired for NK expansion.CONCLUSION:Wilms tumor is sensitive to human NK cellsand is highly efficient for selective expansion of NK cellsfrom PBMCs. AIM: To induce efficient expansion of natural killer (NK) cells from peripheral blood mononuclear cells (PBMCs) using a culture of anchorage-dependent Wilms tumor celllines, and to provide a reliable supply for adoptive immunotherapy of hepatocellular carcinoma. METHODS: Culture expansion of NK Cells were derived using PBMCs cultured with Wilms tumor cells. Cytotoxicity was measured using a standard ~ (51) Cr release assay and crystal violet staining method. proportions of CD3 +, CD4 +, CD8 +, CD16 +, and CD56 + cells were determined by flow cytometry. PBMCs from healthy donors and hepatocellular carcinoma (HCC) were cultured with irradiated HFWT cells for 10-21 d, CD56 + CD16 + cellsshared more than 50% of the cell population, and morethan 80% of fresh HFVVT cells were killed at an effector / target ratio of 2 over 24 h. NK-enriched lymphocytepopulation from HCC patients killed HCC-1 and 2 cells with sepsitivities comparable to fresh TKB-17RGB cells. HCC cells proliferated 196-fold with irradiated H FWT cells at18 d. Optimization by HFVT cells at intimate cell-cell interaction with PBMC. Despite that the soluble factorsreleased from HFWT cells nor the fixed HFWT cells wereeffective for NK expansion. Lymphocytes expanded with IL-2 killed fresh HFWT target cells more effectively thanthe lymphocytes expanded with the 4-cytokine cocktail. IL-2 was the sole cytokineququired for NK expansion. CONCLUSION: Wilms tumor is sensitive to human NK cells and is highly efficient for selective expansion of NK cellsfrom PBMCs.