Induction of Myeloma Cell Line-specific Cytotoxic T Lymphocytes using Monocyte-derived Dendritic Cells Pulsed with Myeloma Cell Line Lysates / 대한혈액학회지

BACKGROUND: In multiple myeloma (MM), the idiotype (ID) determinant of the paraprotein has been used for immunotherapy using dendritic cells (DCs). However, ID-specific immune responses showed limited clinical responses after the Id vaccination. Therefore, an alternative approach using DCs pulsed with other tumor antigens is required. METHODS: We investigated the possibility of immunotherapy for MM using myeloma cell line-specific cytotoxic T lymphocytes (CTLs), that were stimulated in vitro by monocyte-derived DCs pulsed with the myeloma cell line ysates. CD14+ cells isolated from the peripheral blood of HLA-A0201+ healthy donors were cultured in the presence of GM-CSF and IL-4. On day 6, the immature DCs were pulsed with the myeloma cell line lysates (IM-9: HLA0201+ and ARH-77: HLA0201+), and then maturation of DCs was induced by the addition of TNF- alpha for 2 days. CTL lines were generated by a 2 time stimulation with DCs to the autologous CD3+ T cells. RESULTS: DCs pulsed with myeloma cell lysates showed the production of IL-12p70, but less than that of unpulsed DCs. CTLs lines stimulated with the DCs pulsing, for the myeloma cell line lysates, showed potent cytotoxic activities against autologous target cells, but not against HLA-A2-cell lines (RPMI-8226). Mature DCs pulsed with the myeloma cell line lysates showed a higher stimulatory capacity for autologous CTL when compared with mature non-pulsed DCs. CONCLUSION: These results suggest that DCs pulsed with the myeloma cell line lysates can generate potent myeloma cell line-specific CTLs for the myeloma cell-based immunotherapeutic approach in MM.

Selective Expansion of Natural Killer Cells from Peripheral Blood Mononuclear Cells by K562 Cell Line and IL-2 / 대한혈액학회지

BACKGROUND: Several attempts have been made to expand human NK cells from peripheral blood mononuclear cells (PBMCs). This study examined the selective expansion of NK cells using interleukin 2 (IL-2) plus the K562 cell line, the expression of the NK cell receptors, and the cytotoxic activity. METHODS: The PBMCs from seven healthy volunteers were cultured in a medium containing the IL-2 plus the K562 cell line for 14 days. The expression of the activating and inhibitory receptors on the resting NK cells and the 72 hr-expanded NK cells were analyzed. A flow cytometric cytotoxic assay was used to determined the killing activity of the non-expanded NK cells and the 7 day-expanded NK cells against the K562 target cells. RESULTS: The NK cells from PBMCs expanded 4.5-fold after 7 days, and contained 56.5% CD3-CD56+ cells. The IL-2 or IL-2 plus K562 increased the expression levels of CD158b (MFI, mean florescence intensity), CD158e1/e2 (MFI), and NKp44 (MFI), while it decreased the expression levels of NKp30 (%), CD16 (MFI), and 2B4 (MFI). The non-expanded NK cells lysed 9.0% and 27.6% of the K562 target cells in the 1 : 1 and 5 : 1 effector and target ratio, respectively, and the 7-day expanded NK cells lysed 36.9% and 57.2% of the K562 target cells, respectively. CONCLUSION: The selective expansion of CD3-CD56+ NK cells occurred only during 7 days of culture. IL-2 or IL-2 plus the K562 cells altered the expression of various activating and inhibitory receptors of NK cells, and the cytotoxicity of the expanded NK cells was higher than in the non-expanded cells.