Comparison of the cytotoxic response against ovarian cancer by immune effector cells isolated and expanded from normal donors and ovarian cancer patients.

BACKGROUND/AIMS: The aim of this study was to compare the cytotoxic response against ovarian cancer (OC) cells elicited by different immune effector cells in combination with the cytokines interleukin (IL)-2 and interferon (IFN) α-2b.

METHODS

OC cells were co-cultured with peripheral blood mononuclear cells (PBMC) from normal donors or OC patients and IL-2 or IFN α-2b alone or in combination, in order to determine the cytotoxicity. T cells were isolated from healthy donors to determine T cell cytotoxic activity. PBMC from healthy donors and OC patients were expanded in an IL-2/IL-7/IL-12 cocktail with and without anti-CD3 antibody, and the cytotoxic activity measured. Flow cytometry was performed on primary, selected and expanded cells to determine T, B, and natural killer- (NK) cell percentages.

RESULTS

Healthy donor PBMC elicited a significant cytotoxic response (59%) compared with OC patient PBMC (7%). T cells enriched from normal donors elicited a significant cytotoxic response (18%) compared with controls lacking effector cells (1.4%); however, the cytotoxicity observed was significantly less compared with unselected PBMC. Expanded effector cells consisted primarily of T cells (98%) and the fold-expansion was significantly higher in the presence of anti-CD3 (19- versus 132-fold). No significant difference in the expansion (either fold-expansion or cell type) was observed between OC patients and healthy donors. Expanded cells from both healthy donors and OC patients elicited a significant cytotoxic response in the presence of IL-2 (19% and 22%) compared with controls.

CONCLUSIONS

PBMC from OC patients do not elicit a significant cytotoxic response; however, ex vivo-expanded cells from OC patients are capable of cytotoxic killing similar to unexpanded T cells isolated from normal donors. These data provide the groundwork for further development of cellular therapy against OC.