Abstract:

OBJECTIVE: To study the effects of the heated A375 melanoma cells on natural killer (NK) cells and dendritic cells (DC) generated from human cultured peripheral blood mononuclear cells (PBMCs) in vitro，and to explore the mechanism. METHODS：NK cells and DCs cultured from PBNCs in vitro and  reacted with A375 melanoma cells in  a  water-bath at 43℃. Using CCK-8 kit to test the killing rate of NK cells and DCs against A375 melanoma cells at the effector∶ ratio of efficacy to target(E/T) (NK∶DC∶A375) of 1∶2∶1，3∶6∶1，and 6∶12∶1.  ELISA was used to measure concentrations of γ-INF released by NK cells at the effector∶E/T (NK∶DC∶A375) of 1∶2∶1，3∶6∶1 and 6∶12∶1. RESULTS：At each E/T ，the killing rate of the heated group against A375 melanoma cells were stronger than the unheated group (P<0.05)，and the killing rate increased as the concentrations of NK and DC increased (P<0.05). The concentration of γ-INF released by the heated group was also more than the unheated group(P<0.05). CONCLUSION：Heated A375 melanoma cells could induce NK to release more γ-INF and significantly increased the activity of NK cells ，in which DC played an important role.

Key words: dendritic cell, natural killer cell , melanoma, immunocompetence