Irradiated KHYG-1 retains cytotoxicity: Potential for adoptive immunotherapy with a natural killer cell line

Abstract

Purpose: To evaluate γ-irradiation on KHYG-1, a highly cytotoxic natural killer (NK) cell line and potential candidate for cancer immunotherapy.

Methods and materials: The NK cell line KHYG-1 was irradiated at 1 gray (Gy) to 50 Gy with γ-irradiation, and evaluated for cell proliferation, cell survival, and cytotoxicity against tumor targets.

Results: We showed that a dose of at least 10 Gy was sufficient to inhibit proliferation of KHYG-1 within the first day but not its cytolytic activity. While 50 Gy had an apoptotic effect in the first hours after irradiation, the killing of K562 and HL60 targets was not different from non-irradiated cells but was reduced for the Ph + myeloid leukemia lines, EM-2 and EM-3.

Conclusions: γ-irradiation (at least 10 Gy) of KHYG-1 inhibits cell proliferation but does not diminish its enhanced cytolytic activity against several tumor targets. This study suggests that KHYG-1 may be a feasible immunotherapeutic agent in the treatment of cancers.

Keywords:

• KHYG-1
• natural killer cell line
• irradiation
• adoptive immunotherapy
• cytotoxicity