1. ¹Department of Medicine, Center for Infectious Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
2. ²Division of Hematology, Department of Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
3. ³Division of Pathology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden

Correspondence: Dr DMS Dilber, Division of Hematology, M54, Department of Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, SE-141 86 Stockholm, Sweden. E-mail: sirac.dilber@medhs.ki.se

Received 3 September 2005; Revised 23 November 2005; Accepted 29 November 2005; Published online 2 March 2006.

Abstract

The possibility of using natural killer (NK) cells in treatment of human hematological malignancies has increased in recent years. One factor contributing to this is the introduction of new methods for ex vivo generation of enriched populations of clinical grade NK cells. The objective of the present study was to evaluate the safety and efficacy of human ex vivo expanded clinical grade NK cells against K562 leukemia cells in severe combined immunodeficiency disease (SCID)-beige mice. Irradiated SCID-beige mice were injected intravenously (i.v.) with K562 leukemia cells. Following leukemia cell injection, mice were injected with ex vivo expanded human NK cells. NK cells were followed in vivo and mice monitored for survival from leukemia. Administration of these ex vivo expanded clinical grade NK cells was safe and prevented leukemia development. In conclusion, these results imply possibilities for the use of this NK cell preparation in treatment trials of human hematological malignancies and possibly other forms of cancer.