Cryopreserved NK cells in the treatment of haematological malignancies: preclinical study.
BACKGROUND
Leukaemia is an aggressive cancer of haematopoiesis. Despite increasing treatment success, the relapse rate is still high. Natural killer (NK) cells play a key role in the immune response to malignancies; thus, it is conceivable that NK cell-based immunotherapy may control relapses, while extending the disease-free survival. In our study, we investigated whether cryopreserved NK cells are able to kill the leukaemic K562 cell line, the necessity of IL-2 co-application and the association of activation marker expression (NKp44, NKG2D and CD25) with cytotoxic potential.


METHODS
K562 cells were added to NK cell cultures in different ratios, i.e. 1:5, 1:10 and 1:20 (K562/NK), immediately after thawing NK cells or after 3-6-12-24 h of re-cultivation with or without IL-2.


RESULTS
Our results demonstrated the ability of cryopreserved NK cells to kill K562 in all ratios, times and culture conditions. The number of dead K562 cells depended on the number of NK cells and on the presence of IL-2. NK cells cytotoxic potential decreased gradually in the culture without IL-2. In contrast, NK cell-mediated cytotoxicity remained the same during the entire re-culture period after IL-2 re-application.


CONCLUSIONS
Our study proved the efficacy of using cryopreserved ready-for-use NK cells in relapse treatment and the need for simultaneous administration of IL-2.
Department of Haematology and Oncology, Medical School and Teaching Hospital in Pilsen, Charles University in Prague, Pilsen, Czech Republic. holubovam@fnplzen.cz.|Biomedical Centre, Faculty of Medicine in Pilsen, Charles University in Prague, Pilsen, Czech Republic. holubovam@fnplzen.cz.|Department of Haematology and Oncology, Faculty Hospital in Pilsen, Charles University in Prague, Alej Svobody 80, 304 60, Pilsen, Czech Republic. holubovam@fnplzen.cz.
Monika
M
Holubova
Department of Haematology and Oncology, Medical School and Teaching Hospital in Pilsen, Charles University in Prague, Pilsen, Czech Republic.|Biomedical Centre, Faculty of Medicine in Pilsen, Charles University in Prague, Pilsen, Czech Republic.
Michaela
M
Miklikova
New Technologies for the Information Society European Centre of Excellence, Faculty of Applied Sciences, University of West Bohemia, Pilsen, Czech Republic.
Martin
M
Leba
New Technologies for the Information Society European Centre of Excellence, Faculty of Applied Sciences, University of West Bohemia, Pilsen, Czech Republic.
Daniel
D
Georgiev
Czech National Bone Marrow Donor Registry (CS-2), Pilsen, Czech Republic.
Pavel
P
Jindra
2nd Department of Internal Medicine, Faculty of Medicine, Comenius University, Bratislava, Slovakia.
Martin
M
Caprnda
Department of Internal Medicine, IRCCS Policlinico San Matteo Foundation, University of Pavia, Pavia, Italy.
Rachele
R
Ciccocioppo
Department of Chemical Drugs, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences, Palackeho tr. 1/1946, 612 42, Brno, Czech Republic. kruzliakpeter@gmail.com.
Peter
P
Kruzliak
Department of Haematology and Oncology, Medical School and Teaching Hospital in Pilsen, Charles University in Prague, Pilsen, Czech Republic.|Biomedical Centre, Faculty of Medicine in Pilsen, Charles University in Prague, Pilsen, Czech Republic.
Daniel
D
Lysak
D002478:Cells, Cultured; D015925:Cryopreservation; D003602:Cytotoxicity, Immunologic; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods*; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000276:immunology*; D007938:Leukemia / Q000628:therapy*; D008213:Lymphocyte Activation
Cryopreservation; Cytotoxic potential; Leukaemia; Medical product; NK cells