Induction of micronuclei and apoptosis in natural killer cells compared to T lymphocytes after gamma-irradiation.
OBJECTIVE
To investigate the chromosomal damage caused by gamma-irradiation in T lymphocytes and natural killer (NK) cells and compare this with apoptosis induction in both lymphocyte subsets.


METHODS
Apoptosis induction by gamma-irradiation in T lymphocytes and NK cells was quantified using the annexin V flow cytometric assay. The cytokinesis-block micronucleus (MN) assay was used to evaluate the induced cytogenetic damage. For the MN assays on NK cells, gamma-irradiated peripheral blood mononuclear cells were cultured and stimulated with interleukin 15 (IL-15). Afterwards the NK cells (characterized by the CD3-/CD56+ phenotype) were separated with the FACSort flow cytometer and the number of MN in the sorted binuclear cells was scored. Doses of 1 and 2 Gy gamma-irradiation were applied.


RESULTS
Higher numbers of MN in NK cells were found compared with the MN yield in T lymphocytes. In contrast, NK cells were less than T lymphocytes prone to apoptosis after gamma-irradiation.


CONCLUSIONS
The results support the view that cytogenetic damage and apoptosis after gamma-irradiation are not necessarily correlated.
Louagie
H
H
Department of Clinical Chemistry, Microbiology and Immunology, University Hospital, Gent, Belgium.
Philippé
J
J
Vral
A
A
Cornelissen
M
M
Thierens
H
H
De Ridder
L
L
D017209:Apoptosis / Q000528:radiation effects*; D002478:Cells, Cultured; D005720:Gamma Rays; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology / Q000528:radiation effects* / Q000648:ultrastructure; D048629:Micronuclei, Chromosome-Defective / Q000528:radiation effects*; D013601:T-Lymphocytes / Q000166:cytology / Q000528:radiation effects* / Q000648:ultrastructure