[Apoptosis and modulatory mechanism of human AHH-1 T lymphocytes induced by gamma-irradiation].
OBJECTIVE
To explore the apoptotic characteristics and modulatory mechanism of human AHH-1 T lymphoblast induced by ionizing radiation and provide an experimental basis for preventing and treating immune damage in acute radiation sickness.


METHODS
TdT-mediated dUTP nick end labeling (TUNEL) and May-Grunwald Giemsa (MGG) staining, MTT colorimetry and immunohistochemical staining were used to detect the T lymphocyte apoptosis, cell survival and the expressions of Bax, Bcl-XL and caspase-3 proteins.


RESULTS
(1) Over a definite dose range, apoptotic rate of AHH-1T lymphocytes increased with the elevation of radiation doses, while the lymphocytic survival rate decreased sharply, both showing a good dose-effect relationship. (2) The expression of apoptosis-accelerating protein Bax enhanced obviously with the increase of radiation doses, while apoptosis-inhibiting protein Bcl-XL trended to persistent decline. (3)The activity of activated apoptosis-executing protein caspase-3 heightened significantly with increased radiation doses, which revealed a better corresponding relationship to apoptotic rate.


CONCLUSIONS
A great number of apoptotic AHH-1 T cells may be one of major accounts for the lymphocyte rapid reduction and depressed organism immune function induced by irradiation. Bax, Bcl-XL and caspase-3 proteins play an important role in the regulation of radiation-induced T cell apoptosis.
Cui
Yu-fang
YF
Department of Immunology, Institute of Radiation Medicine, Beijing 100850, China. yufangc@vip.sina.com
Zhang
Ying
Y
Liu
Xiao-lan
XL
Wang
Li-hong
LH
Jiang
Zhu-jun
ZJ
Gu
Qing-yang
QY
Jin
Wei
W
Xu
Han
H
Mao
Bin-zhi
BZ
D017209:Apoptosis / Q000528:radiation effects*; D053148:Caspase 3; D020169:Caspases / Q000096:biosynthesis; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006801:Humans; D011518:Proto-Oncogene Proteins / Q000032:analysis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis; D013601:T-Lymphocytes / Q000166:cytology / Q000528:radiation effects*; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein
C494826:BAX protein, human; C494811:BCL2L1 protein, human; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases