lpr T cells have lower ability to maintain bcl-2 expression ex vivo.
Autoimmune-prone lpr mice develop lymphoproliferative disorders, whereas their lymphocytes show accelerated apoptosis in culture. To elucidate whether the bcl-2 protein, a repressor of apoptosis, is critical to the discrepancy between in vivo and in vitro survival, we examined bcl-2 expression in T cells from +/+ and lpr mice during culture. The expression levels of bcl-2 in cultured T cells from lpr mice were significantly down-modulated compared to those from +/+ mice and freshly obtained T cells. Besides, the reduction of bcl-2 protein levels was inhibited in T cells cultured in the presence of T cell receptor (TCR) signalling. These results suggest that lpr T cells might be susceptible to apoptosis in vitro due to down-modulation of bcl-2 by withdrawal of TCR signalling.
Matsumoto
Y
Y
Department of Internal Medicine, Nagoya University Daiko Medical Centre, Nagoya, Japan. matsukun@tsuru.med.nagoya-u.ac.jp
Shinzato
T
T
Takai
I
I
Kimura
Y
Y
Nakai
S
S
Miwa
M
M
Fuse
K
K
Yoshikai
Y
Y
Maeda
K
K