Am. J. Respir. Cell Mol. Biol., Vol 10, No. 5, May 1994, 493-498.
Manganese superoxide dismutase and heat shock protein 70 are not necessary for suppression of apoptosis in human peripheral blood neutrophils
G Cox, LW Oberley and GW Hunninghake
Department of Medicine, University of Iowa College of Medicine, Iowa City.
We have previously shown that granulocyte (G-CSF) and
granulocyte/macrophage (GM-CSF) colony-stimulating factors present in human
bronchial epithelial cell conditioned medium (HBEC-CM) suppress apoptosis
in neutrophils. In this study, we demonstrate that HBEC-CM also induces
increased expression of manganese superoxide dismutase (MnSOD) and heat
shock protein 70 (HSP70) in neutrophils. However, treatment of neutrophils
with recombinant GM-CSF and G-CSF, which suppressed apoptosis to equivalent
degrees, did not induce MnSOD or HSP 70. Thus, we conclude that induction
of stress proteins is associated with, but not necessary for, suppression
of apoptosis.
