Human eosinophils express bcl-2 family proteins: modulation of Mcl-1 expression by IFN-gamma.
The expression of the Bcl-2 family proteins Bax, Mcl-1, Bcl-2, and Bcl-xL, was examined in human peripheral blood eosinophils or in umbilical-cord-blood-derived eosinophils. Immunoblot analysis disclosed high amounts of the proapoptotic factor Bax in freshly purified eosinophils of both types. Although cord-blood-derived eosinophils expressed easily detectable levels of Mcl-1, Bcl-2, and Bcl-xL, only traces or no expression of these three antiapoptotic proteins were found in peripheral blood eosinophils. Incubation of both eosinophil types for 1 to 3 days in a cytokine-deprived medium led to apoptosis, without changes in the expression of Bax, Mcl-1, Bcl-2, or Bcl-xL. Although addition of interleukin-5 or interferon-gamma (IFN-gamma) to the culture medium increased the survival of both eosinophil types, a rise in the levels of Mcl-1 was observed only in IFN-gamma-treated cord-blood eosinophils. Together, these results indicate that human eosinophils have a specific profile of Bcl-2-family protein expression that depends on their maturation status and may be modulated by stimuli that influence their survival.
Druilhe
A
A
Unité de Pharmacologie Cellulaire, Institut Pasteur, Paris, France.
Arock
M
M
Le Goff
L
L
Pretolani
M
M
D017209:Apoptosis; D002454:Cell Differentiation; D016207:Cytokines / Q000494:pharmacology; D004804:Eosinophils / Q000145:classification / Q000187:drug effects*; D005312:Fetal Blood / Q000166:cytology; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein
C494826:BAX protein, human; C494811:BCL2L1 protein, human; D016207:Cytokines; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein; D007371:Interferon-gamma