Human Eosinophils Express Bcl-2 Family Proteins: Modulation of Mcl-1 Expression by IFN-gamma

• Published in: American journal of respiratory cell and molecular biology Vol. 18; no. 3; pp. 315 - 322
• Main Authors: Druilhe, Anne, Arock, Michel, Le Goff, Liliane, Pretolani, Marina
• Format: Journal Article
• Language: English
• Published: United States Am Thoracic Soc 01.03.1998; American Thoracic Society
• Subjects: Apoptosis; bcl-2-Associated X Protein; bcl-X Protein; Cell Differentiation; Cytokines - pharmacology; Eosinophils - classification; Eosinophils - drug effects; Fetal Blood - cytology; Humans; Interferon-gamma - pharmacology; Myeloid Cell Leukemia Sequence 1 Protein; Neoplasm Proteins - biosynthesis; Proto-Oncogene Proteins - biosynthesis; Proto-Oncogene Proteins c-bcl-2 - biosynthesis
• ISSN: 1044-1549; 1535-4989
• DOI: 10.1165/ajrcmb.18.3.3019

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.