1. The Bactericidal/Permeability-Increasing Protein (BPI) Is Present in Specific Granules of Human Eosinophils
by Jero Calafat, Hans Janssen, Anton Tool, Mieke A. Dentener, Edward F. Knol, Helene F. Rosenberg, and Arne Egesten
Blood
Volume 91(12):
June 15, 1998
©1998 by American Society of Hematology

2. A doublet 55-kD immunoreactive band corresponding to BPI is present in neutrophils (lane 1) and eosinophils (lane 3), but not in lymphocytes (lane 2).
A doublet 55-kD immunoreactive band corresponding to BPI is present in neutrophils (lane 1) and eosinophils (lane 3), but not in lymphocytes (lane 2). Highly purified cells were lysed and subject to SDS-PAGE/Western blotting. The primary antibody was detected by a secondary goat antirabbit antibody conjugated with alkaline phosphatase.
Jero Calafat et al. Blood 1998;91:
©1998 by American Society of Hematology

3. Localization of BPI in eosinophils.
Localization of BPI in eosinophils. Cryosections of eosinophils labeled to detect BPI. Labeling of the core-containing specific granules of eosinophils was heterogeneous. The top of the micrograph shows an eosinophil with labeled granules (large arrows); however, the labeling was less intense than in the neutrophil at the bottom. Some labeling (small arrows) was also observed on the surface membrane of the eosinophil (insert). The nucleus (n) was unlabeled. Bars = 200 nm.
Jero Calafat et al. Blood 1998;91:
©1998 by American Society of Hematology

4. Localization of BPI in eosinophilic myelocytes.
Localization of BPI in eosinophilic myelocytes. Cryosections of bone marrow cells incubated with anti-BPI and visualized by secondary gold-conjugated antibody. An area of an eosinophilic myelocyte is shown. Most of the granules do not possess a crystalloid, but two crystalloid-containing mature specific granules are present (c). BPI (arrows) is present in almost all granules and in the endoplasmic reticulum (er). Bars = 400 nm.
Jero Calafat et al. Blood 1998;91:
©1998 by American Society of Hematology

5. Localization of BPI in eosinophils after coincubation with STZ
Localization of BPI in eosinophils after coincubation with STZ. Cells were prewarmed for 10 minutes at 37°C and activated with IL-5 at 0.1 nmol/l for 20 minutes before the addition of STZ and coincubation for 10 minutes.
Localization of BPI in eosinophils after coincubation with STZ. Cells were prewarmed for 10 minutes at 37°C and activated with IL-5 at 0.1 nmol/l for 20 minutes before the addition of STZ and coincubation for 10 minutes. Ultrathin cryosections were incubated with anti-BPI and visualized by secondary gold-conjugated antibody. Area of an eosinophil showing a phagosome with a STZ containing BPI. Granules are seen fusing with the phagosome (arrowheads), whereas some intact granules (g) are seen close to the membrane of the phagosome. Bar = 400 nm.
Jero Calafat et al. Blood 1998;91:
©1998 by American Society of Hematology