Localization of granule proteins in human eosinophil bone marrow progenitors.
Eosinophils have a characteristic content of cationic proteins, stored in core-containing specific granules and released at sites of inflammation; coreless granules (sometimes called primary) are present in eosinophil promyelocytes. In order to determine a possible relationship between the two granule subsets, immunoelectron-microscopic techniques were used to determine the presence and precise intragranular distribution of major basic protein (MBP), eosinophil cationic protein (ECP), eosinophil peroxidase (EPO), and arylsulfatase B of eosinophil granules, as well as the Charcot-Leyden crystal (CLC) protein, in eosinophil progenitors of the bone marrow. MBP, ECP, EPO, and arylsulfatase B were observed in both coreless and core-containing (specific) granules. The difference in the distribution of MBP, having a uniform distribution in coreless granules and a crystalloid distribution in core-containing (specific) granules, could indicate a maturational process of a common organelle. CLC protein was distributed in the cytosol, in the euchromatin of the nuclei, but was also present in a rare granular compartment of both immature and mature eosinophils. The present findings suggest that coreless granules develop into core-containing specific granules.
Egesten
A
A
Department of Medicine, University Hospital, Lund, Sweden.
Calafat
J
J
Weller
P F
PF
Knol
E F
EF
Janssen
H
H
Walz
T M
TM
Olsson
I
I
D001798:Blood Proteins / Q000302:isolation & purification; D002451:Cell Compartmentation; D002803:Chondro-4-Sulfatase / Q000302:isolation & purification; D003594:Cytoplasmic Granules / Q000737:chemistry / Q000201:enzymology / Q000648:ultrastructure*; D047091:Eosinophil Granule Proteins; D047093:Eosinophil Major Basic Protein; D047209:Eosinophil Peroxidase; D004802:Eosinophilia; D004804:Eosinophils / Q000648:ultrastructure*; D006023:Glycoproteins / Q000302:isolation & purification; D006098:Granulocytes / Q000648:ultrastructure*; D006412:Hematopoietic Stem Cells / Q000648:ultrastructure*; D006801:Humans; D008245:Lysophospholipase; D016253:Microscopy, Immunoelectron; D010544:Peroxidases / Q000302:isolation & purification; D011509:Proteoglycans / Q000302:isolation & purification; D012260:Ribonucleases
D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D006023:Glycoproteins; D011509:Proteoglycans; C074129:PRG2 protein, human; D047209:Eosinophil Peroxidase; D010544:Peroxidases; D012260:Ribonucleases; D008245:Lysophospholipase; C011711:lysolecithin acylhydrolase; D047093:Eosinophil Major Basic Protein; D002803:Chondro-4-Sulfatase