Intracellular localization of glycosyl-phosphatidylinositol-anchored CD67
and FcRIII (CD16) in affected neutrophil granulocytes of patients with
paroxysmal nocturnal hemoglobinuria
CR Jost, ML Gaillard, JA Fransen, MR Daha and LA Ginsel
Laboratory for Electron Microscopy, University of Leiden, The Netherlands.
Immunoelectron microscopical studies performed in healthy human neutrophils
showed the presence of glycosyl-phosphatidylinositol (GPI)- linked CD67 in
granules. The use of immunogold double-labeling of CD67 and lactoferrin
(LF; as marker for specific granules) or CD67 and myeloperoxidase (MPO; as
marker for azurophilic granules) showed that CD67 occurred only in the
specific granules. Furthermore, flow cytometry showed that CD67 has a low
level of expression on the plasma membrane of these cells. In paroxsymal
nocturnal hemoglobinuria (PNH)- affected neutrophils, CD67 was not detected
in any intracellular compartment by immunoelectron microscopy, and flow
cytometry showed no CD67 on the plasma membrane. In earlier studies, FcRIII
was found on the plasma membrane, in electron-lucent vesicles, and in the
Golgi complex of healthy neutrophils, and in the Golgi complex of some of
the PNH-affected neutrophils. Here we have studied FcRIII in PNH-affected
cells of three other patients and found, by immunoelectron microscopy, that
the receptor can not be detected in these cells. However, flow cytometry
showed that FcRIII was not completely absent on the plasma membrane of the
affected cells, but that the level of expression on these cells was low.
Thus, PNH patients can differ from one another with respect to the
occurrence of affected neutrophils that have a detectable level of FcRIII
in the Golgi complex. In summary, these findings show not only that the
expression of the two GPI-linked proteins, CD67 and FcRIII, is markedly
lower on the plasma membrane, but also that neither occurred in any of the
intracellular compartments of affected neutrophils of the PNH patients
examined in this study.
Volume 78,
Issue 11,
pp. 3030-3036,
12/01/1991
Copyright © 1991 by The American Society of Hematology
