The subcellular distribution of five major glycosphingolipids (GSLs) i
n human neutrophils was analyzed, The neutrophils were isolated from t
he blood of six donors and subdivided in three fractions containing th
e cell membranes, and the primary and the secondary granules, respecti
vely. The separation was confirmed with antibodies detecting establish
ed subcellular fraction-specific molecules, The two main neutral GSLs
Gal beta 1-4Glc beta 1-1'Cer (lactosylceramide, LacCer) said nLc(4)Cer
(paragloboside, PG) and the three gangliosides IV(3)NeuAcnLc(4)Cer (2
-3SPG), IV(6)NeuAcnLc(4)Cer (2-6SPG), and VI(3)NeuAcnLc(6)Cer (2-3SnHC
) were quantitated using the immunochemical digoxigenin (DIG) staining
procedure. Secondary granules contained the highest amount of these G
SLs, They are followed by the primary granules and the cell membranes.
Based on this quantitation, we conclude that the majority of the GSLs
of neutrophils occur intracellularly. These findings are in striking
contrast to the general assumption of GSLs being mainly concentrated i
n the cell membrane.