Heterogeneity of granules of murine cytolytic T lymphocytes. Isolation of a homogeneous population of dense granules.
A separation procedure based on Percoll gradient centrifugation is described here that allows enrichment for two main populations of granules, with average densities of 1.05 and 1.1 g/ml. The heavy-density granules, which comprise 5-20% of the total amount of membrane-lytic activity, are morphologically and biochemically more homogeneous than the light-density granules, which are contaminated with other subcellular organelles. A trypsin-like serine esterase activity, used in the past as a granule marker, was mainly found in the free cytosol and in the light-density fractions, while a small portion of this activity was associated with the heavy-density fractions. This enzyme marker is therefore not exclusively associated with granules and should not be used as the only granule marker.
Persechini
P M
PM
Laboratory of Cellular Physiology and Immunology, Rockefeller University, New York, NY 10021.
Liu
C C
CC
Detmers
P A
PA
Young
J D
JD
D000818:Animals; D015415:Biomarkers / Q000032:analysis; D002458:Cell Fractionation; D002460:Cell Line; D002499:Centrifugation, Density Gradient; D003594:Cytoplasmic Granules / Q000201:enzymology; D004950:Esterases / Q000032:analysis*; D006461:Hemolysis; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000032:analysis; D051379:Mice; D008854:Microscopy, Electron; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D013347:Subcellular Fractions / Q000201:enzymology*; D013601:T-Lymphocytes / Q000201:enzymology* / Q000648:ultrastructure
D015415:Biomarkers; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin; D004950:Esterases; C022635:serine esterase