Modifications of sialidase activity during the monocyte-macrophage differentiation in vitro.
Human mononuclear cells were isolated from peripheral blood by centrifugation over Ficoll Hypaque, followed by adherence to plastic dishes. Monocyte-derived macrophages were obtained after culture for 3 or 5 days of the adherent cells in RPMI medium containing 20% heat-inactivated foetal calf serum. The sialidase activities were assayed in the whole homogenate using sodium 4-methyl-umbelliferyl-alpha-D-neuraminate as substrate, at various pHs, ranging from 3.6 to 6. The in vitro differentiation of monocytes into macrophages from day 0 up to day 5 was accompanied by a significant (P less than or equal to 0.01) increase in the sialidase activity on both a per-cell (+360%) and a per-mg protein in the homogenate (+125%) basis.
Lambré
C R
CR
INSERM, U 139, Hôpital H. Mondor, Créteil, France.
Greffard
A
A
Gattegno
L
L
Saffar
L
L
D002454:Cell Differentiation / Q000502:physiology; D006801:Humans; D008264:Macrophages / Q000166:cytology / Q000201:enzymology*; D009000:Monocytes / Q000166:cytology / Q000201:enzymology*; D009439:Neuraminidase / Q000378:metabolism*
D009439:Neuraminidase