Immunocytochemical study of uptake of exogenous carrier-free copper-zinc superoxide dismutase by peripheral blood lymphocytes.
We recently demonstrated that exogenous copper-zinc superoxide dismutase (SOD) reduced HIV replication in tumor necrosis factor alpha activated chronically HIV-infected promonocytic U1 cell line and in peripheral blood mononuclear cells coculture. However, whether exogenous SOD penetrates the cellular membrane or acts extracellularly has been remained controversial. SOD has been considered as not to penetrate the cellular membrane because of its high molecular weight, thus the main site of action is presumed to be extracellular. In order to determine whether exogenous SOD penetrates inside the cell, we utilized a gentle immunocytochemical method to detect Mn and Cu,Zn SOD in peripheral blood lymphocytes incubated with various concentrations of exogenous carrier-free Cu,Zn SOD without prior permeabilization of cell membranes. After 24 hrs. the total SOD activity and immunocytochemical studies were performed. Here we demonstrate clearly that a large amount of carrier-free Cu,Zn SOD, added exogenously, penetrates the cellular membrane and increases total SOD activity.
Edeas
M A
MA
Department of Biochemistry Hôpital Antoine Béclère, Clamart, France.
Peltier
E
E
Claise
C
C
Khalfoun
Y
Y
Lindenbaum
A
A
D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008214:Lymphocytes / Q000166:cytology / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism*
D013482:Superoxide Dismutase