Fas and Fas ligand expression on human peripheral blood leukocytes.
OBJECTIVE
Study of Fas and Fas ligand (Fas-L) expression, as well as sFas-L release, by fresh human peripheral blood leukocytes.


METHODS
Flow cytometry, cytotoxicity, immunofluorescence staining of fresh smears. Western blotting.


RESULTS
Granulocytes and monocytes express a low level of Fas receptor, but no Fas-L. These cells, as well as NK cells, contain presynthesized depots of Fas-L which they express following activation by brief storage (60 min) at room temperature or during separation from whole blood. Such activation also leads to Fas receptor upregulation. NK cells do not express Fas receptor. Once expressed on blood leukocytes, fully functional Fas-L can be released from the membrane and can be detected in plasma-free cell supernatants.


CONCLUSIONS
Human peripheral blood granulocytes, monocytes and NK cells contain intracellular presynthesized Fas-L which they readily express following blood anticoagulation, blood storage or cell separation. Soluble Fas-L is released from those cells and can be detected in protein-free supernatants by immunoblotting.
Mincheff
M
M
Naval Medical Research Institute, Naval Medical Center, Bethesda, MD 20889-5607, USA.
Loukinov
D
D
Zoubak
S
S
Hammett
M
M
Meryman
H
H
D002469:Cell Separation; D053222:Fas Ligand Protein; D005434:Flow Cytometry; D006098:Granulocytes / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007424:Intracellular Fluid / Q000378:metabolism; D007962:Leukocytes / Q000276:immunology / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000097:blood*; D008565:Membrane Proteins / Q000378:metabolism; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D013997:Time Factors; D019014:fas Receptor / Q000096:biosynthesis* / Q000097:blood*
C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D019014:fas Receptor