CD36-mediated signal transduction in human monocytes by anti-CD36 antibodies but not by anti-thrombospondin antibodies recognizing cell membrane-bound thrombospondin.
Mononuclear cells (MNC) treated with anti-CD36 Fab or F(ab')2 fragments and then stimulated with anti-rabbit (F(ab')2 displayed an oxidative burst, suggesting that the crosslinking of CD36 promotes signal transduction in the absence of an Fc receptor involvement. Moreover, intact anti-TSP mediates a weak oxidative burst in MNC, which was strongly enhanced upon pretreatment of monocytes (but not lymphocytes) with TSP. This response, however, was mediated by Fc receptors, not by an involvement of CD36. Other means of crosslinking cell-bound TSP and exposure of MNC to surface-bound TSP failed to promote an oxidative burst. Crosscompetition tests confirmed that the interaction site(s) of TSP with monocytes are distinct from the signal-promoting sites recognized by polyclonal and 3 monoclonal anti-CD36 antibodies.
Schüepp
B J
BJ
Institute of Veterinary Virology, University of Berne, Switzerland.
Pfister
H
H
Clemetson
K J
KJ
Silverstein
R L
RL
Jungi
T W
TW
D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000276:immunology*; D000943:Antigens, Differentiation / Q000276:immunology*; D002462:Cell Membrane / Q000276:immunology / Q000502:physiology; D006801:Humans; D007140:Immunoglobulin Fab Fragments; D066298:In Vitro Techniques; D007700:Kinetics; D008163:Luminescent Measurements; D008562:Membrane Glycoproteins; D009000:Monocytes / Q000276:immunology / Q000502:physiology*; D010980:Platelet Membrane Glycoproteins / Q000276:immunology / Q000502:physiology*; D015398:Signal Transduction; D019699:Thrombospondins
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D007140:Immunoglobulin Fab Fragments; D008562:Membrane Glycoproteins; D010980:Platelet Membrane Glycoproteins; D019699:Thrombospondins; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1