Dual pertussis toxin-sensitive pathway of zymosan-induced activation in guinea pig macrophages. An anti-CR3 antibody-inhibitable stimulation of phagocytosis and -resistant stimulation of O2- production and arachidonate release.
Complement receptor type 3 (CR3)-mediated cellular responses in guinea pig macrophages were investigated by using zymosan and serum-opsonized zymosan (SOZ) as the multivalent ligand for CR3. The ingestion of zymosan and SOZ was accompanied by O2- generation and arachidonate release. These responses were suppressed by prior exposure of macrophages to pertussis toxin (PT). Opsonization of zymosan gave rise to more than 6-fold activation of the ingestion, whereas the magnitude of either arachidonate release or O2- generation was unchanged. The Fab' fragment of anti-Z-1, a monoclonal antibody specific for the alpha chain of guinea pig CR3, inhibited the ingestion of zymosan by 60% without affecting zymosan-induced arachidonate release and O2- generation. These data suggested that there might be at least two functionally distinct binding sites for zymosan. O2- generation and arachidonate release might be regulated through one site and phagocytosis another. Both sites should be coupled to PT-sensitive GTP binding protein.
Hazeki
K
K
Department of Microbiology, Faculty of Pharmaceutical Sciences, Higashi-Nippon-Gakuen University, Ishikari-Tobetsu, Japan.
Tamoto
K
K
Ui
M
M
Mori
Y
Y
D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D001665:Binding Sites; D002478:Cells, Cultured; D019204:GTP-Binding Proteins / Q000378:metabolism; D006168:Guinea Pigs; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D008262:Macrophage Activation; D016177:Macrophage-1 Antigen / Q000276:immunology*; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009895:Opsonin Proteins; D037342:Pertussis Toxin; D010587:Phagocytosis; D013481:Superoxides / Q000378:metabolism*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology; D015054:Zymosan / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology
D007140:Immunoglobulin Fab Fragments; D016177:Macrophage-1 Antigen; D009895:Opsonin Proteins; D010566:Virulence Factors, Bordetella; D013481:Superoxides; D016718:Arachidonic Acid; D009240:N-Formylmethionine Leucyl-Phenylalanine; D015054:Zymosan; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins