Determination of adhesion force between single cell pairs generated by activated GpIIb-IIIa receptors.
A biophysical approach was used to directly determine the avidity of the junction between two Chinese hamster ovary (CHO) cells bearing recombinant GpIIb-IIIa in the presence and absence of fibrinogen. Micromanipulation was used to induce conjugation of the cell pairs with or without activating the GpIIb-IIIa molecules with monoclonal antibody (MoAb) 62. Activation of GpIIb-IIIa caused an increase in the force required to separate the conjugates. The molecular bonding force between cells bearing activated GpIIb-IIIa and fibrinogen molecules was found to be 2.1 x 10(-7) dyne, which is 3.7 times higher than that between nonactivated GpIIb-IIIa and fibrinogen (5.7 x 10(-8) dyne). The results provide a quantitative assessment of the molecular bonding force between fibrinogen and the GpIIb-IIIa expressed on cell surface. The findings indicate that the activation of GpIIb-IIIa leads to an increase in the adhesive force in CHO cell aggregation by increasing the strength of the GpIIb-IIIa-fibrinogen bonds rather than the number of these bonds.
Sung
K L
KL
Department of AMES-Bioengineering, University of California, San Diego, La Jolla 92093-0412.
Frojmovic
M M
MM
O'Toole
T E
TE
Zhu
C
C
Ginsberg
M H
MH
Chien
S
S
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D016466:CHO Cells; D002448:Cell Adhesion / Q000187:drug effects; D003001:Cloning, Molecular; D006224:Cricetinae; D005340:Fibrinogen / Q000378:metabolism* / Q000494:pharmacology; D015723:Gene Library; D006801:Humans; D007700:Kinetics; D004915:Leukemia, Erythroblastic, Acute; D046911:Macromolecular Substances; D010980:Platelet Membrane Glycoproteins / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism; D013997:Time Factors; D014162:Transfection; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D046911:Macromolecular Substances; D010980:Platelet Membrane Glycoproteins; D011994:Recombinant Proteins; D005340:Fibrinogen