Details

Autor(en) / Beteiligte

• Koch, Christian
• Staffler, Günther
• Hüttinger, Robert
• Hilgert, Ivan
• Prager, Elisabeth
• Černý, Jan
• Steinlein, Peter
• Majdic, Otto
• Hořejší, Václav
• Stockinger, Hannes

Titel

T cell activation-associated epitopes of CD147 in regulation of the T cell response, and their definition by antibody affinity and antigen density

Ist Teil von

• International immunology, 1999-05, Vol.11 (5), p.777-786

Ort / Verlag

England: Oxford University Press

Erscheinungsjahr

1999

Quelle

Oxford Journals 2020 Medicine

Beschreibungen/Notizen

• CD147 is a broadly expressed cell surface glycoprotein of the Ig superfamily whose expression is up-regulated upon T cell activation. In order to elucidate a possible role of CD147 in T cell biology, we established 15 specific mAb. Seven distinct epitopes were defined by the mAb panel. Most of the mAb bound only to phytohemagglutinin (PHA)-activated but not resting T cells. We demonstrate that this was not because of true expression of activation-dependent neoepitopes but rather due to bivalent binding of the relatively low-affinity mAb (affinity constant KA values between 2.25 × 108 and 7 × 109 M–1) to the more densely expressed and/or more clustered CD147 molecules on the activated T cells. In contrast, the mAb with higher affinity (KA > 7 × 109 M–1) could stably bind in a monovalent fashion even to the relatively low dense CD147 molecules on resting T cells. This model might more generally explain the nature of `activation epitopes' described previously in other leukocyte surface molecules. Finally, we provide evidence that induction of ordered dimerization of CD147 by a mAb directed to a unique epitope results in strong inhibition of CD3-mediated T cell activation.