| Autor: |
Drbal, K., Cerný, J., Angelisová, P., Hilgert, I., Cebecauer, M., Šinkora, J., Horejši´, V. |
| Předmět: |
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| Zdroj: |
Tissue Antigens; Sep2000, Vol. 56 Issue 3, p258, 10p, 11 Graphs |
| Abstrakt: |
One of the recently described antigens broadly expressed on human leukocytes is CDw149, which was defined at the 6th Human Leukocyte Differentiation Antigen (HLDA) Workshop by means of 2 monoclonal antibodies (mAbs). Molecular characterization of this antigen has been lacking. In the present study we demonstrate that these anti-CDw149 mAbs actually recognize a clustered subset of a well-defined membrane protein, CD47, also known as integrin-associated protein (IAP). This clustered subset is present on leukocytes but not erythrocytes. The anti-CDw149 mAbs bind with only low affinity to a monomeric (unclustered) subset of CD47 but with high avidity to the CD47 clusters. A fraction of CD47 is associated with large complexes containing cytoplasmic signaling molecules (Src family kinases and heterotrimeric G-proteins) similar to glycosphingolipid-enriched microdomains (GEMs), which may explain the previously described signaling capacity of CD47. The low-affinity anti-CD47 mAbs may be useful tools targeting specific receptor complexes involved in cell activation. Specific reactivity of low-affinity mAbs with clustered subsets of cell surface antigens may more generally explain the nature of poorly defined 'activation forms' or activation neoepitopes described previously for several cell surface molecules. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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