1. A Novel Anti-CD 18 mAb Recognizes an Activation-Related Epitope and Induces a High-Affinity Conformation in Leukocyte Integrins
- Author
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Pavla Angelisova, Jan Černý, Václav Hořejší, Ivan Hilgert, and Karel Drbal
- Subjects
Models, Molecular ,Integrins ,Protein Conformation ,medicine.drug_class ,Immunoprecipitation ,Immunology ,Cell ,Integrin ,Kinetics ,CD18 ,Lymphocyte Activation ,Monoclonal antibody ,Epitope ,Epitopes ,Jurkat Cells ,Mice ,Leukocytes ,medicine ,Animals ,Humans ,Immunology and Allergy ,Cell Aggregation ,biology ,Chemistry ,Antibodies, Monoclonal ,Hematology ,Ligand (biochemistry) ,Molecular biology ,Lymphocyte Function-Associated Antigen-1 ,Cell biology ,medicine.anatomical_structure ,CD18 Antigens ,biology.protein - Abstract
Monoclonal antibody MEM-148 was previously shown to recognize CD18 chains in a free form unassociated within leukocyte integrin heterodimers, but yet it is paradoxically able to induce a high-affinity conformation in the native, cell surface expressed LFA-1 molecules.Our results based on kinetics of binding, immunoprecipitation and cell-aggregation experiments demonstrate that the mAb does bind to and stabilizes a specific conformation of LFA-1 heterodimers apparently distinguished by an increased affinity to its cellular ligand(s).A similar high-affinity conformation of LFA-1, in which the MEM-148 epitope becomes exposed, is induced also by a Mg 2+ /EDTA or low pH (5.5-6.5) treatments which may mimic physiologically relevant situations in normal or inflamed tissues.Thus, mAb MEM-148 is a novel valuable tool for detection and induction of specific conformations of human leukocyte imegrins.
- Published
- 2001