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A proteolytically truncated form of free CD18, the common chain of leukocyte integrins, as a novel marker of activated myeloid cells
- Source :
- Blood. 98(5)
- Publication Year :
- 2001
-
Abstract
- An unusual CD18 monoclonal antibody (mAb) MEM-148 binds, in contrast to standard CD18 mAbs, specifically to peripheral blood monocytes and neutrophils activated by various stimuli such as phorbol myristate acetate, opsonized zymosan, heat-aggregated immunoglobulin, and (after priming with lipopolysaccharide, tumor necrosis factor, or granulocyte-macrophage colony-stimulating factor) also by formyl-methionyl-leucyl-phenylalanine. In addition, in vivo activated neutrophils obtained from urine of patients following recent prostatectomy were also strongly positive for MEM-148. On the activated myeloid cells the mAb recognized a 65- to 70-kd protein identified immunochemically and by mass spectrometric peptide sequencing as a membrane-anchored fragment of CD18 (the common chain of leukocyte integrins) produced by proteolytic cleavage. The CD18 fragment originated mainly from integrin molecules stored intracellularly in resting cells, it was unassociated with CD11 chains, and its formation was inhibited by several types of protease inhibitors. Thus, the 65- to 70-kd CD18 fragment represents a novel abundant activation marker of myeloid cells of so far unknown function but possibly involved in conformational changes in leukocyte integrin molecules resulting in increased affinity to their ligands.
- Subjects :
- Lipopolysaccharides
Male
medicine.drug_class
Neutrophils
Immunology
Integrin
Blotting, Western
CD18
Monoclonal antibody
Biochemistry
Mass Spectrometry
Monocytes
chemistry.chemical_compound
Epitopes
Antibody Specificity
Endopeptidases
medicine
Cell Adhesion
Humans
Electrophoresis, Gel, Two-Dimensional
Myeloid Cells
biology
Cell adhesion molecule
Tumor Necrosis Factor-alpha
Monocyte
Zymosan
Antibodies, Monoclonal
Granulocyte-Macrophage Colony-Stimulating Factor
Cell Biology
Hematology
Molecular biology
Peptide Fragments
N-Formylmethionine Leucyl-Phenylalanine
medicine.anatomical_structure
chemistry
CD18 Antigens
Immunoglobulin G
biology.protein
Tetradecanoylphorbol Acetate
Tumor necrosis factor alpha
Antibody
Biomarkers
Subjects
Details
- ISSN :
- 00064971
- Volume :
- 98
- Issue :
- 5
- Database :
- OpenAIRE
- Journal :
- Blood
- Accession number :
- edsair.doi.dedup.....5b7f38dfd3dbd1133c393d639c7a77d5