The effect of fragment B of staphylococcal protein A on the binding of rabbit IgG to human granulocytes and monocytes

• Published in: Molecular immunology Vol. 19; no. 3; p. 407
• Main Authors: Barnett Foster, D E, Sjoquist, J, Painter, R H
• Format: Journal Article
• Language: English
• Published: England 01.03.1982
• Subjects: Animals; Binding Sites, Antibody; Dose-Response Relationship, Immunologic; Granulocytes - immunology; Humans; Immunoglobulin G - immunology; Monocytes - immunology; Peptide Fragments - immunology; Rabbits; Receptors, Fc - immunology; Rosette Formation; Staphylococcal Protein A - immunology
• ISSN: 0161-5890
• DOI: 10.1016/0161-5890(82)90206-1

The effect of fragment B of staphylococcal protein A on the binding of rabbit IgG to human granulocytes has been examined. When rabbit IgG sensitized sheep erythrocytes (EA) were preincubated with increasing amounts of fragment B, a dose dependent inhibition of rosette formation between the human granulocytes and the treated EA was observed. In contrast, rosette formation between human monocytes and fragment B treated EA was not impaired. These results confirm previous findings which revealed differences in the specificities of the human Fc receptors of these cells. Rabbit IgG was used in place of human IgG for the preparation of the sensitized erythrocytes since human IgG coated human erythrocytes were agglutinated by fragment B, indicating the possibility of a secondary binding site for human IgG in this fragment.