Back to Search
Start Over
Different rosette assays for detecting Fc receptor-bearing lymphocytes measure different subpopulations.
- Source :
- Immunology; Aug78, Vol. 35 Issue 2, p407-414, 8p
- Publication Year :
- 1978
-
Abstract
- The capacity of purified lymphocytes from human peripheral blood to bind the Fc portion of IgG was investigated by the rosette technique using ox erythrocytes sensitized with rabbit anti-ox IgG (EA<subscript>ox</subscript>) and human erythrocytes sensitized with anti-CD IgG (EA<subscript>CD</subscript>). With unfractionated lymphocytes EA<subscript>ox</subscript> always detected more rosette-forming cells (RFC) than did EA<subscript>CD</subscript>; however, in lymphocyte populations specifically depleted of B lymphocytes by passage through copolymer styrene bead columns, the proportion of rosettes formed with EA<subscript>ox</subscript> and with EA<subscript>CD</subscript> was the same. Double labelling for Fc receptors and surface immunoglobulin (SIg) demonstrated that most of the lymphocytes which formed rosettes with either EA<subscript>ox</subscript> or EA<subscript>CD</subscript> also carried SIg. Pre-incubation of lymphocytes at 37° to remove heat-labile SIg did not affect their ability to form EA rosettes but reduced the proportion of SIg-bearing cells. Following pro-incubation a significant proportion of EA<subscript>ox</subscript> RFC still remained SIg positive but the lymphocytes which formed rosettes with EA<subscript>CD</subscript> no longer carried SIg. These studies suggest that rosette formation with EA<subscript>CD</subscript> detects only ‘K’ lymphocytes (non-T, non-B cells bearing heat-labile SIg) while EA<subscript>ox</subscript> detects some B lymphocytes as well. By reducing the amount of IgG bound to ox erythrocytes sensitivity was reduced to the point where EA<subscript>ox</subscript> no longer formed rosettes with B lymphocytes but still detected ‘K’ lymphocytes indicating either a qualitative or quantitative difference between the Fc receptors on B and ‘K’ lymphocytes. Treatment of lymphocytes with trypsin decreased the percentage of rosettes formed with EA<subscript>ox</subscript> but not with EA<subscript>CD</subscript> supporting the conclusion that there is a structural difference between the Fc receptors on B and ‘K’ lymphocytes although a difference in receptor density is not excluded. When EA<subscript>CD</subscript> and fluorescein-labelled ox erythrocytes sensitized with a low concentration of rabbit anti-ox IgG were mixed, most RFC bound both the indicator erythrocytes simultaneously suggesting that the Fc receptors on ‘K’ lymphocytes do not exhibit species specificity. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00192805
- Volume :
- 35
- Issue :
- 2
- Database :
- Complementary Index
- Journal :
- Immunology
- Publication Type :
- Academic Journal
- Accession number :
- 13989291