A ligand-epitope in vitro analysis of major histocompatibility determinants expressed on B and T lymphocytes.
Human histocompatibility leucocyte antigen (HLA)-specific monoclonal antibody probes were used to determine the affinity constant, and cell-surface density of HLA class I and class II determinants. The measurements were estimated for single-cell units of B-lymphoblastoid cell line (B-LCL) and cloned activated T cells in different functional states. Each HLA subset showed unimodal affinity constant values for the interaction with the corresponding HLA-specific antibodies. Such values ranged between 2.2 x 10(7) M-1 (class I) and 4.0 x 10(7) M-1 (class II) for different histocompatibility epitopes. In both B and T cells there was a rank order of epitope expression, class I being highly expressed (5 x 10(6) epitopes/cell) followed by DR, DQ and DP, (1.1-3.0 x 10(6) epitopes/cell). Suppressive clones carrying functionally defined stimulating determinants previously designated 'DY' carried similar numbers of DR, DQ and DP binding sites to DY- non-suppressive clones, but showed selective increases of class II determinants reactive with broad class II-specific antibodies. The results are discussed in the context of the functional consequences of different patterns of HLA epitope expression in immune responses.
Fernandez
N
N
Department of Immunology, London Hospital Medical College, U.K.
Kurpisz
M
M
Labeta
M
M
Sachs
J
J
Pawelec
G
G
D000911:Antibodies, Monoclonal / Q000276:immunology; D000915:Antibody Affinity / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D000939:Epitopes / Q000032:analysis*; D006680:HLA Antigens / Q000032:analysis*; D006681:HLA-D Antigens / Q000032:analysis; D015395:Histocompatibility Antigens Class I / Q000032:analysis; D006801:Humans; D008024:Ligands; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000939:Epitopes; D006680:HLA Antigens; D006681:HLA-D Antigens; D015395:Histocompatibility Antigens Class I; D008024:Ligands