A model system for the analysis of B-cell activation and effector T-cell functions. T cell-dependent B-cell responses facilitated by anti-I-A antibodies.
We have attempted to develop an in vitro system where polyclonal B lymphocyte responses could be induced in 'antigen-like' conditions, that is, where surface immunoglobulin-dependent binding mediates interaction with a mitogen. Monoclonal anti-mu and anti-delta antibodies were covalently bound to lipopolysaccharide (LPS) and these complexes were shown to display mitogenic activity. Polyclonal plaque-forming cell (PFC) responses, however, were diminished in cultures stimulated by anti-mu-LPS (but not by anti-delta-LPS) indicating that 'anti-mu inhibition' of terminal B-cell differentiation also applies to 'specific' antibody responses. Moreover, the analysis of the functional activity of monoclonal antibodies to major histocompatibility complex (MHC) class II molecules revealed a surprising synergy between low, non-stimulatory concentrations of anti-mu-LPS (but not anti-delta-LPS) with anti-I-A antibodies. These responses are T-cell dependent and synergy with anti-mu-LPS conjugates can also be obtained with 'naturally' activated CD4+ cells isolated from normal donors. A model of molecular and cellular interactions was derived, which accounts for the present findings and is applicable in antigen-dependent lymphocyte collaboration.
Pereira
P
P
Department of Immunology, Pasteur Institute, Paris, France.
Bandeira
A
A
Kleine
B
B
Marquez
C
C
Coutinho
A
A
Martinez
C
C
D000276:Adjuvants, Immunologic / Q000502:physiology; D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000502:physiology; D001402:B-Lymphocytes / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D007072:Immunoglobulin D / Q000276:immunology / Q000502:physiology; D007075:Immunoglobulin M / Q000276:immunology / Q000502:physiology; D007518:Isoantibodies / Q000502:physiology*; D008070:Lipopolysaccharides; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008954:Models, Biological; D013601:T-Lymphocytes / Q000276:immunology*
D000276:Adjuvants, Immunologic; D000888:Antibodies, Anti-Idiotypic; D000949:Histocompatibility Antigens Class II; D007072:Immunoglobulin D; D007075:Immunoglobulin M; D007518:Isoantibodies; D008070:Lipopolysaccharides; C039951:anti-IgD; C044203:anti-IgM