Ig VH-dependent interaction between immunoglobulins and CD4.
CD4 interacts with the immunoglobulin (Ig)-VH domains by a virtue of its solvent-exposed C and C strands. These two strands also contribute to the full HIV-gp120 binding and participate significantly in binding to class II MHC molecules. In this paper we hypothesize that any high-affinity interaction between serum (or membrane-expressed) Ig and CD4 may have impact on early T cell activation events. The existing data provide evidence for different outcomes of a high affinity Ig/CD4 interaction on T cell proliferation and cytokine secretion: costimulation and inhibition. We will also discuss how a low affinity CD4/Ig interaction could play an important role in B cell stimulation initiated through surface Ig receptors, and how CD4 may be involved in shaping the B cell repertoire.
Lenert
P
P
Louis-Charles Simard Research Center, Notre-Dame Hospital, University of Montreal, Quebec, Canada.
Lenert
G
G
Zanetti
M
M
D000818:Animals; D000936:Antigen-Antibody Complex / Q000378:metabolism; D001402:B-Lymphocytes / Q000276:immunology; D001665:Binding Sites; D015704:CD4 Antigens / Q000378:metabolism*; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000378:metabolism*; D007135:Immunoglobulin Variable Region / Q000378:metabolism*; D008213:Lymphocyte Activation; D051379:Mice; D018345:Mice, Knockout; D013205:Staphylococcal Protein A / Q000276:immunology / Q000378:metabolism; D018089:Superantigens / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology
D000936:Antigen-Antibody Complex; D015704:CD4 Antigens; D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region; D013205:Staphylococcal Protein A; D018089:Superantigens