A "network antigen" for human CD4. A murine monoclonal anti-idiotype to Leu-3a induces an anti-CD4 response in naive mice.
Previous studies have evaluated anti-CD4 mAb as idiotypic models of the HIV gp120-binding site for CD4. The success of this strategy depends upon the concept of internal image, whereby the binding paratope of the anti-CD4 structurally mimics the equivalent binding surface on HIV gp120. To test this concept of internal image, anti-idiotypic antibodies were raised against the anti-CD4, Leu-3a. If any of these anti-Id detect the paratopic idiotope on the anti-CD4 antibody, their own respective paratopes should structurally model the corresponding binding epitope on CD4 bound by Leu-3a. Consequently, the immunization of naive mice with the selected anti-Id should induce an anti-CD4 response which reflects the binding specificities of Leu-3a. Four anti-Id to Leu-3a were characterized and tested for their ability to induce anti-CD4 responses in naive animals. Although one anti-Id induced an anti-CD4 response in mice, no such response could be detected in other species. Thus the failure to raise anti-Id with internal image characteristics may provide an explanation for the lack of anti-gp120 activity reported in anti-Id antisera raised to multiple anti-CD4 antibodies.
Human Tumour Immunology Group, Imperial Cancer Research Fund, London, UK.
D G
DG
Healey
L
L
Dianda
P C
PC
Beverley
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology; D015704:CD4 Antigens / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D003429:Cross Reactions; D000939:Epitopes; D006801:Humans; D007130:Immunoglobulin Idiotypes / Q000276:immunology*; D007518:Isoantibodies / Q000276:immunology; D051379:Mice
D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D000939:Epitopes; D007130:Immunoglobulin Idiotypes; D007518:Isoantibodies