In vitro and in vivo targeting of radiolabeled monovalent and divalent haptens with dual specificity monoclonal antibody conjugates: enhanced divalent hapten affinity for cell-bound antibody conjugate.
A method of pretargeted immunolocalization of a mouse cell subset, using dual specificity monoclonal antibody conjugates and labeled divalent haptens, is described. Conjugates were prepared by coupling F(ab')2 fragments of an antibody specific for the allelic mouse B cell antigen Lyb8.2, to Fab' fragments of an anti-2,4-dinitrophenyl antibody. Divalent and monovalent haptens were obtained by coupling dinitrophenyl to peptides or to diethylene-triamine-pentaacetic acid. In vitro, divalent haptens bind with higher affinity to mouse spleen lymphocyte-bound than to excess soluble conjugate (affinity enhancement). In vivo, localization of 125I- or 111In-labeled divalent haptens in mouse spleen is much higher than that of the monovalent analogs. Thus, using divalent haptens, a new kind of specificity to target cells was achieved, suggesting that affinity enhancement may improve target to background ratios in radioimmunoscintigraphy.
Le Doussal
J M
JM
Immunotech S.A., Campus de Luminy, Marseilles, France.
Martin
M
M
Gautherot
E
E
Delaage
M
M
Barbet
J
J
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D001402:B-Lymphocytes / Q000276:immunology; D004136:Dinitrobenzenes / Q000276:immunology; D006241:Haptens / Q000276:immunology*; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D066298:In Vitro Techniques; D007205:Indium Radioisotopes; D007457:Iodine Radioisotopes; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D004369:Pentetic Acid / Q000276:immunology; D010455:Peptides / Q000276:immunology
D000911:Antibodies, Monoclonal; D004136:Dinitrobenzenes; D006241:Haptens; D007140:Immunoglobulin Fab Fragments; D007205:Indium Radioisotopes; D007457:Iodine Radioisotopes; D010455:Peptides; D004369:Pentetic Acid