ELICITATION OF DISTINCT POPULATIONS OF MONOCLONAL-ANTIBODIES SPECIFICFOR THE VARIABLE DOMAINS OF MONOCLONAL ANTIFLUORESCEIN ANTIBODY 4-4-20

Armenian hamsters were immunized with non-liganded, partially liganded or affinity-labeled anti-fluorescein Mab 4-4-20. Seventeen hybridoma producing monoclonal anti-4-4-20 antibodies were characterized from ch emically-mediated fusions of immune hamster lymphocytes with murine Sp 2/O-Ag14 myeloma cells. Distinct populations of anti-4-4-20 monoclonal antibodies were isolated from hamsters receiving immunizations with p artially liganded Mab 4-4-20 relative to those receiving affinity-labe led 4-4-20. Two of the three monoclonal antibodies produced in respons e to partially liganded 4-4-20 were inhibited in their interaction wit h 4-4-20 by fluorescyl ligand. These two clones, 1F4 and 1B7, recogniz ed unique epitopes on the 4-4-20 molecule, as demonstrated by non-reac tivity with members of the 4-4-20 idiotype family. Additionally, 1F4 a nd 1B7 demonstrated the ability to delay the association of fluorescei n with Mab 4-4-20. The 14 characterized non-ligand-inhibitable Mabs el icited to affinity-labeled 4-4-20 were classified into four separate g roups based on various binding properties with members of the 4-4-20 i diotype family and binding to resolved H- and L-chains in a western bl ot. Members of three of the four groups showed strong reactivity with both 04-01 Ig and 04-01 SCA, which utilizes the same L-chain as Mab 4- 4-20. Six non-ligand-inhibitable Mabs, 4A6, P1E11, 3A5-1, 2C3, 2C4, an d 1A4, delayed the dissociation rate of ligand from Mab 4-4-20 and mut ant 4-4-20 SCA L32phe.