PRIMARY STRUCTURES OF 3 ARMENIAN HAMSTER MONOCLONAL-ANTIBODIES SPECIFIC FOR IDIOTOPES AND METATOPES OF THE MONOCLONAL ANTIFLUORESCEIN ANTIBODY-4-4-20

paper reports the complete V-gamma, V-kappa, C(gamma)l and C-kappa nuc leotide and deduced amino acid sequences of two hamster monoclonal ant i-metatype antibodies, 3A5-1 and 4A6. These antibodies have been previ ously characterized in terms of their binding and molecular stabilizat ion properties with liganded murine monoclonal and single-chain antibo dy 4-4-20 active sites. Also reported are the complete V-kappa and C-k appa nucleotide and deduced amino acid sequence of hamster monoclonal anti-idiotype antibody 1F4, which is specific for the unliganded 4-4-2 0 active site. Oligonucleotide primers based on the 5' ends of murine variable genes, along with primers specific for murine IgG C(gamma)l a nd kappa constant region genes, have been used in cDNA and polymerase chain reactions (PCRs) to amplify IgG cDNA from Armenian hamster/mouse hybridomas. The hamster C(gamma)l and C-kappa domain sequences are hi ghly homologous to previously reported murine sequences. The anti-idio type mAb V-kappa gene demonstrated strong similarity to the murine Vka ppaV gene subgroup while the two anti-metatype mAb V-kappa genes appro ximated more closely to the murine VkappaIII gene subgroup. The two an ti-metatype mAbs utilized highly homologous V-gamma genes, with differ ing HCDR 3 regions, that appeared similar to the murine VgammaI(a) sub group. These sequence determinations represent the first primary struc tures reported for antibodies with anti-metatype activity and are addi tions to the relatively sparse hamster immunoglobulin genetic database . Results are discussed in terms of 4-4-20 active site specificity and anti-metatype activity, as well as immunoglobulin structural diversit y in an anti-Ig immune response.