Immune response against poly(Glu⁶⁰, Ala³⁰, Tyr¹⁰) (GAT): immunization with monoclonal anti‐idiotypic antibodies leads to the predominant stimulation of idiotypically similar immunoglobulins with anti‐GAT activity

Abstract

Two monoclonal anti-idiotypic antibodies (HP-Id20 and HP-Id22) recognizing two different public idiotopes expressed in the anti-poly(Glu60,Ala30,Tyr10) (GAT) response were used to immunize BALB/c and C57BL/6 mice. From these animals hybridomas were isolated. From BALB/c and C57BL/6 mice eight and seven monoclonal antibodies were characterized, respectively. The reagents were classified according to the expression of the public idiotypic specificity p.GAT (recognized by a rabbit antiserum). The anti-GAT activity and the expression of the various idiotopes characterized on anti-GAT polyclonal and monoclonal antibodies were also studied. Most of the reagents are Ab1'-type of antibody resembling anti-GAT antibodies. One anti-anti-idiotypic monoclonal antibody (Ab3) was also isolated from BALB/c mice. This suggests that in this experimental model the repertoire induced after HP-Id immunization and antigen stimulation is comparable. The idiotypic analysis of a large number of anti-GAT and of Ab1' monoclonal antibodies suggests that only two public idiotopes are involved in the anti-GAT response.

Gene repertoire of the anti-poly(Glu60Ala30Tyr10) (GAT) immune response: comparison of VH, V kappa, and D regions used by anti-GAT antibodies and monoclonal antibodies produced after anti-idiotypic immunization.

“…For the detection of the two idiotopes identified in the GAT response by HP-Id20 and HP-Id22 a solid-phase radioimmunoassay (RIA) was used (25). The idiotope binding inhibitory capacity (IBIC) of each AbN was determined.…”

“…The GAT-binding assay has been described (25). Results are expressed as the reciprocal of the dilution of supernatant giving 50% of maximal binding.…”

“…In this paper we report the nucleotide sequences of two sets of monoclonal antibodies obtained from BALB/c mice immunized with two different monoclonal anti-idiotypic antibodies (HP-Id) recognizing the two idiotopes previously defined (25). The VH, VK, and diversity (D) sequences ofthese monoclonals are compared to the corresponding sequences previously reported for HP-GAT.…”

“…At the idiotypic level the anti-GAT response is characterized by the expression of the public idiotypic specificity p.GAT defined by a xenogeneic antiserum (20,21) and expressed in all HP-GAT (15). More recently, two discrete idiotopes characteristic of the anti-GAT responses have been identified (22)(23)(24)(25).…”

Pathogenicity of human anti-platelet factor 4 (PF4)/heparin in vivo: generation of mouse anti-PF4/heparin and induction of thrombocytopenia by heparin

“…If the primary antigen is itself an antibody (or an autoantibody) the specificity of Ab 3 (anti-anti-Id) may be almost identical to the original immunizing autoantibody [22,42]. The capacity of the idiotypic cascade to produce autoantibodies and, more importantly, autoimmune disease has been demonstrated in other situations [43][44][45]. In these settings, the similarity between Ab 1 and Ab 3 has been further confirmed by amino acid sequence analysis of the complementarity determining regions (CDRs) of their respective heavy chains [46].…”