Shared idiotypes are expressed on mouse and human anti-DNA autoantibodies.

The expression of common idiotypes on human and mouse anti-DNA monoclonal autoantibodies made by hybridomas was examined by their competitive binding to anti-idiotype antibodies. Some murine autoantibodies inhibited the binding of a human anti-DNA autoantibody 16/6 to monoclonal or polyclonal anti-idiotypic antibodies. Another human antibody (134) was not inhibited in its binding to homologous anti-idiotypic antibodies. The expression of the human 16/6 idiotype on mouse antibodies was restricted to those that had a specificity similar to the 16/6 antibody itself, their major properties being that they reacted more strongly with single stranded DNA (ssDNA) than double stranded DNA (dsDNA). One mouse antibody expressing the 16/6 idiotype also bound weakly to RNA. The results imply structural similarities between the binding sites of the antibodies in the two species, and are consistent with evolutionary conservation of V genes coding for primitive ancestral antibodies that react with DNA and become diversified through somatic mutation.     

A common anti-cardiolipin antibody idiotype in autoimmune disease: identification using a mouse monoclonal antibody directed against a naturally-occurring anti-phospholipid antibody

We have recently produced a series of human monoclonal antibodies reacting with cardiolipin. One of these, H3, a polyspecific IgM/k derived from a normal individual, was used to raise mouse monoclonal antibody to its idiotype. Two anti-idiotypic antibodies, S2.9 (IgG2b) and S2.10 (IgM) were selected for their specific reaction with H3.S2.9 did not react with five other human monoclonal antibodies of IgM/k class despite the fact that these shared some antigen-binding characteristics with H3.S2.9 was able to block the binding of H3 to all of its cross-reactive antigens including cardiolipin, while S2.10 was not. S2.9 was equally efficient in blocking the binding of H3 to three of its cross-reactive antigens, cardiolipin, diphtheria and tetanus toxoids; greater than 90% inhibition could be achieved at an equimolar ratio of H3 to S2.9. The anti-idiotype S2.9 was used to demonstrate the presence of the H3 idiotype in serum. This idiotype was found in amounts greater than that seen in 42 normal individuals, in 30 of 36 patients with systemic lupus erythematosus (SLE), eight of 20 patients with rheumatoid arthritis (RA), 8 of 20 patients with Felty's syndrome as well as 10 of 23 patients with syphilis. Not one of nine patients with drug-induced lupus syndrome had abnormal levels. In patients with SLE and Felty's syndrome there was a good correlation between the amount of anti-cardiolipin antibodies and the amount of H3 idiotype (rs = 0.70 and 0.69 respectively). No such correlation was found in syphilitics or in patients with RA. In patients with SLE the H3 idiotype was present on IgM and IgG anti-cardiolipin antibodies. In 15 of 16 SLE sera with high levels of cardiolipin antibody, S2.9 blocked binding of serum antibodies to cardiolipin by 13-72%, with a mean value of 49%. One patient had a high level of anti-cardiolipin antibody which could not be blocked by S2.9. These results indicate that a mouse monoclonal antibody which reacts with an idiotope in the antigen-binding region of a naturally-occurring phospholipid antibody also defines a common idiotype of anti-cardiolipin antibodies in patients with autoimmune disease.     

A sensitive radioimmunoassay for the detection of monoclonal anti-idiotope antibodies

A radioimmunoassay was developed in order to detect anti-idiotypic antibodies in the supernatants of hybrid cells. This assay is both sensitive and specific for anti-idiotypic (but not anti-allotypic) antibodies. Monoclonal antibodies present in test supernatants are bound by an anti-immunoglobulin coated solid phase. Subsequent incubation with a source of mouse immunoglobulin 'blocks' unreacted anti-immunoglobulin antibodies on the solid phase. Anti-idiotypic antibodies are then detected by their ability to bind 125I-labelled idiotype-bearing antibody. This paper describes the use of this assay to detect monoclonal anti-idiotypic antibodies in 2 systems: the cross-reactive idiotype of A/J anti-ABA antibodies, and the idiotype expressed by the myeloma protein HOPC 8. Similarly, 125I-labelled anti-idiotype antibodies may be used in this assay to detect monoclonal idiotype-bearing antibodies. Further modifications are described which would allow the detection of monoclonal anti-allotype antibodies.     

Anti-Idiotypic Antibody Used for the Localization of Parenterally Administered Monoclonal Anti-Progesterone Antibody in Mice

Affinity-purified rabbit and sheep anti-idiotypic antisera raised against mouse monoclonal anti-progesterone IgG1 antibody (DB3) or mouse myeloma IgG1 protein P3 (MOPC 21) showed high binding specificities to the respective idiotypes used for immunization as determined by RIA or ELISA. They have been used in an indirect immunofluorescent method to demonstrate the localization of parenterally administered idiotypes in pregnant or pseudopregnant BALB/c mouse frozen tissue preparations, at known stages post coitum after a single intraperitoneal or intravenous injection of DB3 or P3. DB3 was visualized on the surface of uterine luminal and glandular epithelia of pregnant mice 36 h after treatment; the localization was DB3-specific as it was not seen in mice treated with P3 (using sheep anti-P3 anti-idiotype as a probe) or saline. The fluorescent staining reaction in oviduct was weak and only appeared on the surface of the oviducal serosa (peritoneal side). Both DB3 and P3 were also localized in liver (granules of Kupffer cells), kidney (glomerular basement membrane), spleen (on the membrane surface of mononuclear cells in the white pulp), and peritoneal exudate cells (on the membrane surface). Staining could be completely blocked by the addition of the free idiotypes against which the anti-idiotypes were made but not by the unrelated idiotype. Anti-idiotypic labelling in vivo is more specific and selective than anti-whole immunoglobulin labelling.     

Therapeutic strategies for B cell malignancies involving idiotype-anti-idiotype interactions

The therapeutic use of unmodified monoclonal anti-idiotypic antibody for human B cell malignancies has met with limited success. Some factors thwarting antibody attack can be identified, such as the presence of extracellular idiotypic immunoglobulin (Ig), and the escape of the target cell by antigenic modulation. Another possibility is a change in idiotypic determinants due to somatic mutation. For direct attack on tumor cells in vivo it might be necessary to use antibody derivatives: univalent antibodies will avoid modulation, and chimeric univalent antibodies consisting of mouse Fab' gamma linked to host Ig of appropriate subclass can be engineered to mediate particular effector functions while reducing immunogenicity. Another approach is to use toxin or isotope-bearing antibodies. However, the final eradication of tumor might involve the natural non-specific, and specific anti-idiotypic mechanisms of the host which should not be damaged by antibody therapy, and which appear to be involved in control of tumor progression in patients in long-term remission. Rapidly growing animal lymphomas presently available as models cannot mimic more than a small fraction of human lymphoma but they provide useful information for design of passive anti-idiotype therapy. However host anti-idiotypic immunity must be induced in such models by pre-immunization with purified idiotype. Such a procedure can generate effective anti-idiotypic immunity which is highly protective in mouse and guinea pig lymphomas. Analysis of mechanisms involved should give insight into the role of the idiotype networks in the behavior of human disease.     

An anti-idiotypic antibody against Graves' IgG

Rabbit antibodies were raised against Graves' IgG adsorbed onto a TSH-receptor affinity and eluted thereof by [3H]NaCl. The rabbit serum absorbed against normal human IgG (ARI) still bound to Graves', control and Hashimoto's IgG preparations but in the latter two, binding was inhibited by bTSH (10 mU/ml). In addition, ARI stimulated thyroid cell cyclic AMP accumulation in both human and rat thyroid cells. The ARI preparation may, therefore, contain an "internal image" anti-idiotype causing thyroid (Ab2) stimulation, a Graves' disease specific anti-idiotype whose binding with Ab2 inhibits its ability to bind TSH and anti-anti-idiotype (Ab3) to "internal image" Ab2. In further studies, Graves' specific cross-reactive idiotype was found in 10/11 IgGs from patients with active Graves' disease. This study emphasizes the workings of Jerne's immunologic network and the complexity of polyclonal "anti-idiotypic" antibodies.     

Analysis of the hepatobiliary transport of IgA with monoclonal anti-idiotype and anti-allotype antibodies

The processing and fate of mixed immune complexes is influenced by the antibody isotypes present. The hepatobiliary transport of mixed immune complexes containing the mouse IgA myeloma protein J558 and corresponding monoclonal IgG or IgM anti-J558 idiotype or monoclonal IgG anti-mouse IgA allotype antibodies has been studied. The anti-idiotype or anti-allotype antibodies were radiolabeled and injected into mice with or without mouse polymeric IgA (J558). IgG anti-idiotype antibodies to J558 IgA were selectively transported into bile by J558 IgA. This process occurred with a radiolabeled Fab preparation of the IgG anti-idiotype and was inhibitable with IgA of an irrelevant antigenic specificity. Thus, polymeric IgA influenced the fate of IgA-IgG idiotype-anti-idiotype serum immune complexes. A monoclonal anti-idiotype antibody of the IgM isotype (D8-3) was not selectively transported into bile by itself or as an IgA-IgM complex. A monoclonal IgG antibody (CB5-6) to a mouse allotype determinant in the Fc portion of IgA was not selectively transported into bile. This anti-allotype monoclonal antibody inhibited the hepatobiliary transport of 125I-polymeric J558 IgA and therefore appeared to directly or indirectly block the site in the Fc region of IgA recognized by the hepatic receptor.     

Gangliosides, Ab1 and Ab2 antibodies III. The idiotype of anti-ganglioside mAb P3 is immunogenic in a T cell-dependent manner

P3 mAb is an IgM monoclonal antibody specific for N-glycolyl-containing gangliosides. The immunogenicity of the P3 idiotype has been previously described by immunizing syngeneic BALB/c mice with the purified murine IgM or the mouse-human chimeric IgG antibody. In the present work we study the antibody response against the idiotype of P3 mAb through immunization with DNA. We used small immune proteins (SIP) consisting on the idiotype in the scFv format, covalently linked to gamma1CH3, the self-dimerizing domain of murine IgG1. SIPs were previously shown to be appropriate to induce specific anti-idiotypic responses. By gene gun immunization, a polyspecific response was occasionally generated, particularly with the P3 idiotype. A single shot of DNA was sufficient to induce a strong and long-lasting anti-P3 idiotype response. In addition, by delivery of the same DNA construct with a recombinant adeno-associated virus the unique immunogenicity of the P3 idiotype was demonstrated. The requirement of T cells in the anti-P3 idiotype response was indicated by the lack of P3-specific anti-idiotypic antibodies following immunization of both, allogeneic C57BL/6 and athymic BALB/c mice.     

Characterisation of a mouse monoclonal anti-idiotype reactive with a V region sequence commonly used by human immunoglobulins.

BACKGROUND: A mouse monoclonal antibody (2C7/IgG2b kappa) has been described recently, which is directed against the major house dust mite allergen Der p 1, and whose epitope specificity is representative of a major component of the human IgE anti-Der p 1 response. AIMS: To characterise an anti-idiotypic antibody (2G10/IgG1 kappa) raised against monoclonal antibody 2C7 as surrogate human IgE anti-Der p 1. METHODS: The specificity of the anti-idiotype antibody 2G10 was determined by competitive inhibition experiments using human and mouse immunoglobulins of known VH gene families. The epitope recognised by monoclonal antibody 2G10 was located on the molecular model of the Fv (fragment variable) region of monoclonal antibody 2C7. RESULTS: The data suggest that monoclonal antibody 2G10 is directed against a crossreactive idiotype on human IgE that is shared by polyclonal IgG. Competitive inhibition studies against human immunoglobulins, representative of VH2, VH3, and VH4 gene families, showed that monoclonal antibody 2G10 is mostly likely to be directed against sequences encoded by either VH3 or VH4 genes. The fact that monoclonal antibody 2G10 binds to the humanized (complementarity determining region (CDR) grafted) CAMPATH-1H antibody, but not to the original rat CAMPATH-1 YTH34.5.6 antibody, indicates that it is directed against a framework region rather than the CDRs. Analysis of amino acids in the VH region for charge, hydrophobicity, and accessibility suggests that reactivity with monoclonal antibody 2G10 is defined by a hexapeptide spanning residues 74-79 within framework region 3. CONCLUSION: The anti-idiotype monoclonal antibody 2G10 could potentially be used as a probe for determining the contribution of the VH3 and VH4 gene segments to antigenic specificity.     

Studies of Monoclonal Antibodies Specific for Major Histocompatibility Complex Products of the Rat

Polyclonal syngeneic, allogeneic, and xenogeneic and monoclonal syngeneic anti-anti-idiotypic antibodies have been produced against previously described monoclonal anti-idiotypic antibodies with specificity for monoclonal RT1 alloantigen-specific antibodies. The anti-anti-idiotypes could again be shown to be highly specific for the monoclonal anti-idiotype used for the induction of the anti-anti-idiotypic antibodies and to carry the same, or a very similar, idiotype as the original monoclonal idiotypic antibody used to induce the monoclonal anti-idiotypic. Among the 30 syngeneic and allogeneic and the five xenogeneic polyclonal anti-anti-idiotypic antisera and the three monoclonal anti-anti-idiotypes, only one polyclonal antiserum showed binding capacity to the corresponding RT1-encoded antigenic determinants on spleen cells. All the other antibodies were idiotypic but not antigen binding.