A VH-associated idiotype in human anti-tetanus antibodies

DNA antibody idiotypes: an analysis of their clinical connections and origins

Approximately thirty common DNA antibody idiotypes have been described on hybridoma derived or affinity purified DNA-binding antibodies. There are associations between some idiotypes and the clinical manifestations of systemic lupus erythematosus although none are sufficiently firm to be clinically useful in identifying subsets of SLE or in assessing disease activity in individual patients. The expression of these idiotypes is not confined to DNA antibodies in SLE. They may be found in the serum from patients with a range of autoimmune rheumatic disorders, infectious disease and blood dyscrasias. In most cases the antigen binding specificity of the antibody bearing the idiotype is unknown. The precise relationship between the various idiotypes is becoming better understood with increasing availability of genetic and structural data. DNA antibody idiotype manipulation may provide a potential new therapeutic modality in SLE.

Idiotypic characteristics of immunoglobulins associated with systemic lupus erythematosus. Studies of antibodies deposited in glomeruli of humans

Indirect immunofluorescence with monoclonal antibodies to 6 different idiotypes was used to characterize immunoglobulins deposited in the glomeruli of renal biopsy samples from 32 patients with systemic lupus erythematosus (SLE) and 19 patients with nonlupus immune glomerulonephritis. IdGN2 was present in 75% of the biopsy specimens from SLE patients and in 6% of those from patients with non-lupus nephritis; IdGN1 occurred in 38% and 6%, respectively. The other idiotypes were not increased in biopsy samples from patients with SLE. Deposition of IdGN2 was associated with a subendothelial location of Ig and proliferative changes in the glomeruli. In studies of glomerular eluates from 4 immunosuppressed SLE patients, an average of 26% of total Ig and 37% of anti-DNA was composed of IdGN2. Compared with IdGN2- immunoglobulin, IdGN2+ immunoglobulin was enriched in IgG1 in all 4 eluates, and was enriched in high-avidity anti-DNA in 2 eluates. IdGN2 is a marker of antibody subsets that are characteristic of SLE and are associated with severe lupus nephritis.

DNA antibody idiotypes: a review of their genetic, clinical, and immunopathologic features

The initial studies of anti-DNA antibody idiotypes we performed, along with those of our colleagues and other groups, focused on the narrow question of their relevance to lupus autoantibodies. The subsequent studies in this report have forced us to examine a much broader range of issues. It is evident that despite the great advances in understanding the structure and function of antibodies, lymphocytes, and receptors, our knowledge of many fundamental elements in autoimmune disease is woefully incomplete. We are still unsure whether the germ line gene sequences controlling antibody production have evolved solely in response to exposure to new foreign antigens. Alternatively, these antibodies (and the idiotypes they bear) may have developed largely in response to changes in the internal environment. Superficially, it can be argued that "self reactivity" associated with the clinical expression of a disease results from a combination of immunologic, genetic, hormonal, and environmental elements. For example, the expression of the 16/6 Id in an appropriate setting may have pathogenetic consequences for some individuals. However, our knowledge of the precise sequence of events that result in devastating disease for some but minimal disease for others is just one of the remaining mysteries.

Crossreactivity and inheritance of idiotypes restricted to human anti-tetanus toxoid antibodies

The presence of cross-reactive idiotypes on human IgG antibodies of tetanus toxoid (TT) antigen was assessed by examining the capacity of two anti-idiotypic (ID) antisera raised against IgG (Fab')2 anti-TT (idiotype) from two subjects to bind radiolabeled "idiotype" and to inhibit the binding of radiolabeled TT to IgG from unrelated subjects and from family members of the idiotype donors. Idiotypic crossreactivity with unrelated individuals was infrequent and weak but was frequent and stronger among siblings. The strongest idiotypic crossreactivity was seen between identical twins in studies using four anti-ID raised against the anti-TT idiotypes of two sets of twins. The results of the present study suggest that idiotypic determinants restricted to human anti-TT antibodies are, at least in part, encoded by inherited genes, which are infrequently shared among unrelated individuals.

The human immune response against major allergens from house dust mite, Dermatophagoides pteronyssinus. II. Idiotypic cross-reactions of allergen-specific antibodies

Antisera were prepared in rabbits against the idiotypic (Id) determinants of antiallergen antibodies. These antibodies were isolated from the plasma of 10 unrelated patients by immunoabsorption. Three major allergens isolated from the house dust mite, Dermatophagoides pteronyssinus (DPT), were used. The anti-Id antisera were rendered specific by successive absorption on insolubilized allergens, IgG and IgM from a pool of human sera and Ig from the donor after removal of anti-DPT antibodies by absorption. Anti-Id antibodies raised essentially against IgG antibodies were found to inhibit the agglutinating activity of both IgG and IgM anti-DPT antibodies toward allergen-coated latex. These anti-Id antibodies were also able to inhibit partly the binding of radiolabeled allergen to IgE anti-DPT antibodies. Matching the anti-Id antisera with the various individual anti-DPT antibodies revealed an Id cross-reactivity of about 71% for IgG, 61% for IgM and 62% for IgE. A second and predominant type of anti-Id antibodies recognized bystander idiotopes as the allergen did not inhibit Id-anti-Id reaction. These idiotopes were apparently more specific to individuals (private) as the anti-DPT antibodies of a given patient did not agglutinate latex particles coated with anti-Id antibodies prepared against Id of another patient.

Cross-reactive idiotypes in immunoglobulin A-deficient sera

Mice of inbred strains immunized with simple antigens can produce antibodies that share similar V regions, which result in serologic similarities called cross-reactive idiotypes (CRI). In this study, we considered the possibility that IgA-deficient humans, who are continuously immunized via the intestinal tract by dietary protein, might also produce antibodies sharing CRI. For this, anti-casein antibodies were isolated from the blood of 16 adult IgA-deficient donors (4 Finns and 12 North Americans) and an autologous anti-anti-casein from the blood of one of the Finnish donors. In addition, a heterologous anti-anti-casein was raised to the casein-anti-casein immune complexes of this donor. Comparing the activities of the two anti-idiotypes, it was found that both bind anti-casein in the region of the antigen binding site, but that each binds additional determinants not located within this region, with the heterologous reagent having more affinity for these latter determinants than the autologous anti-idiotype. Using both reagents in enzyme-linked immunosorbent assay inhibition assays, extensive cross-reactivities between anti-caseins were demonstrated. Using the autologous anti-idiotype, 5 of 16 anti-caseins were found to share CRI, and with the heterologous reagent 12 of 16 shared CRI. In both assays, the anti-caseins of Finnish donors displayed more cross-reactivity than those derived from Northern American donors. These studies show that specific, commonly shared CRI can be identified in this human system in which antibodies are raised as a result of natural immunization across the gastrointestinal mucosa.