RESUMO
The variable regions from P3, a murine monoclonal antibody (MAb) against NeuGc-containing gangliosides, and two anti-idiotype MAbs directed to P3 MAb were cloned and sequenced. Comparisons with previously reported sequences showed that P3 is a germline antibody encoded by genes from the V(H)Q52 and V(kappa)19 families. Analysis of nucleotides at the heavy chain CDR3 (H-CDR3) showed the presence of an extensive 3' N region that contains almost 50% of the nucleotides of this CDR. In addition, amino acid sequence analysis of the H-CDRs of this MAb revealed the presence of three arginines, two of which are present in the H-CDR3, that could be involved in the interaction of P3 MAb with its electronegative epitope on gangliosides. Anti-idiotype 1E10, which seems to define a "regulatory" idiotope on P3 MAb (it induces Id+ Ab3), represents a germline Ab2 that belongs to the V(H)J558 and V(kappa)10 gene families. By contrary, the anti-idiotype 3B11 is an extensively mutated antibody that belongs to the V(H)3660 and V(kappa)4/5 gene families, defining a "private" idiotope on P3 MAb. Even when different V genes contribute to the variable regions of 1E10 and 3B11 MAbs, they share an acidic motif E/D-D-Y/D-Y-D in H-CDR3, suggesting that both Ab2s recognize paratope positive residues on the Ab1. Therefore, complementary electrostatic interactions involving H-CDR3 from both Ab1 and Ab2, might provide a clue to understand the molecular basis for the generation of gamma-type anti-idiotype antibodies to V regions recognizing glycolylated ganglioside antigens.
Assuntos
Anticorpos Monoclonais/genética , Gangliosídeo G(M3)/análogos & derivados , Gangliosídeo G(M3)/imunologia , Região Variável de Imunoglobulina/genética , Sequência de Aminoácidos , Animais , Especificidade de Anticorpos , Sequência de Bases , Regiões Determinantes de Complementaridade/genética , Primers do DNA/química , Epitopos/análise , Humanos , Imunogenética , Cadeias Pesadas de Imunoglobulinas/genética , Idiótipos de Imunoglobulinas/análise , Idiótipos de Imunoglobulinas/genética , Cadeias Leves de Imunoglobulina/genética , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido NucleicoRESUMO
Patients with primary antiphospholipid syndrome (PAPS) have few or no autoantibodies, other than the antiphospholipid antibodies (aPL) that could be natural autoantibodies encoded by germline genes. Some of the autoantibodies marked by the human anti-DNA common idiotype 16/6 have been found to be encoded by unmutated germline genes. Hence, we tested the sera of 19 patients with PAPS for the presence of the 16/6 idiotype which has also been found to be expressed on antibodies that bind cardiolipin. For this we used an ELISA method with antiserum against the SA1 idiotype which recognizes the 16/6. Five of our patients had the idiotype in at least one serum. Among the patients there was one with a variant of PAPS with hemolytic anemia and an IgM antibody to phosphatidylcholine that is akin to the natural autoantibody of normal mice encoded by germline genes VH11 and VH12. Inhibition studies with ssDNA, dsDNA and cardiolipin revealed that all 3 antigens decreased the serum levels of the SA1 idiotype despite absence of detectable anti-DNA antibodies by other methods. Our findings suggest that within the B cell clones that produce aPL in patients with PAPS there are some that produce immunoglobulins bearing 16/6 related idiotypes. This could indicate that some of the aPL present in patients with PAPS derive from natural autoantibody producing cell clones.
Assuntos
Anticorpos Antinucleares/análise , Anticorpos/análise , Síndrome Antifosfolipídica/imunologia , Cardiolipinas/imunologia , Idiótipos de Imunoglobulinas/análise , Anticorpos/imunologia , Anticorpos Antinucleares/imunologia , Síndrome Antifosfolipídica/genética , Ensaio de Imunoadsorção Enzimática , Feminino , Genes de Imunoglobulinas/genética , Genes de Imunoglobulinas/imunologia , Humanos , Idiótipos de Imunoglobulinas/imunologia , Imunoglobulina M/análise , Região Variável de Imunoglobulina/genética , Região Variável de Imunoglobulina/imunologia , MasculinoRESUMO
The 16/6 anti-DNA idiotype (id) is a pathogenic idiotype first identified on a human hybridoma antibody derived from a patient with systemic lupus erythematosus (SLE). The SA-1 anti-DNA, which antibody was established in a similar fashion from a patient with polymyositis, also carries the 16/6 id, although it has a greater reactivity with dsDNA. The presence of the 16/6 id as defined by anti-16/6 and anti-SA-1 was determined in 3 distinct populations of patients with SLE: 502 Mexicans, 98 English (including Caucasians, West Indians, Chinese, Asians) and 93 Israelis. A similar prevalence (around 20%) of the 2 idiotypes was found, with a significant overlap. The latter finding was supported by a significant correlation noted between the prevalence of the 2 idiotypes (r = 0.58 p less than 0.001). Despite the fact that 16/6 antibody is most probably encoded by a germline gene, thus being genetically determined, no distinction in the prevalence of the ids could be detected between completely different populations of patients with SLE. This finding may support the independent pathogenic role ascribed to the 16/6 id.
Assuntos
Anticorpos Antinucleares/análise , DNA/imunologia , Idiótipos de Imunoglobulinas/análise , Lúpus Eritematoso Sistêmico/imunologia , Inglaterra , Humanos , Israel , Lúpus Eritematoso Sistêmico/etnologia , MéxicoRESUMO
Immunoaffinity-purified antibodies against Schistosoma mansoni soluble egg Ag (SEA) from infected patients' sera differ idiotypically according to the donor's clinical form of the disease. The Id differ both by their ability to stimulate proliferation of anti-Id T cells and their recognition by anti-Id-specific sera. Also, mice infected with S. mansoni develop anti-Id T and B cell responses against mouse anti-SEA antibodies. We now show that anti-SEA antibodies from serum pools of chronic, but asymptomatic patients (AM1 and AM5) stimulate proliferation of spleen cells from mice infected with S. mansoni. However, AM8, anti-SEA antibodies from hepatosplenic patients, did not stimulate these spleen cells. The murine responses directly parallel patient studies where AM1 and AM5 Id-stimulated human PBMC, but AM8 Id did not. In competitive ELISA, using AM1 or AM-5-specific rabbit antisera or human anti-SEA mAb E5-specific rabbit antiserum, sera from mice infected for 8 and 16 wk (but not from uninfected mice) compete with AM1, AM5, or E5. These sera do not compete in the AM8/anti-AM8 competitive ELISA. Sera from 8-wk-infected mice inhibit more against AM1, AM5, and E5 than do sera from later infections, and anti-SEA immunoaffinity-purified antibodies from 8-wk-infected mice stimulate spleen cells from infected mice more than anti-SEA antibodies from sera of mice late in infection. However, spleen cells from more chronically infected mice are more responsive to either the murine or human anti-SEA antibody preparations than cells from mice with earlier infections. Both the ELISA data and lymphocyte responses indicate that anti-SEA antibodies from mice infected with S. mansoni for 8 wk bear Id cross-reactive with those expressed on anti-SEA antibodies from humans with chronic, asymptomatic schistosomiasis, but not those from hepatosplenic patients.
Assuntos
Anticorpos Anti-Helmínticos/análise , Antígenos de Helmintos/imunologia , Proteínas de Helminto , Idiótipos de Imunoglobulinas/análise , Esquistossomose mansoni/imunologia , Animais , Anticorpos Anti-Helmínticos/imunologia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos CBA , Coelhos , Schistosoma mansoni/imunologiaRESUMO
Antibodies were purified from pooled sera from patients with different clinical forms of schistosomiasis mansoni on immunoaffinity columns of schistosome soluble egg Ag (SEA). As previously reported, T lymphocytes in PBMC preparations from schistosomiasis patients (but not control subjects who have never been infected) proliferate when cultured in the presence of certain of these anti-SEA purified antibodies. We now show that PBMC from most patients with chronic schistosomiasis, regardless of the clinical form of their infection, respond to anti-SEA antibodies from sera of asymptomatic (intestinal) or hepatointestinal patients. In stark contrast, none responds to anti-SEA antibodies purified from sera of acute or hepatosplenic patients. All of these multiclonal anti-SEA antibody preparations were active in anti-SEA ELISA assays and gave comparable patterns of reactivity with SEA upon immunoblotting analysis. Immunization of rabbits with some of these anti-SEA antibody preparations, followed by absorption of the rabbit antisera on absorbents of normal Ig, produced specific anti-Id reagents. Use of these reagents in competitive ELISA systems demonstrated that the Id in stimulatory and nonstimulatory anti-SEA antibody preparations differ with regard to the proportion of the serologically defined Id expressed by each. It appears possible to screen patients' plasmas for the presence of shared Id by use of suitable Id/anti-Id competitive ELISA assays. Taken together these data indicate that only certain Id-positive preparations are stimulatory to patients' PBMC, and the expression of these T cell stimulatory, immunoregulatory Id on anti-SEA antibodies correlates with the clinical form of a patient's infection.
Assuntos
Anticorpos Anti-Helmínticos/biossíntese , Idiótipos de Imunoglobulinas/biossíntese , Esquistossomose mansoni/imunologia , Doença Aguda , Animais , Anticorpos Anti-Idiotípicos/biossíntese , Anticorpos Anti-Helmínticos/administração & dosagem , Anticorpos Anti-Helmínticos/isolamento & purificação , Especificidade de Anticorpos , Antígenos de Helmintos/imunologia , Ligação Competitiva , Ensaio de Imunoadsorção Enzimática , Humanos , Idiótipos de Imunoglobulinas/análise , Técnicas de Imunoadsorção , Hepatopatias Parasitárias/imunologia , Ativação Linfocitária , Óvulo/imunologia , Coelhos , Esplenopatias/imunologia , Esplenopatias/parasitologiaRESUMO
A human monoclonal IgM kappa paraprotein with rheumatoid factor (RF) activity was used to elicit antiidiotypic antibodies in rabbits. The antiidiotypic antiserum thus obtained reacted with samples from 40% of 72 rheumatoid arthritis patients, but not with any of the samples from 22 aged control subjects having serum RF. Our findings suggest that, despite the similarities between RF from rheumatoid arthritis patients and that from healthy individuals, the expression of V region genes may be different in healthy subjects and those with the disease.
Assuntos
Artrite Reumatoide/genética , Idiótipos de Imunoglobulinas/análise , Fator Reumatoide/genética , Adulto , Idoso , Animais , Artrite Reumatoide/imunologia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Feminino , Regulação da Expressão Gênica , Humanos , Immunoblotting , Pessoa de Meia-Idade , Coelhos , Fator Reumatoide/imunologiaRESUMO
The human T-cell leukemia virus type-I (HTLV-I) is a unique, exogenous, horizontally transmitted retrovirus which is T-cell tropic, and has been associated with a specific type of aggressive leukemia/lymphoma of mature T-cell origin. In a survey of lymphoid malignancies in Jamaica, antibodies to HTLV-I were also found in 6 of 17 patients with chronic lymphocytic leukemia (CLL), raising the possibility of an etiologic relationship. Further studies were undertaken on one of these patients to clarify the nature of the disease and possible virus relationship. Cell surface marker analysis of her peripheral blood cells documented that the majority of circulating lymphocytes were B-cells. DNA-cloned probe analysis with a complete HTLV-I proviral genome of these peripheral malignant B-cells, was negative for integrated virus. A T-cell line was established in culture from her peripheral blood. The presence of HTLV-I in the cultured T-cell line was established by the detection of expressed viral specific gag protein p-19 and proviral DNA. Thus, a B-cell lymphoid malignancy can occur in the presence of HTLV-I infected T-cells, suggesting the possibility of an indirect leukemogenic mechanism.