Repertoire of human antibodies against the polysaccharide capsule of Streptococcus pneumoniae serotype 6B. (1/1306)

We examined the repertoire of antibodies to Streptococcus pneumoniae 6B capsular polysaccharide induced with the conventional polysaccharide vaccine in adults at the molecular level two ways. In the first, we purified from the sera of seven vaccinees antipneumococcal antibodies and determined their amino acid sequences. Their VH regions are mainly the products of VH3 family genes (candidate genes, 3-23, 3-07, 3-66, and 3-74), but the product of a VH1 family gene (candidate gene, 1-03) is occasionally used. All seven individuals have small amounts of polyclonal kappa+ antibodies (Vkappa1 to Vkappa4 families), although kappa+ antibodies are occasionally dominated by antibodies formed with the product of the A27 Vkappa gene. In contrast, lambda+ anti-6B antibodies are dominated by the antibodies derived from one of 3 very similar Vlambda2 family genes (candidate genes, 2c, 2e, and 2a2) and Clambda1 gene product. The Vlambda2(+) antibodies express the 8.12 idiotype, which is expressed on anti-double-stranded-DNA antibodies. In one case, Vlambda is derived from a rarely expressed Vlambda gene, 10a. In the second approach, we studied a human hybridoma (Dob1) producing anti-6B antibody. Its VH region sequence is closely related to those of the 3-15 VH gene (88% nucleotide homology) and JH4 (92% homology). Its VL region is homologous to the 2a2 Vlambda2 gene (91%) and Jlambda1/Clambda1. Taken together, the V region of human anti-6B antibodies is commonly formed by a VH3 and a Vlambda2 family gene product.  (+info)

Human triclonal anti-IgG gammopathy. I. Iso-electric focusing characteristics of the IgG, IgA and IgM anti-IgG and their heavy and light chains. (2/1306)

Human IgG, IgA and IgM anti-IgG autoantibodies have been isolated from the serum of an individual with Felty's syndrome. These were initially noted as soluble circulating serum complexes by analytical ultracentrifugation. Isolation was accomplished by solid phase immunoadsorption and each of the three antibody populations obtained was shown to be of restricted heterogeneity by liquid and polyacrylamide gel electrofocussing methods. Type kappa light chains were obtained from each protein. Co-isoelectric focusing experiments of all possible pairs of these light chains showed them to have identical net charge characteristics. Heavy chains obtained from each protein were also monoclonal and of differing isoelectric point. The availability of this serum provides a human model with which to study the changes which may occur in autoantibodies during the autoimmune response.  (+info)

Induction of Ig light chain gene rearrangement in heavy chain-deficient B cells by activated Ras. (3/1306)

During B cell development, rearrangement and expression of Ig heavy chain (HC) genes promote development and expansion of pre-B cells accompanied by the onset of Ig light chain (LC) variable region gene assembly. To elucidate the signaling pathways that control these events, we have tested the ability of activated Ras expression to promote B cell differentiation to the stage of LC gene rearrangement in the absence of Ig HC gene expression. For this purpose, we introduced an activated Ras expression construct into JH-deleted embryonic stem cells that lack the ability to assemble HC variable region genes and assayed differentiation potential by recombination activating gene (RAG) 2-deficient blastocyst complementation. We found that activated Ras expression induces the progression of B lineage cells beyond the developmental checkpoint ordinarily controlled by mu HC. Such Ras/JH-deleted B cells accumulate in the periphery but continue to express markers associated with precursor B cells including RAG gene products. These peripheral Ras/JH-deleted B cell populations show extensive Ig LC gene rearrangement but maintain an extent of kappa LC gene rearrangement and a preference for kappa over lambda LC gene rearrangement similar to that of wild-type B cells. We discuss these findings in the context of potential mechanisms that may regulate Ig LC gene rearrangement.  (+info)

Characterization of an immunoglobin cDNA clone containing the variable and constant regions for the MOPC 21 kappa light chain. (4/1306)

Nucleotide sequence analysis and restriction endonuclease mapping have been used to characterize a cDNA copy of immunoglobulin MOPC 21 Kappa mRNA clones in the bacterial plasmid pMB9. Three regions of the inserted cDNA of plasmid pL21-1 have been sequenced and match the known protein sequence at amino acid residues 1-24, 128-138 and 171-179. With these sequences to provide absolute correlations between the restriction map and the structural gene sequence it has been possible to exactly deduce the positions of all 11 of the insert restriction sites mapped within the structural gene. The pL21-1 insert contains the complete variable and constant regions as well as parts of the 3' untranslated and polypeptide leader coding sequences.  (+info)

Recombinant DNA clones constructed from immunoglobulin kappa light chain messenger RNA. (5/1306)

Recombinant DNA clones have been generated from mouse myeloma MOPC 21 immunoglobulin kappa light chain mRNA. Complementary DNA (cDNA) synthesized on kappa light chain mRNA by reverse transcriptase was made double stranded and inserted into the bacterial plasmid vector, pMB9. Approximately 70 tetracycline-resistant transformed colonies containing kappa light chain mRNA sequences were identified by colony hybridization. Five of these recombinant clones were selected and characterized. Three clones contain both kappa light chain constant and variable region sequences. Two of these three recombinant clones have been shown to include all of the kappa light chain constant and variable region coding sequences. Another of the five selected recombinant clones contain kappa light chain constant region sequences. The remaining characterized clone appears to be derived from sequences at the 5'-end of kappa light chain mRNA, possibly extending to the terminal cap structure.  (+info)

Contribution of interleukin 1beta and KM loci to alopecia areata. (6/1306)

Alopecia areata is a common skin disease in which proinflammatory cytokines such as IL-1beta may play a pathogenic role. In this study, we examined the distribution of genotypes of an IL-1beta single base change polymorphism at position +3953 in patients with alopecia areata. The distribution of immunoglobulin kappa light chain (KM) genotypes was similarly examined. The data obtained showed that the IL-1beta and KM loci act cooperatively to significantly increase susceptibility to alopecia areata.  (+info)

Assignment of genes for immunoglobulin kappa and heavy chains to chromosomes 6 and 12 in mouse. (7/1306)

Using somatic cell hybrids from fusions of lymphocytes of two different mouse stocks with the myeloma cell line X63-Ag8, we have assigned genes for the immunoglobulin heavy and kappa-type light chains to chromosomes 12 and 6, respectively. The two mouse stocks exhibit karyotypes consisting of nine pairs of metacentric chromosomes as a result of centric fusions of acrocentric chromosomes in different combinations. In the hybrid cells these metacentric chromosomes can be distinguished from the acrocentric chromosomes of myeloma origin, permitting correlation of Ig chain expression with mitotic loss of individual metacentric chromosomes.  (+info)

Spi-C, a novel Ets protein that is temporally regulated during B lymphocyte development. (8/1306)

A novel Ets protein was isolated by yeast one-hybrid screening of a cDNA library made from lipopolysaccharide-stimulated mouse splenic B cells, using the SP6 kappa promoter kappaY element as a bait. The novel Ets protein was most closely related to PU.1 and Spi-B within the DNA binding Ets domain and was therefore named Spi-C. However, Spi-C may represent a novel subgroup within the Ets protein family, as it differed significantly from Spi-B and PU.1 within helix 1 of the Ets domain. Spi-C was encoded by a single-copy gene that was mapped to chromosome 10, region C. Spi-C interacted with DNA similarly to PU.1 as judged by methylation interference, band-shift and site selection analysis, and activated transcription of a kappaY element reporter gene upon co-transfection of HeLa cells. Spi-C RNA was expressed in mature B lymphocytes and at lower levels in macrophages. Furthermore, pre-B cell and plasma cell lines were Spi-C-negative, suggesting that Spi-C might be a regulatory molecule during a specific phase of B lymphoid development.  (+info)