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Biomedical subjects

A R Ibragimov

Publications and source records attributed to A R Ibragimov.

9 recordsLinked to original sources
PubMed1991

[Effect of flanking regions on the expression of the human interleukin-2 chromosomal gene in a murine myeloma cell line].

A human interleukin-2 (IL-2) gene was isolated from genomic DNA library. The isolated gene with 5'- and 3'-flanking sequences of various lengths was inserted into plasmids derived from the retroviral vector pPSneo. The recombinant plasmids were transfected into myeloma X63Ag8-653 cells. The transfected cells, harbouring the IL-2 gene with the shortened (to position -165) or totally deleted 5'-flanking sequence, constitutively expressed biologically active IL-2. Deletion of 3'-flanking region on did not affect the IL-2 expression.

Animals↗
PubMedDate not supplied

[Study of the antigenic structure of human immunoglobulin lambda-chain using monoclonal antibodies].

Nine monoclonals against human Ig lambda chains were produced, 4 antibodies react with C-domain, 5--with V-domain of the lambda chain. Anti-C lambda domain antibodies recognize not less than 3 epitopes and one of them is expressed only on the isolated chain. Anti-V lambda antibodies bind both isolated lambda chain and intact IgG, IgM, IgA. Four epitopes are expressed by few lambda Bence Jones proteins of the III subgroup, the immunogen possessing the same isotype. The 4 mentioned epitopes represent private idiotypic determinants. The epitope 3E10 is characteristic of 50% Bence Jones proteins of the II and III V lambda-subgroups thus representing a common idiotypic determinant. Using anti-V lambda antibodies germ line variability of V lambda III proteins was analysed and the similarity of antigenic structure of normal and myeloma human Ig lambda chains was demonstrated.

Antibodies, Monoclonal↗
PubMedDate not supplied

[Autoantibody genes].

The review is devoted to the mechanisms of generation and coding of human and murine autoantibodies.

Animals↗
PubMedDate not supplied

[Analysis of the frequency of allelic exclusion of immunoglobulin light chain genes and molecular characteristics of immunoglobulins secreted by hybridomas with expression of both allelic genes].

The investigation of 750 B-lymphocyte hybridoma clones obtained by fusion of mouse myeloma and newborn heterozygous Igk-la/Igk-1b rat splenocytes has revealed that 9,8% of Ig kappa-chain genes are rearranged productively. Seventeen hybridomas secrete kappa-chains of both allelic variants. The analysis of IgM molecules of nine such clones demonstrated that in six cases only one L-chain allotype is present in IgM. Thus for the first time the high frequency of selective association of H and L chains was shown. Evidently this selectively may function as one of the allelic exclusion mechanisms at the Ig assembly stage.

Alleles↗
PubMedDate not supplied

[Selective interaction of immunoglobulin polypeptide chains. Quantitative evaluation of the idiotypic and antigen binding activity of reassociated immunoglobulin molecules].

We have analysed reassociated Ig molecules, containing heavy (H) or light (L) chains of Ig-B2 monoclonal antibody with human fibronectin binding activity and L of H chains of normal mouse serum immunoglobulin (Ig-NM). Examination of Ig-B2 idiotype expression in reassociated Ig indicated that 0.4% L-NM and 0.8% H-NM were able to restore Ig-B2 idiotype. The analysis of antigen binding capacity of reassociated Ig demonstrated, that only 4% H-NM created antigen binding site in complex with L-B2. We have determined the leading role of L-chain in creation of idiotype and binding site of Ig-B2. Selectivity of interaction between H and L chains is discussed. The results indicate, that not more than 4-6% of random H--L combinations produce functional Ig.

Amino Acid Sequence↗
PubMedDate not supplied

[Allelic exclusion in hybridomas. I. Isolation and properties of a hybrid clone producing two allelic variants of light chain immunoglobulins in the rat].

Expression of RI-1a and RI-1b allelic genes controlling the production of rat lg kappa L-chains by hybridoma cells in vitro was studied. By fusing mouse myeloma cells with RI-1a/RI-1b heterozygous rat splenocytes the unique cloned hybrid cell line secreting both allelic variants has been established. This line may have appeared because cell hybridization made it possible to fix the rare case of correct rearrangement of the kappa chain gene segments on both homologous chromosomes.

Alleles↗