Search PubMed⌕ Search

Biomedical subjects

C Auffray

Publications and source records attributed to C Auffray.

At least 91 records · Page 5Linked to original sources
PubMed1990

Organization of a functional chicken class II B gene.

Five class II (B-L) B genes are encoded in the major histocompatibility complex (MHC) of chickens of the B12 haplotype. We report here the nucleotide sequence of one of these genes, B-LBII, as well as the primary structure of a corresponding cDNA. The organization of B-LBII, its 5' flanking region including the promotor region, and the amino acid sequence of its product are compared to mammalian class II B genes and to the previously described B-LBIII gene, which probably is a pseudogene since no B-LBIII transcript could be identified. The 5' flanking region of B-LBII exhibits homologs of transcription-controlling sequence motifs, namely S, X, X2, and Y boxes, of class II A and B genes of rodents and man. However, the promotor region of B-LBIII lacks an equivalent of the S box, displays two nucleic acid substitutions in the core sequence of the Y box, and exhibits a 16 base pair (bp) deletion upstream of the site of initiation of transcription. Therefore, an aberrant promotor region is likely to account for the pseudogene-like nature of B-LBIII, which displays open-reading frames in all exons. The data obtained with the functional B-LBII gene are in line with our previous interpretation that both genomic organization and tertiary structure of class II beta molecules are remarkably conserved between birds and mammals.

Amino Acid Sequence↗
PubMed1989

Isolation and characterization of three class II MHC genomic clones from the chicken.

A genomic library was constructed from sperm DNA from an individual of the inbred chicken line G-B2, MHC haplotype B6. The library was screened with a chicken class II probe (beta 2 exon specific) and three MHC class II beta chain genomic clones were isolated. The restriction maps of the three clones showed that each of the three clones was unique. The position of the beta chain sequence was located in each of the three genomic clones by Southern blot hybridization. Subclones containing the beta chain gene were produced from each of the genomic clones and the orientation of the leader peptide, beta 1, beta 2, transmembrane, and cytoplasmic exons was determined by Southern blot hybridization and nucleotide sequencing. The complete nucleotide sequence of two of the three subclones was determined. Comparison of the nucleotide and predicted amino acid sequences of the two subclones with other class II beta chain sequences showed that the B6 chicken beta chain genes are evolutionarily related to the class II beta chain genes from chickens of other MHC haplotypes, and to class II beta chain genes from other species. Analysis of Southern blots of B6 chicken DNA, as well as the isolation of the three beta chain genes, suggests that chickens of the B6 haplotype possess at least three MHC class II beta chain genes.

Amino Acid Sequence↗
PubMed1989

The major histocompatibility complex in the chicken.

The chicken B complex is the first non-mammalian MHC characterized at the molecular level. It differs from the human HLA and murine H-2 complexes in the small size of the class I (B-F) and class II (B-L) genes and their close proximity. This proximity accounts for the absence of recombination between B-F and B-L genes and leaves no space for class III genes. Moreover the B-F and B-L genes are tightly linked to unrelated genes absent from mammalian MHCs, such as the polymorphic B-G genes and a member of the G protein beta subunit family. This linkage could form the basis for resistance to viral-induced tumors associated with some B complex haplotypes.

Animals↗
PubMed1989

Physical linkage of a guanine nucleotide-binding protein-related gene to the chicken major histocompatibility complex.

Several genes were found closely associated with major histocompatibility class I and class II beta-chain genes in chicken genomic DNA clusters by hybridizing tissue-specific cDNA probes to cosmid clones. A cDNA probe for one of these genes, probe C12.3 isolated from a chicken liver cDNA library, was used to clone the homologous sequence H12.3 from a human B-lymphoblastoid cell line cDNA library. C12.3 and H12.3 encode exactly the same 317-residue-long protein. The sequence of 12.3 shows significant homology with the two known guanine nucleotide-binding protein beta subunits (GP beta 1 and GP beta 2) and other proteins that all share the same segmented structure with seven internal homologous repeats about 45 residues in length. Unlike the chicken gene, the human H12.3 gene and its mouse counterpart are not located on the same chromosome as the major histocompatibility complex. A possible involvement of the C12.3 gene product in major histocompatibility complex-linked control of lymphocyte proliferation in chickens is discussed.

Amino Acid Sequence↗
PubMed1989

Restriction fragment length polymorphism analysis of major histocompatibility complex class II genes from inbred chicken lines.

High molecular weight DNA was extracted from sperm from chickens of 14 inbred lines. The DNA was digested with each of four restriction enzymes (Pvu II, Hind III, Bgl II, and Bam HI), electrophoresed for 18 or 45 h, blotted onto nitrocellulose, and hybridized to a chicken major histocompatibility complex (MHC, B complex) class II beta-chain probe (beta 2-exon specific). Restriction fragment length polymorphisms (RFLPs) were found with each of the restriction enzymes used. Birds with the same B haplotype always showed the same RFLP pattern; however, some birds of different B haplotypes also shared the same RFLP pattern. To test for the Mendelian inheritance of the RFLP patterns, the F2 progeny of an informative cross were analysed. The RFLP patterns corresponded with the serologically determined B haplotypes of the F2 birds, thereby showing the Mendelian inheritance of the polymorphic bands.

Animals↗
PubMed1989

Typing of MHC haplotypes in OS chicken by means of RFLP analysis.

For the analysis of the genetic background of autoimmune thyroiditis we used the Obese strain (OS) chicken model which develops a SAT. Practically all animals from this strain show severe lymphoid infiltration of the thyroid gland and circulating autoantibodies against thyroglobulin (Tg-AAb) within a few weeks after hatching. Of the 3 MHC haplotypes (B5, B13, B15) present in the OS, B13 was mostly associated with severe thyroid infiltration. Haplotypes B5 and B15 were associated both with severe, as well as with mild infiltration. To clarify these controversial results published by different groups and to further assess the role of the MHC in the development of SAT, we selected by appropriate breeding sublines with high and low levels of Tg-AAb. With the help of serological methods and GvH assays we were not able to find additional differences in the MHC antigens of that line. Therefore, for further characterization of these haplotypes, RFLP analysis was applied in the present study. Southern blots were done with restriction enzyme digests of erythrocyte DNA hybridized with a chicken cDNA probe (code-p234) for MHC class II antigens. The Southern blots with BamH-I digests showed at least 5 bands, four of which were polymorphic. Four RFLP patterns emerged, two of which were observed within chickens with the B15 haplotype. The confirmation of this RFLP heterogeneity within serologically identical haplotypes requires additional analysis.

Animals↗
PubMed1988

Immunosuppressive properties of synthetic peptides derived from CD4 and HLA-DR antigens.

Synthetic peptides derived from the beta 1 domain of HLA-DR antigens containing RFDS and a peptide derived from the immunoglobulin-like amino-terminal domain of CD4 and containing RADS were shown to exhibit specific dose-dependent inhibitory effects on antigen-induced HLA class II-restricted T-cell proliferation and in vitro antibody synthesis. These inhibitory activities are similar to those exhibited by anti-CD4 and HLA-DR antibodies, respectively. The peptides derived from HLA-DR or CD4 and anti-CD4 or anti-HLA-DR antibodies acted together in synergy to inhibit these responses when the relevant cell populations were incubated with infrainhibitory concentrations of the reagents. In contrast, these peptides were shown to exert no inhibitory activity on nonspecific T-cell activation mediated by ionomycin, phorbol myristate acetate, and interleukin-2.

Antibody Formation↗
PubMed1988

The rat vitamin-D-dependent calcium-binding protein (9-kDa CaBP) gene. Complete nucleotide sequence and structural organization.

The structural organization of the entire rat vitamin-D-dependent calcium-binding protein (9-kDa CaBP) gene was determined by analysis of overlapping genomic clones isolated from a rat genomic library using the rat 9-kDa CaBP cDNA [Desplan C., Heidmann O., Lillie J., Auffray C. and Thomasset M. (1983) J. Biol. Chem. 258, 13502-13505]. These clones together span 30 kbp of rat genomic DNA, with the rat 9-kDa CaBP gene lying in the middle. The 9-kDa CaBP gene is 2.5 kbp long and contains three exons interrupted by two introns. The first exon contains almost the entire 5' untranslated region. The second exon codes for the calcium-binding site I, the third exon codes for site II and the 3' untranslated region. Therefore each of the calcium-binding domains is encoded by single, separate exons. The transcription initiation site was identified by S1 nuclease mapping and primer extension. A consensus sequence TATAAA is localized 31 bp upstream from the cap site and the 'CCAAT-box' lies upstream from the transcription start. Single (AC)25 and (AG)23 repeats are present in the second intron together with an Alu-like sequence. Repetitive elements are present 5 kbp upstream from the cap site and in the 3' flanking region. Comparison of the known rat CaBP sequences (9-kDa CaBP, 28-kDa CaBP, S100 protein) shows that the 9-kDa CaBP is more closely related to the S100 protein than to the 28-kDa CaBP. There is no evidence to indicate that 9-kDa CaBP has arisen from the 28-kDa CaBP.

Amino Acid Sequence↗
PubMed1988

Dopaminergic neurons of the substantia nigra modulate preproenkephalin A gene expression in rat striatal neurons.

The messenger RNA coding for preproenkephalin A (PPA) was detected by in situ hybridization in striatal neurons in normal rats and in rats having had the right substantia nigra destroyed by an injection of 6-hydroxydopamine or by electrolysis. Animals were killed 15, 30, 45 and 70 days following the lesion. A double-stranded PPA cDNA and a single-stranded PPA cRNA labeled with 32P or 35S were used as probes to detect the PPA mRNA in brain sections. The controls demonstrated the specificity of the labeling. The darkening of X-ray film in contact with the striatum was appraised, the optical density was measured, and the density of the cells expressing the PPA gene in sections was calculated using an image analyzer. The mean number of silver grains per labeled cell (reflecting the number of PPA mRNA copies per cell) was also calculated using an image analyzer. The 6-hydroxydopamine lesion which destroyed all dopaminergic neurons in the right substantia nigra, provoked a large increase in the number of PPA mRNA copies in enkephalin neurons of the right striatum, and decreased the number of cells expressing the PPA mRNA in the left striatum. These variations substantia nigra provoked similar variations, but less intense.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗