RT Journal Article
SR Electronic
T1 Polymorphism of the HLA-DR1 haplotype in American blacks. Identification of a DR1 beta-chain determinant recognized in the mixed lymphocyte reaction.
JF The Journal of Immunology
JO J. Immunol.
FD American Association of Immunologists
SP 4019
OP 4023
VO 140
IS 11
A1 Hurley, C K
A1 Ziff, B L
A1 Silver, J
A1 Gregersen, P K
A1 Hartzman, R
A1 Johnson, A H
YR 1988
UL http://www.jimmunol.org/content/140/11/4019.abstract
AB Mixed lymphocyte typing provides an exquisitely sensitive means of detecting the polymorphism of HLA class II molecules. By using this technique, the differences between divergent human populations become apparent. This study describes a DR1 haplotype commonly present in the American black population. Unlike the Northern European population in which almost all DR1 individuals are DQw1 and type as Dw1 by using mixed lymphocyte typing, approximately 50% of DR1, DQw1 positive American blacks express an undefined Dw specificity. The DR beta polypeptide encoded by a DR1,Dw-cell differs from a previously described DR1,Dw1 beta sequence by two amino acid replacements at positions 85 and 86 in the first domain. One silent nucleotide substitution has also been identified. DQ alpha and beta first domain cDNA sequences from this haplotype are identical with previously described DQ sequences from a DR1,Dw1 cell. This relatively minor change in amino acid sequence of the DR molecule appears to produce the undefined HLA-D specificity in this haplotype. The variant DR1 sequence is shared with a DR beta-chain from the DR2,DwMN2 haplotype suggesting that a gene conversion-like mechanism has generated this difference.