Further molecular diversity in the HLA‐B15 group

Abstract

In order to further clarify the diversity of the HLA-B15 antigens and the correspondence of serological types with alleles in Asians, we screened various B15 serological splits by means of a polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) method. Subsequently, the genes encoding various B15 variants were sequenced. Two novel alleles, B*1528 and B*1529, were identified: the nucleotide sequence of the former contained a single-base substitution at position 263 in exon 2 as compared to that of the B*1501 allele, which results in an amino acid change at position 64 in the alpha 1 domain, and the nucleotide sequence of the latter differs from that of B*1518 by a single-base substitution at position 272 of exon 2 which results in an amino acid change at position 67 of the alpha 1 domain. One new allele, B*1521, described recently in Australian Aborigines was also identified in Asians in the present study. Moreover, the results of sequencing demonstrated that Asian HLA-B62, B70, and B77 antigens are encoded by B*1501, B*1518, and B*1513, respectively. Two splits of B75 antigens, B75V (TS-1) and B15N, which have been proposed to exist in the Japanese population were encoded by B*1511 and B*1502, respectively. Most of the B15 alleles detected in the present study showed positive associations with other locus antigens. Especially, B*1502 was strongly associated with Cw8, while B*1521 was strongly associated with A34 and Cw6.

HLA‐B*15 subtypes in the population of north‐eastern Thailand

“…A two‐step PCR was performed (Fig. 1) using the same nucleotide primer sequence as Lin et al . (1996).…”

“…Unfortunately, we did not have all the DNA references, so only nine of the 17 alleles for group I [B*15 (01, 05, 07, 12, 20, 24, 25, 27 and 32)] and four of the six for group II [B*15 (02, 08, 11 and 28)] were included in our study. Specific primers can amplify other alleles at the B locus, such as B*4601, B*5801, B*38, B*39 and B*35 (Lin et al ., 1996), so, in addition to the two alleles per locus in individual samples, the SSCP pattern revealed other bands which were not from B*15 alleles. Thus, including other known alleles present in the sample in the SSCP fragment analysis will help to clarify the B*15 bands.…”

“…Hildebrand et al . (1994) and Lin et al . (1996) proposed a phylogenetic tree for 26 HLA‐B15 alleles and a network of structure relationships among these alleles.…”

“…The exon 2 and 3 fragments amplified by the second PCR were analysed separately using the SSCP method (Lin et al ., 1996; Maruya et al ., 1996). Electrophoresis was carried out in a Miniprotein II polyacrylamide gel (Mini‐PROTEAN II, Biorad, Hercules, CA) (Table 1).…”

A weak association of HLA-B*2702 with Behçet’s disease

“…The HLA-B62 antigen defined by serology is encoded mainly by HLA-B*1501 in Asians. 23 We similarly observed a decrease of B*07 and an increase of B*15 alleles in Turkish patients, although these differences did not reach statistical significance.…”