J. Longas

A new HLA-B15 allele (B*1541) found in a Mexican of Nahua (Aztec) descent

The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the following accession numbers: B*1541, a) exon 2, AF033501, b) exon 3, AF033502, c) intron 1, AF034961, d) intron 2, AF034962. The name B*1541 was officially assigned by the WHO Nomenclature Committee in January 1998. This follows the agreed policy that, subject to the conditions stated in the most recent Nomenclature Report (Bodmer et al 1997), names will be assigned to new sequences as they are identified. A list of such new names will be published in the following WHO Nomenclature Report.

An evolutionary overview of the MHC-G polymorphism: clues to the unknown function(s)

The functions of the major histocompatibility complex-G (MHC-G) molecule are still unknown. The idea that this molecule may be involved in preventing the rejection of fetuses is suggested by only indirect evidence. In the present paper, we review the structure, in vitro function and tissue distribution of MHC-G genes and proteins in different primate species. From available data, we conclude the following. First, the nomenclature of MHC-G alleles needs to be revised. Rhesus monkey A/G gene cannot be orthologous to MHC-G because of a lack of structural similarity. Cotton-top tamarin G molecules (which are also structurally similar to E molecules) cannot be orthologous to classical class I molecules. Second, selective pressure to maintain a low degree of polymorphism appears to operate only at the peptide-binding region (PBR) of the MHC-G molecule. Thus, this observation contradicts the idea that the MHC-G leader peptide is the only functional part of the molecule, and suggests that G proteins may have an antigen presenting function to clonotypic T cell receptors besides the ability to interact with NK receptors. Third, MHC-G may also have a function in the thymus, because it is expressed in the thymic epithelium. MHC-G may be important for creating an appropriate T-cell repertoire. Fourth, the presence of HLA-G proteins in tumours and the specific absence of soluble HLA-G mRNA isoforms in the tissues taken from patients with autoimmune diseases suggest that MHC-G may have a role in the immune response and inflammation control.

A novel HLA-A*6816 allele possibly generated by a point mutation in a Chilean from Punta Arenas (Magellan Strait)

The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned accession number AF 144013. The name A*6816 was officially assigned by the WHO Nomenclature Committee in November 1999. This follows the agreed policy that, subject to the conditions stated in the most recent Nomenclature Report (Bodmer et al. 1999), names will be assigned to new sequences as they are identified. Lists of such new names will be published in the following WHO Nomenclature Report.

Las Alpujarras region (South East Spain) HLA genes study: evidence of a probable success of 17th century repopulation from North Spain

Conquest of Granada Muslim Kingdom (1492 AD) finished with Muslim occupation; they were mostly North African Berbers who had reached Iberia by 711 AD. A politics of Iberian Christianization followed after this date: Jewish were expelled in 1492 and Moriscos (Spaniards practicing Muslim religion or speaking Arab) were expelled from all Spanish territory on 1609 AD. Las Alpujarras is a southern Spain mountainous secluded region, which underwent a repopulation from North Spain and a specific Muslim (Moriscos)–Christian war took place according to historical records. Both Las Alpujarras repopulation by northern Iberians and Moriscos expulsion success have been debated and are regarded as non-clarified episodes. In this study, we have addressed the question whether the repopulation succeeded by determining HLA genes of present day Las Alpujarras inhabitants and compared with those of other Mediterranean populations HLA frequencies and genealogies. HLA frequencies show ambiguous results because of extant HLA similar gene frequencies there exist in North Africa and Spain. This is reflected by the finding of North and South western Mediterraneans close relatedness of HLA dendrograms and correspondence analyses. However, the genealogical study of extended HLA haplotypes particularly Alpujarran high frequency of HLA-A29-B44-DRB1*0701-DQA1*02-DQB1*02 (not found in Algerians but frequent in North and Central Spain) and Alpujarran low frequency extended haplotype HLA-A3-B7-DRB1*1501-DQA1*0102-DQB1*0602 (frequent in North Europe) reveals that a significant HLA gene flow from North Spain is observed in present day Alpujarrans: both haplotypes are characteristic of North Spain and North Europe, respectively. This may indicate that enforced Alpujarran repopulation from North Spain may have been a success, which was started by Spanish King Philip II in 1571 AD.