Authors:
M. ALIZADEH (Rennes, FR)
X. Lafarge (Bordeaux, FR)
C. Picard (Marseille, FR)
C. FRASSATI (Marseille, FR)
A. Walencik (Nantes, FR)
A. Cesbron (FR)
F. BENNASARD (Rennes, FR)
F. VERITE (Rennes, FR)
G. SEMANA (Rennes, FR)
W/S, X, X2 and Y-boxes are conserved cis-acting regulatory elements present within the first 150–300 base pairs upstream of the transcription initiation site of each MHC class II gene and bind to proteins forming the enhanceosome complex. We developed an approach using NGS sequencing from the long range PCR for HLA-DRB1, -DRB3 and -DRB5 typing. All these loci are amplified in a single vial in two different PCRs, one amplifying exon 1 from 5’UTR to intron 1 and the other from intron 2 to 3’ UTR. We developed also software that allows analysis of all loci. We describe here the 5’UTR sequences of these genes, determined by 4 different laboratories on 41 Workshop B lymphoblastoid cell lines: 20 different DRB1 alleles, 4 DRB3 and 2 DRB5 alleles, each present in 1-6 lines. Of those, the 5’UTR has not yet been described for 5 DRB1, 2 DRB3 and the 2 DRB5 alleles tested. Comparing the sequences published (in particular for DRB4) and those obtained we could conclude that these DNA motifs are identical between, all the DRB1*07 and *09 alleles (called DRB1*07 group), all the DRB1*01, *15 and *16 alleles (called DRB1*01 group), all the DRB1*03, *11, *12, *13, *14, *08 alleles (called DRB1*03 group). Only 1 position is different between DRB1*01 and DRB1*03 groups, between DRB5 alleles and DRB1*01 group, 2 between DRB1*04 alleles and DRB1*07 group, 3 between DRB3 alleles and DRB1*03 group respectively. DRB4 and DRB1*04, *07, *09 alleles are more distant. These observations are in line with the evolutionary theory of the “two branches” for DR haplotypes generation, the DR53 haplotype diverging from all the other human DR-haplotypes after the separation of the new and old world monkeys. The DR1 haplotype probably emerged by DRB5 deletion in a DR51 haplotype, and the DRB1*08 gene was created through a gene contraction event in a primordial DR52 haplotype between a DRB1* and a DRB3* gene. These interesting data can be useful for studies on MHC class II expression regulation.