IDENTIFICATION OF TWO NOVEL ALLELES, CD1D*03 AND*04, IN INDIVIDUALS FROM MOROCCO

CD1 is a small multigene family consisting of five MHC-like genes (CD1a, -b, -c, -d, and -e) located on the q22 arm of chromosome 1. CD1 proteins present self and foreign lipid antigens to specific T and NKT cells, which are important in controlling autoimmune diseases, tumor growth, and host defense against pathogens. CD1 genes exhibit a limited sequence polymorphism, mainly located in exon 2, whose functions and effects are still unknown. Here, we report two novel CD1d allelic variants, identified in three unrelated Moroccan healthy individuals. CD1d*03 (Genbank accession no. KF742502) and *04 (Genbank accession no. KF751734) are the novel CD1d alleles detected by sequence analysis in our laboratory, during HLA-related immunogenetic analyses of individuals from a Berber population of North Morocco. The novel sequences were confirmed by repeating the sequencing procedure on independent PCRs and cloning. Alleles have been assigned by the IMGT Nomenclature Committee and the sequences entered in IMGT/GENE-DB (http://www.imgt.org). CD1d*03 differs from the common CD1d*01 for a C->T nonsynonymous substitution at nucleotide position 102 (codon 48, Arg->Cys) and CD1d*04 for C->T nonsynonymous substitution at nucleotide position 70 of the exon 2 (codon 37, Thr->Met). A growing interest is rising on CD1d molecule because of its role in diseases and for new therapeutic perspectives. Studies on CD1 polymorphism in different ethnic groups could contribute to determine if CD1-restricted immune responses to lipid antigens are significantly involved in disease susceptibility/protection, taking into account variations in population/microbial ecology in different geographic areas.