Identification of the CCR5-Δ32 HIV resistance allele and new mutations of the CCR5 gene in different Tunisian populations

• Published in: Human immunology Vol. 68; no. 12; pp. 993 - 1000
• Main Authors: Jlizi, Asma, Edouard, Joanne, Fadhlaoui-Zid, Karima, Frigi, Sabah, Debré, Patrice, Slim, Amine, Theodorou, Ioannis, El Gaaied, Amel Ben Ammar, Carpentier, Wassila
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 2007
• Subjects: Allergy and Immunology; CCR5; Chemokine receptor; HIV infection; Polymorphism; Tunisian populations; Tunisian populations; Chemokine receptor; CCR5; HIV infection; Polymorphism
• ISSN: 0198-8859; 1879-1166
• DOI: 10.1016/j.humimm.2007.10.003

Summary Polymorphisms in some chemokine receptor genes are associated with susceptibility to and progression of human immunodeficiency virus–1 (HIV-1) infection. Most mutations detected in the CC-chemokine receptor 5 (CCR5) gene are specific to different populations. In this study, we focused on polymorphisms of the CCR5 coding region in three healthy populations from Tunisia, corresponding to a cosmopolitan population from Tunis, and two isolated Berber populations. In addition to the CCR5-Δ32 deletion, eleven single nucleotide polymorphisms were detected. Some of these point mutations were associated with the same genotype and even the same haplotype. The (L55Q-C101X), I124, V131F, T143N, A159V, I237, T239A and G301R alleles have not been described previously, whereas the CCR5-Δ32, L55Q, A335V and Y339F variants have already been reported in the literature. The distribution and frequency of these variants were different among the three groups studied, a result in agreement with the mosaic genetic structure of the Tunisian population. To determine whether these alleles affect HIV-1 transmission, we compared allele frequencies between healthy and HIV-1 infected individuals from Tunis. The frequency of the CCR5-Δ32 variant was significantly different between the two groups, leading us to conclude that this mutation might confer protection against HIV infection in Tunisian populations.