Beyond genome-wide scan: Association of a cis-regulatory NCR3 variant with mild malaria in a population living in the Republic of Congo

Sabrina Baaklini (1) , Sarwat Afridi (1) , Thy Ngoc Nguyen (1) , Felix Koukouikila-Koussounda (2) , Mathieu Ndounga (3) , Jean Imbert (1) , Magali Torres (1) , Lydie Pradel (1) , Francine Ntoumi (2) , Pascal Rihet (1)

1 TAGC - Technologies avancées pour le génôme et la clinique
2 UMNG - Université Marien Ngouabi [Brazzaville]
3 Centre d’Etudes sur les Ressources Végétales

Linkage studies have revealed a linkage of mild malaria to chromosome 6p21 that contains the NCR3 gene encoding a natural killer cell receptor, whereas NCR3-412G>C (rs2736191) located in its promoter region was found to be associated with malaria in Burkina Faso. Here we confirmed the association of rs2736191 with mild malaria in a Congolese cohort and investigated its potential cis-regulatory effect. Luciferase assay results indicated that rs2736191-G allele had a significantly increased promoter activity compared to rs2736191-C allele. Furthermore, EMSAs demonstrated an altered binding of two nuclear protein complexes to the rs2736191-C allele in comparison to rs2736191-G allele. Finally, after in silico identification of transcription factor candidates, pull-down western blot experiments confirmed that both STAT4 and RUNX3 bind the region encompassing rs2736191 with a higher affinity for the G allele. To our knowledge, this is the first report that explored the functional role of rs2736191. These results support the hypothesis that genetic variation within natural killer cell receptors alters malaria resistance in humans.

Domaines: Génétique humaine; Maladies infectieuses

Sabrina Baaklini, Sarwat Afridi, Thy Ngoc Nguyen, Felix Koukouikila-Koussounda, Mathieu Ndounga, et al.. Beyond genome-wide scan: Association of a cis-regulatory NCR3 variant with mild malaria in a population living in the Republic of Congo. PLoS ONE, 2017, 12 (11), pp.e0187818. ⟨10.1371/journal.pone.0187818⟩. ⟨hal-01633311⟩