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Human genetics of leishmania infections.

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Peer-reviewed

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Authors

Blackwell, Jenefer M  ORCID logo  https://orcid.org/0000-0002-0784-7277
Fakiola, Michaela 
Castellucci, Léa C 

Abstract

Identifying genetic risk factors for parasitic infections such as the leishmaniases could provide important leads for improved therapies and vaccines. Until recently most genetic studies of human leishmaniasis were underpowered and/or not replicated. Here, we focus on recent genome-wide association studies of visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL). For VL, analysis across 2287 cases and 2692 controls from three cohorts identified a single major peak of genome-wide significance (Pcombined = 2.76 × 10-17) at HLA-DRB1-HLA-DQA1. HLA-DRB11501 and DRB11404/DRB11301 were the most significant protective versus risk alleles, respectively, with specific residues at amino acid positions 11 and 13 unique to protective alleles. Epitope-binding studies showed higher frequency of basic AAs in DRB11404-/1301-specific epitopes compared to hydrophobic and polar AAs in DRB11501-specific epitopes at anchor residues P4 and P6 which interact with residues at DRB1 positions 11 and 13. For CL, genome-wide significance was not achieved in combined analysis of 2066 cases and 2046 controls across 2 cohorts. Rather, multiple top hits at P < 5 × 10-5 were observed, amongst which IFNG-AS1 was of specific interest as a non-coding anti-sense RNA known to influence responses to pathogens by increasing IFN-γ secretion. Association at LAMP3 encoding dendritic cell lysosomal associated membrane protein 3 was also interesting. LAMP3 increases markedly upon activation of dendritic cells, localizing to the MHC Class II compartment immediately prior to translocation of Class II to the cell surface. Together these GWAS results provide firm confirmation for the importance of antigen presentation and the regulation of IFNγ in determining the outcome of Leishmania infections.

Description

Keywords

Gene Expression Regulation, Genetic Predisposition to Disease, HLA Antigens, Human Genetics, Humans, Leishmania, Leishmaniasis, Polymorphism, Single Nucleotide

Journal Title

Hum Genet

Conference Name

Journal ISSN

0340-6717
1432-1203

Volume Title

139

Publisher

Springer Science and Business Media LLC