A Non-synonymous Coding Variant (L616F) in the TLR5 Gene is Potentially Associated with Crohn's Disease and Influences Responses to Bacterial Flagellin
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Background And Objectives: Although numerous studies have implicated TLR5, or its ligands, bacterial flagellins, in the pathogenesis of Crohn's disease (CD), genome-wide association studies (GWAS) have not reported associations with the TLR5 gene. We aimed to examine potential CD-associated TLR5 variants and assess whether they modified inflammatory responses to bacterial flagellins.
Methods And Principal Results: A two-stage study was carried out. In stage 1, we genotyped tagging single-nucleotide polymorphisms (tag-SNPs) in the TLR5 gene in a sample of CD cases (<20 years of age, N = 566) and controls (N = 536). Single SNP and haplotype analysis was carried out. In Stage 2, we assessed the functional significance of potential CD-associated variant(s) vis-à-vis effects on the inflammatory response to bacterial flagellin using HEK293T cells. We observed marginal association between a non-synonymous coding SNP rs5744174 (p = 0.05) and CD. Associations between SNP rs851139 that is in high linkage disequilibrium (LD) with SNP rs5744174 were also suggested (p = 0.07). Haplotype analysis revealed that a 3 marker haplotype was significantly associated with CD (p = 0.01). Functional studies showed that the risk allele (616F) (corresponding to the C allele of SNP rs5744174) conferred significantly greater production of CCL20 in response to a range of flagellin doses than the comparator allele (616L).
Conclusions: Our findings suggest that a non-synonymous coding variation in the TLR5 gene may confer modest susceptibility for CD.
Membrive-Jimenez C, Perez-Ramirez C, Arias-Santiago S, Richetta A, Ottini L, Pineda-Lancheros L Int J Mol Sci. 2023; 24(10).
PMID: 37240048 PMC: 10218224. DOI: 10.3390/ijms24108703.
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Tiruvayipati S, Hameed D, Ahmed N Front Microbiol. 2022; 13:960326.
PMID: 36312954 PMC: 9615552. DOI: 10.3389/fmicb.2022.960326.
Bruno M, Dewi I, Matzaraki V, Ter Horst R, Pekmezovic M, Rosler B Comput Struct Biotechnol J. 2021; 19:647-663.
PMID: 33510868 PMC: 7817431. DOI: 10.1016/j.csbj.2020.12.036.
Toward a porcine model to analyze the pathogenesis of TLR5-dependent enteropathies.
Pieper R, van Best N, Vorst K, Ebner F, Reissmann M, Hornef M Gut Microbes. 2020; 12(1):1782163.
PMID: 32715918 PMC: 7524303. DOI: 10.1080/19490976.2020.1782163.
Tormanen S, Terasjarvi J, Lauhkonen E, Helminen M, Koponen P, Korppi M Health Sci Rep. 2019; 1(6):e38.
PMID: 30623075 PMC: 6266536. DOI: 10.1002/hsr2.38.