Association of TLR2 and TLR6 gene polymorphism with Trichomoniasis vaginalis Infection

Background: Toll-like receptors (TLR2 and TLR6) are a group of receptors that play a crucial role in the innate immune response and recognition of T. vaginalis. Single nucleotide polymorphisms (SNPs) in TLRs were manifested as important determinant affecting the susceptibility to trichomoniasis. This study aims to examine the impact of rs5743708 SNP in TLR2and rs5743810 SNP in TLR6 on Iraqi women infected with T. vaginalis.Methods: Vaginal swabs and blood samples were isolated from 186 female patients who were admitting the gynecology clinics in three public hospitals in Babel governorate in Iraq. The collected samples were obtained for molecular identification of the parasite, sequencing of the TLR2 and TLR6 genes as well as performing the corresponding immunological studies.Results: The PCR assays showed 40 positive women (95% CI, 15.85 to 28.11) of T. vaginalis β-tubulin gene. Genetic studies of rs5743708 SNP in TLR2 showed that the frequency of non-mutant G allele was clearly higher in infected women (37/64) than controls (27/64), and the GG genotype has significantly higher prevalence (90%) within infected women versus the GA (5%) and AA (5%) genotypes (p<0.001).Genetic analysis of rs5743810 SNP in TLR6, revealed that the mutant G allele was significantly higher in infected women (17/24) than healthy controls (5/24) (p=0.021), in addition, the heterozygous AG and the homozygous GG demonstrated significantly higher frequencies (13/16 and 2/3) in trichomoniasis women versus controls (3/13 and 1/3), respectively, p=0.013. Moreover, elevated concentrations of these two receptors were detected during T. vaginalis infection.Conclusion: G allele of rs5743708 might play a protective role against trichomonas is for TLR2, and women homozygous for AA were not significantly associated with increased risk of trichomonas infection. While the mutant G allele of rs5743810 SNP may make women more sensitive for infection with T. vaginalis and subjects carrying AG heterozygous and GG homozygous genotypes might have higher risk of trichomoniasis compared with AA homozygous genotype. However, more studies are needed to confirm these findings and to understand the underlying involved mechanisms.Keywords: T. vaginalis; Trichomoniasis; TLR2; TLR6; SNPs