Toll-like receptor 7 Gln11Leu, c.4-151A/G, and +1817G/T polymorphisms in Crimean Congo hemorrhagic fever

Abstract

Crimean-Congo hemorrhagic fever (CCHF) is a viral zoonosis. Toll-like receptors (TLRs) initiate signaling cascades leading to the activation of the innate immune system following CCHF infection. In this study, TLR7 (Gln11Leu, c.4-151A/G, and +1817G/T) polymorphisms were investigated in CCHF patients using polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP). The study population comprised 149 CCHF patients and 171 controls. For the TLR7 Gln11Leu polymorphism, there was no significant difference between the case and control groups in allele (P = 0.144) and genotype frequencies (P = 0.219). In the TLR7 IVS1 +1817G/T polymorphism, a statistically significant difference was found in allele frequencies (P = 0.026), but there was no significant difference in the TLR7 c.4-151A/G polymorphism (P = 0.310). There was a statistically significant difference in the distribution of the TLR7 c.4-151GG genotypes frequencies between patients and controls (P = 0.042; OR = 2.23). Furthermore, there were statistically significant associations between the TLR7 c.4-151A/G polymorphism and both severe disease and patient mortality (P < 0.001 and P = 0.047, respectively). The TLR7 IVS1 +1817TT genotype was also significantly associated with the case group but not the control group (P = 0.045). A strong positive linkage among TLR 7 variants was found using haplotype analysis. The incidence of two haplotypes, AGG and AGT, was determined to exhibit significant differences between the case and control groups (P < 0.001 and P < 0.001, respectively). These findings suggest that the TLR7 IVS1 +1817G/T and TLR7 c.4-151A/G polymorphisms may be important in the susceptibility or clinical course of CCHF disease.

Is there any relationship between Toll‐like receptor 3 c.1377C/T and −7C/A polymorphisms and susceptibility to Crimean Congo hemorrhagic fever?

“…This study was supported by grants (Project no: T‐415) from the Cumhuriyet University, Scientific Research Program (CUBAP). We have previously investigated several SNPs in the TLR7, TLR8, and TLR9 [Engin et al, ; Arslan et al, ] and the present study is a continuation of the previous study. In the literature, due to lack of knowledge about TLR3 polymorphisms in CCHF disease, we investigated the frequencies of TLR3 c.1377C/T (rs3775290) and TLR3 −7C/A (rs3775296) polymorphisms and whether these polymorphisms were related to the severity or mortality of CCHF disease in this study.…”

“…In this study, TLR3 (c.1377C/T and −7C/A) polymorphisms were investigated in 149 CCHF patients and age‐matched 171 healthy adults using polymerase chain reaction (PCR)‐based restriction fragment length polymorphism (RFLP) in Cumhuriyet University, Sivas/Turkey. Because this study is a continuation of the previous study, the control and patient groups were composed of the people who included in our previous studies [Engin et al, ; Arslan et al, ]. Healthy control subjects were volunteers from our university staff with no known chronic diseases.…”

Relationship betweenIFNA1,IFNA5,IFNA10, andIFNA17gene polymorphisms and Crimean‐Congo hemorrhagic fever prognosis in a Turkish population range

“…Until now, there are a few published studies to identify the genetic predisposition toward the clinical course and outcome of CCHF infection. In those studies the role of polymorphisms in toll‐like receptor (TLR)7 [Arslan et al, ], TLR8, TLR9 [Engin et al, ], nuclear factor (NF)‐κB1, NF‐κBIA [Arslan and Engin, ], tumor necrosis factor (TNF)‐alpha and interleukin (IL)‐6 [Yilmaz et al, ] genes have been investigated. Thus, this study is the first in the determination of SNPs of IFNA subtype genes in CCHF patients.…”

Association of TLR3 L412F Polymorphism with Cytomegalovirus Infection in Children

“…The selection of SNPs was based on their possible functional effect and due to the existence of previous associations with infectious diseases. The identification of SNPs was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using primers described previously by Noguchi et al [29] ( TLR3 SNPs), Cheng et al [30] ( TLR7 SNP rs179008), and Arslan et al [31] ( TLR7 SNP rs5741880). Each PCR reaction contained 200 ng of genomic DNA, primers (1 μM each), dNTPs (2.5 mM), 10x Taq buffer (100 mM Tris-HCl, 500 mM KCl, 0.8% Nonidet-P40; pH 8.8), 2 mM MgCl 2 , and 1 U of Taq DNA Polymerase (Fermentas, Glen Burnie, MD, USA).…”