Association of Toll-like receptor 3 gene polymorphism with the severity of enterovirus 71 infection in Chinese children

TMEM173 rs7447927 genetic polymorphism and susceptibility to severe enterovirus 71 infection in Chinese children

INTRODUCTION

This study was designed to explore the association between the TMEM173 polymorphism (rs7447927) and the severity of enterovirus 71 (EV71) infection among Chinese children.

METHODS

The TMEM173 polymorphism was identified in EV71-infected patients (n = 497) and healthy controls (n = 535) using the improved multiplex ligation detection reaction (iMLDR). The interferon-α (IFN-α) serum levels were detected using enzyme linked immunosorbent assay (ELISA).

RESULTS

The frequencies of the GG genotype and G allele of TMEM173 rs7447927 in the mild EV71 infection and severe EV71 infection groups were markedly higher than those in the control group. The GG genotype and G allele frequencies in severely infected EV71 patients were significantly higher than those in mildly infected EV71 patients. Severely infected EV71 patients with the GG genotype had higher white blood cell counts (WBC), and C-reactive proteins (CRP), and blood glucose (BG) levels, longer fever duration, higher vomiting frequency, spirit changes, and electroencephalography (EEG) abnormalities. IFN-α serum concentration in severely infected patients was significantly higher than in the mildly infected group. The IFN-α concentration in the GG genotype was significantly higher compared with those in the GC and CC genotypes in severe cases.

CONCLUSIONS

The TMEM173 rs7447927 polymorphism was associated with EV71 infection susceptibility and severity. The G allele and GG genotype are susceptibility factors in the development of severe EV71 infection in Chinese children.

Association of TLR3 gene 1377C/T (rs3775290) and TLR7 gene C/G (rs3853839) polymorphism with hand, foot, and mouth disease caused by human enterovirus 71 infection susceptibility and severity in the Chinese Han population: A meta-analysis of case-control studies

BACKGROUND

Several case-control studies have been conducted on the relationship between rs3775290 C/T and rs3853839 C/G single nucleotide polymorphisms of the Toll-like receptor (TLR) gene and hand, foot, and mouth disease (HFMD) susceptibility and severity. This meta-analysis aimed to offer a systemic review of HFMD susceptibility and severity among the Chinese Han population associated with the C/T (rs3775290) polymorphism of the TLR3 gene or C/G (rs3853839) polymorphism of the TLR7 gene.

METHODS

A computer search was conducted using PubMed, Web of Science, Embase, CNKI, CBM, VIP, and WanFang databases. The time ranges were from database establishment to 30/7/2021. Articles selected according to the inclusion and exclusion criteria underwent data extraction and methodological quality evaluation. RevMan 5.4 and Stata 16.0 were adopted for meta-analysis, and the incorporated odds ratio (OR) values and 95% confidence intervals (CIs) were calculated. Sensitivity and publication bias assessments were performed.

RESULTS

8 articles with 9 studies were selected. Among them, there were 858 cases and 577 controls in TLR3 rs3775290 studies as well as 2151 cases and 1554 controls in TLR7 rs3853839 studies. Regarding rs3775290 of TLR3, susceptibilities of the severe type of T-possessing individuals were larger than those of C-possessing individuals [OR = 1.34, 95%CI (1.10, 1.64), P = .004]. The susceptibility of individuals with the severe TT genotype was 1.61 times that of individuals with the CC genotype [95%CI (1.07, 2.43), P=0.02], while susceptibility to HFMD was not influenced by the genotype. In terms of the rs3853839 of the TLR7 gene, C allele carriers have a higher risk of developing HFMD than G allele carriers. The susceptibility to HFMD in CC+CG individuals was 1.24 times than that in GG individuals [95%CI (1.07, 1.43), P = .004]. However, no relationship was found between this polymorphism and severity of the severe type. No significant publication bias was observed in this study.

CONCLUSIONS

rs3775290 (C/T) of TLR3 is associated with susceptibility to the severe type, whereas rs3853839 (C/G) of TLR7 is associated with susceptibility to HFMD. However, owing to the limited quantity and quality of the research, the aforementioned conclusions are yet to be justified by more high-quality research.

Association of the IRAK4 rs4251545 genetic polymorphism with severity of enterovirus-71 infection in Chinese children

INTRODUCTION

This study aimed to explore the association between the IRAK4 polymorphism rs4251545 and the severity of enterovirus 71 (EV71) infection in Chinese children.

METHODS

We analyzed the IRAK4 polymorphism rs4251545 in 617 EV71-infected patients and 410 controls using the improved multiplex ligation detection reaction. IRAK4 mRNA expression was tested by qRT-PCR. Serum concentrations of IL-6 and NF-κB were detected using ELISA.

RESULTS

The frequencies of the GA + AA genotype and A allele in the mild EV71 infection group and in the severe EV71 infection group were significantly higher than those in the normal control group. The frequency of the GA + AA genotype and A allele in severely infected EV71 patients was markedly higher than that in mildly infected EV71 patients. IRAK4 mRNA expression in mildly infected EV71 patients and severely infected patients was significantly higher than that in the control group. IRAK4 mRNA expression in GA + AA genotypes in both mild and severe EV71 infection groups was significantly higher than that in patients with the GG genotype. IL-6 concentration and the ratio of IL-6/NF-κB in severe EV71 cases were significantly lower in patients with the GA + AA genotype than in those with the GG genotype. The ratio of IL-6/NF-κB was distinctly higher in severely infected EV71 patients than in mildly infected and control subjects.

CONCLUSIONS

The IRAK4 polymorphism rs4251545 was associated with the susceptibility and severity of EV71 infection. The A allele is a susceptible factor in the development of severe EV71 infection in Chinese children.

TLR3 polymorphisms are associated with the severity of hand, foot, and mouth disease caused by enterovirus A71 in a Chinese children population

Hand, foot, and mouth disease (HFMD) caused by enterovirus A71 (EV-A71) is a contagious viral disease, and toll-like receptors (TLRs) play essential roles in resisting the pathogen. The aim of this study was to assess the potential relationship between several TLRs polymorphisms and the HFMD severity in a Chinese children population. A total of 328 Chinese children with HFMD were included in the present study. The polymorphisms of TLR3 (rs3775290, rs3775291, rs3775296, rs1879026, rs5743312, rs5743313, rs5743303, rs13126816, and rs3775292), TLR4 (rs4986790, rs4986791, rs2149356, rs11536889, and rs41426344), TLR7 (rs179009, rs179010, rs179016, rs3853839, rs2302267, rs1634323, and rs5741880), and TLR8 (rs3764880, rs2159377, rs2407992, rs5744080, rs3747414, rs3764879, and rs5744069) genes were selected. The study indicated that individuals with the GG genotype of TLR3 single-nucleotide polymorphism rs1879026 had a higher risk of developing severe cases (GG vs. GT: OR = 1.875; 95% CI, 1.183-2.971; p = .007). Meanwhile, TLR3 rs3775290 CC genotype and C allele were associated with lower disease severity in females (CC vs. CT: OR = 0.350; 95% CI, 0.163-0.751; p = .006; C vs. T: OR = 0.566; 95% CI, 0.332-0.965; p = .036). TLR3 rs3775291 CC genotype showed 2.537 folds higher risk of developing severe cases in females (CC vs. CT: OR = 2.537; 95% CI, 1.108-5.806; p = .026). Moreover, TLR3 rs1879026 GG genotype was found to be related to increased risk of severe cases in males (GG vs. GT: OR = 2.076; 95% CI, 1.144-3.768; p = .016). The current findings show that the genetic variants of TLR3 rs1879026, rs3775290, and rs3775291 are associated with the severity of EV-A71-associated HFMD in a Chinese children population.

Interplays between Enterovirus A71 and the innate immune system

Enterovirus A71 (EV-A71) is a growing threat to public health, particularly in the Asia-Pacific region. EV-A71 infection is most prevalent in infants and children and causes a wide spectrum of clinical complications, including hand-foot-and-mouth disease (HFMD), pulmonary and neurological disorders. The pathogenesis of EV-A71 infection is poorly understood at present. It is likely that viral factors and host immunity, and their interplay, affect the pathogenesis and outcome of EV-A71 infection. The mammalian innate immune system forms the first layer of defense against viral infections and triggers activation of adaptive immunity leading to full protection. In this review, we discuss recent advances in our understanding of the interaction between EV-A71 and the innate immune system. We discuss the role of pattern-recognition receptors (PRRs), including Toll-like receptors (TLRs), RIG-I-like receptors (RLRs), and inflammasomes, in the detection of EV-A71 infection and induction of antiviral immunity. As a counteraction, EV-A71 viral proteins target multiple innate immune pathways to facilitate viral replication in host cells. These novel insights at the virus-host interphase may support the future development of vaccines and therapeutics against EV-A71 infection.

Identification and characterization of rare toll-like receptor 3 variants in patients with autoimmune Addison's disease

Autoimmune Addison's disease (AAD) is a classic organ-specific autoimmune disease characterized by an immune-mediated attack on the adrenal cortex. As most autoimmune diseases, AAD is believed to be caused by a combination of genetic and environmental factors, and probably interactions between the two. Persistent viral infections have been suggested to play a triggering role, by invoking inflammation and autoimmune destruction. The inability of clearing infections can be due to aberrations in innate immunity, including mutations in genes involved in the recognition of conserved microbial patterns. In a whole exome sequencing study of anonymized AAD patients, we discovered several rare variants predicted to be damaging in the gene encoding Toll-like receptor 3 (TLR3). TLR3 recognizes double stranded RNAs, and is therefore a major factor in antiviral defense. We here report the occurrence and functional characterization of five rare missense variants in TLR3 of patients with AAD. Most of these variants occurred together with a common TLR3 variant that has been associated with a wide range of immunopathologies. The biological implications of these variants on TLR3 function were evaluated in a cell-based assay, revealing a partial loss-of-function effect of three of the rare variants. In addition, rare mutations in other members of the TLR3-interferon (IFN) signaling pathway were detected in the AAD patients. Together, these findings indicate a potential role for TLR3 and downstream signaling proteins in the pathogenesis in a subset of AAD patients.

Viruses Seen by Our Cells: The Role of Viral RNA Sensors

The role of the innate immune response in detecting RNA viruses is crucial for the establishment of proper inflammatory and antiviral responses. Different receptors, known as pattern recognition receptors (PRRs), are present in the cytoplasm, endosomes, and on the cellular surface. These receptors have the capacity to sense the presence of viral nucleic acids as pathogen-associated molecular patterns (PAMPs). This recognition leads to the induction of type 1 interferons (IFNs) as well as inflammatory cytokines and chemokines. In this review, we provide an overview of the significant involvement of cellular RNA helicases and Toll-like receptors (TLRs) 3, 7, and 8 in antiviral immune defenses.

Crosstalk between Toll-like receptor 3 and Notch signaling contributes to CD14+ monocytes activity in enterovirus 71 infected hand, foot, and mouth disease

Interaction between Toll-like receptor (TLR) and Notch signaling contributes to inflammatory response in nephropathy and fungicidal infection, however, the role of this crosstalk remains not fully elucidated in enterovirus 71 (EV71)-induced hand, foot, and mouth disease (HFMD). The aim of this study was to investigate the crosstalk between TLR and Notch in inflammatory regulation in EV71 infection. Thirty-seven EV-71-indcued HFMD (16 mild and 21 severe cases) and eleven normal control (NC) were enrolled. CD14⁺ monocytes were purified, and were stimulated with either TLR3/4 agonists [poly(I: C) or LPS] or Notch signaling inhibitor. TLRs and Notch receptors expression, proinflammatory cytokines production, and important molecules in signaling pathways were measured by real-time PCR, ELISA, and Western blot. TLR3 and TLR4 was significantly elevated in CD14⁺ monocytes from HFMD patients than NC. Notch1 and Notch2 mRNA was also remarkably increased in CD14⁺ monocytes from severe HFMD. Poly(I: C) stimulation resulted in robust increase of IL-8, IL-6, and TNF-α by CD14⁺ monocytes in severe HFMD compared to NC. Activation of Notch1, Notch2, and target genes, Hes1 and Hes5 was also enhanced upon ploy(I: C) treatment. Although inhibition of Notch signaling did not affect TLR3 expression, poly(I: C)-induced inflammatory response was robustly attenuated, which was accompanied by silencing Src phosphorylation in CD14⁺ monocytes from severe HFMD patients. The current data indicated that crosstalk between TLR3 and Notch signaling modulated CD14⁺ monocytes function and inflammatory responses in the progression of EV71-induced HFMD.

Association of Interleukin-17F gene polymorphisms with susceptibility to severe enterovirus 71 infection in Chinese children

Enterovirus 71 (EV71) is a single-strand RNA virus that causes hand, foot and mouth disease (HFMD) in infants and young children, leading to neurological complications with significant morbidity and mortality. Unfortunately, the pathogenesis of EV71 infection is not well understood. In this study, we investigated the IL-17F rs1889570 and rs4715290 gene polymorphisms in a Chinese Han population. Severe cases and cases with EV71 encephalitis had a significantly higher frequency of the rs1889570 T/T genotype and T allele. The serum IL-17F levels in rs1889570 T/T and C/T genotypes were also significantly elevated when compared to C/C genotypes. However, there was no significant difference observed in rs4715290 genotype distribution and allele frequency. These findings suggest that IL-17F rs1889570 gene polymorphisms are significantly associated with the susceptibility to severe EV71 infection in Chinese Han children.