Association of TLR1, TLR2, TLR4, TLR6, and TIRAP polymorphisms with disease susceptibility

Screening optimal DC-targeting peptide to enhance the immune efficacy of recombinant Lactobacillus expressing RHDV VP60

Dendritic cells (DCs) present an ideal target for delivering immunogenic cargo due to their potent antigen-presenting capabilities. This targeting approach holds promise in vaccine development by enhancing the efficiency of antigen recognition and capture by DCs. To identify a high-affinity targeting peptide binding to rabbit DCs, rabbit monocyte-derived DCs (raMoDCs) were isolated and cultured, and a novel peptide, HS (HSLRHDYGYPGH), was identified using a phage-displayed peptide library. Alongside HS, two other DC-targeting peptides, KC1 and MY, previously validated in our laboratory, were employed to construct recombinant Lactgobacillus reuteri fusion-expressed rabbit hemorrhagic disease virus (RHDV) capsid protein VP60. These recombinant Lactobacillus strains were named HS-VP60/L. reuteri, KC1-VP60/L. reuteri, and MY-VP60/L. reuteri. The ability of these recombinant Lactobacillus to bind rabbit DCs was evaluated both in vivo and in vitro. Results demonstrated that the DC-targeting peptide KC1 significantly enhanced the capture efficiency of recombinant Lactobacillus by raMoDCs, promoted DC maturation, and increased cytokine secretion. Furthermore, oral administration of KC1-VP60/L. reuteri effectively induced SIgA and IgG production in rabbits, prolonged rabbit survival post-challenge, and reduced RHDV copies in organs. In summary, the DC-targeting peptide KC1 exhibited robust binding to raMoDCs, and recombinant Lactobacillus expressing KC1-VP60 protein antigens efficiently induced systemic and mucosal immune responses in rabbits, conferring protective efficacy against RHDV. This study offers valuable insights for the development of novel RHDV vaccines.

Therapeutic potential of plant-derived natural compounds in Alzheimer's disease: Targeting microglia-mediated neuroinflammation

Microglia are resident immune cells of the central nervous system (CNS) with roles in sensing, housekeeping, and defense. Exploring the role of microglia in the occurrence and development of Alzheimer's disease (AD) and the possible therapeutic mechanism of plant-derived natural compounds (PDNCs) that regulate microglia-associated neuroinflammation may potentially help in elucidating the pathogenesis of AD and provide novel insights for its treatment. This review explores the role of abnormal microglial activation and its dominant neuroinflammatory response, as well as the activation of their target receptors and signaling pathways in AD pathogenesis. Additionally, we report an update on the potential pharmacological mechanisms of multiple PDNCs in modulating microglia-associated neuroinflammation in AD treatment. Dysregulated activation of microglial receptors and their downstream pathways impaired immune homeostasis in animal models of AD. Multiple signaling pathways, such as mitogen-activated protein kinase (MAPK), nuclear factor kappa light chain enhancer of activated B cells (NF-κB), and Toll-like receptors, play important roles in microglial activation and can exacerbate microglia-mediated neuroinflammation. PDNCs, such as magnolol, stigmasterol, matrine, naringenin, naringin, and resveratrol, can delay the progression of AD by inhibiting the proinflammatory receptors of microglia, activating its anti-inflammatory receptors, regulating the receptors related to β-amyloid (Aβ) clearance, reversing immune dysregulation, and maintaining the immune homeostasis of microglial downstream pathways. This review summarizes the mechanisms by which microglia cause chronic inflammation in AD and evaluates the beneficial effects of PDNCs on immune regulation in AD by regulating microglial receptors and their downstream pathways.

TLR2 and TLR4 Polymorphisms Are Not Associated with Dental Caries in Polish Children

The aim of the present study was to analyze the association of the TLR2 (Toll-like receptor 2 gene) 2258G>A (rs5743708), TLR4 (Toll-like receptor 4 gene) 896A>G (rs4986790), and TLR4 1196C>T (rs4986791) polymorphisms with dental caries in Polish children. The participants, 261 15-year-old children, were divided into two groups: 82 cases (i.e., children with DMFT (Decayed, Missing, and Filled Teeth) index >5, having either moderate or high caries experience, assigned as the "higher" caries experience group) and 179 controls (i.e., children with DMFT ≤ 5, having either low or very low caries experience, assigned as the "lower" caries experience group). Genomic DNA was isolated from buccal swabs, and genotyping was determined by means of real-time PCR (polymerase chain reaction). There were no significant differences in the genotype or allele distributions in all tested SNPs (single nucleotide polymorphisms) between children with "higher" caries experience and those with "lower" caries experience. TLR4 haplotype frequencies did not differ significantly between cases and controls. In an additional analysis with another case definition applied (subjects with DMFT ≥ 1 were assigned as "cases", whereas children with DMFT = 0 were assigned as "controls"), no significant differences in the TLR2 and TLR4 genotype, allele frequencies, and TLR4 haplotype frequencies were found between the case and the control groups. The results of the present study broaden our knowledge on the potential genetic factors that might affect caries risk and suggest that TLR2 rs5743708 and TLR4 rs4986790 and rs4986791 SNPs are not associated with dental caries susceptibility in Polish children.

Tirap controls Mycobacterium tuberculosis phagosomal acidification

Progression of tuberculosis is tightly linked to a disordered immune balance, resulting in inability of the host to restrict intracellular bacterial replication and its subsequent dissemination. The immune response is mainly characterized by an orchestrated recruitment of inflammatory cells secreting cytokines. This response results from the activation of innate immunity receptors that trigger downstream intracellular signaling pathways involving adaptor proteins such as the TIR-containing adaptor protein (Tirap). In humans, resistance to tuberculosis is associated with a loss-of-function in Tirap. Here, we explore how genetic deficiency in Tirap impacts resistance to Mycobacterium tuberculosis (Mtb) infection in a mouse model and ex vivo. Interestingly, compared to wild type littermates, Tirap heterozygous mice were more resistant to Mtb infection. Upon investigation at the cellular level, we observed that mycobacteria were not able to replicate in Tirap-deficient macrophages compared to wild type counterparts. We next showed that Mtb infection induced Tirap expression which prevented phagosomal acidification and rupture. We further demonstrate that the Tirap-mediated anti-tuberculosis effect occurs through a Cish-dependent signaling pathway. Our findings provide new molecular evidence about how Mtb manipulates innate immune signaling to enable intracellular replication and survival of the pathogen, thus paving the way for host-directed approaches to treat tuberculosis.

Toll-like receptors in cardiac hypertrophy

Toll-like receptors (TLRs) are a family of pattern recognition receptors (PRRs) that can identify pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). TLRs play an important role in the innate immune response, leading to acute and chronic inflammation. Cardiac hypertrophy, an important cardiac remodeling phenotype during cardiovascular disease, contributes to the development of heart failure. In previous decades, many studies have reported that TLR-mediated inflammation was involved in the induction of myocardium hypertrophic remodeling, suggesting that targeting TLR signaling might be an effective strategy against pathological cardiac hypertrophy. Thus, it is necessary to study the mechanisms underlying TLR functions in cardiac hypertrophy. In this review, we summarized key findings of TLR signaling in cardiac hypertrophy.

Pattern-recognition receptors in endometriosis: A narrative review

Endometriosis is closely associated with ectopic focal inflammation and immunosuppressive microenvironment. Multiple types of pattern recognition receptors (PRRs) are present in the innate immune system, which are able to detect pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs) in both intracellular and external environments. However, the exact role of PRRs in endometriosis and the underlying molecular mechanism are unclear. PRRs are necessary for the innate immune system to identify and destroy invasive foreign infectious agents. Mammals mainly have two types of microbial recognition systems. The first one consists of the membrane-bound receptors, such as toll-like receptors (TLRs), which recognize extracellular microorganisms and activate intracellular signals to stimulate immune responses. The second one consists of the intracellular PRRs, including nod-like receptors (NLRs) and antiviral proteins retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (MDA-5) with helix enzyme domain. In this review, we mainly focus on the key role of PRRs in the pathological processes associated with endometriosis. PRRs recognize PAMPs and can distinguish pathogenic microorganisms from self, triggering receptor ligand reaction followed by the stimulation of host immune response. Activated immune response promotes the transmission of microbial infection signals to the cells. As endometriosis is characterized by dysregulated inflammation and immune response, PRRs may potentially be involved in the activation of endometriosis-associated inflammation and immune disorders. Toll-like receptor 2 (TLR2), toll-like receptor 3 (TLR3), toll-like receptor 4 (TLR4), nod-like receptor family caspase activation and recruitment domain (CARD) domain containing 5 (NLRC5), nod-like receptor family pyrin domain containing 3 (NLRP3), and c-type lectin receptors (CLRs) play essential roles in endometriosis development by regulating immune and inflammatory responses. Absent in melanoma 2 (AIM2)-like receptors (ALRs) and retinoic acid-inducible gene I-like receptors (RLRs) may be involved in the activation of endometriosis-associated immune and inflammation disorders. PRRs, especially TLRs, may serve as potential therapeutic targets for alleviating pain in endometriosis patients. PRRs and their ligands interact with the innate immune system to enhance inflammation in the stromal cells during endometriosis. Thus, targeting PRRs and their new synthetic ligands may provide new therapeutic options for treating endometriosis.

Investigation of TLR2 and TLR4 Polymorphisms and Sepsis Susceptibility: Computational and Experimental Approaches

Toll-like receptors (TLR) play an eminent role in the regulation of immune responses to invading pathogens during sepsis. TLR genetic variants might influence individual susceptibility to developing sepsis. The current study aimed to investigate the association of genetic polymorphisms of the TLR2 and TLR4 with the risk of developing sepsis with both a pilot study and in silico tools. Different in silico tools were used to predict the impact of our SNPs on protein structure, stability, and function. Furthermore, in our prospective study, all patients matching the inclusion criteria in the intensive care units (ICU) were included and followed up, and DNA samples were genotyped using real-time polymerase chain reaction (RT-PCR) technology. There was a significant association between TLR2 Arg753Gln polymorphisms and sepsis under the over-dominant model (p = 0.043). In contrast, we did not find a significant difference with the TLR4 Asp299Gly polymorphism with sepsis. However, there was a significant association between TLR4 Asp299Gly polymorphisms and Acinetobacter baumannii infection which is quite a virulent organism in ICU (p = 0.001) and post-surgical cohorts (p = 0.033). Our results conclude that the TLR2 genotype may be a risk factor for sepsis in adult patients.

Delivery of antigen to porcine dendritic cells by fusing antigen with porcine dendritic cells targeting peptide

Dendritic cells (DCs) are professional antigen-presenting cells that can recognize, capture, and process antigens. Fusing molecules targeting DCs with antigens can effectively improve the efficiency with which antigens are recognized and captured by DCs. This targeting strategy can be used for vaccine development to effectively improve the efficiency of antigen recognition and capture by DCs. The targeting sequence of porcine cytotoxic T-lymphocyte associated protein 4 (CTLA4), which binds porcine DCs, was identified in this study. Recombinant Lactobacillus reuteri (L. reuteri) expressing CTLA4-6aa (LYPPPY) and CTLA4-87aa fused to the porcine epidemic diarrhea virus (PEDV) protective antigen core neutralizing epitope (COE) were used to evaluate the ability of the two targeting motifs to bind the B7 molecule on DCs. Our results demonstrate that CTLA4-6aa could bind porcine DCs, and recombinant Lactobacillus expressing the CTLA4-6aa captured by porcine DCs was more efficient than those expressing CTLA4-87aa. In addition, the expression of DC markers, toll-like receptors, and cytokines was significantly higher in the 6aa-COE/L. reuteri-stimulated porcine DCs compared to DCs treated with 87aa-COE/L. reuteri (p<0.01) and recombinant Lactobacillus expressing CTLA4-6aa enhanced the ability of porcine DCs to activate T-cell proliferation. Our analysis of the protein structure revealed that CTLA4-87aa contains intramolecular hydrogen bonds, which may have weakened the intermolecular force between the residues on porcine CTLA4 and that on B7. In conclusion, recombinant Lactobacillus expressing CTLA4-6aa were more efficiently captured by porcine DCs and had a stronger ability to promote DC maturation and enhance T-cell proliferation. The LYPPPY motif is the optimal sequence for binding to porcine DCs. Piglets immunized with recombinant Lactobacillus showed that recombinant Lactobacillus expressing CTLA4-6aa induced significant levels of anti-PEDV-specific IgG and IgA antibody responses. Our study may promote research on DC-targeting strategies to enhance the effectiveness of porcine vaccines.

Human dendritic cell targeting peptide can be targeted to porcine dendritic cells to improve antigen capture efficiency to stimulate stronger immune response

Dendritic cells (DCs) play a key role in the natural recognition of pathogens and subsequent activation of adaptive immune responses due to their potent antigen-presenting ability. Dendritic cell-targeting peptide (DCpep) is strongly targeted to DCs, which often express antigens, to enhance the efficacy of vaccines. Our previous study showed that recombinant Lactobacillus expressing human DCpep could significantly induce stronger immune responses than recombinant Lactobacillus without DCpep, but the mechanism remains unclear. In this study, the mechanism by which DCpep enhances the immune response against recombinant Lactobacillus was explored. Fluorescence-labeled human DCpep was synthesized to evaluate the binding ability of human DCpep to porcine monocyte-derived dendritic cells (Mo-DCs) and DCs of the small intestine. The effects of Mo-DC function induced by recombinant Lactobacillus expressing human DCpep fused with the porcine epidemic diarrhea virus (PEDV) core neutralizing epitope (COE) antigen were also investigated. The results showed that human DCpep bind to porcine DCs, but not to porcine small intestinal epithelial cells. Human DCpep can also improve the capture efficiency of recombinant Lactobacillus by Mo-DCs, promote the maturation of dendritic cells, secrete more cytokines, and enhance the ability of porcine DCs to activate T-cell proliferation. Taken together, these results promote advanced understanding of the mechanism by which DCpep enhances immune responses. We found that some DCpeps are conserved between humans and pigs, which provides a theoretical basis for the development of a DC-targeted vaccine.

TIRAP Rs8177376, Rs611953, Rs3802814, and Rs8177374 Polymorphisms and Their Association with Cervical Cancer Phenotype and Prognosis

Cervical cancer is one of the most common cancers in women worldwide, which is typically caused by human papillomavirus (HPV). Usually, the toll-like receptor (TLR) signaling pathways eliminate the virus from the organism, but in some cases, persistent infection may develop. Unfortunately, the mechanism of immune tolerance is still unclear. Therefore, this study aimed to analyze TIRAP rs8177376, rs611953, rs3802814, and rs8177374 polymorphisms and to identify their impact on cervical cancer phenotype and prognosis. This study included 172 cervical cancer patients. Genotyping was performed using the PCR-RFLP assay. Univariate and multivariate logistic regression and Cox′s regression models were applied for statistical analysis. The results revealed that older age at the time of diagnosis was statistically linked with the rs8177376 T allele (OR = 2.901, 95% Cl 1.750–4.808, p = 0.000) and the rs611953 G allele (OR = 3.258, 95% Cl 1.917–5.536, p = 0.000). Moreover, the T allele of rs8177376 (OR = 0.424, 95% Cl 0.220–0.816, p = 0.010) was found to be statistically associated with the lower tumor grade. Thus, TIRAP polymorphisms might be employed in the future as potential biomarkers for determining the phenotype and prognosis of cervical cancer.

Corynebacterium pyruviciproducens-peptidoglycan: A novel bacterial peptidoglycan inhibiting overexpression of MyD88 in macrophages

Objectives:

Bacterial peptidoglycan (PGN) is an essential ligand of TLR2 inducing inflammatory damage by boosting MyD88 overexpression in pathogen invasion, such as Methicillin-resistant Staphylococcus aureus (MRSA) infection. CP-PGN is a novel PGN from an adjuvant bacterium, displaying anti-infection immune regulation. This study aimed to clarify the unique moderation of MyD88 expression by CP-PGN.

Methods:

Compared with other ligands of TLR2, high expression of MyD88 in macrophages was established by MRSA and virus to investigate the immunomodulation of CP-PGN.

Results:

Compared with PGN derived from MRSA (M-PGN) and chemosynthetic Pam3CSK4 of model agonists of TLR2, CP-PGN could inhibit overexpression of MyD88 in a time- and dose-dependent way in infected macrophages by MRSA or Abelson leukemia virus. CP-PGN also promoted more anti-inflammatory IL-10 and less pro-inflammatory TNF-α in immature primary macrophages. Furthermore, IL-10 secretion induced by CP-PGN was reduced most significantly by blocking the dimer formation of MyD88 with ST2825 and lowering down expression by si-MyD88.

Conclusion:

CP-PGN could inhibit MyD88 overexpression by infection to moderate inflammatory cytokines. Therefore, CP-PGN is a novel potential ligand of TLR2 to induce inflammatory balance in the process of host defense against invading pathogens.

Role of Toll-Like Receptors and Th Responses in Viral Myocarditis

Myocarditis is the common cause of sudden cardiac death, dilated cardiomyopathy (DCM) and heart failure (HF) in young adults. The most common type of myocarditis is viral myocarditis (VMC). Toll-like receptors (TLRs) are vital to identify pathogens in vivo. TLRs promote the differentiation of naive CD4⁺T cells to T helper (Th) cells, activate the immune response, and participate in the pathogenesis of autoimmune and allergic diseases. Although the pathogenesis of VMC is unclear, autoimmune responses have been confirmed to play a significant role; hence, it could be inferred that VMC is closely related to TLRs and Th responses. Some drugs have been found to improve the prognosis of VMC by regulating the immune response through activated TLRs. In this review, we discuss the role of TLRs and Th responses in VMC.

TLR4 polymorphisms as potential predictors of atopic dermatitis in Chinese Han children

Background

Toll‐like receptor 4 (TLR4) is considered to be involved in the pathogenesis and progression of atopic dermatitis (AD). In the present study, we evaluated the relationship between TLR4 gene polymorphisms and the susceptibility or severity of AD among Chinese Han children.

Methods

A total of 132 AD patients and 100 healthy controls were enrolled in this study. Four single‐nucleotide polymorphisms (rs19277914, rs11536891, rs7869402, and rs11536889) of the TLR4 gene were genotyped by multiplex PCR combined with next‐generation sequencing.

Results

Our results showed that a significantly reduced risk for AD was associated with C allele [p = 0.008; odds ratio (OR) = 0.41, C vs. T], TC genotype (p = 0.022; OR = 0.41, TC vs. TT), and TC + CC genotype (p = 0.010; OR = 0.39, TC + CC vs. TT) of TLR4 rs11536891. The frequency of the haplotype GCCG (rs1927914–rs11536891–rs7869402–rs11536889) in AD patients was lower than that in the controls (p = 0.010; OR = 0.38). Moreover, the results indicated that a higher risk of severe AD was related to the T allele (p = 0.019; OR = 2.97, T vs. C) and the TC genotype (p = 0.021; OR = 3.34, TC vs. CC) of TLR4 rs7869402. A risk haplotype of TLR4 (GTTG) was found in severe AD patients (p = 0.010; OR = 5.26).

Conclusions

Our data suggested that TLR4 rs11536891 polymorphism was associated with the susceptibility to AD in Chinese Han children. And TLR4 rs7869402 might confer the severity of pediatric AD patients.

Qiu's Neiyi Recipe Regulates the Inflammatory Action of Adenomyosis in Mice via the MAPK Signaling Pathway

Background

The management of adenomyosis is challenging and limiting. Qiu's Neiyi recipe (Qiu) is a traditional Chinese medicine (TCM) prescription clinically used for endometriosis treatment in China, but the effect and mechanism of Qiu on adenomyosis are undefined.

Methods

An experimental adenomyosis model was induced in female neonatal ICR mice administrated with tamoxifen. The adenomyosis mice were divided into five groups: high-, middle-, and low-Qiu's group, danazol group, and model group. The mice just administrated with the solvent only (no tamoxifen or drugs) were served as the control group. After 28 days of administration, the body, uterine, spleen, and thymus weights of all mice were examined. Then, the myometrial infiltration and the expression of inflammatory factors were detected by histology examination, ELISA, and qRT-PCR in the uterus. In addition, the MAPK/ERK signaling pathway-related protein expression in adenomyosis mice was detected by immunohistochemical (IHC) staining, qRT-PCR, and western blotting.

Results

In experimental adenomyosis mice, Qiu treatment improved the symptoms of adenomyosis by reducing the myometrial infiltration and increasing the index of spleen and thymus. The elevated levels of IL-1β, IL-6, and TNF-α in serum and uterus tissues of adenomyosis model mice were also decreased after Qiu treatment. The improvement of Qiu on the adenomyosis was achieved by inhibiting the activated MAPK/ERK signaling pathway, including reducing the mRNA and protein expressions of p-ERK/ERK, p-JNK/JNK, and p-p38/p38 in the uterus tissues.

Conclusion

Qiu alleviated the inflammatory reaction and uterus histological changes in mice with adenomyosis, and the potential mechanism is through the inhibition of the MAPK/ERK signaling pathway. Qiu may be a promising treatment for adenomyosis.

Toll-Like Receptors (TLRs): Structure, Functions, Signaling, and Role of Their Polymorphisms in Colorectal Cancer Susceptibility

Toll-like receptors (TLRs) are the important mediators of inflammatory pathways in the gut which play a major role in mediating the immune responses towards a wide variety of pathogen-derived ligands and link adaptive immunity with the innate immunity. Numerous studies in different populations across the continents have reported on the significant roles of TLR gene polymorphisms in modulating the risk of colorectal cancer (CRC). CRC is one of the major malignancies affecting the worldwide population and is currently ranking the third most common cancer in the world. In this review, we have attempted to discuss the structure, functions, and signaling of TLRs in comprehensive detail together with the role played by various TLR gene SNPs in CRC susceptibility.

TLR3 agonists: RGC100, ARNAX, and poly-IC: a comparative review

Toll-like receptors 3 (TLR3) have been broadly studied among all TLRs over the last few decades together with its agonists due to their contribution to cancer regression. These agonists undeniably have some shared characteristics such as mimicking dsRNA but pathways through which they exhibit antitumor properties are relatively diverse. In this review, three widely studied agonists RGC100, ARNAX, and poly-IC are discussed along with their structural and physiochemical differences including the signaling cascades through which they exert their actions. Comparison has been made to identify the finest agonist with maximum effectivity and the least side effect profile.

Protective role of TIRAP functional variant against development of coronary artery disease

Coronary artery disease (CAD) is the leading cause of sudden death worldwide. Inflammation is proved to be an important player in development of the CAD. Inflammation is directly regulated by the Toll like receptors (TLRs). Susceptibility of CAD is influenced by genetic variations within TLRs and the proteins involved in its signaling cascade. The TIRAP/MAL {TIR domain containing adaptor protein / MyD88 (myeloid differentiation primary response gene 88) adaptor-like} exhibits maximum genetic variations of all adaptor proteins involved in TLR signaling cascade. Susceptibility to a number of diseases can be influenced due to presence of S180L single nucleotide polymorphism (SNP) of TIRAP/MAL. This study was conducted to investigate the functional role of this well characterized S180L polymorphism on susceptibility to CAD among Pakistani patients. A total of 146 Pakistani CAD patients and 147 controls were genotyped by Amplification Refractory Mutation System-Polymerase Chain Reaction (ARMS-PCR) and the data was analyzed by using 2-tailed Chi square (x2 ) test. The p value ≤ 0.05 was considered to be significant. Significantly high frequency of homozygous L180L genotype was observed among healthy subjects as compared to the CAD patients [24 (16%) vs 7 (5%); x2 11.85; p = 0.003]. Moreover, the allele frequency of the minor allele; 180L was observed to be significantly higher among controls than the CAD patients, having same direction of association [156 (53%) vs 131 (45%); OR (95% CI) = 0.7198 (0.520-0.996); p < 0.05). Our results indicate that protective effect of L180L; a coding variant of TIRAP/MAL against CAD is discernible.

Lactobacillus johnsonii activates porcine monocyte derived dendritic cells maturation to modulate Th cellular immune response

Lactobacilli are abundant in the intestinal tract where they constantly regulate immune system via interacting with a great diversity of immune cells, such as dendritic cells (DCs). Notably, DCs are powerful antigen-presenting cells and they are capable of initiating primary immune responses. In this study, we studied the effects of Lactobacillus johnsonii (L. johnsonii) and Lactobacillus johnsonii cell-free supernatant (L. johnsonii-CFS) on the activation of porcine monocyte-derived dendritic cells (MoDCs) and their regulation of Th cellular immune responses in vitro. The MoDCs generated from porcine peripheral blood monocytes were stimulated by L. johnsonii and L. johnsonii-CFS, respectively. Pre-incubation with L. johnsonii increased expression of CD172a, CD80, major histocompatibility complex class II (MHCII) in MoDCs, and enhanced the ability of MoDCs to induce the proliferation of CD4⁺ T cell, while pre-incubation with L. johnsonii-CFS merely upregulated the expression of MHCII. Analysis of the cytokines showed that L. johnsonii stimulated up-regulation of Th1-type cytokines (IL-12p40, IFN-γ, TNF-α), pro-inflammatory cytokine IL-1β, chemokine CCL20, and Treg-type / anti-inflammatory cytokines IL-10 in MoDCs. Notably, a high production of IL-10 was observed in the MoDCs treated with L. johnsonii-CFS, indicating L. johnsonii-CFS exerted anti-inflammatory effects. Furthermore, L. johnsonii induced up-regulation of TLR2 and TLR6, but L. johnsonii-CFS not. Moreover, MoDCs stimulated by L. johnsonii mainly promoted T cell differentiate into Th1/Th2/Treg cells and plays an important role in improving the balance between Th1/Th2/Treg-type cells, whereas MoDCs stimulated by L. johnsonii-CFS mainly directed T cell to Th2/Treg subset polarization. In conclusion, L. johnsonii and L. johnsonii-CFS exhibited the ability of modulating innate immunity by regulating immunological functions of MoDCs in vitro, suggesting their potential ability to use as microecological preparations and medicines.

Sequence and Structural Characterization of Toll-Like Receptor 6 from Human and Related Species

Toll-like receptors (TLRs) play an important role in the innate immune response against various pathogens. They serve as expected targets of natural selection in those species which are adapted to habitats with contrasting pathogen burdens. Till date, sufficient literature about TLRs especially TLR6 is not available. The current study was therefore planned to show evolutionary patterns of human TLRs generally and TLR6 specifically along with their conservation and diversity. The study also deals with characteristic polymorphic patterns of TLR6 in humans which are involved in serious clinical consequences. The sequence analysis of TLR6 from different mammals revealed conserved regions in the protein sequence. With respect to TLR6 evolution, human showed a close evolutionary relationship with chimpanzee and orangutans, while monkeys were appeared in a separate clade showing a distant evolutionary relationship. Old World monkeys and New World monkeys made their separate clades but both have evolved from a common ancestor. The C-terminal of human TLRs (TLR1 to TLR10) exhibited more conservation as compared to other regions. The phylogram of human TLRs showed that TLR6 is closely related to TLR1 and both TLRs shared a common ancestor with TLR10. The domain analysis has revealed that TLR1 and TLR10 have least (i.e., 4) number of leucine-rich repeat (LRR) while TLR6 contains five LRRs. Three single nucleotide polymorphisms were found in TLR6 which were found to be associated with benign. Conclusively, the current comparative sequence analyses and phylogenetic analyses provided informative insights into the process of TLR evolution in mammals. Furthermore, the polymorphism analysis would serve as a useful marker in the early detection of susceptibility and resistance against cancers and other diseases in humans.

Associations of toll-like receptor 4 and 2 gene polymorphisms with susceptibility to ankylosing spondylitis: A meta-analysis

BACKGROUND

The published evidences on the correlations of toll-like receptor 4 (TLR4) and TLR9 gene polymorphisms and ankylosing spondylitis (AS) were conflicting. The purpose of this study was to investigate whether TLR4 and TLR9 gene polymorphisms conferred susceptibility to AS through a meta-analysis approach.

METHODS

Databases of PubMed, Web of Science, EMBASE, Cochrane Library, CNKI and Wanfang were retrieved for relevant publications up to 20 June 2020. Study quality was assessed based on Newcastle-Ottawa scale (NOS). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to judge the associations.

RESULTS

Totally, 13 articles with 3,055 AS cases and 4,238 controls were incorporated into this meta-analysis, and four most widely reported polymorphisms (TLR4-rs4986790, TLR4-rs4986791, TLR9-rs55704465 and TLR9-rs187084) were analysed. All included studies were in high quality. The pooled data did not support any significant association between the four studied polymorphisms and AS susceptibility.

CONCLUSIONS

The present meta-analysis suggests there is no significant association between TLR4-rs4986790, TLR4-rs4986791, TLR9-rs55704465 and TLR9-rs187084 polymorphisms and AS.

Identification of Systems Level Molecular Signatures from Glioblastoma Multiforme Derived Extracellular Vesicles

Glioblastoma multiforme (GBM) is one of the most lethal malignancies of the central nervous system characterized by high mortality rate. The complexity of GBM pathogenesis, progression, and prognosis is not fully understood yet. GBM-derived extracellular vesicles (EVs) carry several oncogenic elements that facilitate GBM progression. The purpose of this study was to identify systems level molecular signatures from GBM-derived EVs using integrative analysis of publicly available transcriptomic data generated from plasma and serum samples. The dataset contained 19 samples in total, of which 15 samples were from plasma (11 GBM patients and 4 healthy samples) and 4 samples were from serum (2 GBM and 2 healthy samples). We carried out statistical analysis to identify differentially expressed genes (DEGs), functional enrichment analysis of the DEGs, protein-protein interaction networks, module analysis, transcription factors and target gene regulatory networks analysis, and identification of hub genes. The differential expression of the identified hub genes were validated with the independent TCGA-GBM dataset. We have identified a few crucial genes and pathways associated with GBM prognosis and therapy resistance. The DEGs identified from plasma were associated with inflammatory processes and viral infection. On the other hand, the hub genes identified from the serum samples were significantly associated with protein ubiquitinylation processes and cytokine signaling regulation. The findings indicate that GBM-derived plasma and serum DEGs may be associated with distinct cellular processes and pathways which facilitate GBM progression. The findings will provide better understanding of the molecular mechanisms of GBM pathogenesis and progression. These results can further be utilized for developing and validating minimally invasive diagnostic and therapeutic molecular biomarkers for GBM.

Lys694Arg polymorphism leads to blunted responses to LPS by interfering TLR4 with recruitment of MyD88

TLR4 polymorphisms such as Asp299Gly and Thr399Ile related to Gram-negative sepsis have been reported to result in significantly blunted responsiveness to LPS. Our study group previously screened other TLR4 polymorphic variants by checking the NF-κB activation in comparison to wild type (WT) TLR4 in human embryonic kidney 293T cells. In this study, we found that the Lys694Arg (K694R) polymorphism reduced the activation of NF-κB, and the production of downstream inflammatory factors IL-1, TNF-α and IL-6, representing the K694R polymorphism, led to blunted responsiveness to LPS. Then, we examined the influence of the K694R polymorphism on total and cell-surface TLR4 expression by Western blotting and flow cytometry, respectively, but observed no differences between the K694R polymorphism and WT TLR4. We also used co-immunoprecipitation to determine the interaction of the K694R polymorphism and WT TLR4 with their co-receptor myeloid differentiation factor 2 (MD2) and their downstream signal adaptor MyD88. We found that K694R reduced the recruitment of MyD88 in TLR4 signalling but had no impact on the interaction with MD2.

Study of Toll‑Like Receptor 4 Gene Polymorphisms in Colorectal Cancer: Correlation with Clinicopathological Features

Polymorphisms of Toll-like receptor 4 (TLR4) as a key player in cell proliferation, apoptosis, and angiogenesis have been linked to colorectal cancer (CRC) in different populations. We aimed in this study to determine genetic associations of TLR4 variants with CRC progression in Egyptian patients. Genotype and allelic frequencies of Asp299Gly (rs4986790) and Thr399Ile (rs4986791) were compared between 127 CRC patients and 141 healthy Egyptians using restriction fragment length polymorphism, and were correlated to clinicopathological findings. Results revealed that the variant alleles (G of Asp299Gly) and (T of Thr399Ile) were significantly associated with CRC among Egyptians. Confirmed by haplotype analysis, AT and GT haplotypes were more frequent in CRC patients than controls with increased CRC odds (OR = 3.54 and 3.45, 95% CI = 1.48-8.48 and 1.09-10.83, respectively). In addition, the G allele of Asp299Gly SNP was observed to be significantly associated with progressive CRC, including stage IV (P = .001), grade III (P = .025), N2 lymph nodes (P = .020), and metastasis (P = .001). On the other hand, Thr399Ile variant did not show any association with tumor behavior. Taken together, we conclude a significant association of Asp299Gly and Thr399Ile variants with the risk of development of CRC in Egypt. Asp299Gly variant, but not the Thr399Ile variant, may serve as a biomarker of this disease progression in Egyptian population.

Toll-like receptor bioactivity in endothelial progenitor cells

Cardiovascular disease is the main cause of death globally that can be mitigated by the modulation of angiogenesis. To achieve this goal, the application of endothelial progenitor cells and other stem cell types is useful. Following the onset of cardiovascular disease and pro-inflammatory conditions as seen during bacterial sepsis, endothelial progenitor cells enter systemic circulation in response to multiple cytokines and activation of various intracellular mechanisms. The critical role of Toll-like receptors has been previously identified in the dynamics of various cell types, in particular, immune cells. To our knowledge, there are a few experiments related to the role of Toll-like receptors in endothelial progenitor cell activity. Emerging data point of endothelial progenitor cells and other stem cells having the potential to express Toll-like receptors to control different activities such as multipotentiality and dynamics of growth. In this review article, we aim to collect data related to the role of Toll-like receptors in endothelial progenitor cells bioactivity and angiogenic potential.

Diastereoselective Synthesis of 3,4-Dihydropyran-3-carboxamides with in Vitro Anti-inflammatory Activity

A versatile and economical reaction of diketene (1), aryl amines 2, cyclic 1,3-diketones 3, primary amines 4, and aryl aldehydes 5 was explored to synthesize 3,4-dihydropyran-3-carboxamide derivatives under mild conditions. Three stereogenic centers are generated in the products, and the structure of the major diastereomer of 6{1,1,3,1} was identified by X-ray diffraction and 2D NMR spectroscopy. The scope and limitation investigation provided two series of (2S,3R,4S)-chromene-3-carboxamides in good to excellent yields with high diastereoselectivity. Two products, 6{5,3,1,1} and 6{7,3,1,1}, exhibited in vitro anti-inflammatory activity with significant inhibition of pro-inflammatory cytokine IL-6 and TNF-α expression in lipopolysaccharide (LPS)-treated Raw 264.7 cells.

Ambient fine particulate matter induces inflammatory responses of vascular endothelial cells through activating TLR-mediated pathway

This study aims to investigate the role of Toll-like receptors (TLRs) on fine particulate matter (PM_2.5)-induced inflammatory responses of vascular endothelial cells. Inflammatory factors and TLRs were examined in the aorta of mice after nonsurgical intratracheal instillation of PM_2.5 as well as in the human umbilical vein endothelial cells (HUVECs) treated with PM_2.5. In addition, the effects of TLR2 and TLR4 inhibitors in the secretion of interleukin 6 (IL-6) and IL-1β and the expression of TLRs were determined in the HUVECs. The results showed that PM_2.5 could increase the expression of IL-1β, IL-6, TLR2, and TLR4 in vitro and in vivo. Anti-TLR2 IgG or TAK242, an inhibitor of TLR4, decreased the secretion of IL-1β and IL-6 by HUVECs and reduced the expression of corresponding TLRs. In conclusion, we demonstrate that both TLR2 and TLR4 are involved in PM_2.5-induced inflammatory responses of vascular endothelial cells. Inhibition of TLR2 and TLR4 expression has the potential to prevent PM_2.5-induced cardiovascular diseases.

MYC gene associated polymorphisms and Wilms tumor risk in Chinese children: a four-center case-control study

BACKGROUND

Wilms tumor (WT) is a common embryonal malignancy in the kidney, ranking fourth in childhood cancer worldwide. MYC, a critical proto-oncogene, plays an important role in tumorigenesis. Single nucleotide polymorphisms in the MYC gene may lead to the deregulation of MYC proto-oncogene protein and thereby promote the initiation and development of tumors.

METHODS

Here, we assessed the association between MYC gene associated polymorphisms and WT susceptibility by performing a case-control study with 355 cases and 1070 controls. Two MYC gene associated polymorphisms (rs4645943 C > T, rs2070583 A > G) were genotyped by TaqMan technique. Odds ratios (ORs) and 95% confidence intervals (CIs) were used for evaluating the association between these two polymorphisms and WT susceptibility.

RESULTS

No significant association was detected between the selected polymorphisms and WT risk in the overall analysis as well as stratification analysis.

CONCLUSIONS

These results indicate that neither of two selected MYC gene associated polymorphisms might affect WT susceptibility in the Chinese population. Large well-designed studies with diverse ethnicities are warranted to verify these results.

The Systemic Lupus Erythematosus Infection Predictive Index (LIPI): A Clinical-Immunological Tool to Predict Infections in Lupus Patients

Among autoimmune diseases, systemic lupus erythematosus (SLE) patients have a unique predisposition to develop infections, which represents one of their main causes of morbidity and mortality. Many infections occur at disease diagnosis in the absence of immunosuppressive therapy, suggesting that the immunological abnormalities in SLE patients might be fundamental for the development of this complication. The aim of this study was to address the main clinical and immunological features associated with the development of infection and to create and validate a compound clinical-immunological infection predictive index in a cohort of SLE patients. We included 55 SLE patients with < 5 years since diagnosis. The clinical and immunological features were evaluated periodically and patients were followed-up during 1 year, searching for the development of infection. Immunophenotyping was performed by multiparametric flow cytometry and neutrophil extracellular traps (NETs) were assessed by confocal microscopy. Eighteen patients (32.7%) presented 19 infectious events, 5 (26.3%) were severe. For the construction of the index, we performed a logistic regression analysis and the cutoff points were determined with ROC curves. Increased numbers of peripheral Th17 cells, B cell lymphopenia, and lower TLR2 expression in monocytes, as well as the use of cyclophosphamide were the major risk factors for the development of infection and thus were included in the index. Besides, patients that developed infection were characterized by increased numbers of low-density granulocytes (LDGs) and higher expression of LL-37 in NETs upon infection. Finally, we validated the index retrospectively in a nested case-control study. A score >1.5 points was able to predict infection in the following year (AUC = 0.97; LR- = 0.001, specificity 100%, P = 0.0003). Our index encompasses novel immunological features able to prospectively predict the risk of infection in SLE patients.

Whole-genome sequencing reveals novel genes in ossification of the posterior longitudinal ligament of the thoracic spine in the Chinese population

BACKGROUND

Ossification of the posterior longitudinal ligament (OPLL) of the spine is a complex, multifactorial disease. Although several genes that are linked to cervical OPLL susceptibility have been reported, specific genetic studies regarding thoracic OPLL are lacking. Whole-genome sequencing has been considered as an efficient strategy to search for disease-causing genes.

METHODS

We analysed whole-genome sequences in a cohort of 25 unrelated patients with thoracic OPLL. Bioinformatics analysis and various algorithms were used to predict deleterious variants. Sanger sequencing was used to confirm the variants.

RESULTS

Four deleterious mutations in three genes (c.2716C>T (p.Arg906Cys) in collagen type VI α6 (COL6A6); c.1946G>C (p.Gly649Ala) in collagen type IX α1 (COL9A1); and c.301T>C (p.Ser101Pro) and c.171A>G (p.Ile57Met) in toll-like receptor 1 (TLR1)) were successfully identified. All the variants were confirmed by Sanger sequencing.

CONCLUSION

The novel deleterious mutations of the three genes may contribute to the development of thoracic OPLL.

Genome analysis of Yucatan miniature pigs to assess their potential as biomedical model animals

Objective

Pigs share many physiological, anatomical and genomic similarities with humans, which make them suitable models for biomedical researches. Understanding the genetic status of Yucatan miniature pigs (YMPs) and their association with human diseases will help to assess their potential as biomedical model animals. This study was performed to identify non-synonymous single nucleotide polymorphisms (nsSNPs) in selective sweep regions of the genome of YMPs and present the genetic nsSNP distributions that are potentially associated with disease occurrence in humans.

Methods

nsSNPs in whole genome resequencing data from 12 YMPs were identified and annotated to predict their possible effects on protein function. Sorting intolerant from tolerant (SIFT) and polymorphism phenotyping v2 analyses were used, and gene ontology (GO) network and Kyoto encyclopedia of genes and genomes (KEGG) pathway analyses were performed.

Results

The results showed that 8,462 genes, encompassing 72,067 nsSNPs were identified, and 118 nsSNPs in 46 genes were predicted as deleterious. GO network analysis classified 13 genes into 5 GO terms (p<0.05) that were associated with kidney development and metabolic processes. Seven genes encompassing nsSNPs were classified into the term associated with Alzheimer’s disease by referencing the genetic association database. The KEGG pathway analysis identified only one significantly enriched pathway (p<0.05), hsa04080: Neuroactive ligand-receptor interaction, among the transcripts.

Conclusion

The number of deleterious nsSNPs in YMPs was identified and then these variants-containing genes in YMPs data were adopted as the putative human diseases-related genes. The results revealed that many genes encompassing nsSNPs in YMPs were related to the various human genes which are potentially associated with kidney development and metabolic processes as well as human disease occurrence.

Selective constraint acting on TLR2 and TLR4 genes of Japanese Rana frogs

Toll-like receptors (TLRs) are an important component of innate immunity, the first line of pathogen defence. One of the major roles of TLRs includes recognition of pathogen-associated molecular patterns. Amphibians are currently facing population declines and even extinction due to chytridiomycosis caused by the Batrachochytrium dendrobatidis (Bd) fungus. Evidence from other vertebrates shows that TLR2 and TLR4 are involved in innate immunity against various fungi. Such genes therefore may play a functional role in amphibian-chytridiomycosis dynamics. Frogs from East Asia appear to be tolerant to Bd, so we examined the genetic diversity that underlies TLR2 and TLR4 from three Japanese Ranidae frog species, Rana japonica, R. ornativentris and R. tagoi tagoi (n = 5 per species). We isolated 27 TLR2 and 20 TLR4 alleles and found that these genes are evolutionarily conserved, with overall evidence supporting purifying selection. In contrast, site-by-site analysis of selection identified several specific codon sites under positive selection, some of which were located in the variable leucine rich repeat domains. In addition, preliminary expression levels of TLR2 and TLR4 from transcriptome data showed overall low expression. Although it remains unclear whether infectious pathogens are a selective force acting on TLRs of Japanese frogs, our results support that certain sites in TLRs of these species may have experienced pathogen-mediated selection.

Arctigenin Induces an Activation Response in Porcine Alveolar Macrophage Through TLR6-NOX2-MAPKs Signaling Pathway

Arctigenin (ARG), one of the most active ingredients abstracted from seeds of Arctium lappa L., has been proved to exert promising biological activities such as immunomodulatory, anti-viral, and anti-cancer etc. However, the mechanism behind its immunomodulatory function still remains elusive to be further investigated. In this study, we found that ARG had no significant effects on the cell proliferation in both porcine alveolar macrophage cell line (3D4/21) and primary porcine derived alveolar macrophage. It remarkably increased the expression and secretion of the two cytokines including tumor necrosis factor-alpha (TNF-α) and transforming growth factor beta1 (TGF-β1) in a dose-dependent manner with the concomitant enhancement of phagocytosis, which are the indicators of macrophage activation. ARG also elevated the intracellular reactive oxygen species (ROS) production by activating NOX2-based NADPH oxidase. Furthermore, inhibition of ROS generation by diphenyliodonium and apocynin significantly suppressed ARG-induced cytokine secretion and phagocytosis increase, indicating the requirement of ROS for the porcine alveolar macrophage activation. In addition, TLR6-My88 excitation, p38 MAPK and ERK1/2 phosphorylation were all involved in the process. As blocking TLR6 receptor dramatically attenuated the NOX2 oxidase activation, cytokine secretion and phagocytosis increase. Inhibiting ROS generation almost abolished p38 and ERK1/2 phosphorylation, and the cytokine secretion could also be remarkably reduced by p38 and ERK1/2 inhibitors (SB203580 and UO126). Our finding gave a new insight of understanding that ARG could improve the immune-function of porcine alveolar macrophages through TLR6-NOX2 oxidase-MAPKs signaling pathway.

Toll-like receptors in immunity and inflammatory diseases: Past, present, and future

The immune system is a very diverse system of the host that evolved during evolution to cope with various pathogens present in the vicinity of environmental surroundings inhabited by multicellular organisms ranging from achordates to chordates (including humans). For example, cells of immune system express various pattern recognition receptors (PRRs) that detect danger via recognizing specific pathogen-associated molecular patterns (PAMPs) and mount a specific immune response. Toll-like receptors (TLRs) are one of these PRRs expressed by various immune cells. However, they were first discovered in the Drosophila melanogaster (common fruit fly) as genes/proteins important in embryonic development and dorso-ventral body patterning/polarity. Till date, 13 different types of TLRs (TLR1-TLR13) have been discovered and described in mammals since the first discovery of TLR4 in humans in late 1997. This discovery of TLR4 in humans revolutionized the field of innate immunity and thus the immunology and host-pathogen interaction. Since then TLRs are found to be expressed on various immune cells and have been targeted for therapeutic drug development for various infectious and inflammatory diseases including cancer. Even, Single nucleotide polymorphisms (SNPs) among various TLR genes have been identified among the different human population and their association with susceptibility/resistance to certain infections and other inflammatory diseases. Thus, in the present review the current and future importance of TLRs in immunity, their pattern of expression among various immune cells along with TLR based therapeutic approach is reviewed.

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TLRs are first described PRRs that revolutionized the biology of host-pathogen interaction and immune response

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The discovery of different TLRs in humans proved milestone in the field of innate immunity and inflammation

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The pattern of expression of all the TLRs expressed by human immune cells

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An association of various TLR SNPs with different inflammatory diseases

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Currently available drugs or vaccines based on TLRs and their future in drug targeting along with the role in reproduction, and regeneration

SNP-based susceptibility-resistance association and mRNA expression regulation analyses of tlr7 to grass carp Ctenopharyngodon idella reovirus

Eleven single nucleotide polymorphisms (SNP) in Ctenopharyngodon idella toll-like receptor 7 (citlr7) gene, containing two in the 5'-flanking region, three within the single intron and six distributed in the coding sequence (CDS), were identified. A case-control study of 73 susceptible individuals and 67 resistant individuals was conducted to test the SNPs-based susceptibility-resistance association and mRNA expression of citlr7 to grass carp reovirus (GCRV), showing that both 820 A/G and 1726 A/G were significantly correlative sites in genotype (P < 0·05). Multifactor dimensionality reduction (MDR) analysis suggested the exertion of antiviral effects of 820 A/G might rely on SNPs interactions of citlr7 and C. idella toll-like receptor 8 (citlr8). Combining the mortality rate and citlr7 mRNA expression, it was suggested that 1726 GG-genotyped individuals might be more resistant than 1726 A/G genotyped individuals, indicating the selection on synonymous mutations in 1726 A/G might be susceptibility-resistance-type specific. In addition, haplotype analysis uncovered no significantly correlative haplotypes in citlr7. These findings may provide an in-depth insight for the further functional research of citlr7. The potential genetic markers identified may contribute to the molecular and transgenic breeding of C. idella.

Probing subtle conformational changes induced by phosphorylation and point mutations in the TIR domains of TLR2 and TLR3

Extensive research performed on Toll-like receptor (TLR) signaling has identified residues in the Toll/interleukin-1 receptor (TIR) domains that are essential for its proper functioning. Among these residues, those in BB loop are particularly significant as single amino acid mutations in this region can cause drastic changes in downstream signaling. However, while the effect of these mutations on the function is well studied (like the P681H mutation in TLR2, the A795P mutation in TLR3, and the P714H mutation in TLR4), their influence on the dynamics and inter-residue networks is not well understood. The effects of local perturbations induced by these mutations could propagate throughout the TIR domain, influencing interactions with other TIR domain-containing proteins. The identification of these subtle changes in inter-residue interactions can provide new insights and structural rationale for how single-point mutations cause drastic changes in TIR-TIR interactions. We employed molecular dynamics simulations and protein structure network (PSN) analyses to investigate the structural transitions with special emphasis on TLR2 and TLR3. Our results reveal that phosphorylation of the Tyr 759 residue in the TIR domain of TLR3 introduces rigidity to its BB loop. Subtle differences in the intra BB loop hydrogen bonding network between TLR3 and TLR2 are also observed. The PSN analyses indicate that the TIR domain is highly connected and pinpoints key differences in the inter-residue interactions between the wild-type and mutant TIR domains, suggesting that TIR domain structure is prone to allosteric effects, consistent with the current view of the influence of allostery on TLR signaling.

IFN-τ Mediated Control of Bovine Major Histocompatibility Complex Class I Expression and Function via the Regulation of bta-miR-148b/152 in Bovine Endometrial Epithelial Cells

IFN-τ, a type I interferon produced by the trophoblasts of ruminants, has various important immune functions, including effects on the expression of major histocompatibility complex (MHC) class I (MHC-I). A previous study has reported that IFN-τ promotes the expression of MHC-I molecules on endometrial cells. However, the immunological mechanisms by which IFN-τ regulates MHC-I molecules remain unknown. Here, we investigated which microRNA (miRNAs) may be involved in the regulation of MHC-I molecule expression and function in bovine endometrial epithelial cells (bEECs). By using TargetScan 6.2 and http://www.microRNA.org, two miRNAs were suggested to target the 3'UTR of the bovine MHC-I heavy chain: bta-miR-148b and bta-miR-152. Dual luciferase reporter and miRNA mimic/inhibitor assays suggested that bta-miR-148b/152 were negatively correlated with bovine MHC-I heavy chain genes. The function of the MHC-I heavy chain was then investigated using qRT-PCR, ELISA, western blotting, immunofluorescence, and RNA interference assays in primary bEECs and an endometrial epithelial cell line (BEND). The results demonstrated that bta-miR-148b/152 could promote TLR4-triggered inflammatory responses by targeting the bovine MHC-I heavy chain, and the MHC-I molecule negatively regulated TLR4-induced inflammatory reactions may through the Fps-SHP-2 pathway. Our discovery offers novel insight into negative regulation of the TLR4 pathway and elucidates the mechanism by which bovine MHC-I molecules control congenital inflammatory reactions.

Expression profiles of genes involved in TLRs and NLRs signaling pathways of water buffaloes infected with Fasciola gigantica

Infection of ruminants and humans with Fasciola gigantica is attracting increasing attention due to its economic impact and public health significance. However, little is known of innate immune responses during F. gigantica infection. Here, we investigated the expression profiles of genes involved in Toll-like receptors (TLRs) and NOD-like receptors (NLRs) signaling pathways in buffaloes infected with 500F. gigantica metacercariae. Serum, liver and peripheral blood mononuclear cell (PBMC) samples were collected from infected and control buffaloes at 3, 10, 28, and 70days post infection (dpi). Then, the levels of 12 cytokines in serum samples were evaluated by ELISA. Also, the levels of expression of 42 genes, related to TLRs and NLRs signaling, in liver and PBMCs were determined using custom RT² Profiler PCR Arrays. At 3 dpi, modest activation of TLR4 and TLR8 and the adaptor protein (TICAM1) was detected. At 10 dpi, NF-κB1 and Interferon Regulatory Factor signaling pathways were upregulated along with activation of TLR1, TLR2, TLR6, TLR10, TRAF6, IRF3, TBK1, CASP1, CD80, and IFNA1 in the liver, and inflammatory response with activated TLR4, TLR9, TICAM1, NF-κB1, NLRP3, CD86, IL-1B, IL-6, and IL-8 in PBMCs. At 28 dpi, there was increase in the levels of cytokines along with induction of NLRP1 and NLRP3 inflammasomes-dependent immune responses in the liver and PBMCs. At 70 dpi, F. gigantica activated TLRs and NLRs, and their downstream interacting molecules. The activation of TLR7/9 signaling (perhaps due to increased B-cell maturation and activation) and upregulation of NLRP3 gene were also detected. These findings indicate that F. gigantica alters the expression of TLRs and NLRs genes to evade host immune defenses. Elucidation of the roles of the downstream effectors interacting with these genes may aid in the development of new interventions to control disease caused by F. gigantica infection.

Association of C-myc and p53 Gene Expression and Polymorphisms with Hepatitis C (HCV) Chronic Infection, Cirrhosis and Hepatocellular Carcinoma (HCC) Stages in Egypt

The aim of this study is to investigate c-myc and p53 gene expression and polymorphisms in different stages of HCV infection,. Expression levels of c-myc and p53 were evaluated by RT-PCR and polymorphisms were determined by PCR-RFLP in 60 HCV patients classified into chronic infection, cirrhosis and HCC groups along with 30 controls. c-myc gene expression significant increased through the stages as compared to the control level (1.17, 1.82, 3.33 and 0.32, respectively), whereas p53 significantly declined (4,375, 3,842, 525 and 5,498, respectively). The C-myc CC genotype was predominant in the HCC group (90%) to a greater extent than in the cirrhosis, chronic infection and control cases (80%, 20% and 10%, respectively), while the GG genotype was predominant in controls (83%, as compared to 65%, 10% and 10%). The CG genotype was most common in chronic infection (15%). The p53 PP genotype predominated in controls (87%, with 15%, 10% and 20%, respectively, for the three stages) while the AA genotype demonstrated only slight increase to HCC (13%, 25% and 30%, respectively) and PA genotype was predominant in cirrhosis cases (90%). These findings reveal that c-myc and p53 gene expression and polymorphisms may be considered as promising sensitive genetic biomarkers for progression of HCV infection.

The Expression of Toll-like receptors in eutopic and ectopic endometrium and its implication in the inflammatory pathogenesis of adenomyosis

In this study, we investigated the expression profiles of Toll-like receptors(TLRs) in eutopic endometrium(EU) and ectopic endometrium(EC) and its implication in the inflammatory pathogenesis of adenomyosis. Thirty adenomyosis patients who underwent laparoscopy were recruited in this study. We tested the mRNA and protein expression of TLRs, and the mRNA expression of IL-6 and IL-8 in EU and EC of adenomyosis patients, and control endometrium without adenomyosis(CE). We found that the mRNA expression of IL-6 and IL-8 in EU was significantly higher than that in CE, and was the highest in EC (P < 0.01). The mRNA and protein expression of TLRs were higher in EU, with the expression of TLR1-6, 8 and 9 being significantly higher in EU than in CE, and were the highest in EC (except TLR6) (P < 0.05 or P < 0.01). Pearson correlation analysis showed that the expression of TLR1, 2, 4, 5 and 9 in EU and EC was positively correlated with that of IL-6 and IL-8 (P < 0.00139). This study suggested that adenomyosis was a state of inflammatory pathology. High expression of TLRs in EU and EC were positively correlated with IL-6 and IL-8, which may be involved in the inflammatory pathogenesis of adenomyosis.

Identifying genetic hypomethylation and upregulation of Toll-like receptors in Kawasaki disease

Kawasaki disease (KD) is an acute febrile systemic vasculitis that occurs in children and is characterized by elevated levels of proinflammatory cytokines. Toll-like receptors (TLRs) serve as the sensor arm of the innate immune system and induce proinflammatory cytokine expressions.

We recruited a total of 18 paired KD patients, before intravenous immunoglobulin (IVIG) and at least 3 weeks after IVIG treatment, 18 healthy controls, and 18 febrile controls. For TLR genes and their cytosine-phosphate-guanine (CpG) markers, we used Affymetrix GeneChip^® Human Transcriptome Array 2.0 and Illumina HumanMethylation450 BeadChip to evaluate gene expression levels and methylation patterns, respectively.

KD patients demonstrated a significantly differential expression of TLR mRNA levels compared to both the healthy and febrile controls, with only TLR 3 and 7 not differing between the KD patients and the controls. After patients underwent IVIG treatment, the TLR mRNA levels, except for TLR3, decreased significantly in KD patients. In contrast, the methylation status of the CpG sites of TLR1, 2, 4, 6, 8, and 9 demonstrated an opposite tendency between the two stages of both the KD samples and the controls.

TLRs, particularly TLR1, 2, 4, 6, 8, and 9, may stimulate the immunopathogenesis of KD. These results are among the first to use TLRs to prove that a bacterial inflammatory response may trigger KD.

IFN-τ Alleviates Lipopolysaccharide-Induced Inflammation by Suppressing NF-κB and MAPKs Pathway Activation in Mice

IFN-τ, which is a type I interferon with low cytotoxicity, is defined as a pregnancy recognition signal in ruminants. Type I interferons have been used as anti-inflammatory agents, but their side effects limit their clinical application. The present study aimed to determine the anti-inflammatory effects of IFN-τ in a lipopolysaccharide-stimulated acute lung injury (ALI) model and in RAW264.7 cells and to confirm the mechanism of action involved. The methods used included histopathology, measuring the lung wet/dry ratio, determining the myeloperoxidase activity, ELISA, qPCR, and western blot. The results revealed that IFN-τ greatly ameliorated the infiltration of inflammatory cells and the expression of TNF-α, IL-1β, and IL-6. Further analysis revealed that IFN-τ down-regulated the expression of TLR-2 and TLR-4 mRNA and the activity of the NF-κB and MAPK pathways both in a lipopolysaccharide-induced ALI model and in RAW264.7 cells. The results demonstrated that IFN-τ suppressed the levels of pro-inflammatory cytokines by inhibiting the phosphorylation of the NF-κB and MAPK pathways. Thus, IFN-τ may be an optimal target for the treatment of inflammatory diseases.

Role of Thr399Ile and Asp299Gly polymorphisms of toll-like receptor-4 gene in acute dental abscess

BACKGROUND

Apical Periodontitis (AP) is an inflammatory disease that affects the tissues surrounding the root end of a tooth. The disease which is caused by endodontic infections presents in different clinical ways including development of an acute abscess. Recent studies have provided information suggesting role of a multitude of factors in pathogenesis of acute apical abscess (AAA). In this case-control study, our goal was to evaluate the frequency and potential role of two common polymorphisms of toll like receptor-4 (TLR-4) gene; Thr399Ile (1196 C>T) and Asp299Gly (+896 A>G), in 50 patients with AAA as cases and 50 patients with asymptomatic apical periodontitis (AAP) as controls.

MATERIAL AND METHODS

Saliva sample containing mucosal epithelial cells was used for DNA extraction. Polymorphisms were detected by Tetra-ARMS (Amplification Refractory Mutation System) PCR method. Statistical analyses were carried out in SPSS 21 software.

RESULTS

Homozygous wild type (CC) and heterozygous (CT) genotypes of Thr399Ile polymorphism were detected in 84% and 16% of AAA patients respectively. In controls, respective ratios were 94% (CC) and 6% (CT). Observed difference was not statistically significant (P>0.05) for distribution of these genotypes. The mutant homozygous (TT) genotype of this polymorphism was identified in neither of the participants. Overall, T allele frequency was obtained 8% in AAA and 3% in AAP (OR=2.6, 95% CI; 0. 6-10.6, p>0.05). For Asp299Gly polymorphism, no individual was detected with the mutant allele in case or control groups.

CONCLUSIONS

Our results indicated a possible role for Thr399Ile polymorphism in acute presentations of abscess in AAA. However, the impact of this polymorphism needs to be more assessed in future studies. Key words:Genetic polymorphism, periapical abscess, periapical periodontitis, toll-like receptor 4.

Effect of smoking on the genetic makeup of toll-like receptors 2 and 6

Background

Cigarette smoking is a major risk factor for lung cancer, asthma, and oral cancer, and is central to the altered innate immune responsiveness to infection. Many hypotheses have provided evidence that cigarette smoking induces more genetic changes in genes involved in the development of many cigarette-related diseases. This alteration may be from single-nucleotide polymorphisms (SNPs) in innate immunity genes, especially the toll-like receptors (TLRs).

Objective

In this study, the genotype frequencies of TLR2 and TLR6 in smoking and nonsmoking population were examined.

Methods

Saliva samples were collected from 177 smokers and 126 nonsmokers. The SNPs used were rs3804100 (1350 T/C, Ser450Ser) and rs3804099 (597 T/C, Asn199Asn) for TLR2 and rs3796508 (979 G/A, Val327Met) and rs5743810 (745 T/C, Ser249Pro) for TLR6.

Results

Results showed that TLR2 rs3804100 has a significant effect in short-term smokers (OR =2.63; P=0.04), and this effect is not observed in long-term smokers (>5 years of smoking). Therefore, this early mutation may be repaired by the DNA repair system. For TLR2 rs3804099, the variation in genotype frequencies between the smokers and control patients was due to a late mutation, and its protective role appears only in long-term smokers (OR =0.40, P=0.018). In TLR6 rs5743810, the TT genotype is significantly higher in smokers than in nonsmokers (OR =6.90). The effect of this SNP is observed in long-term smokers, regardless of the smoking regime per day.

Conclusion

TLR2 (rs3804100 and rs3804099) and TLR6 (rs5743810) can be used as a potential index in the diagnosis and prevention of more diseases caused by smoking.

MYD88 and functionally related genes are associated with multiple infections in a model population of Kenyan village dogs

The purpose of this study was to seek associations between immunity-related molecular markers and endemic infections in a model population of African village dogs from Northern Kenya with no veterinary care and no selective breeding. A population of village dogs from Northern Kenya composed of three sub-populations from three different areas (84, 50 and 55 dogs) was studied. Canine distemper virus (CDV), Hepatozoon canis, Microfilariae (Acantocheilonema dracunculoides, Acantocheilonema reconditum) and Neospora caninum were the pathogens studied. The presence of antibodies (CDV, Neospora), light microscopy (Hepatozoon) and diagnostic PCR (Microfilariae) were the methods used for diagnosing infection. Genes involved in innate immune mechanisms, NOS3, IL6, TLR1, TLR2, TLR4, TLR7, TLR9, LY96, MYD88, and three major histocompatibility genes class II genes were selected as candidates. Single nucleotide polymorphism (SNP) markers were detected by Sanger sequencing, next generation sequencing and PCR-RFLP. The Fisher´s exact test for additive and non-additive models was used for association analyses. Three SNPs within the MYD88 gene and one TLR4 SNP marker were associated with more than one infection. Combined genotypes and further markers identified by next generation sequencing confirmed associations observed for individual genes. The genes associated with infection and their combinations in specific genotypes match well our knowledge on their biological role and on the role of the relevant biological pathways, respectively. Associations with multiple infections observed between the MYD88 and TLR4 genes suggest their involvement in the mechanisms of anti-infectious defenses in dogs.