Evolutionary Origins of Toll-like Receptor Signaling

Deletion of the alr gene in Brucella suis S2 attenuates virulence by enhancing TLR4-NF-κB-NLRP3- mediated host inflammatory responses

Brucella is an intracellular parasitic bacterium lacking typical virulence factors, and its pathogenicity primarily relies on replication within host cells. In this study, we observed a significant increase in spleen weight in mice immunized with a Brucella strain deleted of the gene for alanine racemase (Alr), the enzyme responsible for alanine racemization (Δalr). However, the bacterial load in the spleen markedly decreased in the mutant strain. Concurrently, the ratio of white pulp to red pulp in the spleen was increased, serum IgG levels were elevated, but no significant damage to other organs was observed. In addition, the inflammatory response was potentiated and the NF-κB-NLRP3 signaling pathway was activated in macrophages (RAW264.7 Cells and Bone Marrow-Derived Cells) infect ed with the Δalr mutant. Further investigation revealed that the Δalr mutant released substantial amounts of protein in a simulated intracellular environment which resulted in heightened inflammation and activation of the TLR4-NF-κB-NLRP3 pathway in macrophages. The consequent cytoplasmic exocytosis reduced intracellular Brucella survival. In summary, cytoplasmic exocytosis products resulting from infection with a Brucella strain deleted of the alr gene effectively activated the TLR4-NFκB-NLRP3 pathway, triggered a robust inflammatory response, and reduced bacterial survival within host cells. Moreover, the Δalr strain exhibits lower toxicity and stronger immunogenicity in mice.

Dietary anti-inflammatory and anti-bacterial medicinal plants and its compounds in bovine mastitis associated impact on human life

Bovine mastitis (BM) is the most common bacterial mediated inflammatory disease in the dairy cattle that causes huge economic loss to the dairy industry due to decreased milk quality and quantity. Milk is the essential food in the human diet, and rich in crucial nutrients that helps in lowering the risk of diseases like hypertension, cardiovascular diseases and type 2 diabetes. The main causative agents of the disease include various gram negative, and positive bacteria, along with other risk factors such as udder shape, age, genetic, and environmental factors also contributes much for the disease. Currently, antibiotics, immunotherapy, probiotics, dry cow, and lactation therapy are commonly recommended for BM. However, these treatments can only decrease the rise of new cases but can't eliminate the causative agents, and they also exhibit several limitations. Hence, there is an urgent need of a potential source that can generate a typical and ideal treatment to overcome the limitations and eliminate the pathogens. Among the various sources, medicinal plants and its derived products always play a significant role in drug discovery against several diseases. In addition, they are also known for its low toxicity and minimum resistance features. Therefore, plants and its compounds that possess anti-inflammatory and anti-bacterial properties can serve better in bovine mastitis. In addition, the plants that are serving as a food source and possessing pharmacological properties can act even better in bovine mastitis. Hence, in this evidence-based study, we particularly review the dietary medicinal plants and derived products that are proven for anti-inflammatory and anti-bacterial effects. Moreover, the role of each dietary plant and its compounds along with possible role in the management of bovine mastitis are delineated. In this way, this article serves as a standalone source for the researchers working in this area to help in the management of BM.

Glycyrrhiza polysaccharides may have an antitumor effect in γδT cells through gut microbiota and TLRs/NF-κB pathway in mice

Tumor immunotherapy can be a suitable cancer treatment option in certain instances. Here we investigated the potential immunomodulatory effect of oral glycyrrhiza polysaccharides (GCP) on the antitumor function of γδT cells in intestinal epithelial cells in mice. We found that GCP can inhibit tumor growth and was involved in the regulation of systemic immunosuppression. GCP administration also promoted the differentiation of gut epithelia γδT cells into IFN-γ-producing subtype through regulation of local cytokines in gut mucosa. GCP administration increased local cytokine levels through gut microbiota and the gut mucosa Toll-like receptors / nuclear factor kappa-B pathway. Taken together, our results suggest that GCP might be a suitable candidate for tumor immunotherapy, although further clinical research, including clinical trials, are required to validate these results.

Low-concentration imiquimod treatment promotes enhanced skin barrier functions through epidermal melanization reaction regulation

The primary function of the skin is to form a mechanical, permeability, antimicrobial, and ultraviolet radiation barrier, which is essential for maintaining physiological homeostasis. Our previous studies demonstrated that cutaneous pigmentation could promote skin barrier function in addition to providing anti-ultraviolet irradiation defense. The present study aimed to develop a new regimen that enhances skin barrier function by regulating skin pigmentation using low-concentration imiquimod. Results showed that topical application of low-concentration imiquimod effectively induced skin hyperpigmentation in the dorsal skin and external ear of mice without inducing inflammatory cell infiltration. An in vitro study also revealed that low-concentration imiquimod did not induce any cytotoxic effects on melanoma cells but triggered excessive melanin synthesis. In coculture systems, low-concentration imiquimod was noted to increase tyrosinase activity in a broader cellular context, revealing the potential role of neighboring cells in melanin production. The next-generation sequencing result indicated that PKCη and Dnm3 might regulate melanin synthesis and release during imiquimod treatment. Overall, our study presents new insights into the regulation of melanin production by low-concentration imiquimod, both in a mice model and cultured cells. Furthermore, our study highlights the potential benefits of imiquimod in promoting melanin synthesis without causing skin disruptions or inducing inflammation, validating its potential to serve as a method for enhancing skin barrier functions by regulating the epidermal melanization reaction.

Transcriptional profiling of Bulinus globosus provides insights into immune gene families in snails supporting the transmission of urogenital schistosomiasis

Schistosomiasis, urogenital and intestinal, afflicts 251 million people worldwide with approximately two-thirds of the patients suffering from the urogenital form of the disease. Freshwater snails of the genus Bulinus (Gastropoda: Planorbidae) serve as obligate intermediate hosts for Schistosoma haematobium, the etiologic agent of human urogenital schistosomiasis. These snails also act as vectors for the transmission of schistosomiasis in livestock and wildlife. Despite their crucial role in human and veterinary medicine, our basic understanding at the molecular level of the entire Bulinus genus, which comprises 37 recognized species, is very limited. In this study, we employed Illumina-based RNA sequencing (RNAseq) to profile the genome-wide transcriptome of Bulinus globosus, one of the most important intermediate hosts for S. haematobium in Africa. A total of 179,221 transcripts (N50 = 1,235) were assembled and the benchmarking universal single-copy orthologs (BUSCO) was estimated to be 97.7%. The analysis revealed a substantial number of transcripts encoding evolutionarily conserved immune-related proteins, particularly C-type lectin (CLECT) domain-containing proteins (n = 316), Toll/Interleukin 1-receptor (TIR)-containing proteins (n = 75), and fibrinogen related domain-containing molecules (FReD) (n = 165). Notably, none of the FReDs are fibrinogen-related proteins (FREPs) (immunoglobulin superfamily (IgSF) + fibrinogen (FBG)). This RNAseq-based transcriptional profile provides new insights into immune capabilities of Bulinus snails, helps provide a framework to explain the complex patterns of compatibility between snails and schistosomes, and improves our overall understanding of comparative immunology.

Toll-like receptors in health and disease

Toll-like receptors (TLRs) are inflammatory triggers and belong to a family of pattern recognition receptors (PRRs) that are central to the regulation of host protective adaptive immune responses. Activation of TLRs in innate immune myeloid cells directs lymphocytes to produce the most appropriate effector responses to eliminate infection and maintain homeostasis of the body's internal environment. Inappropriate TLR stimulation can lead to the development of general autoimmune diseases as well as chronic and acute inflammation, and even cancer. Therefore, TLRs are expected to be targets for therapeutic treatment of inflammation-related diseases, autoimmune diseases, microbial infections, and human cancers. This review summarizes the recent discoveries in the molecular and structural biology of TLRs. The role of different TLR signaling pathways in inflammatory diseases, autoimmune diseases such as diabetes, cardiovascular diseases, respiratory diseases, digestive diseases, and even cancers (oral, gastric, breast, colorectal) is highlighted and summarizes new drugs and related clinical treatments in clinical trials, providing an overview of the potential and prospects of TLRs for the treatment of TLR-related diseases.

Toll-like receptor signaling pathway involved in pathogenesis of thromboangiitis obliterans through activating of NF-κB

OBJECTIVES

The pathogenic mechanisms of Thromboangiitis Obliterans (TAO) are not entirely known and autoimmune inflammation plays a vital role in the initiation and continuance of TAO activity. The authors investigated in this study the role of the TLR signaling pathway in the pathogenesis of TAO.

METHODS

First, the authors detected the expressions of MyD88, TRIF and NF-κB in vascular walls of 46 patients with TAO and 32 patients with trauma and osteosarcoma by western blot assay. Second, the authors detected the cellular localization of MyD88, TRIF and NF-κB in vascular walls of patients with TAO by immunofluorescent assay.

RESULTS

The protein expressions of MyD88, TRIF and NF-κB were much higher in vascular walls of TAO patients (p < 0.05). Higher expressions of MyD88 and NF-κB were detected both on vascular endothelial and vascular smooth muscle cells of TAO patients. However, higher expression of TRIF was just detected on vascular smooth muscle cells of TAO patients.

CONCLUSIONS

These dates suggest that the TLR signaling pathway might play an important role in the pathogenesis of TAO, it might induce vasospasm, vasculitis and thrombogenesis to lead to the pathogenesis and progression of TAO.

Twelve toll-like receptor (TLR) genes in the family Equidae - comparative genomics, selection and evolution

Toll-like receptors (TLRs) represent an important part of the innate immune system. While human and murine TLRs have been intensively studied, little is known about TLRs in non-model species. The order Perissodactyla comprises a variety of free-living and domesticated species exposed to different pathogens in different habitats and is therefore suitable for analyzing the diversity and evolution of immunity-related genes. We analyzed TLR genes in the order Perissodactyla with a focus on the family Equidae. Twelve TLRs were identified by bioinformatic analyses of online genomic resources; their sequences were confirmed in equids by genomic DNA re-sequencing of a panel of nine species. The expression of TLR11 and TLR12 was confirmed in the domestic horse by cDNA sequencing. Phylogenetic reconstruction of the TLR gene family in Perissodactyla identified six sub-families. TLR4 clustered together with TLR5; the TLR1-6-10 subfamily showed a high degree of sequence identity. The average estimated evolutionary divergence of all twelve TLRs studied was 0.3% among the Equidae; the most divergent CDS were those of Equus caballus and Equus hemionus kulan (1.34%) in the TLR3, and Equus africanus somaliensis and Equus quagga antiquorum (2.1%) in the TLR1 protein. In each TLR gene, there were haplotypes shared between equid species, most extensively in TLR3 and TLR9 CDS, and TLR6 amino acid sequence. All twelve TLR genes were under strong negative overall selection. Signatures of diversifying selection in specific codon sites were detected in all TLRs except TLR8. Differences in the selection patterns between virus-sensing and non-viral TLRs were observed.

Immune receptors and aging brain

Aging brings about a myriad of degenerative processes throughout the body. A decrease in cognitive abilities is one of the hallmark phenotypes of aging, underpinned by neuroinflammation and neurodegeneration occurring in the brain. This review focuses on the role of different immune receptors expressed in cells of the central and peripheral nervous systems. We will discuss how immune receptors in the brain act as sentinels and effectors of the age-dependent shift in ligand composition. Within this 'old-age-ligand soup,' some immune receptors contribute directly to excessive synaptic weakening from within the neuronal compartment, while others amplify the damaging inflammatory environment in the brain. Ultimately, chronic inflammation sets up a positive feedback loop that increases the impact of immune ligand-receptor interactions in the brain, leading to permanent synaptic and neuronal loss.

Activation of intestinal immunity by pathogen effector-triggered aggregation of lysosomal TIR-1/SARM1

TIR-domain proteins with enzymatic activity are essential for immunity in plants, animals, and bacteria. However, it is not known how these proteins function in pathogen sensing in animals. We discovered that a TIR-domain protein (TIR-1/SARM1) is strategically expressed on the membranes of a lysosomal sub-compartment, which enables intestinal epithelial cells in the nematode C. elegans to survey for pathogen effector-triggered host damage. We showed that a redox active virulence effector secreted by the bacterial pathogen Pseudomonas aeruginosa alkalinized and condensed a specific subset of lysosomes by inducing intracellular oxidative stress. Concentration of TIR-1/SARM1 on the surface of these organelles triggered its multimerization, which engages its intrinsic NADase activity, to activate the p38 innate immune pathway and protect the host against microbial intoxication. Thus, lysosomal TIR-1/SARM1 is a sensor for oxidative stress induced by pathogenic bacteria to activate metazoan intestinal immunity.

A haplotype-like, chromosome-level assembled and annotated genome of Biomphalaria glabrata, an important intermediate host of schistosomiasis and the best studied model of schistosomiasis vector snails

Schistosomiasis is one of the world's most devastating parasitic diseases, afflicting 251 million people globally. The Neotropical snail Biomphalaria glabrata is an important intermediate host of the human blood fluke Schistosoma mansoni and a predominant model for schistosomiasis research. To fully exploit this model snail for biomedical research, here we report a haplotype-like, chromosome-level assembled and annotated genome of the homozygous iM line of B. glabrata that we developed at the University of New Mexico. Using multiple sequencing platforms, including Illumina, PacBio, and Omni-C sequencing, 18 sequence contact matrices representing 18 haploid chromosomes (2n = 36) were generated (337x genome coverage), and 96.5% of the scaffold sequences were anchored to the 18 chromosomes. Protein-coding genes (n = 34,559), non-coding RNAs (n = 2,406), and repetitive elements (42.52% of the genome) were predicted for the whole genome, and detailed annotations for individual chromosomes were also provided. Using this genomic resource, we have investigated the genomic structure and organization of the Toll-like receptor (TLR) and fibrinogen-domain containing protein (FReD) genes, the two important immune-related gene families. Notably, TLR-like genes are scattered on 13 chromosomes. In contrast, almost all (39 of 40) fibrinogen-related genes (FREPs) (immunoglobulin superfamily (IgSF) + fibrinogen (FBG)) are clustered within a 5-million nucleotide region on chromosome 13, yielding insight into mechanisms involved in the diversification of FREPs. This is the first genome of schistosomiasis vector snails that has been assembled at the chromosome level, annotated, and analyzed. It serves as a valuable resource for a deeper understanding of the biology of vector snails, especially Biomphalaria snails.

Innate immune responses to RNA: sensing and signaling

Nucleic acids are among the most essential PAMPs (pathogen-associated molecular patterns). Animals have evolved numerous sensors to recognize nucleic acids and trigger immune signaling against pathogen replication, cellular stress and cancer. Many sensor proteins (e.g., cGAS, AIM2, and TLR9) recognize the molecular signature of infection or stress and are responsible for the innate immune response to DNA. Remarkably, recent evidence demonstrates that cGAS-like receptors acquire the ability to sense RNA in some forms of life. Compared with the nucleic-acid sensing by cGAS, innate immune responses to RNA are based on various RNA sensors, including RIG-I, MDA5, ADAR1, TLR3/7/8, OAS1, PKR, NLRP1/6, and ZBP1, via a broad-spectrum signaling axis. Importantly, new advances have brought to light the potential clinical application of targeting these signaling pathways. Here, we highlight the latest discoveries in the field. We also summarize the activation and regulatory mechanisms of RNA-sensing signaling. In addition, we discuss how RNA sensing is tightly controlled in cells and why the disruption of immune homeostasis is linked to disease.

Molecular Characteristics of Cisplatin-Induced Ototoxicity and Therapeutic Interventions

Cisplatin is a commonly used chemotherapeutic agent with proven efficacy in treating various malignancies, including testicular, ovarian, cervical, breast, bladder, head and neck, and lung cancer. Cisplatin is also used to treat tumors in children, such as neuroblastoma, osteosarcoma, and hepatoblastoma. However, its clinical use is limited by severe side effects, including ototoxicity, nephrotoxicity, neurotoxicity, hepatotoxicity, gastrointestinal toxicity, and retinal toxicity. Cisplatin-induced ototoxicity manifests as irreversible, bilateral, high-frequency sensorineural hearing loss in 40-60% of adults and in up to 60% of children. Hearing loss can lead to social isolation, depression, and cognitive decline in adults, and speech and language developmental delays in children. Cisplatin causes hair cell death by forming DNA adducts, mitochondrial dysfunction, oxidative stress, and inflammation, culminating in programmed cell death by apoptosis, necroptosis, pyroptosis, or ferroptosis. Contemporary medical interventions for cisplatin ototoxicity are limited to prosthetic devices, such as hearing aids, but these have significant limitations because the cochlea remains damaged. Recently, the U.S. Food and Drug Administration (FDA) approved the first therapy, sodium thiosulfate, to prevent cisplatin-induced hearing loss in pediatric patients with localized, non-metastatic solid tumors. Other pharmacological treatments for cisplatin ototoxicity are in various stages of preclinical and clinical development. This narrative review aims to highlight the molecular mechanisms involved in cisplatin-induced ototoxicity, focusing on cochlear inflammation, and shed light on potential antioxidant and anti-inflammatory therapeutic interventions to prevent or mitigate the ototoxic effects of cisplatin. We conducted a comprehensive literature search (Google Scholar, PubMed) focusing on publications in the last five years.

The interaction of bile acids and gut inflammation influences the pathogenesis of inflammatory bowel disease

Bile acids (BA) are amphipathic molecules originating from cholesterol in the liver and from microbiota-driven biotransformation in the colon. In the gut, BA play a key role in fat digestion and absorption and act as potent signaling molecules on the nuclear farnesoid X receptor (FXR) and membrane-associated G protein-coupled BA receptor-1 (GPBAR-1). BA are, therefore, involved in the maintenance of gut barrier integrity, gene expression, metabolic homeostasis, and microbiota profile and function. Disturbed BA homeostasis can activate pro-inflammatory pathways in the gut, while inflammatory bowel diseases (IBD) can induce gut dysbiosis and qualitative and/or quantitative changes of the BA pool. These factors contribute to impaired repair capacity of the mucosal barrier, due to chronic inflammation. A better understanding of BA-dependent mechanisms paves the way to innovative therapeutic tools by administering hydrophilic BA and FXR agonists and manipulating gut microbiota with probiotics and prebiotics. We discuss the translational value of pathophysiological and therapeutic evidence linking BA homeostasis to gut inflammation in IBD.

Multiple toll-like receptors (TLRs) display differential bacterial and ligand specificity in the earthworm, Eisenia andrei

Toll-like receptors (TLRs), an ancient and well-conserved group of pattern recognition receptors (PRRs), recognize conserved pathogen-associated molecular patterns. TLRs consist of three domains: the extracellular N-terminal domain, containing one or more leucine-rich repeats (LRRs), responsible for the recognizing and binding of antigens; the type-I transmembrane domain; and the intracellular domain known as the Toll/Interleukin-1 receptor (TIR) domain required for the downstream signaling pathway. We identified six new full-length complementary DNA (cDNA) sequences, Ean-TLR1/2/3/4/5/6. The deduced amino acid sequences indicate that Ean-TLRs consist of one signal peptide, one LRR N-terminal domain (Ean-TLR4/5), varying numbers of LRRs, one (Ean-TLR1/2/3/4/5) or two (Ean-TLR6) LRR C-terminal domains, one type-I transmembrane domain, and a TIR domain. In addition, a TIR domain alignment revealed that three conserved motifs, designated as Box 1, Box 2, and Box 3, contain essential amino acid residues for downstream signaling activity. Phylogenetic analysis of earthworm TLRs generated two separate evolutionary branches representing single (sccTLR) and multiple (mccTLR) cysteine cluster TLRs. Ean-TLR1/2/3/4 (sccTLR type) and Ean-TLR6 (mccTLR type) were clustered with corresponding types of previously reported earthworm TLRs as well as TLRs from Clitellata and Polychaete. As PRRs, earthworm TLRs should be capable of sensing a diverse range of pathogens. Except for Ean-TLR3, which was not responsive to any bacteria, earthworm TLR expression was significantly induced by Gram-positive but not Gram-negative bacteria. Moreover, it is likely that earthworms can differentiate between different species of Gram-positive bacteria via their TLR responses. The ligand specificity of earthworm TLRs suggests that their pathogenic ligand recognition is likely to be as specific and diverse as the mammalian TLR pathogen-sensing system.

Neofunctionalization of Toll Signaling in Insects: From Immunity to Dorsoventral Patterning

Toll signaling plays a crucial role in pathogen defense throughout the animal kingdom. It was discovered, however, for its function in dorsoventral (DV) axis formation in Drosophila. In all other insects studied so far, but not outside the insects, Toll is also required for DV patterning. However, in insects more distantly related to Drosophila, Toll's patterning role is frequently reduced and substituted by an expanded influence of BMP signaling, the pathway implicated in DV axis formation in all major metazoan lineages. This suggests that Toll was integrated into an ancestral BMP-based patterning system at the base of the insects or during insect evolution. The observation that Toll signaling has an immune function in the extraembryonic serosa, an early differentiating tissue of most insect embryos, suggests a scenario of how Toll was co-opted from an ancestral immune function for its new role in axis formation.

Identification and characterization of toll-like receptor genes in silver pomfret (Pampus argenteus) and their involvement in the host immune response to Photobacterium damselae subsp. Damselae and Nocardia seriolae infection

Toll-like receptors (TLRs) are vital pattern recognition receptors that play a critical role in the innate immune response against pathogenic attack. Among the bacteria commonly found in the culture process of silver pomfret, Photobacterium damselae subsp. Damselae (PDD, gram-negative) and Nocardia seriolae (NS, gram-positive), can cause large-scale mortality in this fish species. However, there is currently no research on the role of TLRs in mediating the immune response of silver pomfret to these two bacterial infections. Therefore, in this study, we identified nine PaTLRs family members, including several fish-specific TLRs (TLR14 and TLR21). Phylogenetic analysis revealed that these PaTLRs genes could be classified into five subfamilies, namely TLR1, TLR3, TLR5, TLR7, and TLR11, indicating their evolutionary conservation. To further explore the interactions of TLR genes with immune-related mediators, protein and protein interaction network (PPI) results were generated to explain the association of TLR genes with TNF receptor-associated factor 6 (TRAF6) and other relevant genes in the MyD88-dependent pathway and NF-κb signaling pathway. Subsequently, RT-qPCR was conducted to verify the expression patterns of the nine TLR genes in the gills, skin, kidney, liver, and spleen of healthy fish, with most of the TLRs showing high expression levels in the spleen. Following infection with PDD and NS, these PaTLRs exhibited different expression patterns in the spleen, with PaTLR2, PaTLR3, PaTLR5, PaTLR7, PaTLR9, and PaTLR14 being significantly up-regulated. Furthermore, when spleen cells were treated with bacterial compositions, the majority of PaTLRs expression was up-regulated in response to Lipopolysaccharide (LPS) and lipophosphorylcholic acid (LTA) treatment, except for PaTLR21. Finally, changes in the expression levels of TLR-interacting genes were also observed under the stimulation of bacteria and bacterial compositions. The results of this study provide a preliminary reference for further understanding the mechanism of the innate immune response of the TLR gene family in silver pomfret and offer theoretical support for addressing the disease problems encountered during large-scale fish breeding.

Molecular characteristics and therapeutic implications of Toll-like receptor signaling pathway in melanoma

Melanoma is a malignant tumor of melanocytes and is often considered immunogenic cancer. Toll-like receptor-related genes are expressed differently in most types of cancer, depending on the immune microenvironment inside cancer, and the key function of Toll-like receptors (TLRs) for melanoma has not been fully elucidated. Based on multi-omics data from TCGA and GEO databases, we first performed pan-cancer analysis on TLR, including CNV, SNV, and mRNA changes in TLR-related genes in multiple human cancers, as well as patient prognosis characterization. Then, we divided melanoma patients into three subgroups (clusters 1, 2, and 3) according to the expression of the TLR pathway, and explored the correlation between TLR pathway and melanoma prognosis, immune infiltration, metabolic reprogramming, and oncogene expression characteristics. Finally, through univariate Cox regression analysis and LASSO algorithm, we selected six TLR-related genes to construct a survival prognostic model, divided melanoma patients into the training set, internal validation set 1, internal validation set 2, and external validation set for multiple validations, and discussed the correlation between model genes and clinical features of melanoma patients. In conclusion, we constructed a prognostic survival model based on TLR-related genes that precisely and independently demonstrated the potential to assess the prognosis and immune traits of melanoma patients, which is critical for patients' survival.

Surface toll-like receptor 9 on immune cells and its immunomodulatory effect

Toll like receptor 9 (TLR9) has been considered as a crucial intracellular pattern recognition receptor in the immune system, which can directly or indirectly mediate innate and adaptive immune responses by recognizing CpG DNA in endosomes to initiate its downstream signaling. However, TLR9 can also be expressed on the membrane surface of some immune and non-immune cells, called surface TLR9 (sTLR9), which covers the TLR9 and its immunomodulatory role with a mysterious veil. In this review, we mainly focus on the sTLR9 expressed on neutrophils, B cells and erythrocytes, and its immunomodulatory roles displayed alone or in coordination with endosomal TLR9 (eTLR9), providing a theoretical reference for the application of its modulators.

Acetobacter pasteurianus BP2201 alleviates alcohol-induced hepatic and neuro-toxicity and modulate gut microbiota in mice

The excessive consumption of alcohol results in a dysbiosis of the gut microbiota, which subsequently impairs the gut microbiota-brain/liver axes and induces cognitive dysfunction and hepatic injury. This study aimed to investigate the potential effect of Acetobacter pasteurianus BP2201 in reducing the negative effects of alcohol consumption on cognitive function and liver health by modulating the gut microbiota-brain/liver axes. Treatment with A. pasteurianus BP2201 improved alcohol-induced hippocampal damage, suppressed neuroinflammation, promoted neuroprotein expression in the hippocampus and enhanced cognitive function. At the same time, A. pasteurianus BP2201 can also reduce serum lipid levels, relieve oxidative stress, inhibit TLR4/MyD88/NF-κB pathway, reduce the secretion of TNF-α and IL-1β, so as to improve alcoholic liver injury. Concomitantly, the treatment with A. pasteurianus BP2201 leads to a shift in the intestinal microbiota structure towards that of healthy individuals, inhibiting the proliferation of harmful bacteria and promoting the recovery of beneficial bacteria. In addition, it also improves brain cognitive dysfunction and liver health by affecting the gut microbiota-brain/liver axes by promoting the synthesis of relevant amino acids and the metabolism of nucleotide base components. These findings demonstrate the potential of regulating the gut microbiome and gut microbiota-brain/liver axes to mitigate alcohol-induced disease.

Elucidating the role of dsRNA sensing and Toll6 in antiviral responses of Culex quinquefasciatus cells

The first step of any immune response is the recognition of foreign molecular structures inside the host organism. An important molecule that is generally foreign to eukaryotic cells is long double-stranded RNA (dsRNA), which can be generated during virus replication. The mechanisms of sensing viral dsRNA are well-studied in mammalian systems but are only poorly understood in insects, including disease vectors such as Culex quinquefasciatus mosquitoes. These mosquitoes are vectors for important arboviruses, such as West Nile virus, and Culex species mosquitoes are distributed across the globe in many temperate and tropical regions. The major antiviral response triggered by dsRNA in mosquitoes is RNA interference - a sequence-specific response which targets complementary viral RNA for degradation. However, here, we aimed to identify whether sequence-independent dsRNA sensing, mimicked by poly(I:C), can elicit an antiviral response. We observed a significant reduction in replication of La Crosse virus (LACV) in Cx. quinquefasciatus mosquito cells following poly(I:C) priming. We identified a number of antimicrobial peptides and Toll receptors that were upregulated at the transcript level by poly(I:C) stimulation. Notably, Toll6 was upregulated and we determined that a knockdown of Toll6 expression resulted also in increased LACV replication. Future efforts require genetic tools to validate whether the observed Toll6 antiviral activity is indeed linked to dsRNA sensing. However, large-scale functional genomic and proteomic approaches are also required to determine which downstream responses are part of the poly(I:C) elicited antiviral response.

Origin of the OAS-RNase L innate immune pathway before the rise of jawed vertebrates via molecular tinkering

Discriminating self from nonself is fundamental to immunity. Yet, it remains largely elusive how the mechanisms of self and nonself discrimination originated. Sensing double-stranded RNA as nonself, the 2',5'-oligoadenylate synthetase (OAS)-ribonuclease L (RNase L) pathway represents a crucial component of innate immunity. Here, we combine phylogenomic and functional analyses to show that the functional OAS-RNase L pathway likely originated through tinkering with preexisting proteins before the rise of jawed vertebrates during or before the Silurian period (444 to 419 Mya). Multiple concerted losses of OAS and RNase L occurred during the evolution of jawed vertebrates, further supporting the ancient coupling between OAS and RNase L. Moreover, both OAS and RNase L genes evolved under episodic positive selection across jawed vertebrates, suggesting a long-running evolutionary arms race between the OAS-RNase L pathway and microbes. Our findings illuminate how an innate immune pathway originated via molecular tinkering.

Research progress into adipose tissue macrophages and insulin resistance

In recent years, there has been an increasing incidence of metabolic syndrome, type 2 diabetes, and cardiovascular events related to insulin resistance. As one of the target organs for insulin, adipose tissue is essential for maintaining in vivo immune homeostasis and metabolic regulation. Currently, the specific adipose tissue mechanisms involved in insulin resistance remain incompletely understood. There is increasing evidence that the process of insulin resistance is mostly accompanied by a dramatic increase in the number and phenotypic changes of adipose tissue macrophages (ATMs). In this review, we discuss the origins and functions of ATMs, some regulatory factors of ATM phenotypes, and the mechanisms through which ATMs mediate insulin resistance. We explore how ATM phenotypes contribute to insulin resistance in adipose tissue. We expect that modulation of ATM phenotypes will provide a novel strategy for the treatment of diseases associated with insulin resistance.

Variability of the innate immune response is globally constrained by transcriptional bursting

Transcription of almost all mammalian genes occurs in stochastic bursts, however the fundamental control mechanisms that allow appropriate single-cell responses remain unresolved. Here we utilise single cell genomics data and stochastic models of transcription to perform global analysis of the toll-like receptor (TLR)-induced gene expression variability. Based on analysis of more than 2000 TLR-response genes across multiple experimental conditions we demonstrate that the single-cell, gene-by-gene expression variability can be empirically described by a linear function of the population mean. We show that response heterogeneity of individual genes can be characterised by the slope of the mean-variance line, which captures how cells respond to stimulus and provides insight into evolutionary differences between species. We further demonstrate that linear relationships theoretically determine the underlying transcriptional bursting kinetics, revealing different regulatory modes of TLR response heterogeneity. Stochastic modelling of temporal scRNA-seq count distributions demonstrates that increased response variability is associated with larger and more frequent transcriptional bursts, which emerge via increased complexity of transcriptional regulatory networks between genes and different species. Overall, we provide a methodology relying on inference of empirical mean-variance relationships from single cell data and new insights into control of innate immune response variability.

Lipids as a key element of insect defense systems

The relationship between insect pathogenic fungi and their insect hosts is a classic example of a co-evolutionary arms race between pathogen and target host: parasites evolve towards mechanisms that increase their advantage over the host, and the host increasingly strengthens its defenses. The present review summarizes the literature data describing the direct and indirect role of lipids as an important defense mechanism during fungal infection. Insect defense mechanisms comprise anatomical and physiological barriers, and cellular and humoral response mechanisms. The entomopathogenic fungi have the unique ability to digest the insect cuticle by producing hydrolytic enzymes with chitin-, lipo- and proteolytic activity; besides the oral tract, cuticle pays the way for fungal entry within the host. The key factor in insect resistance to fungal infection is the presence of certain types of lipids (free fatty acids, waxes or hydrocarbons) which can promote or inhibit fungal attachment to cuticle, and might also have antifungal activity. Lipids are considered as an important source of energy, and as triglycerides are stored in the fat body, a structure analogous to the liver and adipose tissue in vertebrates. In addition, the fat body plays a key role in innate humoral immunity by producing a range of bactericidal proteins and polypeptides, one of which is lysozyme. Energy derived from lipid metabolism is used by hemocytes to migrate to the site of fungal infection, and for phagocytosis, nodulation and encapsulation. One polyunsaturated fatty acid, arachidonic acid, is used in the synthesis of eicosanoids, which play several crucial roles in insect physiology and immunology. Apolipoprotein III is important compound with antifungal activity, which can modulate insect cellular response and is considered as important signal molecule.

Scutellaria polysaccharide mediates the immunity and antioxidant capacity of giant freshwater prawn (Macrobrachium rosenbergii)

The giant freshwater prawn (Macrobrachium rosenbergii) is a commercially valuable freshwater crustacean species that frequently appears a death affected by various diseases, resulting in substantial economic losses. Improving the survival rate of M. rosenbergii is a hot and essential issue for feeding the prawns. Scutellaria polysaccharide (SPS) extracted from Scutellaria baicalensis (a Chinese medicinal herb) is conducive to the survival rate of organisms by enhancing immunity and antioxidant ability. In this study, M. rosenbergii was fed 50, 100, and 150 mg/kg of SPS. The immunity and antioxidant capacity of M. rosenbergii were tested by mRNA levels and enzyme activities of related genes. The mRNA expressions of NF-κB, Toll-R, and proPO (participating in the immune response) in the heart, muscle, and hepatopancreas were decreased after four weeks of SPS feeding (P < 0.05). This indicated that long-term feeding of SPS could regulate the immune responses of M. rosenbergii tissues. The activity levels of antioxidant biomarkers, alkaline phosphatase (AKP), and acid phosphatase (ACP) had significant increases in hemocytes (P < 0.05). Moreover, catalase (CAT) activities in the muscle and hepatopancreas, as well as superoxide dismutase (SOD) activities in all tissues, significantly decreased after four weeks of culture (P < 0.05). The results demonstrated that long-term feeding of SPS could improve the antioxidant capacity of M. rosenbergii. In summary, SPS was conducive to regulating the immune capacity and enhancing the antioxidant capacity of M. rosenbergii. These results provide a theoretical basis for supporting SPS addition to the feed of M. rosenbergii.

Genome-wide identification and expression analyses of Toll-like receptors provide new insights on adaptation to intertidal benthic environments in Urechis unicinctus (Annelida, Echiura)

Toll-like receptors (TLR) are an important class of pattern recognition receptors involved in innate immunity that recognize pathogen-associated and damage-associated molecular patterns. Although the role of TLRs in immunity has been extensively studied, a systematic investigation of their function in environmental adaptation is still in its infancy. In this study, a genome-wide search was conducted to systematically investigate TLR family members of Urechis unicinctus, a typical benthic organism in intertidal mudflats. A total of 28 TLR genes were identified in the U. unicinctus genome, and their fundamental physiological and biochemical properties were characterized. Gene copy number analysis among species in different habitats indicated that TLR family gene expansion may be probably related with benthic environmental adaptation. To further investigate the expression patterns of TLR members under environmental stress, transcriptome data was analyzed from different developmental stages and the hindgut under sulfide stress. Transcriptome analysis of different developmental stages showed that most TLR genes were highly expressed during a key period of benthic environment adaptation (worm-shaped larva). Transcriptome analysis of the hindgut under sulfide stress showed that the expression of 12 TLR members was significantly induced under sulfide stress. These results indicate that the regulation of TLR gene expression may be probably involved in the adaptation of U. unicinctus to the benthic intertidal zone environment. Taken together, this study may lay the foundation for future functional analysis of the specific role of TLRs in host immune responses against sulfide exposure and benthic environmental stress in annelid.

Expression and function of toll-like receptor 2 in vertebrate

Toll-like receptors (TLRs) are essential for identifying and detecting pathogen-associated molecular patterns (PAMPs) produced by a variety of pathogens, including viruses and bacteria. Since TLR2 is the only TLR capable of creating functional heterodimers with more than two other TLR types, it is very important for vertebrate immunity. TLR2 not only broadens the variety of PAMPs that it can recognize but has also the potential to diversify the subsequent signaling cascades. TLR2 is ubiquitous, which is consistent with the wide variety of tasks and functions it serves. Immune cells, endothelial cells, and epithelial cells have all been found to express TLR2. This review aims to gather currently available information about the preservation of this intriguing immunological molecule in the phylum of vertebrates.

Non-canonical pattern recognition of a pathogen-derived metabolite by a nuclear hormone receptor identifies virulent bacteria in C. elegans

Distinguishing infectious pathogens from harmless microorganisms is essential for animal health. The mechanisms used to identify infectious microbes are not fully understood, particularly in metazoan hosts that eat bacteria as their food source. Here, we characterized a non-canonical pattern-recognition system in Caenorhabditis elegans (C. elegans) that assesses the relative threat of virulent Pseudomonas aeruginosa (P. aeruginosa) to activate innate immunity. We discovered that the innate immune response in C. elegans was triggered by phenazine-1-carboxamide (PCN), a toxic metabolite produced by pathogenic strains of P. aeruginosa. We identified the nuclear hormone receptor NHR-86/HNF4 as the PCN sensor in C. elegans and validated that PCN bound to the ligand-binding domain of NHR-86/HNF4. Activation of NHR-86/HNF4 by PCN directly engaged a transcriptional program in intestinal epithelial cells that protected against P. aeruginosa. Thus, a bacterial metabolite is a pattern of pathogenesis surveilled by nematodes to identify a pathogen in its bacterial diet.

The architecture of transmembrane and cytoplasmic juxtamembrane regions of Toll-like receptors

Toll-like receptors (TLRs) are the important participants of the innate immune response. Their spatial organization is well studied for the ligand-binding domains, while a lot of questions remain unanswered for the membrane and cytoplasmic regions of the proteins. Here we use solution NMR spectroscopy and computer simulations to investigate the spatial structures of transmembrane and cytoplasmic juxtamembrane regions of TLR2, TLR3, TLR5, and TLR9. According to our data, all the proteins reveal the presence of a previously unreported structural element, the cytoplasmic hydrophobic juxtamembrane α-helix. As indicated by the functional tests in living cells and bioinformatic analysis, this helix is important for receptor activation and plays a role, more complicated than a linker, connecting the transmembrane and cytoplasmic parts of the proteins.

Origins and diversification of animal innate immune responses against viral infections

Immune systems are of pivotal importance to any living organism on Earth, as they protect the organism against deleterious effects of viral infections. Though the current knowledge about these systems is still biased towards the immune response in vertebrates, some studies have focused on the identification and characterization of components of invertebrate antiviral immune systems. Two classic model organisms, the insect Drosophila melanogaster and the nematode Caenorhabditis elegans, were instrumental in the discovery of several important components of the innate immune system, such as the Toll-like receptors and the RNA interference pathway. However, these two model organisms provide only a limited view of the evolutionary history of the immune system, as they both are ecdysozoan protostomes. Recent functional studies in non-classic models such as unicellular holozoans (for example, choanoflagellates), lophotrochozoans (for example, oysters) and cnidarians (for example, sea anemones) have added crucial information for understanding the evolution of antiviral systems, as they revealed unexpected ancestral complexity. This Review aims to summarize this information and present the ancestral nature of the antiviral immune response in animals. We also discuss lineage-specific adaptations and future perspectives for the comparative study of the innate immune system that are essential for understanding its evolution.

The Role of TRL7/8 Agonists in Cancer Therapy, with Special Emphasis on Hematologic Malignancies

Toll-like receptors (TLR) belong to the pattern recognition receptors (PRR). TLR7 and the closely correlated TLR8 affiliate with toll-like receptors family, are located in endosomes. They recognize single-stranded ribonucleic acid (RNA) molecules and synthetic deoxyribonucleic acid (DNA)/RNA analogs-oligoribonucleotides. TLRs are primarily expressed in hematopoietic cells. There is compiling evidence implying that TLRs also direct the formation of blood cellular components and make a contribution to the pathogenesis of certain hematopoietic malignancies. The latest research shows a positive effect of therapy with TRL agonists on the course of hemato-oncological diseases. Ligands impact activation of antigen-presenting cells which results in production of cytokines, transfer of mentioned cells to the lymphoid tissue and co-stimulatory surface molecules expression required for T-cell activation. Toll-like receptor agonists have already been used in oncology especially in the treatment of dermatological neoplastic lesions. The usage of these substances in the treatment of solid tumors is being investigated. The present review discusses the direct and indirect influence that TLR7/8 agonists, such as imiquimod, imidazoquinolines and resiquimod have on neoplastic cells and their promising role as adjuvants in anticancer vaccines.

Interaction between nanomaterials and the innate immune system across evolution

Interaction of engineered nanomaterials (ENMs) with the immune system mainly occurs with cells and molecules of innate immunity, which are present in interface tissues of living organisms. Immuno-nanotoxicological studies aim at understanding if and when such interaction is inconsequential or may cause irreparable damage. Since innate immunity is the first line of immune reactivity towards exogenous agents and is highly conserved throughout evolution, this review focuses on the major effector cells of innate immunity, the phagocytes, and their major sensing receptors, Toll-like receptors (TLRs), for assessing the modes of successful versus pathological interaction between ENMs and host defences. By comparing the phagocyte- and TLR-dependent responses to ENMs in plants, molluscs, annelids, crustaceans, echinoderms and mammals, we aim to highlight common recognition and elimination mechanisms and the general sufficiency of innate immunity for maintaining tissue integrity and homeostasis.

Ginseng polysaccharides: Potential antitumor agents

As a famous herbal medicine in China and Asia, ginseng (Panax ginseng C. A. Meyer) is also known as the "King of All Herbs" and has long been used in medicine and healthcare. In addition to the obvious biological activities of ginsenosides, ginseng polysaccharides (GPs) exhibit excellent antitumor, antioxidant stress, and immunomodulatory effects. In particular, GPs can exert an antitumor effect and is a potential immunomodulator. However, due to the complexity and diversity in the structures and components of GPs, their specific physicochemical properties, and underlying mechanisms remain unclear. In this article, we have summarized the factors influencing the antitumor activity of GPs and their mechanism of action, including the stimulation of the immune system, regulation of the gut microbiota, and direct action on tumor cells.

OfGNBP silencing enhances the toxicity of Serratia marcescens Bizio (SM1) to Odontotermes formosanus (Shiraki)

The immunity of insects plays a vital role in their survival. Our experiments found that lipopolysaccharide (LPS) and glucono-δ-lactone (GDL) could influence the virulence of Serratia marcescens Bizio (SM1) to Odontotermes formosanus (Shiraki) by affecting the immunity. Gram-negative binding proteins (GNBPs) are an important pattern recognition proteins that play a crucial role in the innate immune system. Therefore, two OfGNBPs were cloned in O. formosanus. The expression of OfGNBPs was significantly changed by LPS,SM1 and GDL, not prick. In addition, the immune-related gene expression, the phenoloxidase activity and antibacterial activity of donor termites and recipient termites were significantly induced by SM1. Furthermore, the knockdown of OfGNBP by RNA interference reduced not only individual immunity but also social immunity in O. formosanus, which increased the virulence of SM1 to O. formosanus. Importantly, dsOfGNBP alone also had good control effect on O. formosanus. In summary, we concluded that dsOfGNBPs are important termite immunosuppressants.

Looking for biomarkers in interferon response pathway to predict response to oncolytic HSV-1 in breast cancer: An ex vivo study

Breast cancer is the most common malignancy in women worldwide. Administration of oncolytic viruses is one of the novel promising cancer therapy approaches. Replication of these viruses is usually limited to cancer cells that have interferon (IFN) signaling defects. However, Interferon signaling is not completely impaired in all cancer cells which may limit the benefits of virotherapy.    Identification of realistic IFN-mediated biomarkers to identify patients who most likely respond to virotherapy would be helpful. In this study, eight patients-derived primary tumor cultures were infected with an ICP34.5 deleted oHSV, then the rate of infectivity, cell survival, and expression of the gene involved in IFN pathway were analyzed.Data showed that mRNA expressions of Myeloid differentiation primary response protein (Myd88) is significantly higher in tumors whose primary cultures showed less cell death and resistance to oHSV infectivity (P-value < 0.05). The differentiating cut off of Myd88 expression, inferred from the receiver operating characteristic (ROC) curve, predicted that only 13 out of 16 other patients could be sensitive to this oHSV. Identifying such biomarker improves our ability to select the patients who do not exhibit resistance to virotherapy.

Cisplatin-induced ototoxicity: From signaling network to therapeutic targets

Administration of cisplatin, a common chemotherapeutic drug, has an inevitable side effect of sensorineural hearing loss. The main etiologies are stria vascularis injury, spiral ganglion degeneration, and hair cell death. Over several decades, the research scope of cisplatin-induced ototoxicity has expanded with the discovery of the molecular mechanism mediating inner ear cell death, highlighting the roles of reactive oxygen species and transport channels for cisplatin uptake into inner ear cells. Upon entering hair cells, cisplatin disrupts organelle metabolism, induces oxidative stress, and targets DNA to cause intracellular damage. Recent studies have also reported the role of inflammation in cisplatin-induced ototoxicity. In this article, we preform a narrative review of the latest reported molecular mechanisms of cisplatin-induced ototoxicity, from extracellular to intracellular. We build up a signaling network starting with cisplatin entering into the inner ear through the blood labyrinth barrier, disrupting cochlear endolymph homeostasis, and activating inflammatory responses of the outer hair cells. After entering the hair cells, cisplatin causes hair cell death via DNA damage, redox system imbalance, and mitochondrial and endoplasmic reticulum dysfunction, culminating in programmed cell death including apoptosis, necroptosis, autophagic death, pyroptosis, and ferroptosis. Based on the mentioned mechanisms, prominent therapeutic targets, such as channel-blocking drugs of cisplatin transporter, construction of cisplatin structural analogues, anti-inflammatory drugs, antioxidants, cell death inhibitors, and others, were collated. Considering the recent research efforts, we have analyzed the feasibility of the aforementioned therapeutic strategies and proposed our otoprotective approaches to overcome cisplatin-induced ototoxicity.

Heterogeneous Genomic Divergence Landscape in Two Commercially Important European Scallop Species

Two commercially important scallop species of the genus Pecten are found in Europe: the north Atlantic Pecten maximus and the Mediterranean Pecten jacobaeus whose distributions abut at the Almeria-Orán front. Whilst previous studies have quantified genetic divergence between these species, the pattern of differentiation along the Pecten genome is unknown. Here, we mapped RADseq data from 235 P. maximus and 27 P. jacobaeus to a chromosome-level reference genome, finding a heterogeneous landscape of genomic differentiation. Highly divergent genomic regions were identified across 14 chromosomes, while the remaining five showed little differentiation. Demographic and comparative genomics analyses suggest that this pattern resulted from an initial extended period of isolation, which promoted divergence, followed by differential gene flow across the genome during secondary contact. Single nucleotide polymorphisms present within highly divergent genomic regions were located in areas of low recombination and contrasting patterns of LD decay were found between the two species, hinting at the presence of chromosomal inversions in P. jacobaeus. Functional annotations revealed that highly differentiated regions were enriched for immune-related processes and mRNA modification. While future work is necessary to characterize structural differences, this study provides new insights into the speciation genomics of P. maximus and P. jacobaeus.

Inappropriate Activation of TLR4/NF-κB is a Cause of Heart Failure

Significance: Heart failure, a disease with extremely high incidence, is closely associated with inflammation and oxidative stress. The Toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) pathway plays an important role in the occurrence and development of heart failure.

Recent advances: Previous studies have shown that TLR4/NF-κB causes heart failure by inducing oxidative stress and inflammation; damaging the endothelia; promoting fibrosis; and inducing myocardial hypertrophy, apoptosis, pyroptosis, and autophagy.

Critical issues: Understanding the pathogenesis of heart failure is essential for the treatment of this disease. In this review, we outline the mechanisms underlying TLR4/NF-κB pathway-mediated heart failure and discuss drugs that alleviate heart failure by regulating the TLR4/NF-κB pathway.

Future directions: During TLR4/NF-κB overactivation, interventions targeting specific receptor antagonists may effectively alleviate heart failure, thus providing a basis for the development of new anti-heart failure drugs.

Potential role of gut microbiota and its metabolites in radiation-induced intestinal damage

Radiation-induced intestinal damage (RIID) is a serious disease with limited effective treatment. Nuclear explosion, nuclear release, nuclear application and especially radiation therapy are all highly likely to cause radioactive intestinal damage. The intestinal microecology is an organic whole with a symbiotic relationship formed by the interaction between a relatively stable microbial community living in the intestinal tract and the host. Imbalance and disorders of intestinal microecology are related to the occurrence and development of multiple systemic diseases, especially intestinal diseases. Increasing evidence indicates that the gut microbiota and its metabolites play an important role in the pathogenesis and prevention of RIID. Radiation leads to gut microbiota imbalance, including a decrease in the number of beneficial bacteria and an increase in the number of harmful bacteria that cause RIID. In this review, we describe the pathological mechanisms of RIID, the changes in intestinal microbiota, the metabolites induced by radiation, and their mechanism in RIID. Finally, the mechanisms of various methods for regulating the microbiota in the treatment of RIID are summarized.

CP-25 exerts a protective effect against ConA-induced hepatitis via regulating inflammation and immune response

Hepatitis is a complex multifactorial pathological disorder, which can eventually lead to liver failure and even potentially be life threatening. Paeoniflorin-6′-O-benzene sulfonate (CP-25) has proven to have critical anti-inflammatory effects in arthritis. However, the effects of CP-25 in the pathogenesis of hepatitis remains unclear. In this experiment, mice were intragastrically administered with CP-25 (25, 50 and 100 mg/kg), and then ConA (25 mg/kg) was intravenous injected to establish hepatitis model in vivo. CP-25 administration attenuated liver damage and decreased ALT and AST activities in mice with hepatitis. Besides, CP-25 modulated immune responses including down-regulated the proportions of activated CD4+, activated CD8+ T cells, and ratio of Th1/Th2 in ConA-injected mice. Furthermore, ConA-mediated production of reactive oxygen species (ROS), release of inflammatory cytokines including IFN-γ, TNF-α, activation of MAPK pathways and nuclear translocation of nuclear factor-kappaB (NF-κB) were significantly decreased in CP-25 administrated mice. In ConA-stimulated RAW264.7 cells, CP-25 suppressed inflammatory cytokines secretion and reduced ROS level, which were consistent with animal experiments. Otherwise, the data showed that CP-25 restrained phosphorylation of ERK, JNK and p38 MAPK pathways influenced by ROS, accompanied with inhibiting NF-κB nuclear translocation. In conclusion, our findings indicated that CP-25 protected against ConA-induced hepatitis may through modulating immune responses and attenuating ROS-mediated inflammation via the MAPK/NF-κB signaling pathway.

An innate ability: How do basal invertebrates manage their chronic exposure to microbes?

Homologs of mammalian innate immune sensing and downstream pathway proteins have been discovered in a variety of basal invertebrates, including cnidarians and sponges, as well as some single-celled protists. Although the structures of these proteins vary among the basal organisms, many of the activities found in their mammalian counterparts are conserved. This is especially true for the Toll-like receptor (TLR) and cGAS-STING pathways that lead to downstream activation of transcription factor NF-κB. In this short perspective, we describe the evidence that TLR and cGAS-STING signaling to NF-κB is also involved in immunity in basal animals, as well as in the maintenance of microbial symbionts. Different from terrestrial animals, immunity in many marine invertebrates might have a constitutively active state (to protect against continual exposure to resident or waterborne microbes), as well as a hyperactive state that can be induced by pathogens at both transcriptional and posttranscriptional levels. Research on basal immunity may be important for (1) understanding different approaches that organisms take to sensing and protecting against microbes, as well as in maintaining microbial symbionts; (2) the identification of novel antimicrobial effector genes and processes; and (3) the molecular pathways that are being altered in basal marine invertebrates in the face of the effects of a changing environment.

Global patterns in symbiont selection and transmission strategies in sponges

Sponges host dense and diverse communities of microbes (known as the microbiome) beneficial for the host nutrition and defense. Symbionts in turn receive shelter and metabolites from the sponge host, making their relationship beneficial for both partners. Given that sponge-microbes associations are fundamental for the survival of both, especially the sponge, such relationship is maintained through their life and even passed on to the future generations. In many organisms, the microbiome has profound effects on the development of the host, but the influence of the microbiome on the reproductive and developmental pathways of the sponges are less understood. In sponges, microbes are passed on to oocytes, sperm, embryos, and larvae (known as vertical transmission), using a variety of methods that include direct uptake from the mesohyl through phagocytosis by oocytes to indirect transmission to the oocyte by nurse cells. Such microbes can remain in the reproductive elements untouched, for transfer to offspring, or can be digested to make the yolky nutrient reserves of oocytes and larvae. When and how those decisions are made are fundamentally unanswered questions in sponge reproduction. Here we review the diversity of vertical transmission modes existent in the entire phylum Porifera through detailed imaging using electron microscopy, available metabarcoding data from reproductive elements, and macroevolutionary patterns associated to phylogenetic constraints. Additionally, we examine the fidelity of this vertical transmission and possible reasons for the observed variability in some developmental stages. Our current understanding in marine sponges, however, is that the adult microbial community is established by a combination of both vertical and horizontal (acquisition from the surrounding environment in each new generation) transmission processes, although the extent in which each mode shapes the adult microbiome still remains to be determined. We also assessed the fundamental role of filtration, the cellular structures for acquiring external microbes, and the role of the host immune system, that ultimately shapes the stable communities of prokaryotes observed in adult sponges.

Analysis of the Value of Serum Biomarker LBP in the Diagnosis of Spinal Tuberculosis

Objective

To investigate the correlation between the expression of lipopolysaccharide-binding protein (LBP) in peripheral blood of spinal tuberculosis and clinical diagnosis and to evaluate its value as a diagnostic marker of spinal tuberculosis.

Methods

In the experimental group, clinical history data and peripheral blood were collected from 100 patients with spinal tuberculosis who were admitted to the Department of Spine Surgery, General Hospital of Ningxia Medical University from May 2017 to May 2020, and peripheral blood was collected from 30 healthy volunteers in the control group. Screening of differential LBP expression by proteomics and ELISA to verify its expression in peripheral blood of spinal tuberculosis patients. t-test, Spearman analysis, linear regression and ROC curve were used to evaluate the diagnostic value of LBP in peripheral blood for spinal tuberculosis.

Results

The expression of LBP protein in peripheral blood is significantly higher in patients with spinal tuberculosis than in the normal population; LBP assay values were significantly and positively correlated with CRP and ESR values (P < 0.01); the AUC of LBP in the diagnosis of spinal tuberculosis for pathological examination, bacteriological culture, T-cell spot test for tuberculosis infection (T-SPOT), imaging diagnosis, and acid fast bacillus were, respectively, 0.677 (P < 0.01), 0.707 (P < 0.01), 0.751 (P < 0.01), 0.714 (P < 0.01), and 0.656 (P < 0.05), and there was a correlation between LBP and the diagnostic evaluation of spinal tuberculosis.

Conclusion

LBP could be a new candidate biomarker for the diagnosis of spinal tuberculosis.

Comprehensive Bioinformatics Analysis of Toll-Like Receptors (TLRs) in Pan-Cancer

Background

To conduct a comprehensive bioinformatics analysis on the transcriptome signatures of Toll-like receptors (TLRs) in pan-cancer. Materials and methods. A total of 11,057 tissues consisting of 33 types of carcinoma in The Cancer Genome Atlas (TCGA) were retrieved, and then we further explored the correlation between TLRs' expression with tumorigenesis, immune infiltration, and drug sensitivity. We conducted a comprehensive bioinformatics analysis on TLR1 to 10 in pan-cancer, including differential expression analysis between normal and tumor tissues, differential immune subtype correlation, survival analysis, tumor immune infiltration estimating, stemness indices correlation, and drug responses correlation.

Results

TLR2 was highly expressed in most types of tumors. TLR9 was hardly expressed compared to other TLR genes, which lead to TLR9 showing less correlation with both immune-estimate scores and stromal-estimate scores. All the TLRs were related with immune subtype of tumor samples that all of them were differentially expressed in differential immune subtype samples. The expression of TLRs was positively related with immune-estimate scores and stromal-estimate scores in almost all types of tumor. The expression of TLRs was negatively correlated with mRNA expression-based stemness scores (RNAss) in nearly almost type of tumors except kidney renal clear cell carcinoma (KIRC) and also negatively correlated with DNA methylation-based stemness scores (DNAss) in many types of tumors except adrenocortical carcinoma (ACC), cholangiocarcinoma (CHOL), KIRC, acute myeloid leukemia (LAML), low-grade glioma (LGG), testicular germ cell tumors (TGCT), thyroid carcinoma (THCA), thymoma (THYM), and uveal melanoma (UVM). The expression of TLR9 was significantly positively correlated with the drug sensitivity of fluphenazine, alectinib, carmustine, and 7−hydroxystaurosporine. TLR7 was significantly positively correlated with the drug sensitivity of alectinib.

Conclusions

Our study reveals the significant role of TLRs family in pan-cancer and provides potential therapeutic strategies of cancer.

Aligned electrospun poly(L-lactide) nanofibers facilitate wound healing by inhibiting macrophage M1 polarization via the JAK-STAT and NF-κB pathways

Delayed wound healing remains a challenge, and macrophages play an important role in the inflammatory process of wound healing. Morphological changes in macrophages can affect their phenotype, but little is known about the underlying mechanism. Aligned electrospun nanofibers have natural advantages in modulating cell morphology. Therefore, the current study constructed aligned electrospun nanofibers that could transform macrophages into elongated shapes. Our results demonstrated that aligned nanofibers without exogenous cytokines could downregulate the proinflammatory M1 phenotype and upregulate the prohealing M2 phenotype in an inflammatory environment. Importantly, our study revealed that aligned electrospun nanofibers could inhibit macrophage M1 polarization via the JAK-STAT and NF-κB pathways. Furthermore, the conditioned medium from macrophages cultured on aligned nanofibers could encourage fibroblast migration, proliferation and collagen secretion. In vivo, aligned nanofibers alleviated the inflammatory microenvironment, promoted angiogenesis and accelerated wound healing in mouse skin defects by modulating macrophage phenotypes. Collectively, aligned electrospun nanofibers can influence macrophage polarization via the JAK-STAT and NF-κB pathways and attenuate the local inflammatory response in skin wounds. This study provides a potential strategy to modulate macrophage polarization and promote wound healing by controlling the topology of biomaterials and offers a new perspective for the application of nanotechnology in wound healing.

Immune-Triggered Forms of Plasticity Across Brain Regions

Immune cells play numerous roles in the host defense against the invasion of microorganisms and pathogens, which induces the release of inflammatory mediators (e.g., cytokines and chemokines). In the CNS, microglia is the major resident immune cell. Recent efforts have revealed the diversity of the cell types and the heterogeneity of their functions. The refinement of the synapse structure was a hallmark feature of the microglia, while they are also involved in the myelination and capillary dynamics. Another promising feature is the modulation of the synaptic transmission as synaptic plasticity and the intrinsic excitability of neurons as non-synaptic plasticity. Those modulations of physiological properties of neurons are considered induced by both transient and chronic exposures to inflammatory mediators, which cause behavioral disorders seen in mental illness. It is plausible for astrocytes and pericytes other than microglia and macrophage to induce the immune-triggered plasticity of neurons. However, current understanding has yet achieved to unveil what inflammatory mediators from what immune cells or glia induce a form of plasticity modulating pre-, post-synaptic functions and intrinsic excitability of neurons. It is still unclear what ion channels and intracellular signaling of what types of neurons in which brain regions of the CNS are involved. In this review, we introduce the ubiquitous modulation of the synaptic efficacy and the intrinsic excitability across the brain by immune cells and related inflammatory cytokines with the mechanism for induction. Specifically, we compare neuro-modulation mechanisms by microglia of the intrinsic excitability of cerebellar Purkinje neurons with cerebral pyramidal neurons, stressing the inverted directionality of the plasticity. We also discuss the suppression and augmentation of the extent of plasticity by inflammatory mediators, as the meta-plasticity by immunity. Lastly, we sum up forms of immune-triggered plasticity in the different brain regions with disease relevance. Together, brain immunity influences our cognition, sense, memory, and behavior via immune-triggered plasticity.

Hepatitis C Virus Infection and Intrinsic Disorder in the Signaling Pathways Induced by Toll-Like Receptors

In this study, we examined the interplay between protein intrinsic disorder, hepatitis C virus (HCV) infection, and signaling pathways induced by Toll-like receptors (TLRs). To this end, 10 HCV proteins, 10 human TLRs, and 41 proteins from the TLR-induced downstream pathways were considered from the prevalence of intrinsic disorder. Mapping of the intrinsic disorder to the HCV-TLR interactome and to the TLR-based pathways of human innate immune response to the HCV infection demonstrates that substantial levels of intrinsic disorder are characteristic for proteins involved in the regulation and execution of these innate immunity pathways and in HCV-TLR interaction. Disordered regions, being commonly enriched in sites of various posttranslational modifications, may play important functional roles by promoting protein-protein interactions and support the binding of the analyzed proteins to other partners such as nucleic acids. It seems that this system represents an important illustration of the role of intrinsic disorder in virus-host warfare.

Roles of Micro Ribonucleic Acids in Astrocytes After Cerebral Stroke

Cerebral stroke is one of the highest-ranking causes of death and the leading cause of disability globally, particularly with an increasing incidence and prevalence in developing countries. Steadily more evidence has indicated that micro ribonucleic acids (miRNAs) have important regulatory functions in gene transcription and translation in the course of cerebral stroke. It is beyond arduous to understand the pathophysiology of cerebral stroke, due in part to the perplexity of influencing the network of the inflammatory response, brain edema, autophagy and neuronal apoptosis. The recent research shows miRNA plays a key role in regulating aquaporin 4 (AQP4), and many essential pathological processes after cerebral stroke. This article reviews the recent knowledge on how miRNA influences the inflammatory response, brain edema, infarction size, and neuronal injury after cerebral stroke. In addition, some miRNAs may serve as potential biomarkers in stroke diagnosis and therapy since the expression of some miRNAs in the blood is stable after cerebral stroke.