Innate Immunity Activation in Newly Diagnosed Ileocolonic Crohn's Disease: A Cohort Study

BACKGROUND

Recent studies showed that early surgery for Crohn's disease leads to a lower recurrence rate. However, the underlying mechanism is unknown.

OBJECTIVE

The study aims to analyze the innate immunity microenvironment in ileal mucosa according to the duration of Crohn's disease.

DESIGN

A prospective cohort study.

SETTINGS

Tertiary referral center for IBD surgery.

PATIENTS

A total of 88 consecutive patients with Crohn's disease undergoing ileocolonic resection were prospectively enrolled. Mucosal samples were obtained from both healthy and inflamed ileum. Data from a public data set were analyzed as an external validation cohort.

MAIN OUTCOME MEASURES

Neutrophil infiltration was evaluated by histological asessment and macrophage subpopulation was assessed by immunohistochemistry. Expressions of TLR2 , TLR4 , TLR5 , DEFB1 , DEFB4A , DEFB103 , DEFA5 , and DEFA6 were quantified by real-time quantitative polymerase chain reaction. Concentrations of BDNF, CCL-11, ICAM-1, IL-1A, IL-1β, IL-1RN, IL-12p40, IL-12p70, IL-15, IL-17A, IL-23A, MMP-3, CCL-3, KITLG, and VEGFA were determined with an immunometric assay.

RESULTS

Neutrophil infiltration is inversely correlated with disease duration. DEFB4A mRNA expression tended to be higher in late-stage Crohn's disease ( p = 0.07). A higher number of macrophages expressed CD163 at low intensity in late-stage Crohn's disease ( p = 0.04). The concentration of IL-15 ( p = 0.02) and IL-23A ( p = 0.05) was higher in healthy ileal mucosa of early-stage patients. In the external cohort, expressions of DEFB1 ( p = 0.03), DEFB4A ( p = 0.01), IL-2 ( p = 0.04), and IL-3 ( p = 0.03) increased in patients with late-stage Crohn's disease.

LIMITATIONS

A relatively small number of patients, especially in the newly diagnosed group.

CONCLUSIONS

In newly diagnosed Crohn's disease, high levels of IL-15 and IL-23 in healthy mucosa suggest that innate immunity is the starter of acute inflammation. Moreover, M2 macrophages increase in the healthy mucosa of patients with late-stage Crohn's disease, suggesting that reparative and profibrotic processes are predominant in the long term, and in this phase, anti-inflammatory therapy may be less efficient. See Video Abstract .

ACTIVACIN DE LA INMUNIDAD INNATA EN LA RECIENTEMENTE DIAGNOSTICADA ENFERMEDAD DE CROHN ILEOCLICA UN ESTUDIO DE COHORTE

ANTECEDENTES:Estudios recientes demostraron que la cirugía temprana para la enfermedad de Crohn (EC) conduce a una menor tasa de recurrencia. Sin embargo, se desconoce el mecanismo subyacente.OBJETIVO:El estudio tiene como objetivo analizar el microambiente de la inmunidad innata en la mucosa ileal según la duración de la EC.DISEÑO:Un estudio de cohorte prospectivo.AJUSTES:Centro terciario de referencia para cirugía de EII.PACIENTES:Fueron registrados de manera prospectiva y consecutiva 88 pacientes con EC sometidos a resección ileocolónica. Se obtuvieron muestras de mucosa ileal, tanto del íleon sano como del íleon inflamado. Los datos se analizaron como una cohorte de validación externa.PRINCIPALES MEDIDAS DE RESULTADO:Fueron evaluados la infiltración de neutrófilos por histología y la subpoblación de macrófagos por inmunohistoquímica. La expresión de TLR2, TLR4, TLR5, DEFB1, DEFB4A, DEFB103, DEFA5 y DEFA6 fueron cuantificados mediante qPCR en tiempo real. Las concentraciones de BDNF, CCL-11, ICAM-1, IL-1A, IL-1B, IL-1RN, IL-12 p40, IL-12 p70, IL-15, IL-17A, IL-23A, MMP-3, CCL-3, KITLG, VEGFA se determinaron con ensayo inmunométrico.RESULTADOS:La infiltración de neutrófilos se correlaciona inversamente con la duración de la enfermedad. La expresión del ARNm de DEFB4A mostro una tendencia a ser mayor en la EC en etapa tardía ( p = 0,07). Un mayor número de macrófagos expresaron CD163 a baja intensidad en la etapa tardía ( p = 0,04). La concentración de IL15 ( p = 0,02) e IL23A ( p = 0,05) fue mayor en la mucosa ileal sana de pacientes en estadio temprano. En la cohorte externa, la expresión de DEFB1 ( p = 0,03) y DEFB4A ( p = 0,01), IL2 ( p = 0,04) e IL3 ( p = 0,03) aumentó en pacientes en etapa tardía.LIMITACIONES:Un número relativamente pequeño de pacientes, especialmente en el grupo recién diagnosticado.CONCLUSIONES:En la EC recién diagnosticada, los altos niveles de IL-15 e IL-23 en la mucosa sana sugieren que la inmunidad innata es el promotor de la inflamación aguda. Además, los macrófagos M2 aumentan en la mucosa sana de pacientes con EC en etapa tardía, lo que sugiere que los procesos reparadores y profibróticos son predominantes a largo plazo y en esta fase, la terapia antiinflamatoria puede ser menos eficiente. (Traducción-Dr. Osvaldo Gauto ).

An in vitro study elucidating the synergistic effects of aqueous cinnamon extract and an anti-TNF-α biotherapeutic: implications for a complementary and alternative therapy for non-responders

BACKGROUND

Tumor necrosis factor-alpha (TNF-α) is a critical pro-inflammatory cytokine, and its abnormal production is associated with several immune mediated inflammatory diseases (IMID). Biological anti-TNF-α therapy includes treatment with monoclonal antibodies such as infliximab which have proven successful and are well-tolerated in most patients. Unfortunately, some patients may not respond to therapy (primary non-responders) or may lose sensitivity to the biological agent over time (early and late secondary non-responders). Natural products can reduce inflammation and act synergistically with small molecules or biologics, although evidence remains limited. This study aimed to investigate whether complementary and alternative medicine (CAM) could play a role in infliximab non-responders. Reportedly, cinnamon can help manage chronic inflammatory conditions owing to its anti-inflammatory properties.

METHODS

We studied the synergistic effects of cinnamon and infliximab in vitro using a two-step approach. First, we investigated whether cinnamon and infliximab act synergistically. Second, we selected conditions that supported statistically significant synergy with infliximab and studied the mRNA expression of several genes involved in non-response to infliximab. We used aqueous cinnamon extract (aCE) from Cinnamomum cassia, Cinnamomum zeylanicum, and Cinnamomum loureiroi and bioactive trans-cinnamaldehyde (TCA), cinnamic acid (CA), and eugenol to study the synergy between infliximab and aCE/bioactive compounds using bioassays in fibroblast (L929) and monocytic (U937) cell lines, followed by qPCR for molecular-level insights. TCA, C. cassia aCE, and C. zeylanicum aCE demonstrated a dose-dependent synergistic effect with infliximab. Moreover, we saw differential gene expression for adhesion molecules, apoptotic factors, signaling molecules, and matrix remodelers in presence and absence of aCE/bioactives.

RESULTS

CAM supplementation was most effective with C. cassia aCE, where a synergistic effect was observed for all the tested genes specifically for MMP-1, BcL-xL, Bax and JAK2, followed by TCA, which affected most of the tested genes except TLR-2, MMP1, MMP3, TIMP-1, and BAX, and C. zeylanicum aCE, which did not affect ICAM-1, VCAM-1, TLR-2, TLR-4, MMP1, MMP3, TIMP-1, and STAT3.

CONCLUSION

In conclusion, cinnamon acted synergistically with infliximab to mitigate inflammation when used as an extract. Purified bioactive TCA also showed synergistic activity. Thus, aCE, or cinnamon bioactive may be used as a CAM to improve patients' quality of life.

Polyethylene microplastics induced gut microbiota dysbiosis leading to liver injury via the TLR2/NF-κB/NLRP3 pathway in mice

Microplastics (MPs) are ubiquitous environmental contaminants that have negative impacts on health and safety. The gut microbiota plays multiple roles as a newly discovered virtual metabolic organ. The objective of this study was to investigate the potential of MPs to cause liver injury by disrupting the balance of gut microbiota. The results indicated that exposure to MPs resulted in liver damage and disrupted the homeostasis of gut microbiota. MPs significantly reduced the liver organ coefficient, leading to liver cell injury and impaired function. Additionally, there was an increase in the expression of fibril-related proteins, which positively correlated with MPs concentration. Furthermore, MPs increased the relative abundances of Desulfovibrio, Clostridia, Enterorhabdus, Bacteroides, and Gemella while decreasing the abundance of Dubosoella. Different concentrations of MPs exhibited varying effects on specific bacterial groups, however, both concentrations resulted in an increase in pathogenic bacteria and a decrease in beneficial bacteria, as well as alterations in microbial structure. Moreover, MPs induced oxidative stress, inflammation, apoptosis and necrosis in liver cells. The study found that MPs disrupted gut microbiota homeostasis and activated TLR2/NF-κB/NLRP3 pathway in the liver, providing a new insight into the mechanism underlying MPs-induced liver injury. These findings serve as a warning regarding environmental pollution caused by MPs.

TLR2 regulates hair follicle cycle and regeneration via BMP signaling

The etiology of hair loss remains enigmatic, and current remedies remain inadequate. Transcriptome analysis of aging hair follicles uncovered changes in immune pathways, including Toll-like receptors (TLRs). Our findings demonstrate that the maintenance of hair follicle homeostasis and the regeneration capacity after damage depend on TLR2 in hair follicle stem cells (HFSCs). In healthy hair follicles, TLR2 is expressed in a cycle-dependent manner and governs HFSCs activation by countering inhibitory BMP signaling. Hair follicles in aging and obesity exhibit a decrease in both TLR2 and its endogenous ligand carboxyethylpyrrole (CEP), a metabolite of polyunsaturated fatty acids. Administration of CEP stimulates hair regeneration through a TLR2-dependent mechanism. These results establish a novel connection between TLR2-mediated innate immunity and HFSC activation, which is pivotal to hair follicle health and the prevention of hair loss and provide new avenues for therapeutic intervention.

Myotubularin-related protein 6 is an ion channel-associated pro-leishmanial phosphatase

Residing obligatorily as amastigotes within the mammalian macrophages, the parasite Leishmania donovani inflicts the potentially fatal, globally re-emerging disease visceral leishmaniasis (VL) by altering intracellular signaling through kinases and phosphatases. Because the phosphatases that modulate the VL outcome in humans remained unknown, we screened a human phosphatase siRNA-library for anti-leishmanial functions in THP-1, a human macrophage-like cell line. Of the 251 phosphatases, the screen identified the Ca++-activated K+-channel-associated phosphatase myotubularin-related protein-6 (MTMR6) as the only phosphatase whose silencing reduced parasite load and IL-10 production in human macrophages. Virulent, but not avirulent, L. donovani infection increased MTMR6 expression in macrophages. As virulent L. donovani parasites expressed higher lipophosphoglycan, a TLR2-ligand, we tested the effect of TLR2 stimulation or blockade on MTMR6 expression. TLR1/TLR2-ligand Pam3CSK4 enhanced, but TLR2 blockade reduced, MTMR6 expression. L. donovani infection of macrophages ex vivo increased, but miltefosine treatment reduced, MTMR6 expression. Corroboratively, compared to endemic controls, untreated VL patients had higher, but miltefosine-treated VL patients had reduced, MTMR6 expression. The phosphatase siRNA-library screening thus identified MTMR6 as the first TLR2-modulated ion channel-associated phosphatase with significant implications in VL patients and anti-leishmanial functions.

Prostaglandin D2 is involved in the regulation of inflammatory response in Staphylococcus aureus-infected mice macrophages

Staphylococcus aureus (S. aureus) is one of the most infamous and widespread bacterial pathogens, causing a hard-to-estimate number of uncomplicated skin infections and probably hundreds of thousands to millions of more severe, invasive infections globally per year. S. aureus may also be acquired from animals, especially in the livestock industry. The interaction mechanism of host and S. aureus has significance for finding ways to against S. aureus infection and control inflammatory response of host, while the molecular biological activities after S. aureus infection, particular in inflammatory and immune cells are not fully clear. The present study aimed to explore whether pattern recognition receptors (PRRs) mediate prostaglandin D2 (PGD2) synthesis and PGD2 participates in the regulation of inflammatory response in macrophages during S. aureus infection or synthetic bacterial lipopeptide (Pam2CSK4) stimulation. PGD2 secretion level was enhanced by mice peritoneal macrophages infected with the S. aureus. The results indicated that PGD2 secretion was impaired in S. aureus infected-macrophages from toll-like receptors 2 (TLR2)-deficient and NLR pyrin domain-containing 3 (NLRP3)-deficient mice. PGD2 synthetase (hematopoietic PGD synthase, HPGDS) inhibitors could reduce the activation of macrophage mitogen-activated protein kinase (MAPK)/nuclear factor-κ-gene binding (NF-κB) signaling pathways. HPGDS inhibition impaired cytokines (TNF-α, IL-1β, IL-10 and RANTES) secretion and macrophage phagocytosis during S. aureus infection. In addition, inhibition of endogenous PGD2 synthesis was unable to affect the TLR2 and NLRP3 expression in S. aureus-infected macrophages. Taken together, macrophage PGD2 secretion after S. aureus infection depended on receptors TLR2 and NLRP3, and the induced PGD2 participated in the regulation of inflammatory response in S. aureus-infected macrophages. Interestingly, it was found that exogenous PGD2 down-regulated the cytokines secretion and had no effect on phagocytosis in the S. aureus-infected macrophages.

Phosphorylation of RGS16 at Tyr168 promote HBeAg-mediated macrophage activation by ERK pathway to accelerate liver injury

Liver injury is closely associated with macrophage activation following HBV infection. Our previous study showed that only HBeAg, but not HBsAg and HBcAg, stably enhances inflammatory cytokine production in macrophages. And we also indicated that HBeAg could induce macrophage activation via TLR2 and thus aggravate the progression of liver fibrosis. However, the specific molecular mechanism of HBeAg in macrophage activation is not clear. We screened significantly overexpressed RGS16 from RNASeq results of HBeAg-stimulated macrophages and validated them with cellular assays, GSE83148 microarray dataset, and in clinical samples. Meanwhile, small interference, plasmid, and lentivirus transfection assays were used to establish cell models for knockdown and overexpression of RGS16, and q-PCR, ELISA, Transwell, and CCK-8 assays were used to analyze the role of RGS16 in HBeAg-induced macrophage activation. In addition, the upstream and downstream mechanisms of RGS16 in HBeAg-treated macrophage activation were explored using inhibitors, phostag gels, and RGS16 phosphorylation mutant plasmids. Finally, the effect of RGS16 on hepatic inflammation in murine tissues was evaluated by H&E staining, liver enzyme assay and immunofluorescence. RGS16 was significantly upregulated in HBeAg-induced macrophage activation, and its expression was enhanced with increasing HBeAg content and treatment time. Functional experiments showed that overexpression of RGS16 promoted the production of inflammatory factors TNF-α and IL-6 and boosted macrophage proliferation and migration, while knockdown of RGS16 exhibited the opposite effect. Mechanistically, we discovered that RGS16 is regulated by the TLR2/P38/STAT5 signaling pathway. Meanwhile, RGS16 enhanced ERK phosphorylation via its own Tyr168 phosphorylation to contribute to macrophage activation, thereby accelerating liver injury. Finally, in mice, overexpression of RGS16 markedly strengthened liver inflammation. HBeAg upregulates RGS16 expression through the TLR2-P38-STAT5 axis, and the upregulated expression of RGS16 enhances macrophage activation and accelerates liver injury by promoting ERK phosphorylation. In this process, phosphorylation of Tyr168 is necessary for RGS16 to function. KEY MESSAGES: RGS16 boosted HBeAg-induced macrophage inflammation, proliferation, and migration. Tyr168 phosphorylation of RGS16 affected by ERK promoted macrophage activation. HBeAg upregulated the expression of RGS16 through TLR2/P38/STAT5 signal pathway. RGS16 promoted liver injury by regulating macrophage functions in mouse model.

Heat-inactivated mycobacteria activate the toll-like receptor 2 and 4 pathways in the zebrafish model of tuberculosis

Based on previous evidence demonstrating the efficacy of inactivated mycobacteria for the control of fish mycobacteriosis, we explored the protective efficacy of two inactivated Mycobacterium bovis administered via parenteral and mucosal routes against Mycobacterium marinum infection mimicking natural conditions in the zebrafish model of tuberculosis. Although we did not observe a clear effect of any of the immunostimulants on mycobacterial burden, the results showed a significant increase in TLR2 and TLR4 gene expression levels in fishes parenterally immunized with inactivated Bacillus Calmette-Guérin (BCG). Our findings demonstrated that the TLR2 and the TLR4 signaling pathways are involved in the immune response elicited by inactivated mycobacteria in the zebrafish model of tuberculosis and support the use of inactivated mycobacteria in vaccine formulations for the control of mycobacteriosis.

Rationally Designed Self-Assembling Nanovaccines Elicit Robust Mucosal and Systemic Immunity against Rhabdovirus

Viral diseases have constantly caused great threats to global public health, resulting in an urgent need for effective vaccines. However, the current viral vaccines often show low immunogenicity. To counter this, we report a smart strategy of a well-designed modular nanoparticle (LSG-TDH) that recapitulates the dominant antigen SG, low-molecular-weight protamine, and tetralysine-modified H-chain apoferritin (TDH). The constructed LSG-TDH nanovaccine could self-assemble into a nanocage structure, which confers excellent mucus-penetrating, cellular affinity, and uptake ability. Studies demonstrate that the LSG-TDH nanovaccine could strongly activate both mucosal and systemic immune responses. Importantly, by immunizing wild-type and TLR2 knockout (TLR2-KO) zebrafish, we found that TLR2 could mediate LSG-TDH-induced adaptive mucosal and systemic immune responses by activating antigen-presenting cells. Collectively, our findings offer new insights into rational viral vaccine design and provide additional evidence of the vital role of TLR2 in regulating adaptive immunity.

Increased cysteinyl-tRNA synthetase drives neuroinflammation in Alzheimer's disease

BACKGROUND

Microglia-mediated neuroinflammation in Alzheimer's disease (AD) is not only a response to pathophysiological events, but also plays a causative role in neurodegeneration. Cytoplasmic cysteinyl-tRNA synthetase (CARS) is considered to be a stimulant for immune responses to diseases; however, it remains unknown whether CARS is involved in the pathogenesis of AD.

METHODS

Postmortem human temporal cortical tissues at different Braak stages and AD patient-derived serum samples were used to investigate the changes of CARS levels in AD by immunocytochemical staining, real-time PCR, western blotting and ELISA. After that, C57BL/6J and APP/PS1 transgenic mice and BV-2 cell line were used to explore the role of CARS protein in memory and neuroinflammation, as well as the underlying mechanisms. Finally, the associations of morphological features among CARS protein, microglia and dense-core plaques were examined by immunocytochemical staining.

RESULTS

A positive correlation was found between aging and the intensity of CARS immunoreactivity in the temporal cortex. Both protein and mRNA levels of CARS were increased in the temporal cortex of AD patients. Immunocytochemical staining revealed increased CARS immunoreactivity in neurons of the temporal cortex in AD patients. Moreover, overexpression of CARS in hippocampal neurons induced and aggravated cognitive dysfunction in C57BL/6J and APP/PS1 mice, respectively, accompanied by activation of microglia and the TLR2/MyD88 signaling pathway as well as upregulation of proinflammatory cytokines. In vitro experiments showed that CARS treatment facilitated the production of proinflammatory cytokines and the activation of the TLR2/MyD88 signaling pathway of BV-2 cells. The accumulation of CARS protein occurred within dense-core Aβ plaques accompanied by recruitment of ameboid microglia. Significant upregulation of TLR2/MyD88 proteins was also observed in the temporal cortex of AD.

CONCLUSIONS

The findings suggest that the neuronal CARS drives neuroinflammation and induces memory deficits, which might be involved in the pathogenesis of AD.

An Exploration of Some Predictors of Quality of Life-Related to the Innate Immune System, Inflammation, and Disease Activity in Patients with Behcet's Syndrome: An Analytical Cross-sectional Study

BACKGROUND

Behçet's disease (BD) has a growing prevalence in Silk Road countries. The aim of our cross-sectional study was to explore the clinical and molecular predictors of quality of life in BD patients.

MATERIALS AND METHODS

One hundred and fifty consecutive Iranian BD patients with an age range between 20-50 years were included. The Leeds Behçet's disease quality of life (BDQoL) in Persian form was fulfilled to evaluate the quality of life. Anthropometric measurements were carried out using the calibrated scales. Iranian Behcet's Disease Dynamic Activity Measure (IBDDAM), Behcet's disease current activity form (BDCAF), and Total Inflammatory Activity Index (TIAI) were used to assess BD activity. mRNA expression of toll-like receptors 2 and 4 (TLR2 and TLR4) and tumor-necrosis-factor-alpha (TNF-α) levels in serum were measured by real-time polymerase chain reaction (PCR) and ELISA, respectively. Multiple linear backward regression at P = 0.1 was used to study the potential predictors of quality of life.

RESULTS

TLR2 and BDCAF were shown to be the most important predictors of quality of life in BD patients by 22%. There were positive associations between them (β = 0.326, p = 0.013 for BDCAF; β = 0.366, p = 0.006 for TLR2) and BDQoL value.

CONCLUSION

Higher TLR2 expression as a key protein in recognizing pathogens by innate immunity and BDCAF value as a comprehensive BD assessing scale contribute to poor quality of life among BD patients. Emphasizing therapeutically, approaches associated with lower TLR2 expression and BDCAF value can be considered in future studies.

Disease activity is associated with changes in the innate immune function in patients with systemic lupus erythematosus

OBJECTIVE

To address the relationship between systemic lupus erythematosus (SLE) disease activity and the functional parameters of the innate immunity.

METHODS

We evaluated a cohort of 26 adult SLE patients and 10 sex and age-paired healthy donors. When the patients had a disease flare (baseline) and when they achieve clinical response (follow-up), we assessed the systemic lupus erythematosus disease activity index 2 K (SLEDAI 2 K) and the following parameters with flow cytometry and confocal microscopy: monocyte subsets, their expression of TLR2, phagocytic monocytes and neutrophils using the pHrodo Red E. coli BioParticles, the respiratory burst with 123-dihydrorhodamine in neutrophils, and the spontaneous and lipopolysaccharide (LPS)-induced production of neutrophil extracellular traps (NETs). We used the Wilcoxon test to compare the paired medians with interquartile range (IQR) and the Mann-Whitney U test for independent medians. To assess the effect of prednisone and SLEDAI 2 K on the mentioned parameters, we applied a generalized mixed linear model.

RESULTS

Twenty-three patients (88.4%) were women. The SLEDAI 2 K was higher at baseline 8 (6-14) in comparison to that at follow-up (6 (4-8), P = 0.028). At baseline, SLE patients had a decreased percentage of intermediate monocytes, a higher expression of TLR2 in total monocytes, increased phagocytosis in monocytes and neutrophils, a decreased respiratory burst intensity, and an increased production of NETs. In the mix model, the SLEDAI 2 K was the main factor influencing these functional innate immune parameters.

CONCLUSION

Disease activity regulates the innate immune function in SLE which may contribute to the clinical features and infection predisposition. Key points • This is the first cohort study addressing the effect of disease activity and prednisone use on the innate immune function of lupus patients. • Our results show that the disease activity is a key regulator of the respiratory burst, phagocytosis, and the production of neutrophil extracellular traps. • Also, we observed a differential proportion of monocyte subsets according to SLE disease activity. • We consider that our manuscript contributes to the evidence addressing the intrinsic immune abnormalities of patients with SLE regardless of the use of immunosuppressants and set the bases for new research work considering the disease activity as an element to decide the prescription and duration of antibiotic prophylaxis in SLE patients, which is of interest to all rheumatologists.

Extracellular vesicles from periodontal pathogens regulate hepatic steatosis via Toll-like receptor 2 and plasminogen activator inhibitor-1

Plasminogen activator inhibitor-1 (PAI-1) is associated with nonalcoholic fatty liver disease (NAFLD) by lipid accumulation in the liver. In this study, we showed that extracellular vesicles (EVs) from the periodontal pathogens Filifactor alocis and Porphyromonas gingivalis induced steatosis by inducing PAI-1 in the liver and serum of mice fed a low-fat diet. PAI-1 induction was not observed in TLR2-/- mice. When tested using HEK-Blue hTLR2 cells, human TLR2 reporter cells, the TLR2-activating ability of serum from NAFLD patients (n = 100) was significantly higher than that of serum from healthy subjects (n = 100). Correlation analysis confirmed that PAI-1 levels were positively correlated with the TLR2-activating ability of serum from NAFLD patients and healthy subjects. Amphiphilic molecules in EVs were involved in PAI-1 induction. Our data demonstrate that the TLR2/PAI-1 axis is important for hepatic steatosis by EVs of periodontal pathogens.

The ameliorative role of Aloe vera-loaded chitosan nanoparticles on Staphylococcus aureus induced acute lung injury: Targeting TLR/NF-κB signaling pathways

Background

Acute lung injury (ALI) is a severe condition distinguished by inflammation and impaired gas exchange in the lungs. Staphylococcus aureus, a common bacterium, can cause ALI through its virulence factors. Aloe vera is a medicinal plant that has been traditionally used to treat a variety of illnesses due to its anti-inflammatory properties. Chitosan nanoparticles are biocompatible and totally biodegradable materials that have shown potential in drug delivery systems.

Aim

To explore the antibacterial activity of Aloe vera-loaded chitosan nanoparticles (AV-CS-NPs) against S. aureus in vitro and in vivo with advanced techniques.

Methods

The antibacterial efficacy of AV-CS-NPs was evaluated through a broth microdilution assay. In addition, the impact of AV-CS-NPs on S. aureus-induced ALI in rats was examined by analyzing the expression of genes linked to inflammation, oxidative stress, and apoptosis. Furthermore, rat lung tissue was scanned histologically. The rats were divided into three groups: control, ALI, and treatment with AV-CS-NPs.

Results

The AV-CS-NPs that were prepared exhibited clustered semispherical and spherical forms, having an average particle size of approximately 60 nm. These nanoparticles displayed a diverse structure with an uneven distribution of particle sizes. The maximum entrapment efficiency of 95.5% ± 1.25% was achieved. The obtained findings revealed that The minimum inhibitory concentration and minimum bactericidal concentration values were determined to be 5 and 10 ug/ml, respectively, indicating the potent bactericidal effect of the NPs. Also, S. aureus infected rats explored upregulation in the mRNA expression of TLR2 and TLR4 compared to healthy control groups. AV-CS-NP treatment reverses the case where there was repression in mRNA expression of TLR2 and TLR4 compared to S. aureus-treated rats.

Conclusion

These NPs can serve as potential candidates for the development of alternative antimicrobial agents.

The Role of the Toll-like Receptor 2 and the cGAS-STING Pathways in Breast Cancer: Friends or Foes?

Breast cancer stands as a primary malignancy among women, ranking second in global cancer-related deaths. Despite treatment advancements, many patients progress to metastatic stages, posing a significant therapeutic challenge. Current therapies primarily target cancer cells, overlooking their intricate interactions with the tumor microenvironment (TME) that fuel progression and treatment resistance. Dysregulated innate immunity in breast cancer triggers chronic inflammation, fostering cancer development and therapy resistance. Innate immune pattern recognition receptors (PRRs) have emerged as crucial regulators of the immune response as well as of several immune-mediated or cancer cell-intrinsic mechanisms that either inhibit or promote tumor progression. In particular, several studies showed that the Toll-like receptor 2 (TLR2) and the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathways play a central role in breast cancer progression. In this review, we present a comprehensive overview of the role of TLR2 and STING in breast cancer, and we explore the potential to target these PRRs for drug development. This information will significantly impact the scientific discussion on the use of PRR agonists or inhibitors in cancer therapy, opening up new and promising avenues for breast cancer treatment.

Randomized controlled trial of vitamin d supplementation on toll-like receptor-2 (tlr-2) and toll-like receptor-4 (tlr-4) in tuberculosis spondylitis patients

BACKGROUND

Tuberculosis spondylitis accounts for approximately 50% of all cases of skeletal tuberculosis. Vitamin D plays a role in the immune system. Vitamin D helps in the activation of TLR-2 and TLR-4, which play a role in the process of tuberculosis infection. The objective of this study was to investigate the effect of oral supplementation with vitamin D on TLR-2 and TLR-4 levels in tuberculosis spondylitis patients.

METHODS

The true Experiment Design Pretest-Posttest with Control Group (Pretest-Posttest with Control Group) was used for this research. TLR-2 and TLR-4 were measured by ELISA. Repeated ANOVA, ANOVA tests, and Kolmogorov-Smirnov normality tests on the SPSS program were used to statistically analyze the results.

RESULT

In the dose groups of 10,000 IU and 5000 IU, significant increases in the levels of vitamin D, TLR-2, and TLR-4 were observed at weeks 4 and 8 (p < 0.05). In the control group, there was no significant increase.

CONCLUSIONS

Vitamin D supplements can significantly increase TLR-2 and TLR-4 levels. Supplementation with vitamin D 10,000 IU/day for 8 weeks can increase vitamin D levels > 50 ng/dl to optimally act as an immunomodulator.

Immunoinformatics Prediction and Protective Efficacy of Vaccine Candidate PiuA-PlyD4 Against Streptococcus Pneumoniae

Purpose

This study was designed to evaluate the immune protective efficacy of the novel Streptococcus pneumoniae (S. pneumoniae) protein vaccine PiuA-PlyD4 through immunoinformatics prediction and in vitro and in vivo experiments.

Methods

In this study, we conducted immunoinformatics prediction and protection analysis on the fusion protein PiuA-PlyD4. The epitope composition of the vaccine was analyzed based on the prediction of B-cell and helper T-cell epitopes. Meanwhile, the molecular docking of PiuA and TLR2/4 was simulated. After immunizing C57BL/6 mice with the prepared vaccine, the biological safety, immunogenicity and conservation were evaluated. By constructing different infection models and from the aspects of adhesion inhibition and cytokines, the protective effect of the fusion protein vaccine PiuA-PlyD4 on S. pneumoniae infection was explored.

Results

PiuA-PlyD4 has abundant B-cell and helper T-cell epitopes and shows a high antigenicity score and structural stability. Molecular docking analysis suggested the potential interaction between PiuA and TLR2/4. The specific antibody titer of fusion protein antiserum was as high as (7.81±2.32) ×105. The protective effect of the immunized mice on nasal and lung colonization was significantly better than that of the control group, and the survival rate against S. pneumoniae infection of serotype 3 reached 50%. Cytokine detection showed that the humoral immune response, Th1, Th2 and Th17 cellular immune pathways were all involved in the process.

Conclusion

The study indicates that PiuA-PlyD4, whether the results are predicted by immunoinformatics or experimentally validated in vivo and in vitro, has good immunogenicity and immunoreactivity and can provide effective protection against S. pneumoniae infection. Therefore, it can be considered a promising prophylactic vaccine candidate for S. pneumoniae.

The TLR2/TLR6 ligand FSL-1 mitigates radiation-induced hematopoietic injury in mice and nonhuman primates

Thrombocytopenia, hemorrhage, anemia, and infection are life-threatening issues following accidental or intentional radiation exposure. Since few therapeutics are available, safe and efficacious small molecules to mitigate radiation-induced injury need to be developed. Our previous study showed the synthetic TLR2/TLR6 ligand fibroblast stimulating lipopeptide (FSL-1) prolonged survival and provided MyD88-dependent mitigation of hematopoietic acute radiation syndrome (H-ARS) in mice. Although mice and humans differ in TLR number, expression, and function, nonhuman primate (NHP) TLRs are like those of humans; therefore, studying both animal models is critical for drug development. The objectives of this study were to determine the efficacy of FSL-1 on hematopoietic recovery in small and large animal models subjected to sublethal total body irradiation and investigate its mechanism of action. In mice, we demonstrate a lack of adverse effects, an easy route of delivery (subcutaneous) and efficacy in promoting hematopoietic progenitor cell proliferation by FSL-1. NHP given radiation, followed a day later with a single subcutaneous administration of FSL-1, displayed no adversity but showed elevated hematopoietic cells. Our analyses revealed that FSL-1 promoted red blood cell development and induced soluble effectors following radiation exposure. Cytologic analysis of bone marrow aspirates revealed a striking enhancement of mononuclear progenitor cells in FSL-1-treated NHP. Combining the efficacy of FSL-1 in promoting hematopoietic cell recovery with the lack of adverse effects induced by a single administration supports the application of FSL-1 as a viable countermeasure against H-ARS.

Lactobacillus rhamnosus Restores Antiviral Signaling and Attenuates Cytokines Secretion from Human Bronchial Epithelial Cells Exposed to Cigarette Smoke and Infected with SARS-CoV-2

Individuals with chronic obstructive pulmonary disease (COPD) are more susceptible to exacerbation crisis triggered by secondary lung infections due to the dysfunction of antiviral signaling, principally via suppression of IFN-γ. Although the probiotic is known for controlling pulmonary inflammation in COPD, the influence of the Lactobacillus rhamnosus (Lr) on antiviral signaling in bronchial epithelium exposed to cigarette smoke extract (CSE) and viruses, remains unknown. Thus, the present study investigated the Lr effect on the antiviral signaling and the secretion of inflammatory mediators from bronchial epithelial cells (16HBE cells) exposed to CSE and SARS-CoV-2. The 16HBE cells were cultured, treated with Lr, stimulated with CSE, and infected with SARS-CoV-2. The cellular viability was evaluated using the MTT assay and cytotoxicity measured by lactate dehydrogenase (LDH) activity. The viral load, TLR2, TLR3, TLR4, TLR7, TLR8, MAVS, MyD88, and TRIF were quantified using specific PCR. The pro-inflammatory mediators were measured by a multiplex biometric immunoassay, and angiotensin converting enzyme 2 (ACE2) activity, NF-κB, RIG-I, MAD5, and IRF3 were measured using specific ELISA kits. Lr decreased viral load, ACE2, pro-inflammatory mediators, TLR2, TLR4, NF-κB, TLR3, TLR7, and TLR8 as well as TRIF and MyD88 expression in CSE and SARS-CoV-2 -exposed 16HBE cells. Otherwise, RIG-I, MAD5, IRF3, IFN-γ, and the MAVS expression were restored in 16HBE cells exposed to CSE and SARS-CoV-2 and treated with Lr. Lr induces antiviral signaling associated to IFN-γ secreting viral sensors and attenuates cytokine storm associated to NF-κB in bronchial epithelial cells, supporting its emerging role in prevention of COPD exacerbation.

Upper Respiratory Tract OC43 Infection Model for Investigating Airway Immune-Modifying Therapies

Respiratory virus infections initiate and transmit from the upper respiratory tract (URT). Coronaviruses, including OC43, are a major cause of respiratory infection and disease. Failure to mount an effective antiviral immune response in the nasal mucosa increases the risk of severe disease and person-to-person transmission, highlighting the need for URT infection models to support the development of nasal treatments that improve coronavirus antiviral immunity. We aimed to determine if OC43 productively infected the mouse URT and would therefore be a suitable model to assess the efficacy and mechanism of action of nasal-targeting immune-modifying treatments. We administered OC43 via intranasal inoculation to wild-type Balb/c mice and assessed virus airway tropism (by comparing total respiratory tract vs. URT-only virus exposure) and characterized infection-induced immunity by quantifying specific antiviral cytokines and performing gene array assessment of immune genes. We then assessed the effect of immune-modulating therapies, including an immune-stimulating TLR2/6 agonist (INNA-X) and the immune-suppressing corticosteroid fluticasone propionate (FP). OC43 replicated in nasal respiratory epithelial cells, with peak viral RNA observed 2 days after infection. Prophylactic treatment with INNA-X accelerated expression of virus-induced IFN-λ and IFN-stimulated genes. In contrast, intranasal FP treatment increased nasal viral load by 2.4 fold and inhibited virus-induced IFN and IFN-stimulated gene expression. Prior INNA-X treatment reduced the immune-suppressive effect of FP. We demonstrate that the mouse nasal epithelium is permissive to OC43 infection and strengthen the evidence that TLR2 activation is a β-coronavirus innate immune determinant and therapeutic target.

Immune checkpoints as potential theragnostic biomarkers for epithelial ovarian cancer

BACKGROUND

Epithelial ovarian cancer (EOC) is the leading cause of death associated with gynecologic tumors. EOC is asymptomatic in early stages, so most patients are not diagnosed until late stages, highlighting the need to develop new diagnostic biomarkers. Mediators of the tumoral microenvironment may influence EOC progression and resistance to treatment.

AIM

To analyze immune checkpoints to evaluate them as theranostic biomarkers for EOC.

PATIENTS AND METHODS

Serum levels of 16 immune checkpoints were determined in EOC patients and healthy controls using the MILLIPLEX MAP® Human Immuno-Oncology Checkpoint Protein Magnetic Bead Panel.

RESULTS

Seven receptors: BTLA, CD40, CD80/B7-1, GITRL, LAG-3, TIM-3, TLR-2 are differentially expressed between EOC and healthy controls. Serum levels of immune checkpoints in EOC patients are positively significantly correlated with levels of their ligands, with a higher significant correlation between CD80 and CTLA4 than between CD28 and CD80. Four receptors, CD40, HVEM, PD-1, and PD-L1, are positively associated with the development of resistance to Taxol-platinum-based chemotherapy. All of them have an acceptable area under the curve (>0.7).

CONCLUSION

This study has yielded a first panel of seven immune checkpoints (BTLA, CD40, CD80/B7-1, GITRL, LAG-3, TIM-3, TLR-2) associated with a higher risk of EOC and a second panel of four immune checkpoints (CD40, HVEM, PD-1, PD-L1) that may help physicians to identify EOC patients who are at high risk of developing resistance to EOC chemotherapy.

Expression profiling of immune genes associated with black pepper (Piper nigrum) powder supplementation in the diets of broiler chickens

The present study was conducted on three hundred commercial broiler chicks with the aim to evaluate the effect of black pepper supplementation on expression of TLR gene where the negative control (T1) group was given basal diet without antibiotic and in the control group (T2) basal diet with antibiotic was fed, third (T3), fourth (T4), fifth (T5) and sixth (T6) groups were supplemented with black pepper powder (BPP) at levels 0.25, 0.5, 0.75 and 1%, respectively in diet. After 42 days, a significant reduction (p < 0.05) in ileal E. coli count and a higher value of Lactobacilli was recorded in the various black pepper powder supplemented groups, and they differed significantly (p < 0.05) from negative control. The mRNA expression levels of Toll-like receptors (TLR 2 and TLR 4) had shown significant (p < 0.05) changes in experimental groups. The TLR 2 and TLR 4 genes revealed differential expression in all black pepper supplemented groups in comparison to negative control and control group, while TLR 7 did not show any significant change. Thus, supplementation of black pepper powder can be exploited as an immunomodulator to enhance adaptive immune response of broiler chicks after validation on large number of samples.

Immulina as an Immunostimulatory Supplement: Formulation and Pharmacological Studies

Immulina is a commercially available extract of Arthrospira platensis enriched with bacterial lipoproteins that acts as a potent Toll-like receptor 2 agonist. However, the immunostimulatory effect of Immulina is not well understood in vivo. Here, to devise an Immulina formulation suitable for in vivo oral gavage dosing, Immulina nanosuspension was prepared and freeze-dried to yield lyophilized nano-Immulina, which had an average particle size of around 300 nm and fully retained the bioactivity as a Toll-like receptor 2 agonist. Compared to the regular Immulina powder, lyophilized nano-Immulina notably accelerated the dissolution in aqueous media. Immulina nanosuspension was found to stimulate the production of proinflammatory cytokines in murine bone marrow-derived dendritic cells and macrophages. The immune response to Immulina was investigated in healthy mice by longitudinally monitoring the phagocytic activity of circulating neutrophils as a surrogate marker. Following daily oral ingestion of Immulina nanosuspension (10 mg/mouse/day), the phagocytic activity of circulating neutrophils was significantly elevated, suggesting an important mechanism for Immulina to enhance innate immunity.

Cutting Edge: TLR2 Signaling in B Cells Promotes Autoreactivity to DNA via IL-6 Secretion

Autoantibodies to chromatin and dsDNA are a hallmark of systemic lupus erythematosus (SLE). In a mouse model of monogenic human SLE caused by DNASE1L3 deficiency, the anti-DNA response is dependent on endosomal nucleic acid-sensing TLRs TLR7 and TLR9. In this study, we report that this response also required TLR2, a surface receptor for microbial products that is primarily expressed on myeloid cells. Cell transfers into lymphopenic DNASE1L3-deficient mice showed that TLR2 was required for anti-DNA Ab production by lymphocytes. TLR2 was detectably expressed on B cells and facilitated the production of IL-6 by B cells activated in the presence of microbial products. Accordingly, treatment with broad-spectrum antibiotics or Ab-mediated blockade of IL-6 delayed the anti-DNA response in DNASE1L3-deficient mice. These studies reveal an unexpected B cell-intrinsic role of TLR2 in systemic autoreactivity to DNA, and they suggest that microbial products may synergize with self-DNA in the activation of autoreactive B cells in SLE.

Relationship between TLR-2 level and clinical or radiological severity on patients with tuberculosis spondylitis in Dr. Wahidin Sudirohusodo hospital Makassar

Spinal tuberculosis or TB spondylitis is one of the most common types of extra pulmonary tuberculosis, which is about 15% of all cases. It causes severe morbidity, neurological deficits, and severe deformities in the patients. The growth of Mycobacterium tuberculosis in culture specimens obtained from infected tissue is the single gold standard diagnostic test for spinal TB. Toll-like receptor (TLR) is one of the important receptors in the first-line defence system against microbes. TLR-2 and TLR-4 are known to be associated with tuberculosis infection. Based on this background, the researchers were interested in examining the relationship between TLR-2 levels and the clinical and radiological severity of TB spondylitis patients. A cross-sectional study was conducted with patients diagnosed with tuberculosis spondylitis at Dr Wahidin Sudirohusodo Makassar. Patients diagnosed with TB spondylitis confirmed by blood tests, GeneExpert, and magnetic resonance imaging without prior treatment were included. Data analysis were conducted by using descriptive analysis and one-way ANOVA for bivariate analysis. The mean value of TLR2 levels in TB spondylitis patients was 9.1 g/dL. TLR2 levels in paraesthesia were significantly higher than normal (P < .05). Similar trend were analyzed on the motor neurologic status with TLR2 levels in paraparesis were significantly higher than those in normal (P < .05). There is a significant relationship between the TLR2 levels in TB spondylitis and their impaired motor and sensory function. Spinal destruction has been shown to provide significant relationship with TLR2 value in spondylitis TB.

Identification of hub biomarkers and immune-related pathways participating in the progression of Kawasaki disease by integrated bioinformatics analysis

BACKGROUND

Kawasaki disease (KD) is a systemic vasculitis that commonly affects children and its etiology remains unknown. Growing evidence suggests that immune-mediated inflammation and immune cells in the peripheral blood play crucial roles in the pathophysiology of KD. The objective of this research was to find important biomarkers and immune-related mechanisms implicated in KD, along with their correlation with immune cells in the peripheral blood.

MATERIAL/METHODS

Gene microarray data from the Gene Expression Omnibus (GEO) was utilized in this study. Three datasets, namely GSE63881 (341 samples), GSE73463 (233 samples), and GSE73461 (279 samples), were obtained. To find intersecting genes, we employed differentially expressed genes (DEGs) analysis and weighted gene co-expression network analysis (WGCNA). Subsequently, functional annotation, construction of protein-protein interaction (PPI) networks, and Least Absolute Shrinkage and Selection Operator (LASSO) regression were performed to identify hub genes. The accuracy of these hub genes in identifying KD was evaluated using the receiver operating characteristic curve (ROC). Furthermore, Gene Set Variation Analysis (GSVA) was employed to explore the composition of circulating immune cells within the assessed datasets and their relationship with the hub gene markers.

RESULTS

WGCNA yielded eight co-expression modules, with one hub module (MEblue module) exhibiting the strongest association with acute KD. 425 distinct genes were identified. Integrating WGCNA and DEGs yielded a total of 277 intersecting genes. By conducting LASSO analysis, five hub genes (S100A12, MMP9, TLR2, NLRC4 and ARG1) were identified as potential biomarkers for KD. The diagnostic value of these five hub genes was demonstrated through ROC curve analysis, indicating their high accuracy in diagnosing KD. Analysis of the circulating immune cell composition within the assessed datasets revealed a significant association between KD and various immune cell types, including activated dendritic cells, neutrophils, immature dendritic cells, macrophages, and activated CD8 T cells. Importantly, all five hub genes exhibited strong correlations with immune cells.

CONCLUSION

Activated dendritic cells, neutrophils, and macrophages were closely associated with the pathogenesis of KD. Furthermore, the hub genes (S100A12, MMP9, TLR2, NLRC4, and ARG1) are likely to participate in the pathogenic mechanisms of KD through immune-related signaling pathways.

Underpinning Endogeneous Damp EDA-Fibronectin in the Activation of Molecular Targets of Rheumatoid Arthritis and Identifcation of its Effective Inhibitors by Computational Methods

Rheumatoid arthritis (RA) is one of the most severe inflammatory diseases that cause swelling, stiffness and pain in the joints, which pose a significant threat worldwide. Damage-associated molecular patterns (DAMPs) are danger molecules of endogenous origin, released during cell injury or cell death, interacts with various Pattern recognition receptors (PRRs) and activates various inflammatory diseases. One of the DAMP molecules, so-called EDA-fibronectin (Fn) is also responsible for causing RA. EDA-Fn triggers RA through its interaction with TLR4. Apart from TLR4, it is divulged that certain other PRR's are also responsible for RA, but the identity and mechanism of those PRRs remain unknown until now. Hence, for the first time, we tried to reveal those PRR's interaction with EDA-Fn in RA through computational methods. Protein-protein interaction (PPI) was checked using ClusPro between EDA-Fn and certain Pattern recognition receptors (PRRs) to explore the binding affinities of the potential PRRs. Protein-protein docking unveiled that TLR5, TLR2 and RAGE has good interaction with EDA-Fn than the well-reported TLR4. Macromolecular simulation was performed for TLR5, TLR2 and RAGE complexes along with the control group TLR4 for 50 ns to further investigate the stability, leading to the identification of TLR2, TLR5 and RAGE as the stable complexes. Hence, TLR2, TLR5 and RAGE on interaction with EDA-Fn may lead to the progression of RA that may need additional validations through in vitro and in vivo animal models. Molecular docking was used to analyse the binding force of the top 33 active anti-arthritic compounds with the target protein EDA-Fn. Molecular docking study showed that withaferin A has a good binding activity with EDA-fibronectin target. Hence, it is emphasized that guggulsterone and berberine could modulate the EDA-Fn-mediated TLR5/TLR2/RAGE pathways, thereby it could inhibit the deteriorating effects of RA which needs further in vitro and in vivo experimental validations.

Noticeable immune dysregulation-and-suppression in parvovirus affected dogs

Canine parvovirus type 2 (CPV-2) is one of the most common causes of infectious diarrhea in small animals, with high mortality and morbidity. Information on the specific treatment option(s) for CPV diseases (CPVD) is unachievably little. So, the treatment is mainly supportive one. Disruption of dog's innate immune system in viral diseases simply occurs; presumably, the CPV-2 may change the level of some TLRs, interleukins, CD4 and CD8 in the leukocytes of CPVD dogs, and disruptive activities of these immune molecules might be attributable to severe CPVD in dogs. Study on the role of the key immune molecules in CPVD is rare. Herein, by conducting and relating the clinical, para-clinical, immunological and molecular diagnostic tests, we tried to establish how some key immune molecules behave in blood of parvovirus affected dogs. As such, in the 1st study, the mRNA levels of TLR2, TLR4, TLR9, IL-1β, IL-6, CD4 and CD8 genes in the leukocytes of CPVD were assessed with quantitative (q)RT-PCR along with CPV-2 detection by rapid immunochromatography and PCR tests. In a 2nd study, the same measurements as in the 1st study were evaluated in two groups of mild versus severe clinical signs of CPVD. Both in the 1st and the 2nd studies leukopenia, much more pronounced in the severe CPVD, and immune dysregulation were observed. In the 1st study, a noticeable increase in the mRNA levels of TLR2 and TLR4 was detected with a slight decrease in TLR9 and a significant decrease in the expression of IL-1β, IL-6, CD4 and CD8 in leukocytes of CPV-infected dogs. Compared to the mild CPVD, the intense of downregulating effects on those immune molecules in the 2nd study was remarkably much more pronounced in the severe CPVD. Overall, it proves strong immune dysregulation and suppression/incompetence and potential T-cells exhaustion in severely CPV-2-affected dogs. Technically and clinically, this would be substantially applicable in canine medicine. By targeting those key immune molecules and their signaling pathways, new clinicodiagnostic approaches for CPVD can be evolved, and biotechnicoclinically this would be substantially applicable in all physiopathological conditions of dogs.

GBS hyaluronidase mediates immune suppression in a TLR2/4- and IL-10-dependent manner during pregnancy-associated infection

IMPORTANCE

Bacteria such as GBS can cause infections during pregnancy leading to preterm births, stillbirths, and neonatal infections. The interaction between host and bacterial factors during infections in the placenta is not fully understood. GBS secretes a hyaluronidase enzyme that is thought to digest host hyaluronan into immunosuppressive disaccharides that dampen TLR2/4 signaling, leading to increased bacterial dissemination and adverse outcomes. In this study, we show that GBS HylB mediates immune suppression and promotes bacterial infection during pregnancy that requires TLR2, TLR4, and IL-10. Understanding the interaction between host and bacterial factors can inform future therapeutic strategies to mitigate GBS infections.

The Diagnostic Model of Ligusticum Chuanxiong Hort. Against Cerebral Stroke Using Network Pharmacology and Transcriptomics Analyses

BACKGROUND

Cerebral stroke is a leading cause of death and disability worldwide. Ligusticum Chuanxiong Hort. (LCH), a well-known Chinese herb, is widely used for the treatment of cerebral stroke. This study aimed to investigate the underlying mechanisms of LCH in cerebral stroke and develop a diagnostic model.

METHODS

We employed network pharmacology analyses to identify the active compounds, targets, and underlying mechanisms of LCH for treating cerebral stroke. Molecular docking was performed to visualize the binding site between the core active compounds and hub targets. Furthermore, a diagnostic model for cerebral stroke was constructed based on transcriptomic analysis.

RESULTS

Our findings revealed that LCH contains multiple active ingredients, including oleic acid and caffeic acid. Protein-protein interaction network analysis identified IL1B, CCL2, MAPK3, PTGS2, JUN, MMP9, TLR4, HIF1A, PPARA, FOS, PTEN, NFE2L2, TLR2, TIMP1, and SOD2 as the top 15 hub genes. Kyoto Encyclopedia of Genes and Genomes pathway analysis highlighted the enrichment of TNF and IL-17 signaling pathways. Molecular docking analysis demonstrated binding sites between oleic acid, caffeic acid, and MMP9, PPARP, PTEN, and TIMP1. The diagnostic model indicated that FOS, MMP9, PPARA, PTEN, TIMP1, and TLR2 serve as blood biomarkers for cerebral stroke.

CONCLUSIONS

This study demonstrates that LCH alleviates the symptoms following cerebral stroke through interactions with the TNF and IL-17 signaling pathways. The findings contribute to a better understanding of the therapeutic mechanisms of LCH and offer insights into the development of a diagnostic model for cerebral stroke.

Expression of Toll-like Receptors in Stem Cells of the Apical Papilla and Its Implication for Regenerative Endodontics

Regenerative therapies to replace cells and tissues damaged due to trauma and dental infections require temporal and spatial controlled recruitment and the differentiation of progenitor/stem cells. However, increasing evidence shows microbial antigens can interfere with this process. Toll-like receptors (TLRs) are crucial in recognizing pathogen-associated molecular patterns. Stem cells of the apical papilla (SCAP) are required for normal dental development and are intimately involved in the reparative and regenerative capacity of developing teeth. We hypothesized that TLRs are expressed in SCAP and that the activation of TLR2/TLR4 or TLR3 by different ligands results in differential cellular fate, impacting their differentiation into a mineralizing phenotype. We found that most TLRs are expressed as detected by PCR except TLR7 and TLR8; exposure to heat-killed E. coli results in upregulating TLR2 and TLR4 and reducing mineralization capacity. In addition, bacterial exposure resulted in the upregulation of 11 genes, of which 9 were chemokines whose proteins were also upregulated and released, promoting in vitro macrophage migration. On the other hand, TLR3 activation resulted in increased proliferation and a dramatic inhibition of osteogenic and odontoblastic differentiation, which was reversed by inhibition or the knockdown of TLR3 expression. The profound effects of TLR activation resulting in different cell fates that are ligand and receptor-specific warrants further evaluation and represents an important therapeutic target to make regenerative approaches more predictable following dental infections.

Single-cell mass cytometric analysis of peripheral immunity and multiplex plasma marker profiling of non-small cell lung cancer patients receiving PD-1 targeting immune checkpoint inhibitors in comparison with platinum-based chemotherapy

Introduction

The effect of platinum-based chemotherapy (Chem.) and second- or multiple- line immune checkpoint PD-1 blocking therapy by Nivolumab or Pembrolizumab (ICI) was assayed in the peripheral blood of non-small cell lung cancer (NSCLC) patients.

Methods

Flow cytometry was used to detect NSCLC-related antigen binding IgG antibodies. The Luminex MagPix multiplex bead-based cytokine/chemokine detecting system was used to quantitatively measure 17 soluble markers in the plasma samples. Single-cell mass cytometry was applied for the immunophenotyping of peripheral leukocytes.

Results

The incubation of patient derived plasma with human NSCLC tumor cell lines, such as A549, H1975, and H1650, detected NSCLC-specific antibodies reaching a maximum of up to 32% reactive IgG-positive NSCLC cells. The following markers were detected in significantly higher concentration in the plasma of Chem. group versus healthy non-smoker and smoker controls: BTLA, CD27, CD28, CD40, CD80, CD86, GITRL, ICOS, LAG-3, PD-1, PD-L1, and TLR-2. The following markers were detected in significantly higher concentration in the plasma of ICI group versus healthy non-smoker and smoker controls: CD27, CD28, CD40, GITRL, LAG-3, PD-1, PD-L1, and TLR-2. We showed the induction of CD69 and IL-2R on CD4+ CD25+ T-cells upon chemotherapy; the exhaustion of one CD8+ T-cell population was detected by the loss of CD127 and a decrease in CD27. CD19+CD20+, CD79B+, or activated B-cell subtypes showed CD69 increase and downregulation of BTLA, CD27, and IL-2R in NSCLC patients following chemotherapy or ICI.

Discussion

Peripheral immunophenotype caused by chemotherapy or PD-1 blocking was shown in the context of advanced NSCLC.

Clinical indicators combined with S100A12/TLR2 signaling molecules to establish a new scoring model for coronary artery lesions in Kawasaki disease

Coronary artery lesions (CALs) are the most common and serious complication of Kawasaki disease (KD), and the pathogenesis is unknown. Exploring KD-specific biomarkers and related risk factors is significant for clinical diagnosis and treatment. This study aimed to explore the feasibility of combining clinical indicators with S100A12/TLR2-associated signaling molecules for the predictive modeling of CALs in KD. A total of 346 patients (224 males and 122 females) with KD who visited the rheumatology department of Wuhan Children's Hospital between April 2022 and March 2025 were enrolled and divided into two groups according to the presence or absence of CALS (292 patients had CALs and 54 patients did not). Forty-one variables were collected from the two groups, including demographic characteristics, clinical manifestations, and laboratory data. Single nucleated cells from each patient were extracted, and the expression of the S100A12/TLR2 signal transduction-related molecules S100A12, TLR2, MYD88, and NF-κB were detected by real-time fluorescent quantitative polymerase chain reaction. Statistically significant variables were subjected to logistic regression analysis to determine the independent risk factors for KD with CALs, and a new risk score model was established to assess the predictive efficacy based on receiver operating characteristic curves. Sixteen variables significantly differed between the no-CALs and CALs groups: gender, fever duration, white blood cells (WBC), hemoglobin (HGB), Ce reactive protein (CRP), procalcitonin, serum ferritin (SF), erythrocyte sedimentation rate (ESR), fibrinogen (FIB), aspartate aminotransferase-to-alanine aminotransferase ratio (AST/ALT), serum albumin (ALB), sodium (Na), Interleukin (IL-10), tumor necrosis factor (TNF-α), S100 calcium binding protein A12 (S100A12), and Myeloid Differentiation Factor 88 (MYD88) (p < 0.05). After performing a univariate analysis, 12 variables (gender, fever duration, WBC, HGB, CRP, SF, ESR, FIB, AST/ALT, ALB, Na, and S100A12) were included in the multifactorial binary logistic regression, which showed that fever duration ≥ 6.5 days, ESR ≥ 46.5 mm/h, AST/ALT ≤ 1.51, and S100A12 ≥ 10.02 were independent risk factors for KD with CALs and were assigned scores of 3, 2, 1, and 2, respectively, according to the odds ratio (OR). The total score of each patient was counted, and a new prediction model for KD combined with CALs was established, where < 3.5 was considered low risk and ≥ 3.5 was regarded as high risk; the sensitivity, specificity, Jorden index, and area under the curve of this scoring system were 0.667, 0.836, 0.502, and 0.838, respectively. This new scoring model has good efficacy for predicting the occurrence of KD with CALs. The expression of S100A12 was significantly increased in the CALs group and was an independent risk factor for the occurrence of CALs, and has the potential as a biomarker for predicting KD with CALs.

Toll-like receptor 2, hyaluronan, and neutrophils play a key role in plaque erosion: the OPTICO-ACS study

BACKGROUND AND AIMS

In one-third of patients with acute coronary syndrome (ACS), thrombosis occurs despite an intact fibrous cap (IFC) (IFC-ACS, 'plaque erosion'). Recent studies emphasize neutrophils as the immediate inflammatory response in this pathology, but their exact molecular activation patterns are still poorly understood and may represent future therapeutic targets.

METHODS AND RESULTS

Thirty-two patients with IFC-ACS and matched patients with ACS with ruptured fibrous cap (RFC) (RFC-ACS) from the OPTICO-ACS study were included, and blood samples were collected from the local site of the culprit lesion and the systemic circulation. Neutrophil surface marker expression was quantified by flow cytometry. Neutrophil cytotoxicity towards endothelial cells was examined in an ex vivo co-culture assay. Secretion of active matrix metalloproteinase 9 (MMP9) by neutrophils was evaluated using zymography in supernatants and in plasma samples. Optical coherence tomography (OCT)-embedded thrombi were used for immunofluorescence analysis. Toll-like receptor 2 (TLR2) expression was higher on neutrophils from IFC-ACS than RFC-ACS patients. TLR2 stimulation increased the release of active MMP9 from local IFC-ACS-derived neutrophils, which also aggravated endothelial cell death independently of TLR2. Thrombi of IFC-ACS patients exhibited more hyaluronidase 2 with concomitant increase in local plasma levels of the TLR2 ligand: hyaluronic acid.

CONCLUSION

The current study provides first in-human evidence for distinct TLR2-mediated neutrophil activation in IFC-ACS, presumably triggered by elevated soluble hyaluronic acid. Together with disturbed flow conditions, neutrophil-released MMP9 might be promoting endothelial cell loss-triggered thrombosis and therefore providing a potential future target for a phenotype-specific secondary therapeutic approach in IFC-ACS.

Factors Influencing Marker Expressions of Cultured Human Cord Blood-Derived Mast Cells

Mast cells (MCs) are tissue-resident immune cells of a hematopoietic origin that play vital roles in innate and adaptive immunity. Human MCs can be isolated and differentiated from various tissue sources, including cord blood, when supplemented with cytokines such as stem cell factor, interleukin 3, and interleukin 6. Our current research study has shown significant differences in the marker expressions of human cord blood-derived mast cells (hCBMCs) based on donor dependency and the type of medium used for culturing and differentiation. These findings are particularly relevant given the challenges of obtaining specialty media influencing MC phenotypic marker expressions. We found that hCBMCs cultured in StemSpanTM-XF medium had a moderate expression of mast/stem cell growth factor receptor Kit (c-KIT) (mRNA and protein), low expressions of FcεRI (mRNA) and TLR2 (mRNA and protein) but had high levels of MRGPRX2 (mRNA and protein) expressions. In contrast, hCBMCs cultured in Stem Line II medium expressed FcεRI and TLR2 (mRNA and protein) with higher c-KIT but had lower MRGPRX2 expressions compared to the hCBMCs cultured in the StemSpanTM-XF medium. These results suggest that it is crucial to consider both donor dependency and the medium when investigating MC functions and that further research is needed to fully understand the impact of these factors on the hCBMC marker expressions.

Validation of a Toll-like Receptor (TLR)2/TLR1 Activation Assay for Biological Standardization of Arthrospira/Limnospira Immune-Enhancing Potency

Arthrospira/Limnospira is a popular botanical dietary supplement throughout the world and has been consumed as a food product for hundreds of years. Ongoing efforts from our research group are focused on evaluating the utility of a Limnospira-derived oral supplement (Immulina) in promoting resilience against influenza viral infection. Like other botanical extracts, Immulina is inherently a complex matrix with variation in the levels of its chemical constituents. Therefore, to ensure therapeutic consistency for future scientific research and clinical studies, we are developing standardization technology using a bioassay and chemical markers. Braun-type lipoproteins, a class of macromolecules that activate the Toll-like receptor (TLR)2/TLR1 signaling pathway, have been identified as a major active component within Immulina. Based on the mechanism of action of the Braun-type lipoproteins, an in vitro bioassay was established using the HEK-Blue hTLR2/TLR1 cell line to quantitate the immune-enhancing potency of Immulina. The objective of the current research was to validate that bioassay for Immulina activity quantification using the U.S. FDA guidance document for botanical drug development and U.S. Pharmacopeia recommendations. System suitability, reference standards and defining potency units were established. Validation of performance parameters included precision, specificity, accuracy, linearity, and range. Validating this bioassay for Immulina activity provides a tool for ensuring product consistency and quantifying the potency of this botanical for use in future research as well as material in the consumer market.

Structural properties and immune-enhancing activities of galactan isolated from red seaweed Grateloupia filicina

A water-soluble polysaccharide (GFP) was isolated from Grateloupia filicina and fractionated using a DEAE Sepharose Fast Flow column to evaluate immunostimulatory activity. Carbohydrates (62.0%-68.4%) and sulfates (29.3%-34.3%) were the major components of GFP and its fractions (GFP-1 and GFP-2), with relatively lower levels of proteins (4.5%-15.4%) and uronic acid (1.4%-3.9%). The average molecular weight (Mw ) for GFP and its fractions was calculated between 98.2%-243.7 kDa. The polysaccharides were composed of galactose (62.1%-87.2%), glucose (4.5%-33.2%), xylose (3.1%-5.3%), mannose (1.4%-2.2%), rhamnose (1.2%-2.0%), and arabinose (0.9%-1.7%) units connected through →3)-Galp-(1→, →4)-Galp-(1→, →2)-Galp-(1→, →6)-Galp-(1→, →3,4)-Galp -(1→, →3,6)-Galp-(1→, →4,6)-Galp-(1→, →3,4,6)-Galp-(1→, →2,3)-Galp-(1→, →2,4)-Galp-(1→, →4)-Glcp-(1→, →6)-Glcp-(1→ and →4,6)-Glcp-(1→residues. The isolated polysaccharides effectively induced RAW264.7 murine macrophages by releasing nitric oxide (NO) and various cytokines via nuclear factor kappa light chain enhancer of activated B cells (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. Further, the expression of toll-like receptor-2 (TLR-2) and TLR-4 in RAW264.7 cells indicated their activation through TLR-2 and TLR-4 binding receptors. Among the polysaccharides, GFP-1 highly stimulated the activation of RAW264.7 cells, which was mainly constituted of (→1) terminal-D-galactopyranosyl, (1→3)-linked-ᴅ-galactopyranosyl, (1→4)-linked-ᴅ-galactopyranosyl and (1→3,4) -linked-ᴅ-galactopyranosyl residues. These findings demonstrate that GFP-1 from G. filicina are effective at stimulating the immune system and this warrants further investigation to determine potential biomedical applications.

Efficacy of catgut embedding in Baihui (GV20) and Feishu (BL13) and Pishu (BL20) on lung tissue, brain tissue and blood related indexes in rats with allergic rhinitis of lung deficiency type

OBJECTIVE

To investigate the effects of acupoint catgut embedding for 3 weeks on lung tissue, blood immunoglobulin E (IgE) and interleutin-4 (IL-4), brain tissue microglia x-42 (OX-42) and toll-like receptor-2 (TLR-2) in rats with allergic rhinitis of lung deficiency type.

METHODS

Forty-five female Sprague-Dawley rats were randomly divided for two times. The first time, they were randomly divided into model group and blank group (Group C) according to 2:1, and the second time, the model group were randomly divided into model control group (Group B) and intervention treatment group (Group A) according to 1:1. 15 in each group. For Group A and Group B, the lung deficiency model was made by "sulfur-moxa fumigation", and then the allergic rhinitis model was established by "ovalbumin (OVA) sensitization". Then catgut embedding was performed at acupoints in Group A and not in Group B. After 3 weeks, collect lung tissue samples for hematoxylin-eosin staining, then take blood to observe the concentration of IgE and IL-4, and finally take brain tissue to observe the results of OX-42 and TLR-2.

RESULTS

IgE level (μg/mL) was (3.11 ± 0.20) in the Group A, (4.19 ± 0.44) in the Group B, and (2.29 ± 0.30) in the Group C (all < 0.001). IL-4 level (pg/mL) was (14.2 ± 0.7) in the Group A, (18.6 ± 2.4) in the Group B, and (11.4 ± 1.2) for the Group C (all < 0.001). The mean OD for OX-42 is (0.1728 ± 0.0016) in the Group A, (0.1810 ± 0.0046) in the Group B and (0.1674 ± 0.0025) in the Group C (all < 0.001).

CONCLUSION

Although 3 weeks of acupoint catgut embedding already showed obvious efficacy on rats with allergic rhinitis, the allergic reaction in the body still continued. To achieve further treatment, prolonging the catgut embedding time is necessary.

Identification of differential immune cells and related diagnostic genes in patients with diabetic retinopathy

BACKGROUND

Diabetic retinopathy (DR) is a frequent microvascular abnormality associated with diabetes mellitus. The loss of retinal immunity is an important underlying mechanism of the DR pathogenesis, including the change in retinal immunosuppressive characteristics and the blood-retinal barrier disturbances. Therefore, this investigation screens immune-associated biomarkers in the retina of DR patients.

METHODS

In this investigation, the differential expression genes (DEGs) were acquired from Gene Expression Omnibus data GSE102485. The relative expression of 22 immune cell types in each sample was calculated by CIBERSORT analysis based on gene expression profile. The core module closely associated with immune infiltration was also screened by weighted gene co-expression network analysis (WGCNA). The overlapping DEGs and module genes were the differentially expressed immune-related genes (DEIRGs). With the help of the genes/proteins (STRING) database and MCODE plug-in, the protein-protein interaction (PPI) network hub genes were screened. Furthermore, the miRNA-hub genes and transcription factor (TF)-hub gene regulatory network were used to explain the possible signal pathways in DR. The hub genes verification was carried out by Polymerase Chain Reaction. Lastly, select CSF1R and its related pathway factor p-ERK1/2 to verify their expression in RF/6A under normal and high glucose environments.

RESULTS

A total of 3583 principle DEGs, that enriched immune-related GO terms and infection-related pathways were identified. CIBERSORT analysis showed that naive B cells, M2 macrophages, eosinophils, and neutrophil infiltration were significantly different. After intersecting 3583 DEGs, 168 DEIRGs and 181 module genes were identified. Furthermore, 15 hub genes, TYROBP, FCGR3A, CD163, FCGR2A, PTPRC, TLR2, CD14, VSIG4, HCK, CSF1R, LILRB2, ITGAM, CTSS, CD86, and LY86, were identified via PPI network. The identified hub genes were up-regulated in DR and showed a high DR diagnostic value. Regulatory networks of the miRNA- and TF-hub genes can help understand the etiology of disease at the genetic level and optimize treatment strategy. CD14, VSIG4, HCK, and CSF1R were verified to be highly expressed in the vitreous of patients with DR. n RF/6A, CSF1R, and p-ERK1/2 were significantly overexpressed under high glucose conditions, with a statistically significant difference.

CONCLUSION

This investigation identified 15 genes (TYROBP, FCGR3A, CD163, FCGR2A, PTPRC, TLR2, CD14, VSIG4, HCK, CSF1R, LILRB2, ITGAM, CTSS, CD86, and LY86) as hub DR genes, which may serve as a new potential point for the diagnosis and treatment of DR. CSF1R/p-ERK1/2 signaling may promotes the development of retinal neovascularization.

Identification of TLRs as potential prognostic biomarkers for lung adenocarcinoma

Lung adenocarcinoma (LUAD) is one of the most common tumors with the highest cancer-related death rate worldwide. Early diagnosis of LUAD can improve survival. Abnormal expression of the Toll-like receptors (TLRs) is related to tumorigenesis and development, inflammation and immune infiltration. However, the role of TLRs as an immunotherapy target and prognostic marker in lung adenocarcinoma is not well understood and needs to be analyzed. Relevant data obtained from databases such as ONCOMINE, UALCAN, GEPIA, and the Kaplan-Meier plotter, GSCALite, GeneMANIA, DAVID 6.8, Metascape, LinkedOmics and TIMER, to compare transcriptional TLRs and survival data of patients with LUAD. The expression levels of TLR1/2/3/4/5/7/8 in LUAD tissues were significantly reduced while the expression levels of TLR6/9/10 were significantly elevated. LUAD patients having low expression of TLR1/2/3/5/8 and high expression of TLR9 had a poor overall survival while patients with low expression of TLR2/3/7 presented with worse first progress. TLR4, TLR7 and TLR8 are the 3 most frequently mutated genes in the TLR family. Correlation suggested a low to moderate correlation among TLR family. TLR family was also involved in the activation or inhibition of the famous cancer related pathways. Analysis of immune infiltrates analysis suggested that TLR1/2/7/8 levels significantly correlated with immune infiltration level. Enrichment analysis revealed that TLRs were involved in TLR signaling pathway, immune response, inflammatory response, primary immunodeficiency, regulation of IL-8 production and PI3K-Akt signaling pathway. Our results provided information on TLRs expression and potential regulatory networks in LUAD. Moreover, our results suggested TLR2/7/8 as a potential prognostic biomarker for lung adenocarcinoma.

Inducing a Proinflammatory Response with Bioengineered Yeast Vacuoles with TLR2-Binding Peptides (VacT2BP) as a Drug Carrier for Daunorubicin Delivery

Immune adjuvants have roles in immune activation for cancer therapy, and adjuvants derived from microbes have been applied. In this study, we propose the use of bioengineered vacuoles, derived from recombinant yeast with acute myeloid leukemia (AML) specificity and having a TLR-2-binding peptide (VacT2BP) on their surface, to induce a proinflammatory response as a dual-function nanomaterial for daunorubicin (DNR) delivery. Our results demonstrate that nanosized, isolated VacT2BP induced HL-60 cell-specific DNR delivery and apoptosis. Furthermore, we observed the selective release of high-mobility group box 1 from apoptotic HL-60 cells by DNR@VacT2BP. We concluded that DNR@VacT2BP exhibited target selectivity, and the indiscriminate occurrence of damage-associated molecular patterns (DAMPs) was inhibited by the VacT2BP carrier. The therapeutic efficacy of DNR@VacT2BP was confirmed in AML xenograft mice, with about 82% tumor growth inhibition. Following drug delivery, apoptotic cells and DAMPs with residual VacT2BP (apopDNR@VacT2BP) upregulated the proinflammatory immune response of macrophages. In addition, apopDNR@VacT2BP enhanced phagocytosis activity. Macrophages stimulated by apopDNR@VacT2BP suppressed cancer proliferation by about 40%. In summary, our results suggest that dual-functional vacuoles with a target-specific peptide can be a potential strategy for selective drug delivery and construction of an immune environment to fight cancer, thereby improving prognosis.

TLR pathway signaling molecules in burbot (Lota lota): molecular characterization, basal expression, and their response to Poly(I:C)

Burbot (Lota lota), a fish species of economic and ecological significance found across northern hemisphere freshwater ecosystems, was the focus of this study. We characterized 19 Toll-like receptor (TLR) genes in burbot, tracing their expression patterns following pathogen exposure. TLR genes, crucial to the innate immune system, including TLR13-1/2/3, TLR2/2-2/2-3/2-4/2-5, and TLR22a/22b/22c/22d, were discovered to be tandemly repeated, signifying an evolution in the fish's immune system. Notably, different TLR subfamilies displayed tissue-specific expressions, with TLR1 primarily in spleen and head kidney, TLR13 in head kidney, trunk kidney, and heart, TLR22 in trunk kidney and liver, and TLR3 and TLR9 predominantly in spleen and head kidney, but also in trunk kidney. Further, we investigated the response of TLR genes in burbot to pathogen exposure using qRT-PCR. This involved measuring mRNA expressions of identified TLR genes in spleen and liver tissues after injecting Poly(I:C) to simulate a double-stranded RNA viral infection. The results revealed a time and tissue-specific expression pattern. Specifically, LoTLR3 reached peak expression in the spleen 12 h post-injection, declining thereafter, while TLR2 subfamily members only began expressing after 24 h. In the liver, activation of the TLR3-IRF7 and TLR3-IRF3 signaling pathways was noted. Integrating these results with transcriptomic data illuminated the pivotal role of TLR genes in the burbot's immune response. Such findings are vital in shaping future disease prevention and treatment strategies.

Subcutaneous Streptococcus dysgalactiae GAPDH vaccine in mice induces a proficient innate immune response

BACKGROUND

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) on the surface of Streptococcus dysgalactiae, coded with gapC, is a glycolytic enzyme that was reported to be a moonlighting protein and virulence factor.

OBJECTIVE

This study assessed GAPDH as a potential immunization candidate protein to prevent streptococcus infections.

METHODS

Mice were vaccinated subcutaneously with recombinant GAPDH and challenged with S. dysgalactiae in vivo. They were then evaluated using histological methods. rGAPDH of mouse bone marrow-derived dendritic cells (BMDCs) was evaluated using immunoblotting, reverse transcription quantitative polymerase chain reaction, and enzyme-linked immunosorbent assay methods.

RESULTS

Vaccination with rGAPDH improved the survival rates and decreased the bacterial burdens in the mammary glands compared to the control group. The mechanism by which rGAPDH vaccination protects against S. dysgalactiae was investigated. In vitro experiments showed that rGAPDH boosted the generation of interleukin-10 and tumor necrosis factor-α. Treatment of BMDCs with TAK-242, a toll-like receptor 4 inhibitor, or C29, a toll-like receptor 2 inhibitor, reduced cytokines substantially, suggesting that rGAPDH may be a potential ligand for both TLR2 and TLR4. Subsequent investigations showed that rGAPDH may activate the phosphorylation of MAPKs and nuclear factor-κB.

CONCLUSIONS

GAPDH is a promising immunization candidate protein for targeting virulence and enhancing immune-mediated protection. Further investigations are warranted to understand the mechanisms underlying the activation of BMDCs by rGAPDH in a TLR2- and TLR4-dependent manner and the regulation of inflammatory cytokines contributing to mastitis pathogenesis.

Cognitive Alterations in Old Mice Are Associated with Intestinal Barrier Dysfunction and Induced Toll-like Receptor 2 and 4 Signaling in Different Brain Regions

Emerging evidence implicate the 'microbiota-gut-brain axis' in cognitive aging and neuroinflammation; however, underlying mechanisms still remain to be elucidated. Here, we assessed if potential alterations in intestinal barrier function and microbiota composition as well as levels of two key pattern-recognition receptors namely Toll-like receptor (TLR) 2 and TLR4, in blood and different brain regions, and depending signaling cascades are paralleling aging associated alterations of cognition in healthy aging mice. Cognitive function was assessed in the Y-maze and intestinal and brain tissue and blood were collected in young (4 months old) and old (24 months old) male C57BL/6 mice to determine intestinal microbiota composition by Illumina amplicon sequencing, the concentration of TLR2 and TLR4 ligands in plasma and brain tissue as well as to determine markers of intestinal barrier function, senescence and TLR2 and TLR4 signaling. Cognitive function was significantly impaired in old mice. Also, in old mice, intestinal microbiota composition was significantly altered, while the relative abundance of Gram-negative or Gram-positive bacteria in the small and large intestines at different ages was not altered. Moreover, intestinal barrier function was impaired in small intestine of old mice, and the levels of TLR2 and TLR4 ligands were also significantly higher in both portal and peripheral blood. Furthermore, levels of TLR2 and TLR4 ligands, and downstream markers of TLR signaling were higher in the hippocampal and prefrontal cortex of old mice compared to young animals. Taken together, our results suggest that even in 'healthy' aging, cognitive function is impaired in mice going along with an increased intestinal translocation of TLR ligands and alterations of TLR signaling in several brain regions.

Innate Immune Gene Polymorphisms and COVID-19 Prognosis

COVID-19 is characterized by a heterogeneous clinical presentation and prognosis. Risk factors contributing to the development of severe disease include old age and the presence of comorbidities. However, the genetic background of the host has also been recognized as an important determinant of disease prognosis. Considering the pivotal role of innate immunity in the control of SARS-CoV-2 infection, we analyzed the possible contribution of several innate immune gene polymorphisms (including TLR2-rs5743708, TLR4-rs4986790, TLR4-rs4986791, CD14-rs2569190, CARD8-rs1834481, IL18-rs2043211, and CD40-rs1883832) in disease severity and prognosis. A total of 249 individuals were enrolled and further divided into five (5) groups, according to the clinical progression scale provided by the World Health Organization (WHO) (asymptomatic, mild, moderate, severe, and critical). We identified that elderly patients with obesity and/or diabetes mellitus were more susceptible to developing pneumonia and respiratory distress syndrome after SARS-CoV-2 infection, while the IL18-rs1834481 polymorphism was an independent risk factor for developing pneumonia. Moreover, individuals carrying either the TLR2-rs5743708 or the TLR4-rs4986791 polymorphisms exhibited a 3.6- and 2.5-fold increased probability for developing pneumonia and a more severe disease, respectively. Our data support the notion that the host's genetic background can significantly affect COVID-19 clinical phenotype, also suggesting that the IL18-rs1834481, TLR2-rs5743708, and TLR4-rs4986791 polymorphisms may be used as molecular predictors of COVID-19 clinical phenotype.

Unraveling the Role of Toll-like Receptors in the Immunopathogenesis of Selected Primary and Secondary Immunodeficiencies

The human immune system is a complex network of cells, tissues, and molecules that work together to defend the body against pathogens and maintain overall health. However, in some individuals, the immune system fails to function correctly, leading to immunodeficiencies. Immunodeficiencies can be classified into primary (PID) and secondary (SID) types, each with distinct underlying causes and manifestations. Toll-like receptors (TLRs), as key components of the immune system, have been implicated in the pathogenesis of both PID and SID. In this study, we aim to unravel the intricate involvement of TLR2, TLR4, TLR3, TLR7, TLR8, and TLR9 in the immunopathogenesis of common variable immunodeficiency-CVID (as PID)-and chronic lymphocytic leukemia-CLL (as SID). The obtained results indicate a significant increase in the percentage of all tested subpopulations of T lymphocytes and B lymphocytes showing positive expression of all analyzed TLRs in patients with CVID and CLL compared to healthy volunteers, constituting the control group, which is also confirmed by analysis of the concentration of soluble forms of these receptors in the plasma of patients. Furthermore, patients diagnosed with CVID are characterized by the percentage of all lymphocytes showing positive expression of the tested TLR2, TLR4, TLR3, and TLR9 and their plasma concentrations in relation to patients with CLL. By investigating the functions and interactions of TLRs within the immune system, we seek to shed light on their critical role in the development and progression of these immunodeficiencies. Through a comprehensive analysis of the literature and presented experimental data, we hope to deepen our understanding of the complex mechanisms by which TLRs contribute to the pathogenesis of PID and SID. Ultimately, our findings may provide valuable insights into developing targeted therapeutic strategies to mitigate the impact of these disorders on those affected by immunodeficiency.