anti-TLR4 Antibody Research Articles

Therapeutic potential of a systemically applied humanized monoclonal antibody targeting Toll‑like receptor 2 in atopic‑dermatitis‑like skin lesions in a mouse model.

Atopic dermatitis (AD) is a prevalent, persistent inflammatory skin disorder distinguished by pruritic and irritated skin. Toll-like receptors (TLRs) are specialized receptors that recognize specific patterns associated with pathogens and tissue damage, triggering an innate immune response that protects the host from invading pathogens. Previously, it was demonstrated that intradermal injection of the humanized anti-TLR2 monoclonal antibody (Ab) Tomaralimab effectively relieved AD-like skin inflammation in BALB/c mouse models exposed to house dust mite extracts. However, it remains unclear whether allergenic hapten-induced AD can be effectively treated with systemically administered TLR2-targeting Abs. In the present study, it was observed that administrating Tomaralimab through intravenous injection alleviated AD-like skin lesions in BALB/c mice challenged with topical application of 2,4-dinitrochlorobenzene by reducing the infiltration of inflammatory cells into skin lesions and preventing the creation of various inflammatory cytokines, including thymic stromal lymphopoietin, interleukin (IL)-4, IL-13, IL-17 and IL-31, which are associated with the pathogenesis of AD. These findings support the feasibility of using a humanized anti-TLR2 monoclonal Ab as systemic therapy for AD.

TLR2–EGR1 signaling axis modulates TGFβ1-induced differentiation of fibroblasts into myofibroblasts in pulmonary fibrosis

Pulmonary fibrosis is a progressive lung condition characterized by the excessive activation of myofibroblasts. Transforming growth factor beta 1 (TGFβ1) plays a crucial role in the differentiation of fibroblasts into myofibroblasts. In addition, toll-like receptor 2 (TLR2), known for its role in immune responses, contributes to pulmonary fibrosis by promoting myofibroblast differentiation. However, the interplay between TGFβ1 and TLR2 signaling pathways in myofibroblast differentiation has remained elusive. In the present study, we investigated the involvement of TLR2 in TGFβ1-induced fibroblast differentiation into myofibroblasts using IMR-90 human pulmonary fibroblasts as a model cell line. We found that TLR2 activation induced myofibroblast differentiation by enhancing the expression of early growth response 1 (EGR1) via the mitogen-activated protein kinase (MAPK) signaling pathway. Elevated EGR1 levels were detected in the lung tissues of a bleomycin (BLM)-induced mouse model of pulmonary fibrosis. Moreover, the administration of tomaralimab, an antagonistic anti-TLR2 antibody, reduced the EGR1 expression and collagen deposition. Altogether, targeting the TLR2–EGR1 pathway could be a promising therapeutic approach for pulmonary fibrosis by blocking TGFβ1-induced myofibroblast differentiation.

TLR2 immunotherapy suppresses neuroinflammation, tau spread, and memory loss in rTg4510 mice

In Alzheimer’s disease, chronic neuroinflammation is accompanied by amyloid and tau pathologies. Especially, aberrant microglial activation is known to precede the regional tau pathology development, but the mechanisms how microglia affect tau spread remain largely unknown. Here, we found that toll-like receptor 2 (TLR2) in microglia recognizes oligomeric tau as a pathogenic ligand and induces inflammatory responses. Knockout of TLR2 reduced tau pathology and microglial activation in rTg4510 tau transgenic mice. Treatment of oligomeric tau induced TLR2 activation and increased inflammatory responses in microglial cells. TLR2 further mediated the tau-induced microglial activation and promoted tau uptake into neurons in neuron-microglia co-culture system and in mouse hippocampus after intracranial tau injection. Importantly, treatment with anti-TLR2 monoclonal antibody Tomaralimab blocked TLR2 activation and inflammatory responses in a dose-dependent manner, and significantly reduced tau spread and memory loss in rTg4510 mice. These results suggest that TLR2 plays a crucial role in tau spread by causing aberrant microglial activation in response to pathological tau, and blocking TLR2 with immunotherapy may ameliorate tau pathogenesis in Alzheimer’s disease.

Extracellular vesicles promote autophagy in human microglia through lipid raft-dependent mechanisms.

Autophagy dysfunction has been closely related with pathogenesis of many neurodegenerative diseases and therefore represents a potential therapeutic target. Extracellular vesicles (EVs) may act as potent anti-inflammatory agents and also modulators of autophagy in target cells. However, the molecular mechanisms by which EVs modulate autophagy flux in human microglia remain largely unexplored. In the present study, we investigated the effects of EVs derived from human oral mucosa stem cells on the autophagy in human microglia. We demonstrate that EVs promoted autophagy and autophagic flux in human microglia and that this process was dependent on the integrity of lipid rafts. Lipopolysaccharide (LPS) also activated autophagy, but combined treatment with EVs and LPS suppressed autophagy response, indicating interference between these signaling pathways. Blockage of Toll-like receptor 4 (TLR4) with anti-TLR4 antibody suppressed EV-induced autophagy. Furthermore, inhibition of the EV-associated heat shock protein (HSP70) chaperone which is one of the endogenous ligands of the TLR4 also suppressed EV-induced lipid raft formation and autophagy. Pre-treatment of microglia with a selective inhibitor of αvβ3/αvβ5 integrins cilengitide inhibited EV-induced autophagy. Finally, blockage of purinergic P2X4 receptor (P2X4R) with selective inhibitor 5-BDBD also suppressed EV-induced autophagy. In conclusion, we demonstrate that EVs activate autophagy in human microglia through interaction with HSP70/TLR4, αVβ3/αVβ5, and P2X4R signaling pathways and that these effects depend on the integrity of lipid rafts. Our findings could be used to develop new therapeutic strategies targeting disease-associated microglia.

Therapeutic Effects of Arctiin on Alzheimer's Disease-like Model in Rats by Reducing Oxidative Stress, Inflammasomes and Fibrosis.

Alzheimer's disease (AD) affects approximately 50 million people globally and is expected to triple by 2050. Arctiin is a lignan found in the Arctium lappa L. plant. Arctiin possesses anti-proliferative, antioxidative and anti-adipogenic. We aimed to explore the potential therapeutic effects of Arctiin on rats with AD by evaluating the expression of TLR4, NLRP3, STAT3, TGF-β, cyclin D1, and CDK2. AD was induced in rats by administering 70 mg/kg of aluminum chloride through intraperitoneal injection daily for six weeks. After inducing AD, some rats were treated with 25 mg/kg of Arctiin daily for three weeks through oral gavage. Furthermore, to examine the brain tissue structure, hippocampal sections were stained with hematoxylin/eosin and anti-TLR4 antibodies. The collected samples were analyzed for gene expression and protein levels of TLR4, NLRP3, STAT3, TGF-β, cyclin D1, and CDK2. In behavioral tests, rats showed a significant improvement in their behavior when treated with Arctiin. Microimages stained with hematoxylin/eosin showed that Arctiin helped to improve the structure and cohesion of the hippocampus, which was previously impaired by AD. Furthermore, Arctiin reduced the expression of TLR4, NLRP3, STAT3, TGF-β, cyclin D1, and CDK2. Arctiin can enhance rats' behavior and structure of the hippocampus in AD rats. This is achieved through its ability to reduce the expression of both TLR4 and NLRP3, hence inhibiting the inflammasome pathway. Furthermore, Arctiin can improve tissue fibrosis by regulating STAT3 and TGF-β. Lastly, it can block the cell cycle proteins cyclin D1 and CDK2.

Combining antibiotic with anti-TLR2/TLR13 therapy prevents brain pathology in pneumococcal meningitis.

Despite effective antibiotic therapy, brain-destructive inflammation often cannot be avoided in pneumococcal meningitis. The causative signals are mediated predominantly through TLR-recruited myeloid differentiation primary response adaptor 88 (MyD88), as indicated by a dramatic pneumococcal meningitis phenotype of Myd88-/- mice. Because lipoproteins and single-stranded RNA are crucial for recognition of Gram-positive bacteria such as Streptococcus pneumoniae by the host immune system, we comparatively analyzed the disease courses of Myd88-/- and Tlr2-/- Tlr13-/- mice. Their phenotypic resemblance indicated TLR2 and -13 as master sensors of S. pneumoniae in the cerebrospinal fluid. A neutralizing anti-TLR2 antibody (T2.5) and chloroquine (CQ) - the latter applied here as an inhibitor of murine TLR13 and its human ortholog TLR8 - abrogated activation of murine and human primary immune cells exposed to antibiotic-treated S. pneumoniae. The inhibitory effect of the T2.5/CQ cocktail was stronger than that of dexamethasone, the current standard adjunctive drug for pneumococcal meningitis. Accordingly, TLR2/TLR13 blockade concomitant with ceftriaxone application significantly improved the clinical course of pneumococcal meningitis compared with treatment with ceftriaxone alone or in combination with dexamethasone. Our study indicates the importance of murine TLR13 and human TLR8, besides TLR2, in pneumococcal meningitis pathology, and suggests their blockade as a promising antibiotic therapy adjunct.

MDSCs use a complex molecular network to suppress T-cell immunity in a pulmonary model of fungal infection.

Paracoccidioidomycosis (PCM) is a systemic endemic fungal disease prevalent in Latin America. Previous studies revealed that host immunity against PCM is tightly regulated by several suppressive mechanisms mediated by tolerogenic plasmacytoid dendritic cells, the enzyme 2,3 indoleamine dioxygenase (IDO-1), regulatory T-cells (Tregs), and through the recruitment and activation of myeloid-derived suppressor cells (MDSCs). We have recently shown that Dectin-1, TLR2, and TLR4 signaling influence the IDO-1-mediated suppression caused by MDSCs. However, the contribution of these receptors in the production of important immunosuppressive molecules used by MDSCs has not yet been explored in pulmonary PCM. We evaluated the expression of PD-L1, IL-10, as well as nitrotyrosine by MDSCs after anti-Dectin-1, anti-TLR2, and anti-TLR4 antibody treatment followed by P. brasiliensis yeasts challenge in vitro. We also investigated the influence of PD-L1, IL-10, and nitrotyrosine in the suppressive activity of lung-infiltrating MDSCs of C57BL/6-WT, Dectin-1KO, TLR2KO, and TLR4KO mice after in vivo fungal infection. The suppressive activity of MDSCs was evaluated in cocultures of isolated MDSCs with activated T-cells. A reduced expression of IL-10 and nitrotyrosine was observed after in vitro anti-Dectin-1 treatment of MDSCs challenged with fungal cells. This finding was further confirmed in vitro and in vivo by using Dectin-1KO mice. Furthermore, MDSCs derived from Dectin-1KO mice showed a significantly reduced immunosuppressive activity on the proliferation of CD4+ and CD8+ T lymphocytes. Blocking of TLR2 and TLR4 by mAbs and using MDSCs from TLR2KO and TLR4KO mice also reduced the production of suppressive molecules induced by fungal challenge. In vitro, MDSCs from TLR4KO mice presented a reduced suppressive capacity over the proliferation of CD4+ T-cells. We showed that the pathogen recognition receptors (PRRs) Dectin-1, TLR2, and TLR4 contribute to the suppressive activity of MDSCs by inducing the expression of several immunosuppressive molecules such as PD-L1, IL-10, and nitrotyrosine. This is the first demonstration of a complex network of PRRs signaling in the induction of several suppressive molecules by MDSCs and its contribution to the immunosuppressive mechanisms that control immunity and severity of pulmonary PCM.

Lipopolysaccharide Derived from Pantoea agglomerans Directly Promotes the Migration of Human Keratinocytes.

Because the skin is exposed to the external environment, it is important that wound healing processes proceed and terminate rapidly to minimize the risk of infection. A previous case report described the promotion of wound healing by transdermal administration of lipopolysaccharide derived from Pantoea agglomerans (LPSp). However, whether the wound healing-promoting effect of LPSp was due to direct activity on skin cells or indirect effects involving macrophages remained unclear. Therefore, this study investigated the wound healing-promoting effect of LPSp, particularly the promotion of keratinocyte migration. The migration of HaCaT human keratinocytes over time with and without LPSp was assayed using a cell migration assay kit. Migration was also analyzed using HaCaT cells treated with LPSp and an antibody against Toll-like receptor (TLR) 4, a receptor for LPS. Addition of LPSp significantly enhanced cell migration compared to no LPSp addition. Migration was inhibited by the addition of anti-TLR4 antibody. LPSp acts directly on epidermal cells to promote migration and may be one mechanism by which LPSp promotes wound healing.

Molecular insights into the macrophage immunomodulatory effects of Scrophulariae Radix Polysaccharides.

Scrophulariae Radix (SR) has been widely used in Chinese herbal compound prescriptions, health care products and functional foods. The present study aimed to investigate the immunomodulatory activity of polysaccharides from SR (SRPs) in macrophages and explore the potential mechanisms. The results showed that four SRPs fractions (SRPs40, SRPs60, SRPs80 and SRPs100) had similar absorption peaks and monosaccharide compositions, but the intensities of absorption peaks and monosaccharide contents were distinguished. All SRPs fractions significantly enhanced the pinocytic activity, promoted the production of NO and TNF-α, increased the mRNA expressions of inflammatory factors (IL-1β, IL-6, TNF-α and PTGS2) and TLR2, and elevated the phosphorylation levels of p38, ERK, JNK, p65 and IκB. Moreover, the production of NO and TNF-α stimulated by SRPs was dramatically suppressed by anti-TLR2 antibody. These results indicated that SRPs activated macrophages through MAPK and NF-κB signaling pathways via recognition of TLR2.

Oat β-D-glucan ameliorates type II diabetes through TLR4/PI3K/AKT mediated metabolic axis

Diabetes is one of the major global public health problems. Our previous results found that oat β-D-glucan exhibited ameliorative effects on diabetic mice, but the underlying mechanism is unclear. The present study indicates that oat β-D-glucan increased glycogen content, decreased glycogen synthase (GS) phosphorylation and increased hepatic glycogen synthase kinase 3β (GSK3β) phosphorylation for glycogen synthesis via PI3K/AKT/GSK3-mediated GS activation. Moreover, oat β-D-glucan inhibited gluconeogenesis through the PI3K/AKT/Foxo1-mediated phosphoenolpyruvate carboxykinase (PEPCK) decrease. In addition, oat β-D-glucan enhanced glucose catabolism through elevated protein levels of COQ9, UQCRC2, COXIV and ATP5F complexes involved in oxidative phosphorylation, as well as that of TFAM, a key regulator of mitochondrial gene expression. Importantly, our results showed that oat β-D-glucan maintained hepatic glucose balance via TLR4-mediated intracellular signal. After TLR4 blocking with anti-TLR4 antibody, oat β-D-glucan had almost no effect on high glucose-induced HepG2 cells. These data revealed that oat β-D-glucan maintains glucose balance by regulating the TLR4/PI3K/AKT signal pathway.

Exogenous IL-10 posttreatment along with TLR4 and TNFR1 blockade improves tissue antioxidant status by modulating sepsis-induced macrophage polarization.

Multi-organ dysfunction is one of the major reasons behind the high mortality of sepsis throughout the world. With the pathophysiology of sepsis remaining largely unknown, the uncontrolled reactive oxygen species (ROS) production along with the decreased antioxidants contributes to the progression toward septic shock. Being the effector cells of the innate immunity system, macrophages secrete both pro-inflammatory and anti-inflammatory mediators during inflammation. Lipopolysaccharide (LPS) binding to toll-like receptor 4 (TLR4) releases TNF-α, which initiates pro-inflammatory events through tumor necrosis factor receptor 1 (TNFR1) signaling. However, it is counteracted by the anti-inflammatory interleukin 10 (IL-10) causing decreased oxidative stress. Our study thus aimed to assess the effects of exogenous IL-10 treatment post-neutralization of TLR4 and TNFR1 (by anti-TLR4 antibody and anti-TNFR1 antibody, respectively) in an in vivo murine model of LPS-sepsis. We have also examined the tissue-specific antioxidant status in the spleen, liver, and lungs along with the serum cytokine levels in adult male Swiss albino mice to determine the functional association with the disease. The results showed that administration of recombinant IL-10 post-neutralization of the receptors was beneficial in shifting the macrophage polarization to the anti-inflammatory M2 phenotype. IL-10 treatment significantly downregulated the free radicals production resulting in diminished lipid peroxidase (LPO) levels. The increased antioxidant activities of superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GRX ) conferred protection against LPS-induced sepsis. Western blot data further confirmed diminished expressions of TLR4 and TNFR1 along with suppressed stress-activated protein kinases/Jun amino-terminal kinases (SAPK/JNK) and increased SOD and CAT expressions, which altogether indicated that neutralization of TLR4 and TNFR1 along with IL-10 posttreatment might be a potential therapeutic measure for the treatment of sepsis.

Retracted and Republished from: “Gut Microbiota Mediates the Therapeutic Effect of Monoclonal Anti-TLR4 Antibody on Acetaminophen-Induced Acute Liver Injury in Mice”

Acetaminophen (APAP) overdose is one of the most common causes of acute liver injury (ALI) in Western countries. Many studies have shown that the gut microbiota plays an important role in liver injury. Currently, the only approved treatment for APAP-induced ALI is N-acetylcysteine; therefore, it is essential to develop new therapeutic agents and explore the underlying mechanisms. We developed a novel monoclonal anti-Toll-like receptor 4 (TLR4) antibody (ATAB) and hypothesized that it has therapeutic effects on APAP-induced ALI and that the gut microbiota may be involved in the underlying mechanism of ATAB treatment. Male C57BL/6 mice were treated with APAP and ATAB, which produced a therapeutic effect on ALI and altered the members of the gut microbiota and their metabolic pathways, such as Roseburia, Lactobacillus, Akkermansia, and the fatty acid pathway, etc. Furthermore, we verified that purified short-chain fatty acids (SCFAs) could alleviate ALI. Moreover, a separate group of mice that received feces from the ATAB group showed less severe liver injury than mice that received feces from the APAP group. ATAB therapy also improved gut barrier functions in mice and reduced the expression of the protein zonulin. Our results revealed that the gut microbiota plays an important role in the therapeutic effect of ATAB on APAP-induced ALI. IMPORTANCE In this study, we found that a monoclonal anti-Toll-like receptor 4 antibody can alleviate APAP-induced acute liver injury through changes in the gut microbiota, metabolic pathways, and gut barrier function. This work suggested that the gut microbiota can be a therapeutic target of APAP-induced acute liver injury, and we performed foundation for further research.

Retraction for Sun et al., “Gut Microbiota Mediates the Therapeutic Effect of Monoclonal Anti-TLR4 Antibody on Acetaminophen-Induced Acute Liver Injury in Mice”

Volume 10, no. 3, e00647-22, 2022, https://doi.org/10.1128/spectrum.00647-22. We hereby retract this article due to the method for administering the monoclonal anti-TLR4 antibody (ATAB) described in the original paper being inaccurate, as this may influence the readers' understanding of the effect of the ATAB. This inaccuracy was brought to our attention by a Letter to the Editor (https://doi.org/10.1128/spectrum.01863-22). We have responded to the concerns regarding the original paper in our reply to the letter (https://doi.org/10.1128/spectrum.02377-22).

Toll-like receptor 4 and lipopolysaccharide from commensal microbes regulate Tembusu virus infection

Unlike most flaviviruses transmitted by arthropods, Tembusu virus (TMUV) is still active during winter and causes outbreaks in some areas, indicating vector-independent spread of the virus. Gastrointestinal transmission might be one of the possible routes of vector-free transmission, which also means that the virus has to interact with more intestinal bacteria. Here, we found evidence that TMUV indeed can transmit through the digestive tract. Interestingly, using an established TMUV disease model by oral gavage combined with an antibiotic treatment, we revealed that a decrease in intestinal bacteria significantly reduced local TMUV proliferation in the intestine, revealing that the bacterial microbiome is important in TMUV infection. We found that lipopolysaccharide (LPS) present in the outer membrane of Gram-negative bacteria enhanced TMUV proliferation by promoting its attachment. Toll-like receptor 4 (TLR4), a cell surface receptor, can transmit signal from LPS. We confirmed colocalization of TLR4 with TMUV envelope (E) protein as well as their interaction in infected cells. Coherently, TMUV infection of susceptible cells was inhibited by an anti-TLR4 antibody, purified soluble TLR4 protein, and knockdown of TLR4 expression. LPS-enhanced TMUV proliferation could also be blocked by a TLR4 inhibitor. Meanwhile, pretreatment of duck primary cells with TMUV significantly impaired LPS-induced interleukin 6 production. Collectively, our study provides first insights into vector-free transmission mechanisms of flaviviruses.

Immunostimulatory effects of dairy probiotic strains Bifidobacterium animalis ssp. lactis HY8002 and Lactobacillus plantarum HY7717

Previous studies reported that Bifidobacterium animalis ssp. lactis HY8002 (HY8002) improved intestinal integrity and had immunomodulatory effects. Lactobacillus plantarum HY7717 (HY7717) was screened in vitro from among 21 other lactic acid bacteria (LAB) and demonstrated nitric oxide (NO) production. The aims of this study were to investigate the individual and combined ex vivo and in vivo effects of LAB strains HY8002 and HY7717 at immunostimulating mice that have been challenged with an immunosuppressant drug. The combination of HY8002 and HY7717 increased the secretion of cytokines such as interferon (IFN)-γ, interleukin (IL)-12, and tumor necrosis factor (TNF)-α in splenocytes. In a cyclophosphamide (CTX)-induced immunosuppression model, administration of the foregoing LAB combination improved the splenic and hematological indices, activated natural killer (NK) cells, and up-regulated plasma immunoglobulins and cytokines. Moreover, this combination treatment increased Toll-like receptor 2 (TLR2) expression. The ability of the combination treatment to upregulate IFN-γ and TNF-α in the splenocytes was inhibited by anti-TLR2 antibody. Hence, the immune responses stimulated by the combination of HY8002 and HY7717 are associated with TLR2 activation. The preceding findings suggest that the combination of the HY8002 and HY7717 LAB strains could prove to be a beneficial and efficacious immunostimulant probiotic supplement. The combination of the two probiotic strains will be applied on the dairy foods including yogurt and cheese.

Involvement of the visfatin/toll-like receptor 4 signaling axis in human dental pulp cell senescence: Protection via toll-like receptor 4 blockade

/purpose: Dental pulp plays an important role in the maintenance of tooth homeostasis and repair. The aging of dental pulp affects the functional life of the tooth owing to the senescence of dental pulp cells. Toll-like receptor 4 (TLR4) is involved in regulating cellular senescence in dental pulp. We have recently demonstrated that visfatin induces the senescence of human dental pulp cells (hDPCs). Here, we explored the association of TLR4 with visfatin signaling in cellular senescence in hDPCs. mRNA levels were determined using reverse transcription polymerase chain reaction (PCR) and quantitative real time-PCR. Protein levels were determined using immunofluorescence staining and Western blot analysis. Gene silencing was performed using small interfering RNA. The degree of cellular senescence was measured by senescence-associated-β-galactosidase (SA-β-gal) staining. Oxidative stress was determined by measurement of NADP/NADPH levels and intracellular reactive oxygen species (ROS) levels. Neutralizing anti-TLR4 antibodies or TLR4 inhibitor markedly blocked visfatin-induced hDPCs senescence, as revealed by an increase in the number of SA-β-gal-positive hDPCs and upregulation of p21 and p53 proteins. Moreover, visfatin-induced senescence was associated with excessive ROS production; NADPH consumption; telomere DNA damage induction; interleukin (IL)-1β, IL-6, IL-8, cyclooxygenase-2, and tumor necrosis factor-α upregulation; and nuclear factor-κB and mitogen-activated protein kinase activation. All of these alterations were attenuated by TLR4 blockade. Our findings indicate that TLR4 plays an important role in visfatin-induced senescence of hDPCs and suggest that the visfatin/TLR4 signaling axis can be a novel therapeutic target for the treatment of inflammaging-related diseases, including pulpitis.

HSP90α induces immunosuppressive myeloid cells in melanoma via TLR4 signaling

BackgroundTumor cells modulate host immunity by secreting extracellular vesicles (EV) and soluble factors. Their interactions with myeloid cells lead to the generation of myeloid-derived suppressor cells (MDSC), which inhibit the...

Gut Microbiota Mediates the Therapeutic Effect of Monoclonal Anti-TLR4 Antibody on Acetaminophen-Induced Acute Liver Injury in Mice.

ABSTRACTAcetaminophen (APAP) overdose is one of the most common causes of acute liver injury (ALI) in Western countries. Many studies show that the gut microbiota plays an important role in liver injury. Currently, the only approved treatment for APAP-induced ALI is N-acetylcysteine; therefore, it is essential to develop new therapeutic agents and explore the underlying mechanisms. We developed a novel monoclonal anti-Toll-like receptor 4 (TLR4) antibody (ATAB) and hypothesized that it has therapeutic effects on APAP-induced ALI and that gut microbiota may be involved in the underlying mechanism of ATAB treatment. Male C57BL/6 mice were treated with APAP and ATAB, which produced a therapeutic effect on ALI and altered the gut microbiota and their metabolic pathway, such as Roseburia, Lactobacillus, Akkermansia, and the fatty acid pathway, etc. Furthermore, we verified that purified short-chain fatty acids (SCFAs) could alleviate ALI. Moreover, a separate group of mice that received feces from the ATAB group showed less severe liver injury compared with the mice receiving feces from the APAP group. ATAB therapy also improved the gut barrier functions in mice and reduced the expression of protein zonulin. Our results revealed that gut microbiota plays an important role in the therapeutic effect of ATAB on APAP-induced ALI.IMPORTANCE In this study, we found the monoclonal anti-Toll-like receptor 4 antibody can alleviate APAP-induced acute liver injury through the change of the gut microbiota, metabolic pathways, and gut barrier function. This work suggested the gut microbiota can be the therapeutic target of the APAP-induced acute liver injury, and we performed the fundamental research for further research.

IMMUNOCYTOCHEMICAL EVALUATION OF TOLL-LIKE RECEPTORS ON BREAST CANCER CELL LINES UNDER THE TREATMENT OF WORTMANNIN AND THALIDOMIDE IN VITRO

Aim: The aim of this study was to investigate the effects of the PI3K inhibitor Wortmannin and the angiogenesis inhibitor Thalidomide on Toll-Like Receptors (TLR) on breast cancer cell lines which have non (67NR) and high (4T1) metastatic potential using immunocytochemical technique.
 Material and Method: The cells were evaluated using avidin-biotin-peroxidase indirect immunocytochemistry method. Anti-TLR2, anti-TLR4, anti-MyD88, anti-PI3K and anti-NFκB primary antibodies were performed after 24h and 48h administrations of Wortmannin and Thalidomide. The distribution of immunocytochemical intensities of primary antibodies were graded semi-quantitatively as mild (1), moderate (2), strong (3) and very strong (4). The mean values of the staining intensities and the percentage of positively stained cells were calculated using the H-Score. Statistics were comparatively evaluated by using the One-way ANOVA test. Significance was defined as p<0.05.
 Results: On the control group of 67NR breast cancer cell line, immunoreactivity of TLR2 was seen as very strong. While immunoreactivity of MyD88 was seen as strong, immunoreactivities of TLR4, NFκB and PI3K were observed as moderate in this group. On the control group of 4T1 breast cancer cell line, immunoreactivities of MyD88 and NFκB were seen as strong, while immunoreactivities of TLR2, TLR4 and PI3K were observed as moderate/strong in this group.
 Conclusion: It was demonstrated by this study, that the effects on the 24th and 48th hour of the Wortmannin acts as an inhibitor of PI3K and Thalidomide acts as an inhibitor of NFκB were effective on TLR signaling pathway and related molecules on 67NR and 4T1 breast cancer cell lines which have different metastatic properties. It was concluded that these drugs have an important role as inhibitors in cancer signaling pathways included invasion and metastasis. As future expectation, they might be used therapeutically in addition to classical treatments on cancer treatment.

Evidence of a role for interleukin-6 in anoikis resistance in oral squamous cell carcinoma

In an endeavour to understand metastasis from oral squamous cell carcinomas, we characterised the metastatic potential of a human tongue derived cell line (SCC-4 cells) and compared this phenotype to pre-cancerous dysplastic oral keratinocyte (DOK) cells derived from human tongue and primary gingival keratinocytes (PGK). We demonstrate that SCC-4 cells constitutively synthesize and release significant amounts of IL-6, a process that is enhanced by the addition of the TLR2/TLR6 agonist, Pam2CSK4. The expression of TLR2/6 and IL-6Ra/gp130 receptors was also confirmed in SCC-4 cells. Cancerous SCC-4 human tongue cells also have a classic EMT profile, unlike precancerous human tongue DOK cells. We also established that IL-6 is driving anoikis resistance in an autocrine fashion and that anti-IL-6 neutralising antibodies, anti-IL-6 receptor antibodies and anti-TLR2 receptor antibodies inhibit anoikis resistance in cancerous SCC-4 human tongue cells. The data suggest a promising role for anti-IL-6 receptor antibody and anti-TLR2 receptor antibody treatment for oral cancer.