Immunostimulatory effects of Toll-like receptor ligands as adjuvants in establishing a novel mouse model for pemphigus vulgaris.

BACKGROUND: The meticulous selection of appropriate vaccine adjuvants is crucial for optimizing immune responses. Traditionally, pemphigus vulgaris (PV), an autoimmune disorder, has been modelled using complete Freund's adjuvant (CFA). In this study, we aimed to discern potential variations in immune responses elicited by Toll-like receptor (TLR) ligands as compared to CFA. METHODS: A comprehensive investigation was conducted, comparing the effects of these adjuvants in conjunction with ovalbumin or desmoglein-3. Flow cytometry was employed to analyse distinct cell subsets, while enzyme-linked immunosorbent assay quantified antigen-specific antibodies and cytokine levels. Histological examination of harvested skin tissues and transcriptome analysis of skin lesions were performed to identify differentially expressed genes. RESULTS: TLR ligands demonstrated efficacy in inducing PV-like symptoms in wild-type mice, in contrast to CFA. This underscored the substantial impact of the adjuvant on self-antigen tolerance. Furthermore, we proposed an enhanced method for establishing a PV model through adoptive transfer, substituting CFA with TLR ligands. Our results revealed that in contrast to the perception that CFA being the most potent immunopotentiator reported, CFA promoted regulatory T cells (Treg), follicular regulatory T cells and IL-10-producing neutrophils, whereas TLR ligands downregulated CCL17 and IL-10. This suggested potential implications for the recruitment and activation of Treg subsets. While B cell and CD8+ T cell responses exhibited similarity, CFA induced less activation in dendritic cell subsets. A novel mouse model of PV and systemic comparison of immunostimulatory effects of adjuvants were provided by this study. CONCLUSIONS: The systematic comparison of CFA and TLR ligands shed light on the distinctive properties of these adjuvants, presenting innovative mouse models for the investigation of pemphigus. This study significantly contributes to adjuvant research and advances our understanding of PV pathogenesis. KEY POINTS/HIGHLIGHTS: Immunization with desmoglein 3 and Toll-like receptor (TLR) ligands effectively induces pemphigus symptoms in wild-type mice, whereas complete Freund's adjuvant (CFA) fails. TLR ligands heightened the autoreactivity of donor cells in the adoptive transfer pemphigus model. CFA promoted regulatory T cells and IL-10-producing neutrophils, whereas TLR ligands downregulated CCL17 and IL-10, leading to more effective immune responses.

TLR Agonists Modify NK Cell Activation and Increase Its Cytotoxicity in Acute Lymphoblastic Leukemia.

Natural killer (NK) cells play a crucial role in innate immunity, particularly in combating infections and tumors. However, in hematological cancers, NK cells often exhibit impaired functions. Therefore, it is very important to activate its endosomal Toll-like receptors (TLRs) as a potential strategy to restore its antitumor activity. We stimulated NK cells from the peripheral blood mononuclear cells from children with acute lymphoblastic leukemia and NK cells isolated, and the NK cells were stimulated with specific TLR ligands (Poly I:C, Imiquimod, R848, and ODN2006) and we evaluated changes in IFN-γ, CD107a, NKG2D, NKp44 expression, Granzyme B secretion, cytokine/chemokine release, and cytotoxic activity. Results revealed that Poly I:C and Imiquimod enhanced the activation of both immunoregulatory and cytotoxic NK cells, increasing IFN-γ, CD107a, NKG2D, and NKp44 expression. R848 activated immunoregulatory NK cells, while ODN2006 boosted CD107a, NKp44, NKG2D, and IFN-γ secretion in cytotoxic NK cells. R848 also increased the secretion of seven cytokines/chemokines. Importantly, R848 and ODN 2006 significantly improved cytotoxicity against leukemic cells. Overall, TLR stimulation enhances NK cell activation, suggesting TLR8 (R848) and TLR9 (ODN 2006) ligands as promising candidates for antitumor immunotherapy.

Moderate Prenatal Alcohol Exposure Increases Toll-like Receptor Activity in Umbilical Cord Blood at Birth: A Pilot Study.

The prevalence of prenatal alcohol exposure (PAE) is increasing, with evidence suggesting that PAE is linked to an increased risk of infections. PAE is hypothesized to affect the innate immune system, which identifies pathogens through pattern recognition receptors, of which toll-like receptors (TLRs) are key components. We hypothesized that light-to-moderate PAE would impair immune responses, as measured by a heightened response in cytokine levels following TLR stimulation. Umbilical cord samples (10 controls and 8 PAE) from a subset of the Ethanol, Neurodevelopment, Infant and Child Health Study-2 cohort were included. Peripheral blood mononuclear cells (PMBCs) were stimulated with one agonist (TLR2, TLR3, TLR4, or TLR9). TLR2 agonist stimulation significantly increased pro-inflammatory interleukin-1-beta in the PAE group after 24 h. Pro- and anti-inflammatory cytokines were increased following stimulation with the TLR2 agonists. Stimulation with TLR3 or TLR9 agonists displayed minimal impact overall, but there were significant increases in the percent change of the control compared to PAE after 24 h. The results of this pilot investigation support further work into the impact on TLR2 and TLR4 response following PAE to delineate if alterations in levels of pro- and anti-inflammatory cytokines have clinical significance that could be used in patient management and/or attention to follow-up.

Comparative network-based analysis of toll-like receptor agonist, L-pampo signaling pathways in immune and cancer cells.

Toll-like receptors (TLRs) are critical components to stimulate immune responses against various infections. Recently, TLR agonists have emerged as a promising way to activate anti-tumor immunity. L-pampo, a TLR1/2 and TLR3 agonist, induces humoral and cellular immune responses and also causes cancer cell death. In this study, we investigated the L-pampo-induced signals and delineated their interactions with molecular signaling pathways using RNA-seq in immune cells and colon and prostate cancer cells. We first constructed a template network with differentially expressed genes and influential genes from network propagation using the weighted gene co-expression network analysis. Next, we obtained perturbed modules using the above method and extracted core submodules from them by conducting Walktrap. Finally, we reconstructed the subnetworks of major molecular signals utilizing a shortest path-finding algorithm, TOPAS. Our analysis suggests that TLR signaling activated by L-pampo is transmitted to oxidative phosphorylation (OXPHOS) with reactive oxygen species (ROS) through PI3K-AKT and JAK-STAT only in immune and prostate cancer cells that highly express TLRs. This signal flow may further sensitize prostate cancer to L-pampo due to its high basal expression level of OXPHOS and ROS. Our computational approaches can be applied for inferring underlying molecular mechanisms from complex gene expression profiles.

Make it a combo.

Adjuvants that combine TLR agonists and inflammatory agonists promote robust and durable vaccine responses (Bechtold et al. and Arunachalam et al.).

Toll-like Receptor Agonist CBLB502 Protects Against Radiation-induced Intestinal Injury in Mice.

BACKGROUND/AIM: The small intestine is one of the organs most vulnerable to ionizing radiation (IR) damage. However, methods to protect against IR-induced intestinal injury are limited. CBLB502, a Toll-like receptor 5 (TLR5) agonist from Salmonella flagellin, exerts radioprotective effects on various tissues and organs. However, the molecular mechanisms by which CBLB502 protects against IR-induced intestinal injury remain unclear. Thus, this study aimed to elucidate the mechanisms underlying IR-induced intestinal injury and the protective effects of CBLB502 against this condition in mice. MATERIALS AND METHODS: Mice were administered 0.2 mg/kg CBLB502 before IR at different doses for different time points, and then the survival rate, body weight, hemogram, and histopathology of the mice were analyzed. RESULTS: CBLB502 reduced IR-induced intestinal injury. RNA-seq analysis revealed that different doses and durations of IR induced different regulatory patterns. CBLB502 protected against intestinal injury mainly after IR by reversing the expression of IR-induced genes and regulating immune processes and metabolic pathways. CONCLUSION: This study preliminarily describes the regulatory mechanism of IR-induced intestinal injury and the potential molecular protective mechanism of CBLB502, providing a basis for identifying the functional genes and molecular mechanisms that mediate protection against IR-induced injury.

PLGA nanoparticle-delivered Leishmania antigen and TLR agonists as a therapeutic vaccine against cutaneous leishmaniasis in BALB/c mice.

Leishmaniasis, caused by Leishmania (L.) species, remains a neglected infection. Therapeutic vaccination presents a promising strategy for its treatment. In this study, we aimed to develop a therapeutic vaccine candidate using Leishmaniaantigens (SLA) and Toll-like receptor (TLR) 7/8 agonist (R848) encapsulated into the poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs). Moreover, TLR1/2 agonist (Pam3CSK4) was loaded onto the NPs. The therapeutic effects of these NPs were evaluated in L. major-infected BALB/c mice. Footpad swelling, parasite load, cellular and humoral immune responses, and nitric oxide (NO) production were analyzed. The results demonstrated that the PLGA NPs (SLA-R848-Pam3CSK4) therapeutic vaccine effectively stimulated Th1 cell responses, induced humoral responses, promoted NO production, and restricted parasite burden and lesion size.Our findings suggest that vaccination with SLA combined with TLR1/2 and TLR7/8 agonists in PLGA NPs as a therapeutic vaccine confers strong protection againstL. majorinfection. These results represent a novel particulate therapeutic vaccine against Old World cutaneous leishmaniasis.

A novel anti-CD47 protein antibody and toll-like receptor agonist complex detects tumor surface CD-47 changes in early stage lung cancer by in vivo imaging.

CD47, a cell surface protein known for inhibiting phagocytosis, plays a critical role in the tumor microenvironment (TME) and is a potential biomarker for cancer. However, directly applying αCD47, a hydrophilic macromolecular antibody that targets CD47, in vivo for cancer detection can have adverse effects on normal cells, cause systemic toxicities, and lead to resistance against anti-cancer therapies. In this study, we developed a novel complex incorporating aluminum-based metal-organic frameworks (Al-MOF) loaded with indocyanine green (ICG), αCD47, and resiquimod (R848), a hydrophobic small molecule Toll-like receptor 7/8 (TLR7/8) agonist. Upon activation with an infrared 808 nm laser, the nanocomposites exhibited photothermal effects that triggered the release of the loaded reagents, induced ROS production, and induced changes in the TME. This led to the polarization of immune-suppressive M2 macrophages towards an immune-stimulatory M1 phenotype, promoted dendritic cell (DC) maturation, and enabled mature DCs to facilitate antigen presentation, T-cell activation, and critical roles in tumor immunity. Furthermore, in vivo imaging successfully detected the specific binding of αCD47 with CD47 on tumor cells. Overall, the complex composed of αCD47 antibody and toll-like receptor agonist showed promising efficacy in both tumor diagnosis and therapy, providing a potential strategy for detecting early lung cancer and modulating the tumor microenvironment for improved treatment outcomes.

Precision nanoscale patterning of TLR ligands for improved cancer immunotherapy.

In a recent issue of Nature Nanotechnology, Zeng et al. report that arraying immuno-stimulatory CpG molecules with specific nanoscale spacing on DNA origami nanoparticles enhanced Th1-polarized immune responses. These results highlight spatial presentation of adjuvants as a design strategy to optimize cancer vaccine efficacy, safety, and tolerability.

LPS exposure alleviates multiple tissues damage by facilitating macrophage efferocytosis.

Toll-like receptors (TLRs) play a crucial role in mediating immune responses by recognizing pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs), as well as facilitating apoptotic cell (ACs) clearance (efferocytosis), thus contributing significantly to maintaining homeostasis and promoting tissue resolution. In this study, we investigate the impact of TLR agonists on macrophage efferocytosis. Our findings demonstrate that pretreatment with the TLR agonist lipopolysaccharide (LPS) significantly enhances macrophage phagocytic ability, thereby promoting efferocytosis both in vitro and in vivo. Moreover, LPS pretreatment confers tissue protection against damage by augmenting macrophage efferocytic capacity in murine models. Further examination reveals that LPS modulates efferocytosis by upregulating the expression of Tim4.These results underscore the pivotal role of TLR agonists in regulating the efferocytosis process and suggest potential therapeutic avenues for addressing inflammatory diseases. Overall, our study highlights the intricate interplay between LPS pretreatment and efferocytosis in maintaining tissue homeostasis and resolving inflammation.

Effects of toll-like receptor agonists and SARS-CoV-2 antigens on interferon (IFN) expression by peripheral blood CD3+ T cells from COVID-19 patients.

BACKGROUND: Signaling by toll-like receptors (TLRs) initiates important immune responses against viral infection. The role of TLRs in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is not well elucidated. Thus, we investigated the interaction of TLRs agonists and SARS-COV-2 antigens with immune cells in vitro. MATERIAL & METHODS: 30 coronavirus disease 2019 (COVID-19) patients (15 severe and 15 moderate) and 10 age and sex-matched healthy control (HC) were enrolled. Peripheral blood mononuclear cells (PBMCs) were isolated and activated with TLR3, 7, 8, and 9 agonists, the spike protein (SP) of SARS-CoV-2, and the receptor binding domain (RBD) of SP. Frequencies of CD3+IFN-ß+ T cells, and CD3+IFN-γ+ T cells were evaluated by flow cytometry. Interferon (IFN)-ß gene expression was assessed by qRT-PCR. RESULTS: The frequency of CD3+IFN-ß+ T cells was higher in PBMCs from moderate (p < 0.0001) and severe (p = 0.009) patients at baseline in comparison with HCs. The highest increase in the frequency of CD3+IFN-ß+ T cells in cell from moderate patients was induced by TLR8 agonist and SP (p < 0.0001 for both) when compared to HC, while, the highest increase of the frequency of CD3+IFN-ß+ T cells in sample of severe patients was seen with TLR8 and TLR7 agonists (both p = 0.002). The frequency of CD3+IFN-γ+ T cells was significantly increased upon stimulation with TLR agonists in cell from patients with moderate and severe COVID-19, compared with HC (all p < 0.01), except with TLR7 and TLR8 agonists. The TLR8 agonist did not significantly increase the frequency of CD3+IFN-γ+ T cells in PBMCs of severe patients, but did so in cells from patients with moderate disease (p = 0.01). Moreover, IFN-ß gene expression was significantly upregulated in CD3+T cells from moderate (p < 0.0001) and severe (p = 0.002) COVID-19 patients, compared to HC after stimulation with the TLR8 agonist, while, stimulation of T cells with SP, significantly up-regulated IFN-ß mRNA expression in cells from patients with moderate (p = 0.0003), but not severe disease. CONCLUSION: Stimulation of PBMCs from COVID-19 patients, especially patients with moderate disease, with TLR8 agonist and SP increased the frequency of IFN-ß-producing T cells and IFN-ß gene expression.

TLR agonists polarize interferon responses in conjunction with dendritic cell vaccination in malignant glioma: a randomized phase II Trial.

In this randomized phase II clinical trial, we evaluated the effectiveness of adding the TLR agonists, poly-ICLC or resiquimod, to autologous tumor lysate-pulsed dendritic cell (ATL-DC) vaccination in patients with newly-diagnosed or recurrent WHO Grade III-IV malignant gliomas. The primary endpoints were to assess the most effective combination of vaccine and adjuvant in order to enhance the immune potency, along with safety. The combination of ATL-DC vaccination and TLR agonist was safe and found to enhance systemic immune responses, as indicated by increased interferon gene expression and changes in immune cell activation. Specifically, PD-1 expression increases on CD4+ T-cells, while CD38 and CD39 expression are reduced on CD8+ T cells, alongside an increase in monocytes. Poly-ICLC treatment amplifies the induction of interferon-induced genes in monocytes and T lymphocytes. Patients that exhibit higher interferon response gene expression demonstrate prolonged survival and delayed disease progression. These findings suggest that combining ATL-DC with poly-ICLC can induce a polarized interferon response in circulating monocytes and CD8+ T cells, which may represent an important blood biomarker for immunotherapy in this patient population.Trial Registration: ClinicalTrials.gov Identifier: NCT01204684.

The HPV viral regulatory mechanism of TLRs and the related treatments for HPV-associated cancers.

Infection with human papillomavirus (HPV) typically leads to cervical cancer, skin related cancers and many other tumors. HPV is mainly responsible for evading immune tumor monitoring in HPV related cancers. Toll like receptors (TLRs) are particular pattern recognition molecules. When the body is facing immune danger, it can lead to innate and direct adaptive immunity. TLR plays an important role in initiating antiviral immune responses. HPV can affect the expression level of TLR and interfere with TLR related signaling pathways, resulting in sustained viral infection and even carcinogenesis. This paper introduces the HPV virus and HPV related cancers. We discussed the present comprehension of TLR, its expression and signaling, as well as its role in HPV infection. We also provided a detailed introduction to immunotherapy methods for HPV related diseases based on TLR agonists. This will provide insights into methods that support the therapeutic method of HPV related conditions with TLR agonists.

Anti-Inflammatory Effects of Glucagon-Like Peptide-1 Receptor Agonists via the Neuroimmune Axis.

Glucagon-like peptide 1 receptor agonists (GLP-1RAs) have shown efficacy in the treatment of metabolic disease-related complications, partially attributable to their anti-inflammatory properties. However, the specific cell types and pathways involved in these effects were not fully understood. A recent study by Wong et al. demonstrated the importance of the brain GLP-1R in mediating the anti-inflammatory effects of GLP-1RAs in Toll-like receptor and sepsis-mediated inflammation. In this discussion, we review the existing literature on the action of GLP-1RAs in inflammation and explore the implications of these recent findings.

Interferons prime the endothelium for toll-like receptor-mediated thrombin generation.

BACKGROUND: Respiratory infection is associated with microvascular thrombus formation and marked elevation in cytokine levels. The role of cytokines elaborated by the pulmonary epithelium in thrombotic responses is poorly understood. OBJECTIVES: Our goal was to identify cytokines of pulmonary epithelial cell origin that enhance thrombin generation in the endothelium at concentrations equal to or less than those found in the circulation during infection. METHODS: We screened multiple cytokines produced by the pulmonary epithelium for the ability to enhance toll-like receptor (TLR)-mediated endothelial thrombin generation. Effects of cytokines on tissue factor and thrombomodulin expression, cytokine selectivity for different TLRs, and prothrombotic activity of endogenous cytokines in conditioned medium from pulmonary human epithelial cells were evaluated. RESULTS: MIP-1ß, MCP-1, IL-10, IL-6, IL-1ß, TNFα, IFNα, IFNß, and IFNγ were tested for their ability to enhance TLR3-mediated thrombin generation on endothelial cells. Only interferons (IFNs) and TNFα promoted TLR3-mediated thrombin generation at levels that circulate during infection. IFNs robustly enhanced tissue factor expression when used in conjunction with TLR agonists and reduced thrombomodulin expression in the endothelium independently of TLRs. IFNα, which is typically elevated with viral infection, only synergized with TLR3 agonists mimicking viral pathogen-associated molecular patterns. In contrast, IFNγ, which is typically observed in bacterial infection, synergized more effectively with TLR4 agonists released by bacteria. Conditioned media from inflamed pulmonary epithelial cells primed the endothelium for TLR-mediated thrombin generation. Anti-IFN type I antibodies blocked this effect, indicating that endogenous IFNs prime the endothelium for TLR-mediated thrombin generation. CONCLUSION: IFNs elaborated by the pulmonary epithelium are necessary and sufficient to enhance TLR-mediated thrombin generation.

Detection of Nanoparticles' Ability to Stimulate Toll-Like Receptors Using HEK-Blue Reporter Cell Lines.

Nanoparticles can be used to formulate Toll-like receptor (TLR) agonists as vaccine and immunotherapy adjuvants or contain undesirable contaminants (e.g., endotoxin, CpG DNA, flagellin) with TLR-agonist activity. In both scenarios, the activation of the innate immune pattern recognition receptor leads to the inflammatory response that can be beneficial as in the case with vaccines and immunotherapies or adverse as in the case with contaminants. The protocol described herein utilizes commercially available reporter cell lines expressing individual TLRs, which, upon activation with their cognate agonists, stimulate the cells to produce secreted alkaline phosphatase detectable using a plate reader.

Efficiency of Interferon-γ in Activating Dendritic Cells and Its Potential Synergy with Toll-like Receptor Agonists.

Interferon-γ (IFN-γ) is a cytokine that plays an important role in immune regulation, especially in the activation and differentiation of immune cells. Toll-like receptors (TLRs) are a family of pattern-recognition receptors that sense structural motifs related to pathogens and alert immune cells to the invasion. Both IFN-γ and TLR agonists have been used as immunoadjuvants to augment the efficacy of cancer immunotherapies and vaccines against infectious diseases or psychoactive compounds. In this study, we aimed to explore the potential of IFN-γ and TLR agonists being applied simultaneously to boost dendritic cell activation and the subsequent antigen presentation. In brief, murine dendritic cells were treated with IFN-γ and/or the TLR agonists, polyinosinic-polycytidylic acid (poly I:C), or resiquimod (R848). Next, the dendritic cells were stained for an activation marker, a cluster of differentiation 86 (CD86), and the percentage of CD86-positive cells was measured by flow cytometry. From the cytometric analysis, IFN-γ efficiently stimulated a considerable number of the dendritic cells, while the TLR agonists by themselves could merely activate a few compared to the control. The combination of IFN-γ with poly I:C or R848 triggered a higher amount of dendritic cell activation than IFN-γ alone. For instance, 10 ng/mL IFN-γ with 100 µg/mL poly I:C achieved 59.1% cell activation, which was significantly higher than the 33.4% CD86-positive cells obtained by 10 ng/mL IFN-γ. These results suggested that IFN-γ and TLR agonists could be applied as complementary systems to promote dendritic cell activation and antigen presentation. There might be a synergy between the two classes of molecules, but further investigation is warranted to ascertain the interaction of their promotive activities.

Engineered macromolecular Toll-like receptor agents and assemblies.

Macromolecular Toll-like receptor (TLR) agents have been utilized as agonists and inhibitors in preclinical and clinical settings. These agents interface with the TLR class of innate immune receptors which recognize macromolecular ligands that are characteristic of pathogenic material. As such, many agents that have been historically investigated are derived from the natural macromolecules which activate or inhibit TLRs. This review covers recent research and clinically available TLR agents that are macromolecular or polymeric. Synthetic materials that have been found to interface with TLRs are also discussed. Assemblies of these materials are investigated in the context of improving stability or efficacy of ligands. Attention is given to strategies which modify or enhance the current agents and to future outlooks on the development of these agents.

Activation of Most Toll-Like Receptors in Whole Human Blood Attenuates Platelet Deposition on Collagen under Flow.

Platelets have toll-like receptors (TLRs); however, their function in thrombosis or hemostasis under flow conditions is not fully known. Thrombin-inhibited anticoagulated whole blood was treated with various TLR agonists and then perfused over fibrillar collagen using microfluidic assay at venous wall shear rate (100 s-1). Platelet deposition was imaged with fluorescent anti-CD61. For perfusion of whole blood without TLR agonist addition, platelets rapidly accumulated on collagen and eventually occluded the microchannels. Interestingly, most of the tested TLR agonists (Pam3CKS4, MALP-2, polyinosinic-polycytidylic acid HMW, imiquimod, and CpG oligodeoxynucleotides) strongly reduced platelet deposition on collagen, while only the TLR4 agonist endotoxin lipopolysaccharide (LPS) enhanced deposition. Following 90 sec of deposition under flow of untreated blood, the addition of various TLR-7 agonists (imiquimod, vesatolimod, and GSK2245035) all caused immediate blockade of further platelet deposition. Since TLR signaling can activate nuclear factor-kappaB (NF-κB), the IKK-inhibitor (IKK inhibitor VII) and NF-κB inhibitor (Bay 11-7082) were tested. The IKK/NF-κB inhibitors strongly inhibited platelet deposition under flow. Furthermore, addition of Pam3CSK4 (TLR1/2 ligand), MALP-2 (TLR2/6 ligand), and Imquimod (TLR7 ligand) reduced phosphotidylserine (PS) exposure. Activation of TLR1/2, TLR2/6, TLR3, TLR7, and TLR9 in whole blood reduced platelet deposition under flow on collagen; however, LPS (major Gram negative bacterial pathogenic component) activation of LTR4 was clearly prothrombotic.

Therapeutic applications of toll-like receptors (TLRs) agonists in AML.

Acute myeloid leukemia (AML) is an aggressive type of blood cancer affecting bone marrow (BM). In AML, hematopoietic precursors are arrested in the early stages of development and are defined as the presence of ≥ 20% blasts (leukemia cells) in the BM. Toll-like receptors (TLR) are major groups of pattern recognition receptors expressed by almost all innate immune cells that enable them to detect a wide range of pathogen-associated molecular patterns and damage-associated molecular patterns to prime immune responses toward adaptive immunity. Because TLRs are commonly expressed on transformed immune system cells (ranging from blasts to memory cells), they can be a potential option for developing efficient clinical alternatives in hematologic tumors. This is because several in vitro and in vivo investigations have demonstrated that TLR signaling increased the immunogenicity of AML cells, making them more vulnerable to T cell-mediated invasion. This study aimed to review the current knowledge in this field and provide some insight into the therapeutic potentials of TLRs in AML.