Dendritic Cells In Immune Response Research Articles

Indirubin induces tolerogenic dendritic cells via aryl hydrocarbon receptor activation and ameliorates allergic asthma in a murine model by expanding Foxp3-expressing regulatory T cells

Background: Allergic asthma is a chronic bronchial inflammatory disease closely associated with abnormal immune responses of dendritic cells (DCs) and allergen-specific type 2 T helper (Th2) cells. Indirubin (IR), a natural aryl hydrocarbon receptor (AhR) ligand, exerts anti-inflammatory and immunomodulatory properties.Purpose: In this study, we aimed to clarify whether IR exhibits immunomodulatory action on DCs via AhR activation and investigated the antiallergic effects of IR in a mouse model of allergic asthma.Methods: Lipopolysaccharide (LPS)-activated bone marrow-derived DCs were treated with IR. Their mRNA expressions, cytokine production, and phenotype patterns were determined by a quantitative real-time PCR, ELISA, flow cytometry, and RNA sequencing. The mixed lymphocyte reaction was utilized to evaluate the regulatory function of IR-treated DCs on T-cell differentiation. Moreover, mice with ovalbumin (OVA)-induced allergic asthma were treated with IR. Thereafter, the airway hyperresponsiveness (AHR), allergen-specific IgE production, cytokine levels, airway inflammation, and T-cell responses were evaluated.Results: Treatment of LPS-stimulated DCs with 20 μM IR significantly reduced IL-12 and TNF-α production while increasing IL-10 secretion. Meanwhile, these DCs expressed decreased levels of CD80 but increased levels of Jagged 1 surface molecules. However, the effects of IR on DCs were reversed by pretreatment with the AhR antagonist, CH223191. Additionally, the coculture of these tolerogenic-like DCs with allogeneic CD4+ T cells promoted the generation of Foxp3+ regulatory T (Treg) cells. A transcriptomic analysis identified several downregulated genes that are involved in regulating cell migration, cytokine secretion, and inflammatory responses in DCs after IR treatment. In an asthmatic murine model, oral administration of 25 mg/kg body weight of IR efficiently alleviated the development of AHR, OVA-specific IgE production, and levels of Th2-type cytokines (IL-4, IL-5, and IL-13) and the CCL11 chemokine. IR treatment also attenuated inflammatory cell recruitment and mucus production in the lungs. Notably, an enhanced frequency of Foxp3+ Treg cells and reduced effector T-cell proliferation associated with increased levels of IL-10 and TGF-β were observed in IR-treated mice.Conclusion: IR can induce tolerogenic-like BMDCs which promote the differentiation of Treg cells. Importantly, the expansion of Foxp3+ Treg cells contributed to the therapeutic efficacy of IR against allergic asthma.

Profiling of Early Immune Responses to Vaccination Using THP-1-Derived Dendritic Cells.

The COVID-19 pandemic has made assessing vaccine efficacy more challenging. Besides neutralizing antibody assays, systems vaccinology studies use omics technology to reveal immune response mechanisms and identify gene signatures in human peripheral blood mononuclear cells (PBMCs). However, due to their low proportion in PBMCs, profiling the immune response signatures of dendritic cells (DCs) is difficult. Here, we develop a predictive model for evaluating early immune responses in dendritic cells. We establish a THP-1-derived dendritic cell (TDDC) model and stimulate their maturation in vitro with an optimal dose of attenuated yellow fever 17D (YF-17D). Transcriptomic analysis reveals that type I interferon (IFN-I)-induced immunity plays a key role in dendritic cells. IFN-I regulatory biomarkers (IRF7, SIGLEC1) and IFN-I-inducible biomarkers (IFI27, IFI44, IFIT1, IFIT3, ISG15, MX1, OAS2, OAS3) are identified and validated in vitro and in vivo. Furthermore, we apply this TDDC approach to various types of vaccines, providing novel insights into their early immune response signatures and their heterogeneity in vaccine recipients. Our findings suggest that a standardizable TDDC model is a promising predictive approach to assessing early immunity in DCs. Further research into vaccine efficacy assessment approaches on various types of immune cells could lead to a systemic regimen for vaccine development in the future.

Mild magnetic hyperthermia-activated immuno-responses for primary bladder cancer therapy

Surgical intervention followed by chemotherapy is the principal treatment strategy for bladder cancer, which is hindered by significant surgical risks, toxicity from chemotherapy, and high rates of recurrence after surgery. In this context, a novel approach using mild magnetic hyperthermia therapy (MHT) for bladder cancer treatment through the intra-bladder delivery of magnetic nanoparticles is presented for the first time. This method overcomes the limitations of low magnetic thermal efficiency, inadequate tumor targeting, and reduced therapeutic effectiveness associated with the traditional intravenous administration of magnetic nanoparticles. Core-shell Zn–CoFe2O4@Zn–MnFe2O4 (MNP) nanoparticles were developed and further modified with hyaluronic acid (HA) to enhance their targeting ability toward tumor cells. The application of controlled mild MHT using MNP-HA at temperatures of 43–44 °C successfully suppressed the proliferation of bladder tumor cells and tumor growth, while also decreasing the expression levels of heat shock protein 70 (HSP70). Crucially, this therapeutic approach also activated the body's innate immune response involving macrophages, as well as the adaptive immune responses of dendritic cells (DCs) and T cells, thereby reversing the immunosuppressive environment of the bladder tumor and effectively reducing tumor recurrence. This study uncovers the potential immune-activating mechanism of mild MHT in the treatment of bladder cancer and confirms the effectiveness and safety of this strategy, indicating its promising potential for the clinical management of bladder cancer with a high tendency for relapse.

High-Fat Diet Influences Dendritic Cells and T-Cell Infiltration in Apical Periodontitis in Mice

IntroductionDiet-induced metabolic syndrome may influence the progression and healing of apical periodontitis (AP). The aim of this study was to evaluate the inflammatory immune response of dendritic cells (DCs) and T helper (Th) cells in normal versus obese mice with AP. MethodsTwenty male C57BL/6 mice were divided into 2 groups: normal chow (NC) and high-fat diet (HFD) for 12 wk. AP was induced in both groups by creating pulp exposure of the right first maxillary molar to the oral environment. Contralateral first molars from each mouse were used as a control. The animal's body mass was recorded on a weekly basis, and they were euthanized after 30 d. The maxillae were removed and processed for micro-computed tomography (micro-CT), histologic analysis, and immunofluorescence staining for DCs (CD11c), Th17 (IL-17A), and T regulatory cells (FOXP3 and IL-10). Different groups were analyzed by Mann-Whitney U test, Student t test, and ordinary 1-way analysis of variance followed by Tukey's multiple comparisons test. The level of significance (α) was set at 0.05. ResultsThe HFD group showed larger AP lesions than the NC group from micro-CT analysis. For the NC group, induction of AP significantly increased immune cell infiltration when compared with control. HFD showed increased DCs and Th17 infiltration in the control group without AP. In addition, there was no significant change in the amount of DCs and Th17 in the HFD-AP group when compared with the NC-AP and HFD-control groups. ConclusionsHFD resulted in an increased immune cell infiltration in the periapical area without AP. Despite the larger AP lesion observed in HFD-AP than that of NC-AP, the amount of infiltrated inflammatory cells did not differ significantly. The results of this study suggest that the DCs and Th17 inflammatory pathways are affected by HFD in the periapical region, but their contribution toward AP complicated by metabolic syndrome requires further investigation.

Tumor cell lysate with low content of HMGB1 enhances immune response of dendritic cells against lung cancer in mice

To assess the effect of tumor cell lysate (TCL) with low high-mobility group B1 (HMGB1) content for enhancing immune responses of dendritic cells (DCs) against lung cancer. TCLs with low HMGB1 content (LH-TCL) and normal HMGB1 content (NH-TCL) were prepared using Lewis lung cancer (LLC) cells in which HMGB1 was inhibited with 30 nmol/L glycyrrhizic acid (GA) and using LLC cells without GA treatment, respectively. Cultured mouse DCs were exposed to different doses of NH-TCL and LH-TCL, using PBS as the control. Flow cytometry was used to detect the expressions of CD11b, CD11c and CD86 and apoptosis of the stimulated DCs, and IL-12 levels in the cell cultures were detected by ELISA. Mouse spleen cells were co-cultured with the stimulated DCs, and the activation of the spleen cells was assessed by detecting CD69 expression using flow cytometry; TNF-β production in the spleen cells was detected with ELISA. The spleen cells were then co-cultured with LLC cells at the effector: target ratios of 5:1, 10:1 and 20:1 to observe the tumor cell killing. In the animal experiment, C57/BL6 mouse models bearing subcutaneous LLC xenograft received multiple injections with the stimulated DCs, and the tumor growth was observed. The content of HMGB1 in the TCL prepared using GA-treated LLC cells was significantly reduced (P < 0.01). Compared with NH-TCL, LH-TCL showed a stronger ability to reduce apoptosis (P < 0.001) and promote activation and IL- 12 production in the DCs. Compared with those with NH-TCL stimulation, the DCs stimulated with LH-TCL more effectively induced activation of splenic lymphocytes and enhanced their anti-tumor immunity (P < 0.05). In the cell co-cultures, the spleen lymphocytes activated by LH-TCL-stimulated DCs showed significantly enhanced LLC cell killing activity (P < 0.01). In the tumor-bearing mice, injections of LH-TCL-stimulated DCs effectively activated host anti-tumor immunity and inhibited the growth of the tumor xenografts (P < 0.05). Stimulation of the DCs with LH-TCL enhances the anti-tumor immune activity of the DCs and improve the efficacy of DCbased immunotherapy for LLC in mice.

Alisol B 23-Acetate Ameliorates Ovalbumin-Induced Allergic Asthma during Sensitization and Challenge Periods.

Rhizome of Alisma orientale has been used as a traditional medicine for treating kidney diseases in East Asian countries. Its inhibitory effects on hypersensitivity responses have been reported for methanol extracts, with alisol B 23-acetate (AB23Ac) being the most active constituent among six terpenes in inhibiting the direct passive Arthus reaction. However, whether AB23Ac has efficacy against allergic asthma has not been tested to date. The in vivo efficacy of AB23Ac in an ovalbumin (OVA)-induced allergic asthma mouse model was evaluated by administrating AB23Ac before OVA sensitization or OVA challenge in BALB/c mice. AB23Ac suppressed antigen-induced degranulation of RBL-2H3 mast cells in a concentration-dependent manner. The administration of AB23Ac both before OVA sensitization and OVA challenge greatly lowered pulmonary resistance and the increase in immune cell counts and inflammatory responses around the peribronchial and perivascular regions. In addition, the inflammatory cytokine levels of Th1/Th2/Th17 cells in the bronchoalveolar lavage fluid decreased in the AB23Ac-treated groups. AB23Ac reduced the number of PAS-stained cells in the lungs. Furthermore, a computer modeling study indicated that AB23Ac can bind tightly to spleen tyrosine kinase (Syk). These results suggest that AB23Ac may ameliorate allergic asthma by suppressing immune responses in dendritic cells during sensitization and in mast cells during challenge periods.

Comparative genomics identified TLR-dependent fine tuning of the dendritic cell immune response by melatonin

Abstract Melatonin, a neuro hormone, has been shown to activate human monocytes and induce their cytotoxic properties in addition to the production of IL-1, IL-6, and TNF-α. The molecular mechanisms involved in melatonin and dendritic cell interactions are largely unknown. In this study, we performed a comprehensive RNA sequencing (RNA-seq)-based analysis of monocyte-derived human dendritic cells across different melatonin stimulations. We profiled gene expression changes among naïve DCs along with DCs generated with melatonin (MDCs) and DCs matured with melatonin (DCMs). We found that melatonin significantly promoted the morphological maturation of MDCs and increased the expression of DC-related surface markers. Furthermore, MDCs increased the general immune response by promoting the secretion of IL-12, IL-6 and IFN-γ cytokines and enhancing the proliferation of TH cells, while DCM did not. Genome-wide comparative transcriptomic profiling showed that the expression of 7417 genes was significantly upregulated, and 3325 genes were significantly downregulated in MDCs. We observed the spatiotemporal activity of TLR 2-, 4-, 6- and 8-specific genes in MDCs. Interestingly, we found that the expression of TLR 10-specific signaling genes was significantly higher in DCMs. Further in vitro validation showed that along with TLRs, the upregulation of IRAK, GRB2, CREB and TNFRSF was significantly associated with MDCs. Overall, we found that during the differentiation of dendritic cells, the presence of melatonin generates a unique population of dendritic cells with activated TLR4 signaling. DCs generated through this unique culture process may act as good candidates for immunomodulation during cancer and inflammation. Supported by grants fromDST-SERB, GOI (CRG/2019/001296)

Curcumin mediated dendritic cell maturation by modulating cancer associated fibroblasts-derived exosomal miRNA-146a.

Though cancer associated fibroblasts (CAFs), being a main component of tumor microenvironment (TME), are known to modulate immune response through secretion of various growth hormones, exosomes carrying miRNAs and cytokines; their effect on dendritic cells (DCs) are yet to be elucidated. Thus, aim of this study was to assess the effect of miRNAs and cytokines released by lung-CAFs and to evaluate immunomodulatory potential of curcumin on DC maturation through modulating their TME. To check the effect of CAFs derived exosomes on DC maturation, we cultured imDCs in the presence of CAFs derived conditioned media (CAFs-CM) and characterized by the presence of maturation markers CD80, CD83, CD86 and CTLA4 using qRT-PCR. Additionally, expression of miR-221, miR-222, miR-155, miR-142-3p and miR-146a was assessed to evaluate the role of epigenetic regulators on DC maturation. Likewise, cytokine profiling of CAFs-CM as well as CAFs-CM treated with curcumin was also conducted using ELISA. Results revealed the generation of regulatory DCs which were characterized by decreased expression of maturation markers in the presence of CAFs-CM. In addition, such DCs showed higher expression of epigenetic regulator miR-146a which was positively correlated with increased expression of anti-inflammatory cytokines like IL-6, IL-10, TGF-β and decreased expression of TNF-α (pro-inflammatory). Moreover, curcumin had the potential to convert regulatory DCs generated by CAFs into mDCs, which were characterized by high expression of co-stimulatory molecules, low expression of CTLA4, lower levels of immune suppressive cytokines production and lower levels of miR-146a. Collectively, these findings provide insight into understanding the immunomodulatory role of curcumin in targeting CAFs and modulating TME, thus enhancing antitumor immune response in DC based therapy.

The MicroRNA-106a/20b Strongly Enhances the Antitumour Immune Responses of Dendritic Cells Pulsed with Glioma Stem Cells by Targeting STAT3.

Background Evaluate the effect of the miRNA-106a/20b on the efficacy of DCs pulsed with GSCs in activating GSC-specific T cell responses. Methods We cultured GSCs and prepared GSC antigen lysates by apoptosis. Then, immature DCs were pulsed with GSC antigen lysates in vitro. STAT3 levels in DCs were assessed by Western blotting, and the expression of CD80, CD86, and MHC-II was tested by fluorescence-activated cell sorting. The production and secretion of the cytokines IL-6, IL-12, TNF-α, and IL-10 in DCs induced by GSCs were determined by enzyme-linked immunosorbent assay. Finally, the cytotoxic functions of T cells stimulated by GSC-DC fusion cells transfected with a miR-106a/20b mimic in vitro and the antitumour activity in vivo were detected. Results We found that the levels of miR-106a/20b were downregulated, but the expression of STAT3 was significantly upregulated. Simultaneously, the inhibition of STAT3 in the fusion cells by STAT3-specific siRNA caused significant upregulation of the expression of CD80, CD86, and MHC-II, and the secretion of the cytokines IL-6 and IL-12 was substantially increased, IL-10 was markedly decreased. These findings revealed that STAT3 is an important regulator of DC maturation. Furthermore, the interactional binding sites between the 3′-untranslated region (3′-UTR) of STAT3 mRNA and miR-106a/20b were predicted by bioinformatics and verified by a dual-luciferase assay. Moreover, the reduction in STAT3 levels in GSC-DCs enhanced the generation of CD8+ T cells and reduced the generation of Foxp3+ regulatory T cells. Meanwhile, the secretion of the T cell cytokine IFN-γ was significantly increased. Further research showed that DCs after miR-106a/20b-mimics transfection could promote the inhibition of GSC proliferation by T cells in vitro and suppress tumour growth in vivo. Conclusions This study indicted that the miR-106a/20b activation could be one of the important molecular mechanisms leading to enhance antitumour immune responses of GSC-mediated DCs, which downregulated the expression of STAT3 to alleviate its the inhibitory effect.

Combination of different probiotics and berry-derived (poly)phenols can modulate immune response in dendritic cells

• There is an ongoing interest in characterizing probiotic strains for specific health purposes and physiological conditions. • Berry-derived polyphenols are increasingly studied for their anti-inflammatory features. • Synergism between selected probiotic strains from different species and genus might increase their immunomodulatory potential. • Association of probiotics and berry polyphenolic extracts can enhance the anti-inflammatory effects. • Select and characterize a combination of specific probiotic strains and defined berry polyphenolic extracts might be useful for the development of food supplements. The immunomodulatory potential of probiotics and (poly)phenols (PP) is recognized; however, studies regarding microorganisms-PP synergisms are yet to be explored. Here, we investigated the cooperation between probiotics and berry-derived PP extracts in modulating the cytokine responses in dendritic cells. Bacteria elicited immune responses in a strain-dependent manner. PP extracts showed different modulation of cytokine triggered by bacteria. Also with LPS, used as pro-inflammatory stimulus, PP from blueberry (BB) and cranberry (CB) most efficiently reduced IL12 production. L. paracasei LPC-S01 and B. bifidum MIMBb23sg resulted the best bacterial association in abrogating IL12 and increasing IL10. The use of PP fraction from BB50f and CB1 with the LPC-S01 + MIMBb23sg association resulted the most efficient combinations in terms of anti-inflammatory activity. These results provide bases for further investigation in vivo , in the perspective to develop food supplements that might conceivably deliver the single and combined benefits of probiotics and berry (poly)phenols.

Multifunctional manganese-containing vaccine delivery system Ca@MnCO3/LLO for tumor immunotherapy.

The ideal vaccine delivery systems can not only deliver antigens in intelligent manners but also act as adjuvants. Recently found that Mn2+ can effectively stimulate anti-tumor immune responses, and Ca2+ can regulate autophagy to promote the cross-presentation of antigens. Thus, we constructed such a manganese-containing multimode vaccine delivery system by using calcium-doped manganese carbonate microspheres (Ca@MnCO3) and perforin-listeria hemolysin (LLO), as termed as Ca@MnCO3/LLO. The two components Ca@MnCO3 and LLO, not only act as vaccine adjuvants by themselves, but also contribute to achieve cellular immunity. Among them, Ca@MnCO3 microspheres as an excellent Mn2+ and Ca2+ reservoir, can continuously release adjuvants Mn2+ and Ca2+ to enhance immune response in dendritic cells, while LLO can contribute to induce lysosomal escape. Particularly, Ca2+ was added firstly to MnCO3 microspheres to improve the stability and load capacity of the microspheres. Along with the degradation of intracellular Ca@MnCO3 microspheres, and the lysosomal membrane-lytic effects of perforin LLO, the Mn2+, Ca2+ and OVA were released to the cytoplasm. These outcomes cooperatively promote antigen cross-presentation, elicit CD8+ T cell proliferation, and finally achieve prominent anti-tumor effects. The results indicate that the manganese-containing vaccine delivery system Ca@MnCO3/LLO provides a promising platform for the construction of tumor vaccines.

REL and BHLHE40 Variants Are Associated with IL-12 and IL-10 Responses and Tuberculosis Risk.

The major human genes regulating Mycobacterium tuberculosis-induced immune responses and tuberculosis (TB) susceptibility are poorly understood. Although IL-12 and IL-10 are critical for TB pathogenesis, the genetic factors that regulate their expression in humans are unknown. CNBP, REL, and BHLHE40 are master regulators of IL-12 and IL-10 signaling. We hypothesized that common variants in CNBP, REL, and BHLHE40 were associated with IL-12 and IL-10 production from dendritic cells, and that these variants also influence adaptive immune responses to bacillus Calmette-Guérin (BCG) vaccination and TB susceptibility. We characterized the association between common variants in CNBP, REL, and BHLHE40, innate immune responses in dendritic cells and monocyte-derived macrophages, BCG-specific T cell responses, and susceptibility to pediatric and adult TB in human populations. BHLHE40 single-nucleotide polymorphism (SNP) rs4496464 was associated with increased BHLHE40 expression in monocyte-derived macrophages and increased IL-10 from peripheral blood dendritic cells and monocyte-derived macrophages after LPS and TB whole-cell lysate stimulation. SNP BHLHE40 rs11130215, in linkage disequilibrium with rs4496464, was associated with increased BCG-specific IL-2+CD4+ T cell responses and decreased risk for pediatric TB in South Africa. SNPs REL rs842634 and rs842618 were associated with increased IL-12 production from dendritic cells, and SNP REL rs842618 was associated with increased risk for TB meningitis. In summary, we found that genetic variations in REL and BHLHE40 are associated with IL-12 and IL-10 cytokine responses and TB clinical outcomes. Common human genetic regulation of well-defined intermediate cellular traits provides insights into mechanisms of TB pathogenesis.

Primary tumour immune response and lymph node yields in colon cancer

BackgroundThe mechanism underlying improved survival in non-metastatic colon cancer with higher lymph node (LN) yield is unknown. This study aimed to identify whether molecular features in the primary tumour were predictive of LN yield.MethodsClinical, genomic, transcriptomic, proteomic and methylation data of non-metastatic, colon cancers studied in The Cancer Genome Atlas were interrogated for associations with LN yield. Based on maximal survival effects, patients were segregated into high (>15) and low (≤15) LN yield. Gene set enrichment analysis was performed on transcriptomic changes to identify biological processes associated with LN yield. Correlations were validated in an independent set of Stage II colon cancers.ResultsHigh LN yield was found predictive of overall and disease-free survival. There was no association of higher LN yield and increasing nodal positivity. High LN yield was strongly linked with gene expression changes associated with the adaptive and dendritic cell immune response. This association was most prominent in node-negative cancers. Analogous findings were reproduced in the validation dataset.ConclusionThe study shows a strong association of an activated immune response in tumours with a high LN yield. Immunogenic tumours have a better prognosis, likely explaining the survival benefit with higher LN yields.

PD09-03 EXTRACELLULAR VESICLES: A MECHANISM OF ACTION OF BACILLUS CALMETTE-GUERIN AND A POTENTIAL BIOMARKER

You have accessJournal of UrologyBladder Cancer: Non-invasive I (PD09)1 Sep 2021PD09-03 EXTRACELLULAR VESICLES: A MECHANISM OF ACTION OF BACILLUS CALMETTE-GUERIN AND A POTENTIAL BIOMARKER Carlos Ortiz-Bonilla, Scott Gerber, Hiroshi Miyamoto, Edith Lord, Edward Messing, and Yi-Fen Lee Carlos Ortiz-BonillaCarlos Ortiz-Bonilla More articles by this author , Scott GerberScott Gerber More articles by this author , Hiroshi MiyamotoHiroshi Miyamoto More articles by this author , Edith LordEdith Lord More articles by this author , Edward MessingEdward Messing More articles by this author , and Yi-Fen LeeYi-Fen Lee More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001977.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Extracellular vesicles (EVs), small double-membrane vesicles, have recently gained attention because of their potential roles in mediating immune responses and cancer treatments. Intravesical Bacillus Calmette-Guérin (BCG) immunotherapy is arguably one of the most successful immunotherapies for cancer, yet a significant number of patients fail response to BCG, and its underlying mechanisms remain largely unknown. In this study, we aim to test a new mode of BCG action mediated by BCG immune-active EVs (EVsBCG) released by BC cells. METHODS: Two immuno-responsive BC cell lines, human T24 and murine MB49 were used. CFU of cultured Live TICE® BCG was determined and applied on in vitro and in vivo experiments. BCG-induced immuno-molecular alteration in BC cells and EVsBCG was determined by quantitative PCR, Western blotting and Nanoparticle Tracking Analysis. EVsBCG-activated immune responses in dendritic cells were assessed by flow cytometry analyses. Moreover, we examined whether priming mice with EVsBCG can enhance BCG efficacy using the MB49 syngeneic model. The profiles of urinary EVs from BCG patients were evaluated for their predictive value. RESULTS: In response to BCG treatment, T24 and MB49 BC cells showed a significant increase in EVs secretion. EVsBCG contain elevated levels of key proteins in modulating immune responses, including MHC-I, MHC-II and CD80, CD86 co-stimulatory molecules. EVsBCG activated dendritic cells in vitro. Most importantly, priming mice with EVsBCG enhances BCG immunotherapy efficacy as compared to naïve EVs-primed mice. Interestingly, patients who respond to BCG showed significantly increased urinary EV numbers after the third BCG instillation, compared to non-responders in a pilot project. CONCLUSIONS: A novel mode of BCG action was presented. We showed that BCG promotes the release of immuno-active EVs by BC cells. Those EVsBCG can directly activate dendritic cells to modulate BCG-induced anti-tumor host response that warrants the therapeutic benefit of EVsBCG as an adjuvant therapy. Together, these data suggest that BCEVs play an important role in the mechanism of action of BCG immunotherapy. More importantly, patient-derived EVs during BCG immunotherapy may serve as predictive biomarkers. Source of Funding: HOPE Foundation, GR500600 © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e120-e120 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Carlos Ortiz-Bonilla More articles by this author Scott Gerber More articles by this author Hiroshi Miyamoto More articles by this author Edith Lord More articles by this author Edward Messing More articles by this author Yi-Fen Lee More articles by this author Expand All Advertisement Loading ...

Effects of Fatty Acid Oxidation and Its Regulation on Dendritic Cell-Mediated Immune Responses in Allergies: An Immunometabolism Perspective.

Type 1 allergies, involve a complex interaction between dendritic cells and other immune cells, are pathological type 2 inflammatory immune responses against harmless allergens. Activated dendritic cells undergo extensive phenotypic and functional changes to exert their functions. The activation, differentiation, proliferation, migration, and mounting of effector reactions require metabolic reprogramming. Dendritic cells are important upstream mediators of allergic responses and are therefore an important effector of allergies. Hence, a better understanding of the underlying metabolic mechanisms of functional changes that promote allergic responses of dendritic cells could improve the prevention and treatment of allergies. Metabolic changes related to dendritic cell activation have been extensively studied. This review briefly outlines the basis of fatty acid oxidation and its association with dendritic cell immune responses. The relationship between immune metabolism and effector function of dendritic cells related to allergic diseases can better explain the induction and maintenance of allergic responses. Further investigations are warranted to improve our understanding of disease pathology and enable new treatment strategies.

Inhibition of fibroblast IL-6 production by ACKR4 deletion alleviates cardiac remodeling after myocardial infarction

Fibrotic scarring is tightly linked to the development of heart failure in patients with post-myocardial infarction (MI). Atypical chemokine receptor 4 (ACKR4) can eliminate chemokines, such as C–C chemokine ligand 21 (CCL21), which is independently associated with heart failure mortality. However, the role of ACKR4 in the heart during MI is unrevealed. This study aimed to determine whether ACKR4 modulates cardiac remodeling following MI and to illuminate the potential molecular mechanisms. The expression of ACKR4 was upregulated in the border/infarct area, and ACKR4 was predominantly expressed in cardiac fibroblasts (CFs). Knockout of ACKR4 protected against adverse ventricular remodeling in mice post-MI. These protective effects of ACKR4 deficiency were independent of dendritic cell immune response but could be attributed to downregulated CF-derived IL-6, affecting CF proliferation and endothelial cell (EC) functions, which consequently inhibited cardiac fibrosis. ACKR4 promoted IL-6 generation and proliferation of CFs. Besides, ACKR4 induced endothelial-to-mesenchymal transition (EndMT) in ECs through IL-6 paracrine effect. The p38 MAPK/NF-κB signaling pathway was involved in ACKR4 facilitated IL-6 generation. Moreover, ACKR4 overexpression in vivo via AAV9 carrying a periostin promoter aggravated heart functional impairment post-MI, which was abolished by IL-6 neutralizing antibody. Therefore, our study established a novel link between ACKR4 and IL-6 post-MI, indicating that ACKR4 may be a novel therapeutic target to ameliorate cardiac remodeling.

Facile synthesis of magnetic silica-mannan nanocomposites for enhancement in internalization and immune response of dendritic cells

Superparamagnetic iron oxide nanoparticles (SPIONs) have been extensively exploited in biomedicine, especially as contrasting agents. In this work, SPIONs are of our interest as directing agents to the targeted dendritic cells (DCs). Mannan extracted from Saccharomyces cerevisiae was used as DCs targeting moieties. Herein, nanocomposites of silica magnetic nanoparticle-mannan (S-SPION-MN) were successfully synthesized as a magnetically assisted delivery system. The materials before Silica magnetic nanoparticles (S-SPION) and after mannan modification were characterized using a vibrating sample magnetometer to confirm their superparamagnetic character. The change in zeta potential from highly negative charge to slightly negative charge of the composites suggested the successful attachment of mannan on their surface. Chemical analysis using x-ray photoelectron spectroscopy revealed the attachment of mannan through chemical bonding, corresponding to the observation of high stability of the particles over a two-week period. The synthesized materials were investigated for cytotoxicity, DC maturation, cytokine production, and cellular uptake. Moderate cell viability was observed after stimulating cells with the particulate mannan, S-SPION-MN, due to high activation of DCs. Under a magnetic induction, S-SPION-MN showed significant enhancement of DCs targeting within 15 min. Owing to the incorporation of mannan and SPIONs, the S-SPION-MN greatly enhanced cellular uptake and accordingly resulted in high DC activation and maturation. The resulted nanocomposites can be beneficial as a potential candidate in antigen delivery to targeted immune cells for further in vivo study.

Cell Migration Guided by Cell-Cell Contacts in Innate Immunity.

The directed migration of leukocytes to sites of damage or infection is necessary for a productive immune response. There is substantial evidence supporting a key role for chemoattractants in directed migration, however, less is known about how cell-cell contacts affect the migratory behavior of leukocytes in innate immunity. Here, we explore how cell-cell contacts can affect the directed migration of innate immune cells, including their role in attracting, repelling, or stopping cell motility. Further investigation of cell contact dynamics as guidance cues may yield new insights into the regulation of innate immunity.

Nanovaccine Impact on Dendritic Cells: Transcriptome Analysis Enables New Insights Into Antigen and Adjuvant Effects

Aim: For vaccines the combination between an antigen and adjuvants are both crucially important to trigger an effective immune response in dendritic cells. Innovative adjuvants like resiquimodor muramyldipeptidehave their target protein inside the cell. Materials & methods: Up/downregulation and proteome expression was investigated for the adjuvant combination resiquimod and muramyldipeptide in a soluble form versus encapsulated into a nanocarrier. Results: We found that 1225 genes were upregulated after nanocarrier treatment while 478 genes were downregulated. Most prominent were interferon-stimulated genes with more than 25-times higher expression after nanocarrier treatment, for example RSAD2 and ISG15, which were recently found to have antiviral or antitumor effects. Conclusion: Encapsulation gives a more effective upregulation of vaccine-related genes.

Autophagic protein ATG5 controls antiviral immunity via glycolytic reprogramming of dendritic cells against respiratory syncytial virus infection

ABSTRACT Respiratory syncytial virus (RSV) is a leading cause of respiratory tract infections in infants. Macroautophagy/autophagy is a catalytic metabolic process required for cellular homeostasis. Although intracellular metabolism is important for immune responses in dendritic cells, the link between autophagy and immunometabolism remains unknown. Here, we show that the autophagy-related protein ATG5 regulates immunometabolism. Atg5-deficient mouse dendritic cells showed increased CD8A+ T-cell response and increased secretion of proinflammatory cytokines upon RSV infection. Transcriptome analysis showed that Atg5 deficiency alters the expression of metabolism-related genes. Atg5-deficient dendritic cells also showed increased activation of glycolysis and the AKT-MTOR-RPS6KB1 pathway and decreased mitochondrial activity, all of which are cellular signatures for metabolic activation. These cells also showed elevated CD8A+ T-cell priming and surface major histocompatibility complex (MHC) class I expression. Our results suggested that ATG5 regulated host immune responses by modulating dendritic cell metabolism. These findings may help develop potential antiviral therapies that alter host immunity by regulating autophagy and immunometabolism. Abbreviations : 2-DG: 2-deoxyglucose; AAK1: AP2 associated kinase 1; AKT: AKT serine/threonine kinase; AM: alveolar macrophage; ATG: autophagy; ATP: adenosine triphosphate; BAL: bronchoalveolar lavage; BMDC: bone marrow dendritic cell; CSF2/GM-CSF: colony-stimulating factor 2 (granulocyte-macrophage); CTL: cytotoxic T lymphocyte; ELISA: enzyme-linked immunosorbent assay; GFP: green fluorescent protein; GSEA: gene-set enrichment analysis; H-2Db: H-2 class I histocompatibility antigen, D-B alpha chain; H-2Kb: MHC class I H2-K-b; HIF1A: hypoxia-inducible factor 1 alpha; IFNG: interferon-gamma; IL: interleukin; ITGAX: integrin alpha X; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MHC: major histocompatibility complex; MTORC1: mammalian target of rapamycin kinase complex 1; PBS: phosphate-buffered saline; PFU: plaque-forming unit; RLR: retinoic acid-inducible-I-like receptor; ROS: reactive oxygen species; RPMI: Roswell Park Memorial Institute; RPS6KB1/S6K: ribosomal protein S6 kinase, polypeptide 1; RSV: respiratory syncytial virus; Th: T helper; TLR: toll-like receptor; Treg: regulatory T cells; UMAP: uniform manifold approximation and projection.