REVIEW | doi:10.20944/preprints202011.0016.v1
Subject: Life Sciences, Biochemistry Keywords: mast cells; adaptive immunity; dendritic cells; T cells
Online: 2 November 2020 (10:27:12 CET)
Although Mast cells are known as key drivers of type I allergic reactions, there is increasing evidence for their critical role in host defense. MCs do not only play an important role in initiating innate immune responses, but also influence the onset, kinetic and amplitude of the adaptive arm of immunity, or fine-tune the mode of the adaptive reaction. Intriguingly, MCs have been shown to affect T cell activation by direct interaction or indirectly by modifying properties of antigen-presenting cells, and can even modulate lymph node-borne adaptive responses remotely from the periphery. In this review, we provide a summary of recent findings that explain how MCs act as a link between the innate and the adaptive immunity, all the way from sensing inflammatory insult to orchestrating the final outcome of the immune response.
REVIEW | doi:10.20944/preprints201904.0007.v1
Subject: Life Sciences, Immunology Keywords: dendritic cells; Th2 immunity; genetic factors; environmental factors; Th2 disorders; therapeutic approaches
Online: 1 April 2019 (10:14:44 CEST)
Dendritic cells (DCs) are the professional antigen-presenting cells that recognize and present antigens to naïve T cells to induce antigen-specific adaptive immunity. Among the T-cell subsets, T helper type 2 (Th2) cells produce the humoral immune responses required for protection against helminthic disease by activating B cells. DCs induce a Th2 immune response at a certain immune environment. Basophil, eosinophil, mast cells, and type 2 innate lymphoid cells also induce Th2 immunity. However, in the case of DCs, controversy remains regarding which subsets of DCs induce Th2 immunity, which genes in DCs are directly or indirectly involved in inducing Th2 immunity, and the detailed mechanisms underlying induction, regulation, or maintenance of the DC-mediated Th2 immunity against allergic environments and parasite infection. A recent study has shown that a genetic defect in DCs causes an enhanced Th2 immunity leading to a severe atopic dermatitis. We summarize the Th2 immune-inducing DC subsets, the genetic and environmental factors which involved in DC-mediated Th2 immunity, and current therapeutic approaches for Th2-mediated immune disorders. This review is to provide an improved understanding of DC-mediated Th2 immunity and Th1/Th2 immune balancing, leading to control over their adverse consequences.
ARTICLE | doi:10.20944/preprints201808.0156.v1
Subject: Life Sciences, Immunology Keywords: Sporothrix schenckii; bone-marrow-derived dendritic cells; vaccine; sporotrichosis
Online: 8 August 2018 (04:32:10 CEST)
Sporotrichosis is a subcutaneous mycosis affecting humans and other animals that can be transmitted a zoonosis with cats as the main vector. The conventional anti-fungal therapy is especially inefficient in immunocompromised patients, who tend to develop the most severe forms of the disease, thus prompting the search for alternative therapies. Given their antigen-presenting properties, dendritic cells (DCs) have been used in both prophylactic and therapeutic vaccination strategies. Hence, this study aims to assess the use of DCs as a prophylactic tool in sporotrichosis by evaluating the immune profile induced by Sporothrix schenckii cell wall proteins (SsCWP)-stimulated bone-marrow-derived DCs (BMDCs). Mouse BMDCs were stimulated with SsCWP for 24 hours and analyzed for the surface expression of co-stimulatory molecules and TLR-4, as well as the secretion of proinflammatory cytokines and IL-10. Following that, activated BMDCs were cocultured with splenocytes for 72 hours and had the same cytokines measured in the supernatant. SsCWP-stimulated BMDCs showed higher expression of CD80, CD86, and CD40, but not TLR-4, and higher secretion of IL-6, IL-17A, and TNF. On the other hand, higher levels of IFN-γ, IL-10, and IL-2 were found in the supernatants of the coculture as compared with the BMDCs alone; TNF secretion was almost completely abrogated, whereas IL-6 was only partially inhibited and IL-17A was unaffected. Our results thus suggest SsCWP-stimulated BMDCs are able to induce a Th1-prone cytokine profile, known to be protective against other fungal diseases. This result could lead to evaluate the development of prophylactic and/or therapeutic DC-based tools against sporotrichosis.
ARTICLE | doi:10.20944/preprints201908.0062.v1
Subject: Life Sciences, Immunology Keywords: dendritic cell; cancer vaccine; vaccination; acquired immunity; granulocyte colony-stimulating factor; tetramer analysis
Online: 5 August 2019 (12:35:50 CEST)
Significant recent advances in cancer immunotherapeutics include the vaccination of cancer patients with tumor antigen-associated peptide-pulsed dendritic cells (DCs). DC vaccines with homogeneous, mature, and functional activities are required to achieve effective acquired immunity; however, the yield of autologous monocyte-derived DCs varies in each patient. Priming with a low dose of recombinant human granulocyte colony-stimulating factor (rhG-CSF) 16–18 h prior to apheresis resulted in 50% more harvested monocytes, with a significant increase in the ratio of CD11c+CD80+ DCs/apheresed monocytes. The detection of antigen-specific cytotoxic T lymphocytes after Wilms’ tumor 1-pulsed DC vaccination was higher in patients treated with rhG-CSF than those who were not, based on immune monitoring using tetramer analysis. Our study is the first to report that DC vaccines for cancer immunotherapy primed with low-dose rhG-CSF are expected to achieve higher acquired immunogenicity.
ARTICLE | doi:10.20944/preprints201906.0228.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: pancreatic cancer; PDAC; lymph node metastases; WNT; dendritic cells; M2 macrophages; XAV-939; tumour immune-microenvironment
Online: 22 June 2019 (16:50:32 CEST)
Over the past several years there has been much debate with regards to the prognostic and clinical significance of pancreatic ductal adenocarcinoma (PDAC) with lymph nodes metastasis. The PDAC gene-expression knowledge and the biologic alterations underlying the lymph node involvement convey a clinical implication in dealing with the theranostic window.To this end, we provide an original bioinformatic dissection of the gene-expression differences of PDAC according to the nodal involvement from a large public available dataset. Comprehensive transcriptomic analysis from 143 RNA-seq patient’s derived samples indicated that WNT increased activation and a peculiar immune-microenvironment identify subjects with nodal involvement.In frame of this thinking, we validated the WNT pathway role in increasing the likelihood of lymphatic dissemination in vitro. Moreover, we demonstrated for the first time in a PDAC model the potential therapeutic window that XAV-939, a specific WNT pathway inhibitor, has in re-educating a tumour permissive immune system. Finally, we outline the potential implication on bystander molecular drivers exerted by WNT molecular inhibition, providing a picture of the proteomic oncogenic landscape changes elicited by XAV-939 on PDAC cells and their clinical implication. Our findings hold the promise to identify novel immune-based therapeutic strategies targeting WNT to enhance PDAC cytotoxicity and restore anti-PDAC immunity in nodes-positive disease.
ARTICLE | doi:10.20944/preprints202012.0352.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Graves’ disease; autoimmunity; dendritic cells; methimazole
Online: 14 December 2020 (15:50:00 CET)
Graves’ disease (GD) is hyperthyroidism associated with organ-specific autoimmune inflammation. GD occurs more frequently in adults than in children, however, pediatric patients are a therapeutic challenge due to cycles of remissions and relapses requiring constant monitoring at every stage of treatment administered. Dendritic cells (DCs) are considered a link between innate and adaptive immunity. DCs as antigen-presenting cells (APCs) are involved in antigen presentation to T lymphocytes, thereby, initiate shift towards effector cells. In accordance, DCs participates also in the modulation of tolerance to specific antigens. To date, the data on DC role in Graves’ pathological processes are scarce. Therefore, here we evaluated frequencies and role of circulating DCs in GD pediatric patients treated with methimazole. Flow cytometric analysis was implemented to evaluate mDC1, mDC2 and pDC cells and their correlation with clinical GD-related parameters. We found significantly higher levels of DC subsets in patients at admission. Furthermore, methimazole treatment seemed to effectively reduce subsets of DCs which, in addition, were found to differentialy correlate with thyroid function. Our study shed a new light on DCs role in pediatric GD pathomechanism. Further studies are required for mechanistic assessment of DCs exact role in disease progression and influence on thyroid function.
ARTICLE | doi:10.20944/preprints201912.0186.v1
Subject: Life Sciences, Immunology Keywords: transcription factors; cytokines; autoimmunity; dendritic cells
Online: 15 December 2019 (13:16:35 CET)
Tolerogenic dendritic cells are crucial to control development of autoreactive T cell responses and prevention of autoimmunity. We have reported that NOD.CD11cStat5b-CA transgenic mice expressing a constitutively active form of Stat5b under the control of CD11c promoter are protected from diabetes and that Stat5b-CA-expressing DCs are tolerogenic and halt ongoing diabetes in NOD mice. However, the molecular mechanisms by which Stat5b-CA modulates DC tolerogenic function is not fully understood. Here, we used bone marrow-derived DCs from NOD.CD11cStat5b-CA transgenic mice (Stat5b-CA.BMDC) and found that Stat5b-CA.BMDC displayed high levels of MHC class II, CD80, CD86, PD-L1 and PD-L2 and produced elevated amounts of TGFβ but low amounts of TNF and IL-23. Stat5b-CA.BMDCs upregulated Irf4 and downregulated Irf8 genes and protein expression and promoted CD11c+CD11b+ DC2 subset differentiation. Interestingly, we found that the histone methyltransferase Ezh2 interacted with Stat5b-CA complex that bound GAS sequences in the Irf8 enhancer whereas Ezh2 did not interact with GAS sequences in the case of the Irf4 promoter. Injection of Stat5b-CA.BMDCs to prediabetic NOD mice halted progression of islet inflammation and protected against diabetes. Importantly, inhibition of Ezh2 in tolerogenic Stat5b-CA.BMDCs reduced their ability to prevent diabetes development in NOD recipient mice. Taken together, our data suggest that the active form of Stat5b induces tolerogenic DC function by modulating IRF4 and IRF8 expression through recruitment of Ezh2 and highlight the fundamental role of Ezh2 in Stat5b-mediated induction of tolerogenic DCs function.
ARTICLE | doi:10.20944/preprints201908.0125.v1
Subject: Medicine & Pharmacology, Allergology Keywords: allergy; IgE; IgG2c; anaphylaxis; dendritic cells
Online: 11 August 2019 (07:32:32 CEST)
Elevated levels of immunoglobulin E (IgE) are associated with allergies and other immunological disorders. Experimentally, sensitization with alum adjuvant favors IgE production while CpG-ODN adjuvant, a synthetic toll-like receptor 9 (TLR9) agonist, inhibits it. The cellular mechanisms underlying TLR-regulation of immunoglobulin production are still controversial. Specifically, TLR-mediated IgE regulation in vivo is not yet known. We show that augmented levels of IgE induced by sensitizations to OVA with or without alum adjuvant or with OVA-pulsed dendritic cells (DCs) were inhibited when sensitization to OVA was performed in the presence of CpG. Notably, CpG-mediated suppression of IgE production required MyD88-expression on DCs but not on B-cells. This contrasts with previous reports of in vitro regulation IgE where CpG acted directly on B cells via MyD88 pathway. In addition, CpG also inhibited IgE production in a MyD88-dependent manner when sensitization was performed with OVA-pulsed DCs. Finally, CpG signaling through MyD88 pathway was also necessary and sufficient to prevent anaphylactic antibody production involved in active cutaneous anaphylaxis.
SHORT NOTE | doi:10.20944/preprints202012.0493.v2
Online: 24 December 2020 (13:51:51 CET)
Vaccines based on mRNA-containing lipid nanoparticles (LNPs) pioneered by Katalin Karikó and Drew Weissman at the University of Pennsylvania are a promising new vaccine platform used by two of the leading vaccine candidates against coronavirus disease in 2019 (COVID-19). However, there are many questions regarding their mechanism of action in humans that remain unanswered. Here we consider the immunological features of LNP components and off-target effects of the mRNA, both of which could increase the risk of side effects. We suggest ways to mitigate these potential risks by harnessing dendritic cell (DC) biology.
ARTICLE | doi:10.20944/preprints202002.0250.v1
Subject: Life Sciences, Other Keywords: microRNAs; exosomes; astrocytes; hippocampal neurons; dendritic complexity
Online: 17 February 2020 (15:53:24 CET)
In the last decades, it has been established that astrocytes play key roles in the regulation of neuronal morphology. However, the contribution of astrocyte-derived small extracellular vesicles (sEVs) to morphological differentiation of neurons has only recently been addressed. Here, we showed that cultured astrocytes expressing a GFP tagged version of the stress-regulated astrocytic enzyme Aldolase C (Aldo C-GFP) release small extracellular vesicles (sEVs) which are transferred into cultured hippocampal neurons. Surprisingly, Aldo C-GFP-containing sEVs (Aldo C-GFP sEVs) displayed an exacerbated capacity to reduce the dendritic complexity in developing hippocampal neurons compared to sEVs derived from control (i.e. GFP-expressing) astrocytes. Using bioinformatics and biochemical tools, we found that the total content of overexpressed Aldo C-GFP correlates with an increased content of endogenous miRNA-26a-5p in both total astrocyte homogenates and sEVs. Notably, neurons magnetofected with a nucleotide sequence that mimics endogenous miRNA-26a-5p (mimic 26a-5p) not only decreased the levels of neuronal proteins associated to morphogenesis regulation and also reproduced morphological changes induced by Aldo-C-GFP sEVs. Furthermore, neurons magnetofected with a sequence targeting miRNA-26a-5p (antago 26a-5p) were largely resistant to Aldo C-GFP sEVs. Our results support a novel and complex level of astrocyte-to-neuron communication mediated by astrocyte-derived sEVs and the activity of their miRNA content.
ARTICLE | doi:10.20944/preprints202002.0422.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: inertial spiral microfluidics; dendritic cell separation; resource-limited microfluidics
Online: 28 February 2020 (11:54:44 CET)
Microfluidics technology has not impacted the delivery and accessibility of point of care health services like diagnosis of infectious disease diagnosis, monitoring health or delivering interventions. Most microfluidics prototypes from academic research are not easy to manufacture with industrial scale fabrication techniques and cannot be operated without complex manipulations of supporting equipment and additives such as labels or reagents. We propose a label- and reagent-free inertial spiral microfluidic device to separate red blood, white blood and dendritic cells from blood fluid for applications in health monitoring and immunotherapy. We demonstrate that using larger channel widths in the range of 200 to 600 µm allows separation of cells into multiple streams according to different size ranges and we utilize a novel technique to collect the closely separated focused cell streams without constricting the channel. When tested on actual human blood cells, 77% of dendritic cells were separated and 80% of cells remained viable after our assay. Our contribution is a method to adapt spiral inertial microfluidic designs to separate more than two cell types in the same device which is robust against clogging, simple to operate and suitable for fabrication and deployment in resource-limited populations.
ARTICLE | doi:10.20944/preprints201904.0118.v1
Subject: Life Sciences, Immunology Keywords: Receptor-specific antibodies; targeting; nanoparticles; dendritic cells; cross-presentation
Online: 10 April 2019 (07:46:18 CEST)
Abstract Optimal targeting of nanoparticles (NP) to dendritic cells (DCs) receptors to deliver cancer-specific antigens is key to an efficient induction of anti-tumor immune responses. Poly (lactic-co-glycolic acid) (PLGA) nanoparticles containing tètanus toxoid and gp100 melanoma-associated antigen, toll-like receptor adjuvants were targeted to the DC-SIGN receptor in DCs by specific humanized antibodies or by ICAM3-Fc fusion proteins mimicking natural ligand. Despite higher binding and uptake efficacy of anti-DC-SIGN antibody-targeted NP vaccines than ICAM3-Fc ligand, no difference were observed in DC activation markers CD80, CD83, CD86 and CCR7 induced. DCs loaded with NP coated with ICAM3-Fc appeared more potent in activating T cells via cross-presentation than antibody-coated NP vaccines. This fact could be very crucial in the design of new cancer vaccines.
ARTICLE | doi:10.20944/preprints201808.0357.v1
Subject: Life Sciences, Immunology Keywords: Astragalin galactoside, hydrophilic modification, Th1 cell, Dendritic cell, adjuvant
Online: 20 August 2018 (12:58:07 CEST)
A flavonoid Astragalin (kaempferol-3-O-β-D-glucopyranoside, Ast) has several biological activities including anti-oxidant, anti-HIV, and anti-allergic effects. Nonetheless, its insolubility in hydrophilic solvents imposes restrictions on its therapeutic applications. In this study, we investigated the effects of water-soluble astragalin-galactoside (kaempferol-3-O- β-D-isomaltotrioside, Ast-Gal) on dendritic cell (DC) maturation and T helper (Th) cell-mediated immune responses. Ast-Gal significantly increased maturation and activation of DCs through up-regulation of surface markers, such as CD80, CD86, and MHC II in a dose-dependent manner, while Ast had little effects. Also, Ast-Gal-treated DCs markedly secreted immune-stimulating cytokines such as IL-1β, IL-6, and IL-12. Importantly, Ast-Gal strongly increased expression of IL-12, a polarizing cytokine of Th1 cells. In a co-culture system of DCs and CD4+ T cells, Ast-Gal-treated DCs preferentially differentiates naïve CD4+ T cells into Th1 cells. The addition of neutralizing IL-12 mAb to cultures of Ast-Gal-treated DCs and CD4+ T cells significantly increased IFN- γ production, thereby indicating that Ast-Gal-stimulated DCs enhance the Th1 response through IL-12 production by DCs. Injection with Ast-Gal-treated DCs in mice increased IFN-γ-secreting Th1 cell population. Collectively, these findings indicate that hydrophilically modified astragalin can enhance Th1-mediated immune responses via DCs, and point to a possible application of water-soluble astragalin-galactoside as an immune adjuvant.
ARTICLE | doi:10.20944/preprints202203.0212.v1
Subject: Materials Science, Metallurgy Keywords: Corrosion; Solidification; Dendritic growth; Al-Si-Fe alloys; Modification; Intermetallics
Online: 15 March 2022 (11:37:13 CET)
The corrosion behavior of Fe-containing directionally solidified (DS) and centrifugally cast (CC) Al-Si-Cu-Zn alloys with either Co or Ni additions has been investigated. Electrochemical and immersion corrosion methods were used to investigate the corrosion behavior in 0.6 M NaCl after short (1-hour) and long (30-day) exposure periods. The employed solidification methods allowed the production of samples with a wide range of secondary dendrite arm spacing (SDAS) while preserving Si and Fe-containing phases. The 0.5 wt.% Ni and Co additions led to the growth of the AlFeSi(Ni) and AlFeSi(Co) phases, but no binary AlNi nor AlCo intermetallic par-ticles have been generated. Potentiodynamic polarization studies at early exposure revealed an increase in the corrosion potential as the Ni was added for either fast or slow solidified samples. The electrochemical impedance spectroscopy at early exposure demonstrated that the Ni-modified alloy, on the other hand, was associated to smaller charge transfer resistances, in-dicating a reduction in corrosion resistance after short elapsed time into the electrolyte. Howev-er, 30-day immersion tests revealed much lower corrosion rate of the Ni-modified alloy than the other alloys, while the corrosion rates of the Co-modified and non-modified alloys were simi-lar. In the Ni-containing alloy, decreased corrosion rate under long-term corrosion process was attributed to the formation of a thick and dense alumina layer, effectively protecting the surface under such conditions. This work contributes to a better knowledge of the corrosion behavior of Ni- and Co-corrected Al industrial scrap compositions.
ARTICLE | doi:10.20944/preprints202104.0564.v1
Subject: Medicine & Pharmacology, Other Keywords: Dendritic cell; Rapamycin; Mitochondria; Acute kidney injury; Ischemic Reperfusion Injury
Online: 21 April 2021 (09:13:27 CEST)
Dendritic cells (DCs) are unique immune cells that can link innate and adaptive immune responses and Immunometabolism greatly impacts their phenotype. Rapamycin is a macrolide compound that has immunosuppressant functions and is used to prevent graft loss in kidney transplantation. The current study evaluated the therapeutic potential of ex-vivo Rapamycin treated DCs to protect kidneys in a mouse model of acute kidney injury (AKI). For the Rapamycin single (S) treatment (Rapa-S-DC), Veh-DCs were treated with Rapamycin (10 ng/ml) for 1 hour before LPS. In contrast, Rapamycin multiple (M) treatment (Rapa-M-DC) were exposed to 3 treatments over 7 days. Only multiple ex-vivo Rapamycin treatments of DCs induced a persistent reprogramming of mitochondrial metabolism. These DCs had 18-fold more mitochondria, had almost 4-fold higher oxygen consumption rates, and produced more ATP compared to Veh-DCs (Veh treated control DCs). Pathway analysis showed IL10 signaling as a major contributing pathway to the altered immunophenotype after Rapamycin treatment compared to vehicle with significantly lower cytokines Tnfa, Il1b, and Il6, while regulators of mitochondrial content Pgc1a, Tfam, and Ho1 remained elevated. Critically, adoptive transfer of Rapamycin treated DCs to WT recipients 24 hrs before bilateral kidney ischemia significantly protected the kidneys from injury with a significant 3-fold improvement in kidney function. Last, the infusion of DCs containing higher mitochondria numbers (treated ex-vivo with healthy isolated mitochondria (10 µg/ml) one day before) also partially protected the kidneys from IRI. These studies demonstrate that pre-emptive infusion of ex-vivo reprogrammed DCs that have higher mitochondria content has therapeutic capacity to induce an anti-inflammatory regulatory phenotype to protect kidneys from injury.
ARTICLE | doi:10.20944/preprints202107.0502.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: mushroom; immune checkpoints; Axl receptor; lung cancer; dendritic cells; immune response.
Online: 21 July 2021 (15:43:11 CEST)
Agaricus blazei Murrill or Himematsutake is an edible and medicinal mushroom. Agaricus blazei Murrill's fruiting body extracts have anticancer properties, although the mechanism is unknown. Basic or organic solvents, which are hazardous for human health, are generally used to prepare Agaricus blazei Murrill's extracts. Inhibition of immune checkpoint molecules and Axl receptor is an effective therapy in cancer. This study assessed whether subcritical water extracts of the Agaricus blazei Murrill's fruiting body or mycelium affect the expression of Axl and immune checkpoint molecules in lung cancer cells. We used A549 cells and mouse bone marrow-derived dendritic cells in the experiments. We prepared subcritical water extracts from the Agaricus blazei Murrill's fruiting body or mycelium. The subcritical water extracts from the Agaricus blazei Murrill's fruiting body or mycelium significantly inhibited the expression of immune checkpoint molecules and Axl compared to saline-treated cells. Also, the hot water extract, subcritical water extract, and the hot water extraction residue subcritical water extract from the Agaricus blazei Murrill's mycelium significantly enhanced the expression of maturation markers in dendritic cells. These observations suggest that the subcritical water extract from Agaricus blazei Murrill's mycelium is a promising therapeutic tool for stimulating the immune response in cancer.
COMMUNICATION | doi:10.20944/preprints201906.0079.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: ovarian cancer metastasis, chemokines, cytoreductive surgery, Cytotoxic T cells, BDCA3 Dendritic cells.
Online: 10 June 2019 (16:03:23 CEST)
Nowadays the positive immune involvement in the eradication of tumor cells is assigned to the adaptive immune response. By awakening of in vivo responding T cells that are suppressed by the tumor and prevents immunological cure of the cancer. The adaptive immune response is a complex of different cells and protein molecules. Normally activated T cells are well-ordered by several late occurring inhibitors to contain the response to the unknown invaders and spare the normal cells. The tumor strengthens this inhibitory response to escape from immune elimination. Immunotherapy is to unleash the full capacity of the adaptive immune system by blocking this inhibitor response by monoclonal antibodies but with the potential drawback of autoimmune phenomena. Seen the success of the immunotherapy another feature of the immune system is overlooked. Cytokines and chemokines became in oblivion after their suspected necrosis of the tumor (TNF) did not fulfil their initial hope. When patients seek help for their complaints the ovarian cancer is in most cases already metastasized to the peritoneum and omentum. Here, we show that on the one hand chemokines produced by Th2, CD8 and NK cells inhibit cancer spreading and thus leads to a better operability and thus better survival. On the other hand, chemokine receptors are expressed by the tumor that are a decoy by binding chemokines that normally should attract antigen cross-presenting dendritic cells, which start an adaptive T cell response.
REVIEW | doi:10.20944/preprints202011.0295.v1
Subject: Chemistry, Analytical Chemistry Keywords: dendritic polymers; ceramic compounds; biomimetic; nanomaterials; dendrimers; hyperbranched polymers; silica composites; hybrid materials
Online: 10 November 2020 (09:22:43 CET)
As the field of nanoscience is rapidly evolving, interest for novel, upgraded nanomaterials with combinatory features is also inevitably increasing. Hybrid composites, offer simple, budget-conscious and environmental-friendly solutions that can cater multiple needs at the same time and be applicable in many nanotechnology-related and interdisciplinary studies. The physicochemical idiocrasies of dendritic polymers have inspired their implementation as sorbents, active ingredient carriers and templates for complex composites. Ceramics are distinguished for their mechanical superiority and absorption potential that render them ideal substrates for separation and catalysis technologies. The integration of dendritic compounds to these inorganic hosts can be achieved through chemical attachment of the organic moiety onto functionalized surfaces, impregnation and absorption inside the pores, conventional sol-gel reactions or via biomimetic mediation of dendritic matrices, inducing the formation of usually spherical hybrid nanoparticles. Alternatively, dendritic polymers can propagate from ceramic scaffolds. All these variants are covered in detail. Optimization techniques as well as established and prospected applications are also presented.
REVIEW | doi:10.20944/preprints201910.0120.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: reelin; lis2; adlte; autism; schizophrenia; translational models; gabaergic interneurons; dendritic spines; forebrain; cerebellum
Online: 10 October 2019 (15:31:12 CEST)
The Reeler mutation was described in mouse more than fifty year ago. Later, its causative gene (reln) was discovered in mouse, and its human orthologue (RELN) was demonstrated to be causative of lissencephaly 2 (LIS2) and about 20% of the cases of autosomal-dominant lateral temporal epilepsy (ADLTE). In both human and mice the gene encodes for a glycoprotein referred to as Reelin (Reln) that plays a primary role in neuronal migration during development and synaptic stabilization in adulthood. Besides LIS2 and ADLTE, RELN and/or other genes coding for the proteins of the Reln intracellular cascade have been associated more or less substantially to other conditions such as spinocerebellar ataxia type 7 and 37, VLDLR-associated cerebellar hypoplasia, PAFAH1B1-associated lissencephaly, autism and schizophrenia. According to their modalities of inheritances and with substantial differences among each other, these neuropsychiatric disorders can be modeled in the homozygous (reln-/-) or heterozygous (reln+/-) mouse. The usefulness of these mice as translational models is discussed, with focus on their construct and face validity. The latter is mainly treated directing the attention to the histological, neurochemical and functional observations in the cerebral cortex, hippocampus and cerebellum of Reeler mice and their human counterparts.
ARTICLE | doi:10.20944/preprints202112.0268.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: Real-time cell characterization; electrode polarization; cell membrane capacitance; cytoplasm resistance; dendritic gold nanostructures
Online: 16 December 2021 (11:39:56 CET)
Dielectric spectroscopy (DS) is a promising cell screening method that can be used for diagnostic and drug discovery purposes. The primary challenge of using DS in physiological buffers is the electrode polarization (EP) that overwhelms the impedance signal within a large frequency range. These effects further amplify with miniaturization of the measurement electrodes. In this study, we present a microfluidic system and the associated equivalent circuit models for real-time measurements of cell membrane capacitance and cytoplasm resistance in physiological buffers with 10s increments. The current device captures several hundreds of biological cells in individual microwells through gravitational settling and measures the system’s impedance using microelectrodes covered with dendritic gold nanostructures. Using PC-3 cells (a highly metastatic prostate cancer cell line) suspended in cell growth media (CGM), we demonstrate stable measurements of cell membrane capacitance and cytoplasm resistance in the device for over 15 minutes. We also describe a consistent application of the equivalent circuit model, starting from the reference measurements used to determine the system parameters. The circuit model is tested using devices with varying dimensions, and the obtained cell parameters between different devices are nearly identical. Further analyses of the impedance data have shown that accurate cell membrane capacitance and cytoplasm resistance can be extracted using a limited number of measurements in the 5 MHz to 10 MHz range. This will potentially reduce the timescale required for real-time DS measurements below 1s. Overall the new microfluidic device can be used for dielectric characterization of biological cells in physiological buffers for various cell screening applications.
ARTICLE | doi:10.20944/preprints202112.0461.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: Hypertrophic Cardiomyopathy; Left ventricular outflow tract obstruction; single nucleus RNA-sequencing; dendritic cells; integrin-b1.
Online: 29 December 2021 (09:43:00 CET)
Hypertrophic Cardiomyopathy (HCM) is a common inherited disorder characterized by unexplained left ventricular hypertrophy, with or without left ventricular outflow tract (LVOT) obstruction. Single nuclei RNA-sequencing (snRNA-seq) of both obstructive and nonobstructive HCM patient samples have revealed alterations in communication between various cell types but a direct and integrated comparison between the two HCM phenotypes has not been reported. We performed a bioinformatic analysis of HCM snRNA-seq datasets from obstructive and nonobstructive patient samples to identify differentially expressed genes and distinctive patterns of intercellular communication. Differential gene expression analysis revealed 37 differentially expressed genes, predominantly in cardiomyocytes but also in other cell types, relevant to aging, muscle contraction, cell motility and the extracellular matrix. Intercellular communication was generally reduced in HCM, affecting the extracellular matrix, growth factor binding, integrin binding, PDGF binding and SMAD binding, but with increases in adenylate cyclase binding, calcium channel inhibitor activity, and serine-threonine kinase activity in nonobstructive HCM. Increases in neuron to leukocyte and dendritic cell communication, in fibroblast to leukocyte and dendritic cell communication and in endothelial cell communication to other cell types, largely through changes in expression of integrin-b1 and its cognate ligands, were also noted. These findings indicate both common and distinct physiological mechanisms affecting the pathogenesis of obstructive and nonobstructive HCM and provide opportunities for personalized management of different HCM phenotypes.
REVIEW | doi:10.20944/preprints202112.0451.v1
Subject: Chemistry, Applied Chemistry Keywords: Dendritic Polymers; Dendrimers; Metal Nanoparticles; Photocatalysis; Water Purification; dye discoloration; pollutant degradation; nanoparticle catalysis; decomposition; semicoductors
Online: 28 December 2021 (14:19:11 CET)
Radially polymerized dendritic compounds are nowadays an established polymer category next to their linear, branched and cross-linked counterparts. Their uncommon tree-like architecture is characterized by adjustable internal cavities and external groups. They are therefore exceptional absorbents and this attainment of high concentrations into their interior renders them ideal reac-tion media. In this framework they are applied in many environmentally benign implementa-tions. One of the most important among them is water purification though pollutant decomposi-tion. Simple and composite catalysts and photo-catalysts containing dendritic polymers and ap-plied in water remediation will be discussed jointly with some unconventional solutions and fu-ture prospects.
ARTICLE | doi:10.20944/preprints201904.0246.v2
Subject: Medicine & Pharmacology, Behavioral Neuroscience Keywords: Oxytocin, Oxytocin Receptor, Autism, Nepsys Scale, MAST Immune System Disease, Dendritic Spines, Magnocellular Neurons, Desensitization, Labor, Down Regulation
Online: 23 April 2019 (11:12:19 CEST)
This paper develops mathematical models examining possible roles of oxytocin and oxytocin receptors in the development of autism. This is done by demonstrating that mathematical operations on normalized data from the Stanford study (K.J. Parker, 2016), which establishes a correspondence between severity of autism in children and their oxytocin blood levels, generates a graph that is the same as the graph of mathematical operations on a normalized theoretical model for the severity of autism. This procedure establishes the validity of the theoretical model and the significance of oxytocin receptors in autism. A steady-state model follows, explaining the constant baseline concentrations of oxytocin observed in the cerebral spinal fluid and blood in terms of the neuromodulation by oxytocin of oxytocin receptors on the magnocellular neurons that produce oxytocin in nuclei in the hypothalamus. The implications of these models for possible roles of oxytocin and oxytocin receptors in autism is considered for several unrelated conditions that may be associated with autism. These are: oxytocin receptor desensitization and down-regulation as factors during labor in offspring autism development; reductions in the oxytocin receptor numbers in the fixed oxytocin receptor expression that occurs before birth; MAST Immune System disease; and the excess number of dendritic spines from lack of pruning observed in brains of autistic people. Research into the feasibility of generating magnocellular neurons and other neurons from adult stem cells is suggested as a way of doing invitro studies of oxytocin and oxytocin receptors to assess the validity of theories presented in this paper.
ARTICLE | doi:10.20944/preprints201803.0224.v1
Subject: Life Sciences, Immunology Keywords: Myeloid-derived suppressor cells (MDSCs); dendritic cells (DCs); M1 macrophages; M2 macrophages; xenograft tumor; allograft tumor; lipopolysaccharide (LPS)
Online: 27 March 2018 (12:03:56 CEST)
Macrophages and dendritic cells (DCs) acquire functionally distinct properties in response to various environmental stimuli; the interaction of these cells with myeloid-derived suppressor cells (MDSCs) in tumor microenvironments regulates cancer progression. Immunodeficient mice lacking T cells are less likely to reject human cancer cells because of major histocompatibility complex (MHC) mismatches. The xenograft tumor microenvironment, comprising human cancer and mouse host cells, exhibits more complex bidirectional signaling and function than a syngeneic tumor microenvironment. Here human and mouse colorectal cancer cells were transplanted into nude mice to elucidate differences in macrophage, DC, and MDSC functions in human xenograft and mouse allograft tumor models. Plasma interferon-γ and interleukin-18 concentrations in the former model after intraperitoneal lipopolysaccharide (LPS) administration were significantly higher than those in the latter model and non-transplanted control group. Splenic MHC class I, II, and CD80 expression increased in CD11b+ and MDSC populations after LPS administration in only the xenograft tumor model. The number of CD80- and MRC1-expressing cells decreased upon LPS administration in only the xenograft tumor. These results suggxest that macrophages and DCs function normally in xenograft tumor models, whereas their functions in response to LPS administration vary in allograft tumor models.
ARTICLE | doi:10.20944/preprints202208.0144.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: mucosal immunization; mucosal vaccine; vaccine delivery; administration volume; targeted vaccines; M cell targeting; dendritic cell targeting; C5aR1; C5a1R; CD88; EP54; EP67
Online: 8 August 2022 (10:17:30 CEST)
Generating long-lived mucosal and systemic antibodies through respiratory immunization with protective antigens encapsulated in nanoscale biodegradable particles could potentially decrease or eliminate the incidence of many infectious diseases but requires incorporation of a suitable mucosal immunostimulant. We previously found that respiratory immunization with a model protein antigen (LPS-free OVA) encapsulated in PLGA 50:50 nanoparticles (~380 nm diameter) surface modified with complement peptide-derived immunostimulant 02 (CPDI-02; formerly EP67) through 2kDa PEG linkers increases mucosal and systemic OVA-specific memory T-cells with long-lived surface phenotypes in young, naïve female C57BL/6 mice. Here, we determined if respiratory immunization with LPS-free OVA encapsulated in similar PLGA 50:50 microparticles (~1 μm diameter) surface modified with CPDI-02 (CPDI-02-MP) increases long-term OVA-specific mucosal and systemic antibodies. We found that, compared to MP surface modified with inactive, scrambled scCPDI-02 (scCPDI-02-MP), intranasal administration of CPDI-02-MP in 50 μL sterile PBS greatly increased titers of short-term (14 days post-immunization) and long-term (90 days post-immunization) antibodies against encapsulated LPS-free OVA in nasal lavage fluids, bronchoalveolar lavage fluids, and sera of young, naïve female C57BL/6 mice. Thus, surface modification of biodegradable microparticles with CPDI-02 is likely to increase long-term mucosal and systemic antibodies against encapsulated protein antigen after respiratory and possibly other routes of mucosal immunization.
ARTICLE | doi:10.20944/preprints201806.0299.v1
Subject: Life Sciences, Virology Keywords: Crimean-Congo hemorrhagic fever virus; Crimean-Congo hemorrhagic fever; Hyalomma marginatum; human cutaneous immune response; Langerhans cells; dermal dendritic cells; tick-borne virus; tick-virus-host interface
Online: 19 June 2018 (11:50:54 CEST)
Crimean-Congo hemorrhagic fever virus is one the most important and wide spread tick-borne viruses. Very little is known about the transmission from the tick and the early aspects of pathogenesis. Here, we generate human cutaneous antigen presenting cells: dermal dendritic cells and Langerhans cells, from umbilical cord progenitor cells. In order to mimic the environment created during tick feeding, tick salivary gland extract was generated from semi-engorged Hyalomma marginatum ticks. Our findings indicate that human dermal dendritic cells and Langerhans cells are susceptible and permissive to Crimean-Congo hemorrhagic fever virus infection, however, to different degrees. Infection leads to cell activation and cytokine/chemokine secretion, although these responses vary between the different cell types. Hyalomma marginatum salivary gland extract had minimal effect on cell responses, with some synergy with viral infection with respect to cytokine secretion. However, salivary gland extract appeared to inhibit antigen presenting cell (APC) migration. Based on the findings here we hypothesize that human dermal dendritic cells and Langerhans cells serve as early target cells. Rather affecting Crimean-Congo hemorrhagic fever virus replication, tick saliva likely immunomodulates and inhibits migration of these APC from the feeding site.
REVIEW | doi:10.20944/preprints202005.0244.v1
Subject: Biology, Anatomy & Morphology Keywords: COVID-19; SARS-CoV-2; antigen; monovalent; oligovalent; protein; kilodalton (kDa); Th1 response; Th2 response; B cell activation; B cell receptor (BCR); macrophage; dendritic cell; apoptosis; subcapsular sinus; immunoglobulin; interleukin; cytokine; Cytokine Storm Syndrome (CSS); allergen; immune paralysis; vaccine; polymer
Online: 14 May 2020 (15:19:53 CEST)
COVID-19 sepsis immune response remains unclear. Here we propose a new perspective in host response against pathogenic proteins that may lead to a vaccine design by polymerization of antigens of <70 kDa. In COVID-19, initial Th1 response kills infected cells releasing viral proteins. SARS-CoV-2 viral structural proteins are Spike (140 kDa), Nucleocapsid (50 kDa), Membrane (25 kDa) and Envelope (10 kDa). B cell receptor cannot capture antigens >70 kDa. The Spike protein (140 kDa) cannot be captured by B cells and triggers inflammatory Th1 response via the macrophages. Only proteins with a size <70 kDa can activate B cell receptor and trigger Th2 adaptative humoral response. Moreover, M-25 kDa and E-12 kDa glycoproteins can activate IgM-BCR like oligovalent or monovalent antigens. The sustained infected cells lysis overfeeds high levels of viral proteins <70 kDa, increases B cells activation and, in the shift from Th1 to Th2 immune response, triggers the cytokine storm. The continuous BCR activation increases IL-10 releasing and may lead to immune paralysis.