Mechanism Of Desensitization Research Articles

Friction Sensitivity Test Experiment and Desensitization Mechanism of Nitrocellulose-Coated DNTF Explosive Crystals

In response to the problem of the high friction sensitivity of 3,4-bis(3-nitrofurazan-4-yl) furoxan (DNTF) in solid propellants, the inherent component of solid propellants, nitrocellulose (NC), was used to coat DNTF explosives via the water suspension method. The coated samples were characterized by scanning electron microscopy (SEM) and friction sensitivity tests at a fixed 66° swing angle, and molecular dynamics calculations were performed to study the friction sensitivity and desensitization mechanism of NC-based DNTF coatings. The results show that NC, when used as a coating layer, can form a white gel on the surface of DNTF crystals, which can effectively reduce the friction sensitivity of DNTF. The coating effect becomes more obvious as the NC content increases. When the NC content is 5%, the friction sensitivity decreases by 72%, and a prediction formula for the exponential decay of DNTF friction sensitivity is obtained. MD calculation data show that NC can weaken the stiffness, enhance the elastic-plastic properties, increase the ductility and toughness of DNTF materials, and effectively improve the mechanical properties of DNTF. By combining experiments and simulation calculations, while considering the compatibility of new components and changes in propellant energy and other unpredictable new issues, NC can be referred to as a better coating layer for DNTF, as it has a certain feasibility for improving the friction sensitivity of DNTF.

Mechanisms of desensitization with oral immunotherapy and epicutaneous immunotherapy.

Oral immunotherapy (OIT) and epicutaneous immunotherapy (EPIT) are emerging therapies for food allergy. With several recently published exploratory trials and randomized controlled clinical trials that support these procedures, there is a clear progress and interest toward making these treatment options available for allergist/immunologists and patients with food allergies entrusted to their care. However, there still remain many questions and concerns to be addressed before these procedures can be fully understood. The purpose of the present report is to trace some of the important historical milestones in the development of OIT and EPIT that have contributed to their evolving clinical application to the treatment of food allergy, to describe some of the current understandings of the immunologic mechanisms by which these procedures elicit desensitization, and to provide some areas for future inquiry and research. An extensive research was conducted in the medical literature data bases by applying terms such as food allergy, desensitization, tolerance, unresponsiveness, Treg cells, allergen immunotherapy (AIT), oral immunotherapy (OIT), and epicutaneous immunotherapy (EPIT). OIT and EPIT take their origins from AIT (also called desensitization), a procedure first reported for the treatment of hay fever over a 100 years ago in which slowly increasing doses of a specifically relevant allergen were administered until a maintenance dosage was achieved when the patient was free of symptoms. OIT and EPIT differ from AIT in certain aspects including the route of administration of the allergen as well as their relative shorter period of sustained unresponsiveness. The origins and important historical landmarks that have been made in the field of food allergy immunotherapy are presented in the context of the immunologic mechanisms that contribute to the pathogenesis of these disorders. Although considerable progress has been made in recent years toward making these treatment options available for allergist/immunologists and patients with food allergies, there still remain many questions and concerns to be addressed before these procedures can be fully understood, which can be illuminated by future research.

376 Coupling of conformational activation and partial denaturation as a mechanism for TRPV1 sensory pain desensitization

376 Coupling of conformational activation and partial denaturation as a mechanism for TRPV1 sensory pain desensitization

Structural pharmacology of TRPV channels.

Transient Receptor Potential channels from the vanilloid subfamily (TRPV) are a group of cation channels that play a critical role in a variety of physiological and pathophysiological processes. They are modulated by a variety of endogenous stimuli as well as a range of natural and synthetic compounds. Their roles in human health make them of keen interest, particularly from a pharmacological perspective. However, despite this interest, the complexity of these channels has made it difficult to obtain high resolution structures until recently. With the cryo electron microscopy (cryo-EM) resolution revolution, our laboratory produced several TRPV channels structures and determine mechanisms of TRPV channels activation, inhibition and desensitization. This newly obtained information could guide us towards the design of novel TRPV channels specific therapeutic molecules.

Insights into the desensitization mechanisms of acid-sensing ion channels.

Acid-sensing ion channels (ASICs) are proton-gated cation channels contribute to synaptic transmission, learning and memory. ASICs are also involved in a wide range of diseases associated with prolonged tissue acidosis, such as ischemic stroke, chronic pain and neurological disorders. Besides activation, extracellular protonation of ASICs can elicit at least three types of desensitization: (i) reversible desensitization after activation, (ii) Steady-state desensitization (SSD), where the channels desensitize without apparent opening, and (iii) tachyphylaxis, a decrease in the response amplitude in a series of activations. The different mechanisms behind the various types of desensitization are not yet fully understood. Here, we use voltage-clamp fluorometry to track the conformational changes of the extracellular domain of the ASIC1a in parallel with recordings of the functional properties of the channel. We introduce selected mutations in ASIC1a to decrease desensitization after activation. These channels show a full or partial reduction in SSD but are more prone to exhibiting strong tachyphylaxis. While the mutations heavily impact all three types of desensitization at the level of the pore, the extracellular domain still undergoes conformational changes and remains highly sensitive to changes in pH. Additionally, the channels remain affected by known extracellular peptide modulators of ASIC1a. These observations highlight a possible decoupling between the extracellular domain and the pore during desensitization. Understanding the mechanism behind the conformational and functional changes not only during activation, but also desensitization might be particularly relevant for disorders with moderate tissue acidification and thus for pharmacological targeting.

Probing the biotoxicity of starch nanoparticles in vivo and their mechanism to desensitize β-lactoglobulin

Starch nanoparticles (SNPs) were synthesized and characterized in vivo for their subacute biotoxicity. Animal experiments revealed that SNPs would not induce changes in inflammatory cytokines and gut microbiota, avoiding damage to mice's organs. Moreover, SNPs were rapidly excreted from the body after 6 h without any accumulation, demonstrating their biosafety. Based on these findings, SNPs were used for β-lactoglobulin (βLg) desensitization by formation of a protein corona. The thermodynamics and time evolution of βLg's secondary structure were investigated to address the desensitization mechanism. The results showed ∼1600 βLg molecules onto a single SNP coupled with significant changes in secondary structure formed a stable SNPs-βLg corona with binding affinity (Ka) of 8.4 ± 0.5 × 10 5 M −1 . Functionally, the decrease of β-sheet destroyed the conformation of immunoglobulin E (IgE) epitopes and inhibited IgE combining capacity, achieving SNPs' desensitization to βLg. Additionally, it takes ∼2 h to complete changes in βLg's surface hydrophobicity and immunoglobulin E (IgE) combining capacity after incubation with SNPs, consistent with the time evolution of structure changes, indicating protein corona is response for the desensitization. SNPs-βLg corona changed βLg structure, inhibiting the combing with IgE. • Starch nanoparticles (SNPs) were characterized the subacute biotoxicity in vivo and showed biosafety to the mice. • It takes about 2 h to complete secondary structure changes, forming a stable SNPs-βLg corona with about1000 βLg molecules adsorbed. • The time evolution of surface hydrophobicity and IgE combining capacity is corresponding to the changes of secondary structure induce by protein corona.

Sequestration of Gβγ by deubiquitinated arrestins into the nucleus as a novel desensitization mechanism of G protein–coupled receptors

BackgroundDesensitization of G protein–coupled receptors (GPCRs) refers to a rapid attenuation of responsiveness that occurs with repeated or continuous exposure to agonists. GRK-mediated phosphorylation and subsequent binding with arrestins in the activated receptor cytoplasmic cavity in competition with G proteins has been suggested as the conventional mechanism of desensitization. Along with widely accepted conventional mechanism of desensitization, studies of various GPCRs including dopamine D2-like receptors (D2R, D3R, D4R) have suggested the existence of another desensitization mechanism. In this study, loss-of-function approaches and D2-like receptor mutants that display different desensitization properties were used to elucidate the molecular mechanisms responsible for desensitization.ResultsDesensitization development entailed the signaling cascade composed of Src, PDK1, and Akt, the latter of which in turn interacted with USP33, an arrestin deubiquitinase, to promote arrestin deubiquitination. The deubiquitinated arrestin subsequently formed a complex with Gβγ and translocated to the nucleus via an importin complex, wherein it sequestered Gβγ from the receptor and Gα, thereby attenuating receptor signaling. As in D2-like receptors, both USP33 and importin β1 were involved in the desensitization of the β2 adrenoceptor.ConclusionsIn addition to the conventional mechanism of desensitization, which occurs on the plasma membrane and in the cytosol, this study provides a new insight that another desensitization pathway in which nuclear trafficking plays a critical role is operating. It is plausible that multiple, complementary desensitization measures are in place to properly induce desensitization depending on receptor characteristics or the surrounding environment.-2RaxQqo6CD-C8c3iMTZGQVideo

Dentin-desensitizing biomaterials

Dentin hypersensitivity (DH) associated with dentinal tubule exposure is one of the most common causes of toothache with a rapid onset and short duration. Medication, filling repair, laser irradiation, crown therapy, and desensitizing toothpaste are standard clinical treatment strategies, but unsatisfactory treatment modalities are marked by long-term administration, poor dentinal tubule closure, microleakage, and the development of secondary caries. To improve the treatment efficiency of DH, numerous organic or inorganic biomaterials have been developed to relieve toothache and reverse the instability of desensitization. Biomaterials are expected to participate in dental remineralization to achieve desensitization. This review discusses various biomaterials for DH therapy based on different desensitization mechanisms, including dentinal tubule closure and dental nerve blockade, and presents a perspective on the underlying future of dentin regeneration medicine for DH therapy.

Influencing mechanisms of a wax layer on the micro-friction behavior of the β-HMX crystal surface

This study investigated the influence of the wax layer on the micro-friction behavior of the energetic crystal surface by constructing the lubricating interface between wax and β-HMX crystals. The nano-scratch testing of β-HMX crystals with and without wax coating was conducted under the ramp-loading (0–3.5 ​mN) mode and the constant-loading (0.4 ​mN) mode. The testing results are as follows. Compared with the dry friction of β-HMX crystals without wax coating, wax can significantly improve the contact friction between the energetic crystals and the rigid micro-convex body. The influence of wax on the interface friction highly depends on the external load conditions. Under the ramp-loading mode, the wax layer can greatly reduce the average coefficient of friction (COF) from ∼0.7 (dry friction) to ∼0.2 (lubricating interface) and inhibit COF fluctuation. The inherent mechanism of wax reducing the interface friction works in the following way. Wax can effectively suppress the plowing effect of the rigid micro-convex body on the β-HMX crystal surface and further inhibit the occurrence of brittle fracture and crack defects. The wax layer can also suppress the friction anisotropy of the β-HMX crystal surface, significantly reducing the probability of high COF (>0.4). The distribution probabilities of COF in the range of 0–0.1 and 0–0.3 were 33% and 89%, respectively. The stick-slip effect of the friction behavior was observed under the constant-loading mode, with the COF varying periodically with the sliding distance. These study results can help understand the desensitization mechanisms of wax on the energetic crystal surface at a micro-scale quantitative level and provide a necessary basis for building the friction hot-spot model under dry friction and wax lubrication.

A cryptic mode of GPCR regulation revealed.

Over three decades of research have provided thorough insights into G protein-coupled receptor (GPCR) regulation. In a recent issue of Molecular Cell, Fonseca et al. identified a previously overlooked desensitization mechanism. Agonist activation of the β2-adrenoceptor (β2AR) causes its S-nitrosylation that is required for the receptor to internalize and desensitize. Eliminating β2AR S-nitrosylation by mutation of C265 augments β2AR protein kinase A signaling, enables β2AR nitric oxide (NO) signaling, renders mice resistant to bronchoconstriction, and protects mice from allergen-induced asthma.

G protein coupled pattern recognition receptors expressed in neutrophils: Recognition, activation/modulation, signaling and receptor regulated functions.

Neutrophils, the most abundant white blood cell in human blood, express receptors that recognize damage/microbial associated pattern molecules of importance for cell recruitment to sites of inflammation. Many of these receptors belong to the family of G protein coupled receptors (GPCRs). These receptor-proteins span the plasma membrane in expressing cells seven times and the down-stream signaling rely in most cases on an activation of heterotrimeric G proteins. The GPCRs expressed in neutrophils recognize a number of structurally diverse ligands (activating agonists, allosteric modulators, and inhibiting antagonists) and share significant sequence homologies. Studies of receptor structure and function have during the last 40 years generated important information on GPCR biology in general; this knowledge aids in the overall understanding of general pharmacological principles, governing regulation of neutrophil function and inflammatory processes, including novel leukocyte receptor activities related to ligand recognition, biased/functional selective signaling, allosteric modulation, desensitization, and reactivation mechanisms as well as communication (receptor transactivation/cross-talk) between GPCRs. This review summarizes the recent discoveries and pharmacological hallmarks with focus on some of the neutrophil expressed pattern recognition GPCRs. In addition, unmet challenges, including recognition by the receptors of diverse ligands and how biased signaling mediate different biological effects are described/discussed.

Molecular Mechanisms of Desensitization Underlying the Differential Effects of Formyl Peptide Receptor 2 Agonists on Cardiac Structure-Function Post Myocardial Infarction.

Formyl peptide receptor 2 (FPR2) plays an integral role in the transition of macrophages from a pro-inflammatory program to one that is pro-resolving. FPR2-mediated stimulation of resolution post myocardial infarction has demonstrated efficacy in rodent models and is hypothesized to reduce progression into heart failure. FPR2 agonists that promote long-lasting receptor internalization can lead to persistent desensitization and diminished therapeutic benefits. In vitro signaling profiles and propensities for receptor desensitization of two clinically studied FPR2 agonists, namely, BMS-986235 and ACT-389949, were evaluated. In contrast to BMS-986235, pre-stimulation with ACT-389949 led to a decrease in its potency to inhibit cAMP production. Moreover, ACT-389949 displayed greater efficacy for β-arrestin recruitment, while efficacy of Gi activation was similar for both agonists. Following agonist-promoted FPR2 internalization, effective recycling to the plasma membrane was observed only with BMS-986235. Use of G protein-coupled receptor kinase (GRK) knock-out cells revealed a differential impact of GRK2 versus GRK5/6 on β-arrestin recruitment and Gi activation promoted by the two FPR2 agonists. In vivo, decreases of granulocytes in circulation were greatly diminished in mice treated with ACT-389949 but not for BMS-986235. With short-term dosing, both compounds induced a pro-resolution polarization state in cardiac monocyte/macrophages post myocardial infarction. By contrast, with long-term dosing, only BMS-986235 preserved the infarct wall thickness and increased left ventricular ejection fraction in a rat model of myocardial infarction. Altogether, the study shows that differences in the desensitization profiles induced by ACT-389949 and BMS-986235 at the molecular level may explain their distinct inflammatory/pro-resolving activities in vivo.

Distinct transcriptomic and metabolomic profiles characterize NSAID-induced urticaria/angioedema patients undergoing aspirin desensitization

There is limited data on the mechanisms of aspirin desensitization in patients with nonsteroidal anti-inflammatory drug (NSAID)-induced urticaria/angioedema (NIUA). We sought to characterize the transcriptomic and metabolomic profiles of patients with NIUA undergoing aspirin desensitization. PBMCs and plasma were separated from the blood of patients with NIUA undergoing aspirin desensitization for coronary artery disease and NSAID-tolerant controls. RNA was isolated from PBMCs and subjected to messenger RNA (mRNA)- and long noncoding RNA (lncRNA)-sequencing. Plasma samples were analyzed using LC-MS/MS for metabolite shifts using a semitargeted metabolomics panel. Eleven patients with NIUA and 10 healthy controls were recruited. The mRNA gene profiles of predesensitization versus postdesensitization and healthy control versus postdesensitization did not differ significantly. However, we identified 739 mRNAs and 888 lncRNAs as differentially expressed from preaspirin desensitization patients and controls. A12-mRNA gene signature was trained using a machine learning algorithm to distinguish between controls, postdose, and predose samples. Ingenuity Pathway Analysis identified 5 canonical pathways that were significantly enriched in preaspirin desensitization samples. IL-22 was the most upregulated pathway. To investigate the potential regulatory roles of the differentially expressed lncRNA on the mRNAs, 9lncRNAs and 12 mRNAs showed significantly correlated expression patterns in the IL-22 pathway. To validate the transcriptomics data, IL-22 was measured in the plasma samples of the subjects using ELISA. IL-22 was significantly higher in preaspirin desensitization patients compared with controls. In parallel, metabolomic analysis revealed stark differences in plasma profiles of preaspirin desensitization patients and healthy controls. In particular, 2-hydroxybenzoic acid (salicylic acid) was significantly lower in preaspirin desensitization patients compared with healthy controls. This is the first study to combine both transcriptomic and metabolomic approaches in patients with NIUA, which contributes to a deeper understanding about the pathogenesis of NIUA and may potentially pave the way toward a molecular diagnosis of NSAID hypersensitivity.

A Biologically Inspired Neural Network Model to Gain Insight Into the Mechanisms of Post-Traumatic Stress Disorder and Eye Movement Desensitization and Reprocessing Therapy.

Eye movement desensitization and reprocessing (EMDR) therapy is a well-established therapeutic method to treat post-traumatic stress disorder (PTSD). However, how EMDR exerts its therapeutic action has been studied in many types of research but still needs to be completely understood. This is in part due to limited knowledge of the neurobiological mechanisms underlying EMDR, and in part to our incomplete understanding of PTSD. In order to model PTSD, we used a biologically inspired computational model based on firing rate units, encompassing the cortex, hippocampus, and amygdala. Through the modulation of its parameters, we fitted real data from patients treated with EMDR or classical exposure therapy. This allowed us to gain insights into PTSD mechanisms and to investigate how EMDR achieves trauma remission.

The Notable Articles Project

Studies are presented of the interaction of aromatic amine noncompetitive antagonists with the receptor-rich (post-synaptic) membranes isolated from <i>Torpedo marmorata</i> electric organ. When present at micromolar concentrations, methyl iodide quaternary derivatives of the potent non-competitive antagonists proadifen and dimethisoquin increase the affinity of the membrane-bound nicotinic receptor for [³H]acetylcholine and [¹⁴C]dimethyltubocurarine. The equilibrium binding of [¹⁴C]meproadifen (2-(diethylmethylamino)ethyl-2,2-diphenyl valerate) to the receptor-rich membranes is characterized by an ultracentrifugatiom assay. When all acetylcholine binding sites are occupied by the agonist carbamylcholine or the antagonist tubocurarine, [¹⁴C]meproadifen is bound with a dissociation constant <i>K_D</i> = 0.5 µM to a number of sites equal to one-quarter the number of α-neurotoxin binding sites. That high affinity binding site is found in the receptor-rich membranes and not in other membrane fractions isolated from <i>Torpedo</i> electric organ. Other non-competitive aromatic amino antagonists including dimethisoquin, proadifen, and prilocaine displace [¹⁴C]meproadifen, as does perhydrohistrionicotoxin. It is concluded that there is a specific site of binding for the aromatic amine non-competitive antagonists in the isolated nicotinic post-synaptic membrane that is distinct from the site of binding of acetylcholine. Analysis of the interaction of [¹⁴C]meproadifen with the receptor-rich membranes in the absence of cholinergic ligands indicates that under these circumstances the ligand binds weakly to both the anesthetic binding site and the acetylcholine binding site (<i>K_D</i> = 5 µM). The functional significance of the specific binding site for the aromatic amine non-competitive antagonists is discussed in terms of its possible relation to the site of ion translocatiom and to the mechanism of receptor desensitization.

Identification of allergens and allergen hydrolysates by proteomics and metabolomics: A comparative study of natural and enzymolytic bee pollen

Bee pollen as a plant-derived food is consumed as nutritional/functional supplements by humans. But it might confer foodborne allergenicity in susceptible populations, limiting its extensive application. In this study, five potential allergens including profilin, cystatin, prolamin, expansin, and alcohol dehydrogenase in bee pollen derived from Brassica campestris (BP-Bc), were identified through mass spectrometry-based proteomic analysis. Moreover, different types of enzymes (cellulases, pectases, and papains) serve biological roles in pollen wall breaking and expansion, but also promote allergen release and degradation. Proteomic analysis showed that profilin, cystatin, and alcohol dehydrogenase were significantly reduced in BP-Bc following joint treatment with three enzymes. Metabolomic characterization of potential enzymatic hydrolysates of these significantly-decreased allergens was performed, which showed nine major oligopeptides and six amino acids at significantly higher levels in the enzyme-treated BP-Bc. These findings clarified the culprit responsible for bee pollen allergy and the mechanism of enzymatic desensitization for its further development.

Abstract 5670: TRPM8 ion channel role in prostate cancer: Actions as a rapid testosterone signaling receptor

Abstract The transient receptor potential melastatin 8 (TRPM8) is well-known for its role in cold sensation in somatosensory neurons. TRPM8 was first identified as a prostate epithelial cell-specific gene, however, its role was unclear due to the absence of its endogenous agonist. We are the first to discover the novel role of TRPM8 as a rapid testosterone receptor. The TRPM8 mRNA is highly expressed in prostate cancer (PC) and is lost during the transition to androgen-independent prostate cancer (AIPC). Although emerging studies have shed light regarding androgen regulation of TRPM8 mRNA expression, we found that the addition of androgen receptor (AR) on the lipid bilayers inhibited testosterone-TRPM8 induced Ca2+ uptake. Additionally, our IHC revealed increased internalization of the TRPM8 protein in high-grade PC and that TRPM8 protein was targeted for proteasomal degradation in PC. We observed that inhibition of AR and UBA1 promoted the stabilization of TRPM8 on the plasma membrane, triggering Ca2+-induced cytotoxicity and apoptosis in both androgen dependent and androgen independent PC cells. Furthermore, in line with previous studies, we showed that testosterone-induced TRPM8 activation on the planar lipid bilayers also required phosphatidylinositol 4,5-bisphosphate (PIP2). Loss of PTEN is associated with tumor recurrence and the transition to AIPC. Thus, PTEN loss mediated PIP2 deficiency may be an important mechanism of TRPM8 desensitization in PC. Therefore, we propose that the rescue of TRPM8 activity on the plasma membrane combined with AR targeting may be an effective therapy for PC. Citation Format: Kiran Velpula, Katherine Shishido, Susovon Bayen, Swapna Asuthkar. TRPM8 ion channel role in prostate cancer: Actions as a rapid testosterone signaling receptor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5670.

Building the Chordata Olfactory Receptor Database using more than 400,000 receptors annotated by Genome2OR.

Olfactory receptors are poorly annotated for most genome-sequenced chordates. To address this deficiency, we developed a nhmmer-based olfactory receptor annotation tool Genome2OR ( https://github.com/ToHanwei/Genome2OR.git ), and used it to process 1,695 sequenced chordate genomes in the NCBI Assembly database as of January, 2021. In total, 765,248 olfactory receptor genes were annotated, with 404,426 functional genes and 360,822 pseudogenes, which represents a four-fold increase in the number of annotated olfactory receptors. Based on the annotation data, we built a database called Chordata Olfactory Receptor Database (CORD, https://cord.ihuman.shanghaitech.edu.cn ) for archiving, analysing and disseminating the data. Beyond the primary data, we offer derivative information, including pictures of species, cross references to public databases, structural models, sequence similarity networks and sequence profiles in the CORD. Furthermore, we did brief analyses on these receptors, including building a huge protein sequence similarity network covering all receptors in the database, and clustering them into 20 communities, classifying the 20 communities into three categories based on their presences/absences in ray-finned fish and/or lobe-finned fish. We infer that olfactory receptors should have unique activation and desensitization mechanisms by analysing their sequences and structural models. We believe the CORD can benefit the researchers and the general public who are interested in olfaction.

Safety and tolerability of T-SIGn vectors when administered using “flat” versus “low-high-high” (LHH) dosing regimens.

2572 Background: Tumor-selective viruses, particularly those dosed systemically to deliver transgenes, are potentially powerful cancer therapies. However, acute cytokine reactions to viral particle (vp) infusion may affect vector tolerability [Small 2006], thereby limiting the maximum tolerated dose (MTD) and subsequent transgene delivery. T-SIGn vectors (e.g. NG-641 and NG-350A) are transgene-armed variants of the epithelial tumor-selective adenovirus enadenotucirev (EnAd). Acute serum cytokine increases post-dosing have been seen at the MTD of EnAd (“flat” dosing of 3 x 1012 vp on Days [D] 1, 3 and 5) [Machiels 2019]. Following supportive preclinical data [McElwaine-Johnn 2019], we explored if a LHH dosing regimen, in which a lower dose is given on D1 prior to two higher doses on D3 and 5, may improve vector safety/tolerability thereby allowing higher cumulative doses to be given. Methods: Data were pooled from three Phase 1 dose-escalation studies in advanced/metastatic epithelial cancer: SPICE (EnAd + pembrolizumab/nivolumab; NCT02636036), FORTITUDE (NG-350A ± pembrolizumab; NCT03852511) and STAR (NG-641; NCT04053283). Serum cytokines were measured using a 17-analyte Luminex assay. IL-6/MCP-1 data for D1, 3 and 5 (pre- and 6-10 hrs post-dose) were analyzed to examine acute cytokine changes. TNFα/IFNγ were examined due to their association with cytokine release syndrome (CRS). Samples analyzed from SPICE/FORTITUDE were taken before PD-1 inhibitor administration. Results: 84 patients (SPICE n=51; FORTITUDE n=18; STAR n=15) were included in these analyses; 79 had cytokine data. AEs and Gr≥3 AEs within 1 wk of first dose, and DLTs at any time, were less frequent with a LHH vs flat dosing regimen (Tbl). Importantly, a LHH dose of 1-6-6 (1 x 1012 vp on D1; 6 x 1012 vp on D3 and 5; greater than the previous flat MTD) was tolerated. Acute increases in TNFα/IFNγ were limited and no severe CRS was seen. Increases in IL-6/MCP-1 with 1 x 1011 or 1 x 1012 vp flat dosing were negligible, whereas acute increases in IL-6/MCP-1 were seen after the first dose of 3 x 1012 vp when given as a flat dose (negligible increases on D3/5). Notably, cytokine responses with 1-3-3 dosing (1 x 1012 vp on D1; 3 x 1012 vp on D3 and 5), including after the first 3 x 1012 vp dose on D3, were negligible. Cytokine responses after the first dose of 6 x 1012 vp in the 1-6-6 regimen were similar to those seen with the first dose of the flat 3 x 1012 vp regimen. Conclusions: LHH dosing appears to induce a desensitization mechanism allowing higher cumulative doses of T-SIGn vectors to be given without the associated acute reactions to viral infusions. This finding may have implications for optimizing safety-efficacy profiles of viral vectors in cancer. Clinical trial information: NCT02636036, NCT03852511 and NCT04053283. [Table: see text]

Involvement of VIVID in white light-responsive pigmentation, sexual development and sterigmatocystin biosynthesis in the filamentous fungus Podospora anserina.

Light serves as a source of information and regulates diverse physiological processes in living organisms. Fungi perceive and respond to light through a complex photosensory system. Fungi have evolved the desensitization mechanism to adapt to the changing light signal in a natural environment. White light exerts multiple essential impacts on the model filamentous fungus Podospora anserina. However, the light sensing and response in this species has not been investigated. In this study, we demonstrated that the loss of function of the light desensitization protein VIVID (VVD) in P. anserina triggered exacerbated light responses and therefore led to drastic morphological and physiological changes. The white light-sensitive mutant Δvvd showed growth reduction, spermatia overproduction, enhanced hyphae pigmentation and reduced oxidative stress tolerance. We observed the decreased expression level of sterigmatocystin gene cluster by transcriptome analysis and finally detected the reduced production of sterigmatocystin in Δvvd in response to white light. Our data indicate that VVD acts as a repressor of white collar complex. This study exhibits a vital role of VVD in governing white light-responsive gene expression and secondary metabolite production and contributes to a better understanding of the photoreceptor VVD in P. anserina.