Bacteria hijack a meningeal neuroimmune axis to facilitate brain invasion.

The meninges are densely innervated by nociceptive sensory neurons that mediate pain and headache1,2. Bacterial meningitis causes life-threatening infections of the meninges and central nervous system, affecting more than 2.5 million people a year3-5. How pain and neuroimmune interactions impact meningeal antibacterial host defences are unclear. Here we show that Nav1.8+ nociceptors signal to immune cells in the meninges through the neuropeptide calcitonin gene-related peptide (CGRP) during infection. This neuroimmune axis inhibits host defences and exacerbates bacterial meningitis. Nociceptor neuron ablation reduced meningeal and brain invasion by two bacterial pathogens: Streptococcus pneumoniae and Streptococcus agalactiae. S. pneumoniae activated nociceptors through its pore-forming toxin pneumolysin to release CGRP from nerve terminals. CGRP acted through receptor activity modifying protein 1 (RAMP1) on meningeal macrophages to polarize their transcriptional responses, suppressing macrophage chemokine expression, neutrophil recruitment and dural antimicrobial defences. Macrophage-specific RAMP1 deficiency or pharmacological blockade of RAMP1 enhanced immune responses and bacterial clearance in the meninges and brain. Therefore, bacteria hijack CGRP-RAMP1 signalling in meningeal macrophages to facilitate brain invasion. Targeting this neuroimmune axis in the meninges can enhance host defences and potentially produce treatments for bacterial meningitis.

Gasdermin-E mediates mitochondrial damage in axons and neurodegeneration.

Mitochondrial dysfunction and axon loss are hallmarks of neurologic diseases. Gasdermin (GSDM) proteins are executioner pore-forming molecules that mediate cell death, yet their roles in the central nervous system (CNS) are not well understood. Here, we find that one GSDM family member, GSDME, is expressed by both mouse and human neurons. GSDME plays a role in mitochondrial damage and axon loss. Mitochondrial neurotoxins induced caspase-dependent GSDME cleavage and rapid localization to mitochondria in axons, where GSDME promoted mitochondrial depolarization, trafficking defects, and neurite retraction. Frontotemporal dementia (FTD)/amyotrophic lateral sclerosis (ALS)-associated proteins TDP-43 and PR-50 induced GSDME-mediated damage to mitochondria and neurite loss. GSDME knockdown protected against neurite loss in ALS patient iPSC-derived motor neurons. Knockout of GSDME in SOD1G93A ALS mice prolonged survival, ameliorated motor dysfunction, rescued motor neuron loss, and reduced neuroinflammation. We identify GSDME as an executioner of neuronal mitochondrial dysfunction that may contribute to neurodegeneration.

Derivation and validation of a risk classification tree for patients with synovial sarcoma.

BACKGROUND: Synovial sarcoma (SS) accounts for 8%-10% of all soft-tissue sarcomas. Clinical presentation and outcomes vary, yet discrete risk groups based on validated prognostic indices are not defined for the full spectrum of patients with SS. METHODS: We performed a retrospective cohort study using data from the SEER (surveillance, epidemiology, and end results program) database of SS patients who were <70 years of age at diagnosis. We constructed a recursive partitioning model of overall survival using a training cohort of 1063 patients with variables: Age at diagnosis, sex, race, ethnicity, primary site, tumor size, tumor grade, and stage. Based on this model, we grouped patients into three risk groups and estimated 5-year overall survival for each group. We then applied these groups to a test cohort (n = 1063). RESULTS: Our model identified three prognostic groups with significantly different overall survival: low risk (local/regional stage with either <21 years of age OR tumor <7.5 cm and female sex), intermediate-risk (local/regional stage, age ≥ 21 years with either male sex and tumor <7.5 cm OR any sex with appendicular anatomic location) and high risk (local/regional stage, age ≥ 21 years, tumor size ≥7.5 cm and non-appendicular location OR distant stage). Prognostic groups were applied to the test cohort, showing significantly different survival between groups (p < 0.0001). CONCLUSIONS: Our analysis yields an intuitive risk-classification tree with discrete groups, which may provide useful information for researchers, patients, and clinicians. Prospective validation of this model may inform efforts at risk-stratifying treatment.

Catching a killer: Mechanisms of programmed cell death and immune activation in Amyotrophic Lateral Sclerosis.

In the central nervous system (CNS), execution of programmed cell death (PCD) is crucial for proper neurodevelopment. However, aberrant activation of these pathways in adult CNS leads to neurodegenerative diseases including amyotrophic lateral sclerosis (ALS). How a cell dies is critical, as it can drive local immune activation and tissue damage. Classical apoptosis engages several mechanisms to evoke "immunologically silent" responses, whereas other forms of programmed death such as pyroptosis, necroptosis, and ferroptosis release molecules that can potentiate immune responses and inflammation. In ALS, a fatal neuromuscular disorder marked by progressive death of lower and upper motor neurons, several cell types in the CNS express machinery for multiple PCD pathways. The specific cell types engaging PCD, and ultimate mechanisms by which neuronal death occurs in ALS are not well defined. Here, we provide an overview of different PCD pathways implicated in ALS. We also examine immune activation in ALS and differentiate apoptosis from necrotic mechanisms based on downstream immunological consequences. Lastly, we highlight therapeutic strategies that target cell death pathways in the treatment of neurodegeneration and inflammation in ALS.

VLDLR and ApoER2 are receptors for multiple alphaviruses.

Alphaviruses, like many other arthropod-borne viruses, infect vertebrate species and insect vectors separated by hundreds of millions of years of evolutionary history. Entry into evolutionarily divergent host cells can be accomplished by recognition of different cellular receptors in different species, or by binding to receptors that are highly conserved across species. Although multiple alphavirus receptors have been described1-3, most are not shared among vertebrate and invertebrate hosts. Here we identify the very low-density lipoprotein receptor (VLDLR) as a receptor for the prototypic alphavirus Semliki forest virus. We show that the E2 and E1 glycoproteins (E2-E1) of Semliki forest virus, eastern equine encephalitis virus and Sindbis virus interact with the ligand-binding domains (LBDs) of VLDLR and apolipoprotein E receptor 2 (ApoER2), two closely related receptors. Ectopic expression of either protein facilitates cellular attachment, and internalization of virus-like particles, a VLDLR LBD-Fc fusion protein or a ligand-binding antagonist block Semliki forest virus E2-E1-mediated infection of human and mouse neurons in culture. The administration of a VLDLR LBD-Fc fusion protein has protective activity against rapidly fatal Semliki forest virus infection in mouse neonates. We further show that invertebrate receptor orthologues from mosquitoes and worms can serve as functional alphavirus receptors. We propose that the ability of some alphaviruses to infect a wide range of hosts is a result of their engagement of evolutionarily conserved lipoprotein receptors and contributes to their pathogenesis.

Anthrax toxins regulate pain signaling and can deliver molecular cargoes into ANTXR2+ DRG sensory neurons.

Bacterial products can act on neurons to alter signaling and function. In the present study, we found that dorsal root ganglion (DRG) sensory neurons are enriched for ANTXR2, the high-affinity receptor for anthrax toxins. Anthrax toxins are composed of protective antigen (PA), which binds to ANTXR2, and the protein cargoes edema factor (EF) and lethal factor (LF). Intrathecal administration of edema toxin (ET (PA + EF)) targeted DRG neurons and induced analgesia in mice. ET inhibited mechanical and thermal sensation, and pain caused by formalin, carrageenan or nerve injury. Analgesia depended on ANTXR2 expressed by Nav1.8+ or Advillin+ neurons. ET modulated protein kinase A signaling in mouse sensory and human induced pluripotent stem cell-derived sensory neurons, and attenuated spinal cord neurotransmission. We further engineered anthrax toxins to introduce exogenous protein cargoes, including botulinum toxin, into DRG neurons to silence pain. Our study highlights interactions between a bacterial toxin and nociceptors, which may lead to the development of new pain therapeutics.

Nociceptive Sensory Neurons Mediate Inflammation Induced by Bacillus Anthracis Edema Toxin.

Bacterial products are able to act on nociceptive neurons during pathogenic infection. Neurogenic inflammation is an active part of pain signaling and has recently been shown to impact host-pathogen defense. Bacillus anthracis Edema Toxin (ET) produces striking edema in peripheral tissues, but the cellular mechanisms involved in tissue swelling are not completely understood. Here, we find that nociceptive neurons play a role in ET-induced edema and inflammation in mice. Subcutaneous footpad infection of B. anthracis Sterne caused ET-dependent local mechanical allodynia, paw swelling and body weight gain. Subcutaneous administration of ET induced paw swelling and vascular leakage, the early phases of which were attenuated in the absence of Trpv1+ or Nav1.8+ nociceptive neurons. Nociceptive neurons express the anthrax toxin receptor ANTXR2, but this did not mediate ET-induced edema. ET induced local cytokine expression and neutrophil recruitment, which were dependent in part on Trpv1+ nociceptive neurons. Ablation of Trpv1+ or Nav1.8+ nociceptive neurons also attenuated early increases in paw swelling and body weight gain during live B. anthracis infection. Our findings indicate that nociceptive neurons play an active role in inflammation caused by B. anthracis and Edema Toxin to potentially influence bacterial pathogenesis.

Landscape of phase 1 clinical trials for minors with cancer in the United States.

OBJECTIVES: Understanding trends in characteristics of early phase trials that allow minors with cancer to participate may inform additional efforts to improve cancer drug development for young people. METHODS: We accessed data for oncology phase 1 or phase 1/2 trials in the United States from ClinicalTrials.gov with lower age bound for eligibility <18 years. Descriptive statistics were calculated and trends over time evaluated using logistic and multinomial logistic regression. RESULTS: Six hundred twelve trials met inclusion criteria. Sixty-five percent of trials were for older adults that also allowed minors, while 9% were exclusively for patients ≤18 years of age. Eighty-three percent of trials included at least one novel agent, while 17% studied only conventional therapies. Fifty-eight percent of trials studied treatments not yet Food and Drug Administration (FDA) approved (48% if exclusively for patients ≤18 years). Fifteen percent of trials for which dose-escalation method could be determined, utilized a model-based design. Eighteen percent of all trials were industry sponsored (48% if exclusively for patients ≤18 years). Forty-nine percent of all trials were multicenter (69% if exclusively for patients ≤18 years). There was an increase in trials exclusively focused on patients with central nervous system (CNS) tumors over the study period (P ≤ .02). No other temporal trends were seen. The median times from first-in-adult to first-in-pediatric for monotherapy and combination trials were 5.7 and 3.3 years, respectively. CONCLUSION: The paucity of clear temporal trends highlights the need for innovation in early drug development for young people. Our analysis serves as a benchmark against which to evaluate initiatives to improve pediatric cancer drug development.

Sponsorship of oncology clinical trials in the United States according to age of eligibility.

BACKGROUND: The sponsorship mix of trials relevant to young people with cancer has not been reported. Understanding this sponsorship mix may have implications for policies and regulations related to pediatric cancer drug development. METHODS: We analyzed sponsorship of interventional trials first opened in the United States from 2007 to 2018 using the ClinicalTrials.gov registry. A total of 51 781 trials across non-oncology disciplines and 18 431 oncology trials were classified according to lower age of eligibility (≥18 years vs < 18 years). Studies were stratified according to sponsorship (industry vs non-industry). Trial characteristics were compared by sponsorship category. Trends in sponsorship were tracked over time. RESULTS: Within oncology trials for patients ≥ 18 years, sponsorship was 33% industry and 67% non-industry. Among oncology trials that included patients < 18 years, sponsorship was 16.6% industry and 83.4% non-industry (P < .001). 15.5% of industry-sponsored trials in non-oncology disciplines included patients < 18 years, whereas only 5.2% of industry-sponsored oncology trials were open to patients < 18 years (P < .001). Relative to trials with non-industry sponsors, there was a statistically significant increase in industry sponsorship of oncology trials that included patients < 18 years over time (P < .001). Trial characteristics differed significantly according to sponsor type regardless of age of eligibility. CONCLUSIONS: Interventional oncology trials that include patients < 18 years are less likely to be industry-sponsored compared to oncology trials exclusively in patients ≥ 18 years. Compared to other medical disciplines, a smaller proportion of industry-sponsored oncology trials included patients < 18 years. Trial sponsorship is associated with differential trial characteristics, such as trial duration and number of patients enrolled, regardless of age.

Timing of first-in-child trials of FDA-approved oncology drugs.

AIM: The lag time between initial human studies of oncology agents and the first-in-child clinical trials of these agents has not been defined. METHODS: We conducted a systematic analysis of time from first-in-human trials to first-in-child trials (age of eligibility <18 years) of agents first approved by the US Food and Drug Administration (FDA) for any oncology indication from 1997 to 2017. We used clinical trial registry data, published literature and oncology abstracts to identify relevant trials and start dates. RESULTS: From 1997 to 2017, 126 drugs received initial FDA approval for an oncology indication. Of these, 117 were non-hormonal agents used in subsequent analyses. Fifteen of 117 drugs (12.8%) did not yet have a paediatric trial, and six of 117 drugs (5.1%) had an initial approval that included children. The median time between the first-in-human trial and first-in-child trial was 6.5 years (range 0-27.7 years). The median time from initial FDA approval to the first-in-child clinical trial was -0.66 years (range -43 to +19 years). These values were stable regardless of year of initial FDA approval, drug class and initial approved disease indication. CONCLUSION: The median lag time from first-in-human to first-in-child trials of oncology agents that were ultimately approved by FDA was 6.5 years. These results provide a benchmark against which to evaluate recent initiatives designed to hasten drug development relevant to children with cancer.

Stabilization of the Max Homodimer with a Small Molecule Attenuates Myc-Driven Transcription.

The transcription factor Max is a basic-helix-loop-helix leucine zipper (bHLHLZ) protein that forms homodimers or interacts with other bHLHLZ proteins, including Myc and Mxd proteins. Among this dynamic network of interactions, the Myc/Max heterodimer has crucial roles in regulating normal cellular processes, but its transcriptional activity is deregulated in a majority of human cancers. Despite this significance, the arsenal of high-quality chemical probes to interrogate these proteins remains limited. We used small molecule microarrays to identify compounds that bind Max in a mechanistically unbiased manner. We discovered the asymmetric polycyclic lactam, KI-MS2-008, which stabilizes the Max homodimer while reducing Myc protein and Myc-regulated transcript levels. KI-MS2-008 also decreases viable cancer cell growth in a Myc-dependent manner and suppresses tumor growth in vivo. This approach demonstrates the feasibility of modulating Max with small molecules and supports altering Max dimerization as an alternative approach to targeting Myc.

Recent discoveries and applications involving small-molecule microarrays.

High-throughput and unbiased binding assays have proven useful in probe discovery for a myriad of biomolecules, including targets of unknown structure or function and historically challenging target classes. Over the past decade, a number of novel formats for executing large-scale binding assays have been developed and used successfully in probe discovery campaigns. Here we review the use of one such format, the small-molecule microarray (SMM), as a tool for discovering protein-small molecule interactions. This review will briefly highlight selected recent probe discoveries using SMMs as well as novel uses of SMMs in profiling applications.