In Vivo Activity of Repurposed Amodiaquine as a Host-Targeting Therapy for the Treatment of Anthrax

Anthrax is caused by Bacillus anthracis and can result in nearly 100% mortality due in part to anthrax toxin. Antimalarial amodiaquine (AQ) acts as a host-oriented inhibitor of anthrax toxin endocytosis. Here, we determined the pharmacokinetics and safety of AQ in mice, rabbits, and humans as well as the efficacy in the fly, mouse, and rabbit models of anthrax infection. In the therapeutic-intervention studies, AQ nearly doubled the survival of mice infected subcutaneously with a B. anthracis dose lethal to 60% of the animals (LD₆₀). In rabbits challenged with 200 LD₅₀ of aerosolized B. anthracis, AQ as a monotherapy delayed death, doubled the survival rate of infected animals that received a suboptimal amount of antibacterial levofloxacin, and reduced bacteremia and toxemia in tissues. Surprisingly, the anthrax efficacy of AQ relies on an additional host macrophage-directed antibacterial mechanism, which was validated in the toxin-independent Drosophila model of Bacillus infection. Lastly, a systematic literature review of the safety and pharmacokinetics of AQ in humans from over 2 000 published articles revealed that AQ is likely safe when taken as prescribed, and its pharmacokinetics predicts anthrax efficacy in humans. Our results support the future examination of AQ as adjunctive therapy for the prophylactic anthrax treatment.

High-Density Blood Transcriptomics Reveals Precision Immune Signatures of SARS-CoV-2 Infection in Hospitalized Individuals

The immune response to COVID-19 infection is variable. How COVID-19 influences clinical outcomes in hospitalized patients needs to be understood through readily obtainable biological materials, such as blood. We hypothesized that a high-density analysis of host (and pathogen) blood RNA in hospitalized patients with SARS-CoV-2 would provide mechanistic insights into the heterogeneity of response amongst COVID-19 patients when combined with advanced multidimensional bioinformatics for RNA. We enrolled 36 hospitalized COVID-19 patients (11 died) and 15 controls, collecting 74 blood PAXgene RNA tubes at multiple timepoints, one early and in 23 patients after treatment with various therapies. Total RNAseq was performed at high-density, with >160 million paired-end, 150 base pair reads per sample, representing the most sequenced bases per sample for any publicly deposited blood PAXgene tube study. There are 770 genes significantly altered in the blood of COVID-19 patients associated with antiviral defense, mitotic cell cycle, type I interferon signaling, and severe viral infections. Immune genes activated include those associated with neutrophil mechanisms, secretory granules, and neutrophil extracellular traps (NETs), along with decreased gene expression in lymphocytes and clonal expansion of the acquired immune response. Therapies such as convalescent serum and dexamethasone reduced many of the blood expression signatures of COVID-19. Severely ill or deceased patients are marked by various secondary infections, unique gene patterns, dysregulated innate response, and peripheral organ damage not otherwise found in the cohort. High-density transcriptomic data offers shared gene expression signatures, providing unique insights into the immune system and individualized signatures of patients that could be used to understand the patient’s clinical condition. Whole blood transcriptomics provides patient-level insights for immune activation, immune repertoire, and secondary infections that can further guide precision treatment.

Blood-Brain Barrier Penetrating Biologic TNF-α Inhibitor for Alzheimer's Disease

Tumor necrosis factor alpha (TNF-α) driven processes are involved at multiple stages of Alzheimer's disease (AD) pathophysiology and disease progression. Biologic TNF-α inhibitors (TNFIs) are the most potent class of TNFIs but cannot be developed for AD since these macromolecules do not cross the blood-brain barrier (BBB). A BBB-penetrating TNFI was engineered by the fusion of the extracellular domain of the type II human TNF receptor (TNFR) to a chimeric monoclonal antibody (mAb) against the mouse transferrin receptor (TfR), designated as the cTfRMAb-TNFR fusion protein. The cTfRMAb domain functions as a molecular Trojan horse, binding to the mouse TfR and ferrying the biologic TNFI across the BBB via receptor-mediated transcytosis. The aim of the study was to examine the effect of this BBB-penetrating biologic TNFI in a mouse model of AD. Six-month-old APPswe, PSEN 1dE9 (APP/PS1) transgenic mice were treated with saline (n = 13), the cTfRMAb-TNFR fusion protein (n = 12), or etanercept (non-BBB-penetrating biologic TNFI; n = 11) 3 days per week intraperitoneally. After 12 weeks of treatment, recognition memory was assessed using the novel object recognition task, mice were sacrificed, and brains were assessed for amyloid beta (Aβ) load, neuroinflammation, BBB damage, and cerebral microhemorrhages. The cTfRMAb-TNFR fusion protein caused a significant reduction in brain Aβ burden (both Aβ peptide and plaque), neuroinflammatory marker ICAM-1, and a BBB disruption marker, parenchymal IgG, and improved recognition memory in the APP/PS1 mice. Fusion protein treatment resulted in low antidrug-antibody formation with no signs of either immune reaction or cerebral microhemorrhage development with chronic 12-week treatment. Chronic treatment with the cTfRMAb-TNFR fusion protein, a BBB-penetrating biologic TNFI, offers therapeutic benefits by targeting Aβ pathology, neuroinflammation, and BBB-disruption, overall improving recognition memory in a transgenic mouse model of AD.