The rockefeller university

We previously showed that the anticancer drug imatinib mesylate (IMT, trade name: Gleevec) and a chemically distinct compound, DV2-103 (a kinase-inactive derivative of the potent Abl and Src kinase inhibitor, PD173955) lower A beta levels at low micromolar concentrations primarily through a lysosome-dependent mechanism that renders APP less susceptible to proteolysis by BACE1 without directly inhibiting BACE1 enzymatic activity, or broadly inhibiting the processing of other BACE1 substrates. Additionally, IMT indirectly inhibits gamma-secretase and stimulates autophagy, and thus may decrease A beta levels through multiple pathways. In two recent studies we demonstrated similar effects on APP metabolism caused by derivatives of IMT and DV2-103. In the present study, we synthesized and tested radically altered IMT isomers (IMTi's) that possess medium structural similarity to IMT. Independent of structural similarity, these isomers manifest widely differing potencies in altering APP metabolism. These will enable us to choose the most potent isomers for further derivatization.

Background Cryptococcosis is a life-threatening disease caused by Cryptococcus neoformans or C. gattii. Neutralizing autoantibodies (auto-Abs) against granulocyte-macrophage colony-stimulating factor (GM-CSF) in otherwise healthy adults with cryptococcal meningitis have been described since 2013. We searched for neutralizing auto-Abs in sera collected from Colombian patients with non-HIV-associated cryptococcosis in a retrospective national cohort from 1997 to 2016. Methods We reviewed clinical and laboratory records and assessed the presence of neutralizing auto-Abs against GM-CSF in 30 HIV negative adults with cryptococcosis (13 caused by C. gattii and 17 caused by C. neoformans). Results We detected neutralizing auto-Abs against GM-CSF in the sera of 10 out of 13 (77%) patients infected with C. gattii and one out of 17 (6%) patients infected with C. neoformans. Conclusions We report eleven Colombian patients diagnosed with cryptococcosis who had auto-Abs that neutralize GM-CSF. Among these patients, ten were infected with C. gattii and only one with C. neoformans.

Immunization with mosaic-8b (nanoparticles presenting 8 SARS-like betacoronavirus [sarbecovirus] receptor-binding domains [RBDs]) elicits more broadly cross-reactive antibodies than homotypic SARS-CoV-2 RBD-only nanoparticles and protects against sarbecoviruses. To investigate original antigenic sin (OAS) effects on mosaic-8b efficacy, we evaluated the effects of prior COVID-19 vaccinations in non-human primates and mice on anti-sarbecovirus responses elicited by mosaic-8b, admix-8b (8 homotypics), or homotypic SARS-CoV-2 immunizations, finding the greatest cross-reactivity for mosaic-8b. As demonstrated by molecular fate mapping, in which antibodies from specific cohorts of B cells are differentially detected, B cells primed by WA1 spike mRNA-LNP dominated antibody responses after RBD-nanoparticle boosting. While mosaic-8b- and homotypic-nanoparticles boosted cross-reactive antibodies, de novo antibodies were predominantly induced by mosaic-8b, and these were specific for variant RBDs with increased identity to RBDs on mosaic-8b. These results inform OAS mechanisms and support using mosaic-8b to protect COVID-19vaccinated/infected humans against as-yet-unknown SARS-CoV-2 variants and animal sarbecoviruses with human spillover potential.

Small molecule-regulated RNA devices have the potential to modulate diverse aspects of cellular function, but the small molecules used to date have potential toxicities limiting their use in cells. Here we describe a method for creating drug-regulated RNA nanodevices (RNs) using acyclovir, a biologically compatible small molecule with minimal toxicity. Our modular approach involves a scaffold comprising a central F30 three-way junction, an integrated acyclovir aptamer on the input arm, and a variable effector-binding aptamer on the output arm. This design allows for the rapid engineering of acyclovir-regulated RNs, facilitating temporal, tunable, and reversible control of intracellular aptamers. We demonstrate the control of the Broccoli aptamer and the iron-responsive element (IRE) by acyclovir. Regulating the IRE with acyclovir enables precise control over iron-regulatory protein (IRP) sequestration, consequently promoting the inhibition of ferroptosis. Overall, the method described here provides a platform for transforming aptamers into acyclovir-controllable antagonists against physiologic target proteins.

Patients heterozygous for germline CBL loss-of-function (LOF) variants can develop myeloid malignancy, autoinflammation, or both, if some or all of their leukocytes become homozygous for these variants through somatic loss of heterozygosity (LOH) via uniparental isodisomy. We observed an upregulation of the inflammatory gene expression signature in whole blood from these patients, mimicking monogenic inborn errors underlying autoinflammation. Remarkably, these patients had constitutively activated monocytes that secreted 10 to 100 times more inflammatory cytokines than those of healthy individuals and CBL LOF heterozygotes without LOH. CBL-LOH hematopoietic stem and progenitor cells (HSPCs) outgrew the other cells, accounting for the persistence of peripheral monocytes homozygous for the CBL LOF variant. ERIC pathway activation was required for the excessive production of cytokines by both resting and stimulated CBL-LOF monocytes, as shown in monocytic cell lines. Finally, we found that about 1 in 10,000 individuals in the UIC Biobank were heterozygous for CBL LOF variants and that these carriers were at high risk of hematological and inflammatory conditions.

Pachytene piRNAs, a Piwi-interacting RNA subclass in mammals, are hypothesized to regulate non-transposon sequences during spermatogenesis. Caenorhabditis elegans piRNAs, the 21URNAs, are implicated in regulating coding sequences; the messenger RNA targets and biological processes they control during spermatogenesis are largely unknown. We demonstrate that loss of 21URNAs compromises homolog pairing and makes it permissive for nonhomologous synapsis resulting in defects in crossover formation and chromosome segregation during spermatogenesis. We identify Polo-like kinase 3 (PLK-3), among others, as a 21URNA target. 21URNA activity restricts PLK-3 protein to proliferative cells, and expansion of PLK-3 in pachytene overlaps with the meiotic defects. Removal of plk-3 results in quantitative genetic suppression of the meiotic defects. One discrete 21URNA inhibits PLK-3 expression in late pachytene cells. Together, these results suggest that the 21URNAs function as pachytene piRNAs during C. elegans spermatogenesis. We identify their targets and meiotic events and highlight the remarkable intricacy of this multi-effector mechanism during spermatogenesis.

RNA polymerase (RNAP), the central enzyme of transcription, intermittently pauses during the elongation stage of RNA synthesis. Pausing provides an opportunity for regulatory events such as nascent RNA folding or the recruitment of transregulators. NusG (Spt5 in eukaryotes and archaea) regulates RNAP pausing and is the only transcription factor conserved across all cellular life. NusG is a multifunctional protein: its N-terminal domain (NGN) binds to RNAP, and its C-terminal KOW domain in bacteria interacts with transcription regulators such as ribosomes and termination factors. In Escherichia coli, NusG acts as an antipausing factor. However, recent studies have revealed that NusG has distinct transcriptional regulatory roles specific to bacterial clades with clinical implications. Here, we focus on NusG's dual roles in the regulation of pausing.

Radiolabeled small-molecule DOTA-haptens can be combined with antitumor/anti-DOTA bispecific antibodies (BsAbs) for pretargeted radioimmunotherapy (PRIT). For optimized delivery of the theranostic g- and b-emitting isotope 177 Lu with DOTA-based PRIT (DOTA-PRIT), bivalent Gemini (DOTA-Bn-thiourea-PEG4-thiourea-Bn-DOTA, aka (3,6,9,12-tetraoxatetradecane-1,14-diyl)bis(DOTA-benzyl thiourea)) was developed. Methods: Gemini was synthesized by linking 2 S-2(4-isothiocyanatobenzyl)-DOTA molecules together via a 1,14-diamino-PEG4 linker. [177Lu]Lu-Gemini 177 Lu]Lu-Gemini was prepared with no-carrier added 177 LuCl 3 to a molar-specific activity of 123 GBq/mmol m mol and radiochemical purity of more than 99%. The specificity of BsAb177 Lu-Gemini was verified in vitro. Subsequently, we evaluated biodistribution and whole-body clearance for [177Lu]Lu-Gemini 177 Lu]Lu-Gemini and, for comparison, our gold-standard monovalent [177Lu]Lu-S-2-(4-amino- 177 Lu]Lu-S-2-(4-amino- benzyl)-DOTA ([177Lu]Lu-DOTA-Bn) 177 Lu]Lu-DOTA-Bn) in na & iuml;ve (tumor-free) athymic nude mice. For our proof-of-concept system, a 3-step pretargeting approach was performed with an established DOTA-PRIT regimen (anti-GPA33/ anti-DOTA IgG-scFv BsAb, a clearing agent, and [177Lu]Lu-Gemini) 177 Lu]Lu-Gemini) mouse models. Results: Initial in vivo studies showed that [177Lu]Lu- 177 Lu]Lu- Gemini behaved similarly to [177Lu]Lu-DOTA-Bn, 177 Lu]Lu-DOTA-Bn, with almost identical blood and whole-body clearance kinetics, as well as biodistribution and mouse kidney dosimetry. Pretargeting [177Lu]Lu-Gemini 177 Lu]Lu-Gemini to GPA33expressing SW1222 human colorectal xenografts was highly effective, leading to absorbed doses of [177Lu]Lu-Gemini 177 Lu]Lu-Gemini for blood, tumor, liver, spleen, and kidneys of 3.99, 455, 6.93, 5.36, and 14.0 cGy/MBq, respectively. Tumor-to-normal tissue absorbed-dose ratios (i.e., therapeutic indices [TIs]) for the blood and kidneys were 114 and 33, respectively. In addition, we demonstrate that the use of bivalent [177Lu]Lu- 177 Lu]Lu- Gemini in DOTA-PRIT leads to improved TIs and augmented [177Lu]Lu- 177 Lu]Lu- Gemini tumor uptake and retention in comparison to monovalent [177Lu]Lu-DOTA-Bn. 177 Lu]Lu-DOTA-Bn. Finally, we established efficacy in SW1222 tumor bearing mice, demonstrating that a single injection of anti-GPA33 DOTA-PRIT with 44 MBq (1.2 mCi) of [177Lu]Lu-Gemini 177 Lu]Lu-Gemini (estimated tumor-absorbed dose, 200 Gy) induced complete responses in 5 of 5 animals and a histologic cure in 2 of 5 (40%) animals. Moreover, a significant increase in survival compared with nontreated controls was noted (maximum tolerated dose not reached). Conclusion: We have developed a bivalent DOTA-radiohapten, [177Lu]Lu-Gemini, that showed improved radiopharmacology for DOTA-PRIT application. The use of bivalent [177Lu]Lu-Gemini in DOTA-PRIT, as opposed to monovalent [177Lu]Lu-DOTA-Bn, allows curative treatments with considerably less administered 177 Lu activity while still achieving high TIs for both the blood and the

The recurring spillover of pathogenic coronaviruses and demonstrated capacity of sarbecoviruses, such SARS-CoV-2, to rapidly evolve in humans underscores the need to better understand immune responses to this virus family. For this purpose, we characterized the functional breadth and potency of antibodies targeting the receptor binding domain (RBD) of the spike glycoprotein that exhibited cross-reactivity against SARS-CoV-2 variants, SARS-CoV-1 and sarbecoviruses from diverse clades and animal origins with spillover potential. One neutralizing antibody, C68.61, showed remarkable neutralization breadth against both SARS-CoV-2 variants and viruses from different sarbecovirus clades. C68.61, which targets a conserved RBD class 5 epitope, did not select for escape variants of SARS-CoV-2 or SARS-CoV-1 in culture nor have predicted escape variants among circulating SARS-CoV-2 strains, suggesting this epitope is functionally constrained. We identified 11 additional SARS-CoV-2/SARS-CoV-1 cross-reactive antibodies that target the more sequence conserved class 4 and class 5 epitopes within RBD that show activity against a subset of diverse sarbecoviruses with one antibody binding every single sarbecovirus RBD tested. A subset of these antibodies exhibited Fc-mediated effector functions as potent as antibodies that impact infection outcome in animal models. Thus, our study identified antibodies targeting conserved regions across SARS-CoV-2 variants and sarbecoviruses that may serve as therapeutics for pandemic preparedness as well as blueprints for the design of immunogens capable of eliciting cross-neutralizing responses.

Editor's note: This is the 23rd article in a series on clinical research by nurses. The series is designed to be used as a resource for nurses to understand the concepts and principles essential to research. Each column will present the concepts that underpin evidence-based practice-from research design to data interpretation. To see all the articles in the series, go to https://links.lww.com/AJN/A204.