Perinatal thymic-derived CD8αß-expressing γδ T cells are innate IFN-γ producers that expand in IL-7R-STAT5B-driven neoplasms.

The contribution of γδ T cells to immune responses is associated with rapid secretion of interferon-γ (IFN-γ). Here, we show a perinatal thymic wave of innate IFN-γ-producing γδ T cells that express CD8αß heterodimers and expand in preclinical models of infection and cancer. Optimal CD8αß+ γδ T cell development is directed by low T cell receptor signaling and through provision of interleukin (IL)-4 and IL-7. This population is pathologically relevant as overactive, or constitutive, IL-7R-STAT5B signaling promotes a supraphysiological accumulation of CD8αß+ γδ T cells in the thymus and peripheral lymphoid organs in two mouse models of T cell neoplasia. Likewise, CD8αß+ γδ T cells define a distinct subset of human T cell acute lymphoblastic leukemia pediatric patients. This work characterizes the normal and malignant development of CD8αß+ γδ T cells that are enriched in early life and contribute to innate IFN-γ responses to infection and cancer.

Stressed out neutrophils drive metastasis.

Stress hormones can contribute to cancer progression, but how immune cells play a role in this process is unclear. In a recent study in Cancer Cell, He et al. showed that glucocorticoids potentiate metastasis by skewing neutrophils toward pro-tumorigenic functions.

IL-27 maintains cytotoxic Ly6C+ γδ T cells that arise from immature precursors.

In mice, γδ-T lymphocytes that express the co-stimulatory molecule, CD27, are committed to the IFNγ-producing lineage during thymic development. In the periphery, these cells play a critical role in host defense and anti-tumor immunity. Unlike αß-T cells that rely on MHC-presented peptides to drive their terminal differentiation, it is unclear whether MHC-unrestricted γδ-T cells undergo further functional maturation after exiting the thymus. Here, we provide evidence of phenotypic and functional diversity within peripheral IFNγ-producing γδ T cells. We found that CD27+ Ly6C- cells convert into CD27+Ly6C+ cells, and these CD27+Ly6C+ cells control cancer progression in mice, while the CD27+Ly6C- cells cannot. The gene signatures of these two subsets were highly analogous to human immature and mature γδ-T cells, indicative of conservation across species. We show that IL-27 supports the cytotoxic phenotype and function of mouse CD27+Ly6C+ cells and human Vδ2+ cells, while IL-27 is dispensable for mouse CD27+Ly6C- cell and human Vδ1+ cell functions. These data reveal increased complexity within IFNγ-producing γδ-T cells, comprising immature and terminally differentiated subsets, that offer new insights into unconventional T-cell biology.

Chelation-directed interface engineering of in-place self-cleaning membranes.

Water-energy sustainability will depend upon the rapid development of advanced pressure-driven separation membranes. Although energy-efficient, water-treatment membranes are constrained by ubiquitous fouling, which may be alleviated by engineering self-cleaning membrane interfaces. In this study, a metal-polyphenol network was designed to direct the armorization of catalytic nanofilms (ca. 18 nm) on inert polymeric membranes. The chelation-directed mineralized coating exhibits high polarity, superhydrophilicity, and ultralow adhesion to crude oil, enabling cyclable crude oil-in-water emulsion separation. The in-place flux recovery rate exceeded 99.9%, alleviating the need for traditional ex situ cleaning. The chelation-directed nanoarmored membrane exhibited 48-fold and 6.8-fold figures of merit for in-place self-cleaning regeneration compared to the control membrane and simple hydraulic cleaning, respectively. Precursor interaction mechanisms were identified by density functional theory calculations. Chelation-directed armorization offers promise for sustainable applications in catalysis, biomedicine, environmental remediation, and beyond.

Gentrification drives patterns of alpha and beta diversity in cities.

While there is increasing recognition that social processes in cities like gentrification have ecological consequences, we lack nuanced understanding of the ways gentrification affects urban biodiversity. We analyzed a large camera trap dataset of mammals (>500 g) to evaluate how gentrification impacts species richness and community composition across 23 US cities. After controlling for the negative effect of impervious cover, gentrified parts of cities had the highest mammal species richness. Change in community composition was associated with gentrification in a few cities, which were mostly located along the West Coast. At the species level, roughly half (11 of 21 mammals) had higher occupancy in gentrified parts of a city, especially when impervious cover was low. Our results indicate that the impacts of gentrification extend to nonhuman animals, which provides further evidence that some aspects of nature in cities, such as wildlife, are chronically inaccessible to marginalized human populations.

Revving Up Dendritic Cells while Braking PD-L1 to Jump-Start the Cancer-Immunity Cycle Motor.

Although it is successful for some, most melanoma patients are refractory to T cell checkpoint inhibition. In this issue of Immunity, Merad and colleagues (2016) describe a dendritic-cell-based strategy to heighten the efficacy of therapeutic anti-PD-L1 and BRAF inhibitors in mouse melanoma models.

Loss of p53 triggers WNT-dependent systemic inflammation to drive breast cancer metastasis.

Cancer-associated systemic inflammation is strongly linked to poor disease outcome in patients with cancer1,2. For most human epithelial tumour types, high systemic neutrophil-to-lymphocyte ratios are associated with poor overall survival3, and experimental studies have demonstrated a causal relationship between neutrophils and metastasis4,5. However, the cancer-cell-intrinsic mechanisms that dictate the substantial heterogeneity in systemic neutrophilic inflammation between tumour-bearing hosts are largely unresolved. Here, using a panel of 16 distinct genetically engineered mouse models for breast cancer, we uncover a role for cancer-cell-intrinsic p53 as a key regulator of pro-metastatic neutrophils. Mechanistically, loss of p53 in cancer cells induced the secretion of WNT ligands that stimulate tumour-associated macrophages to produce IL-1ß, thus driving systemic inflammation. Pharmacological and genetic blockade of WNT secretion in p53-null cancer cells reverses macrophage production of IL-1ß and subsequent neutrophilic inflammation, resulting in reduced metastasis formation. Collectively, we demonstrate a mechanistic link between the loss of p53 in cancer cells, secretion of WNT ligands and systemic neutrophilia that potentiates metastatic progression. These insights illustrate the importance of the genetic makeup of breast tumours in dictating pro-metastatic systemic inflammation, and set the stage for personalized immune intervention strategies for patients with cancer.

Dynamic Imaging of Blood Coagulation Within the Hematoma of Patients With Acute Hemorrhagic Stroke.

BACKGROUND: The dynamics of blood clot (combination of Hb [hemoglobin], fibrin, and a higher concentration of aggregated red blood cells) formation within the hematoma of an intracerebral hemorrhage is not well understood. A quantitative neuroimaging method of localized coagulated blood volume/distribution within the hematoma might improve clinical decision-making. METHODS: The deoxyhemoglobin of aggregated red blood cells within extravasated blood exhibits a higher magnetic susceptibility due to unpaired heme iron electrons. We propose that coagulated blood, with higher aggregated red blood cell content, will exhibit (1) a higher positive susceptibility than noncoagulated blood and (2) increase in fibrin polymerization-restricted localized diffusion, which can be measured noninvasively using quantitative susceptibility mapping and diffusion tensor imaging. In this serial magnetic resonance imaging study, we enrolled 24 patients with acute intracerebral hemorrhage between October 2021 to May 2022 at a stroke center. Patients were 30 to 70 years of age and had a hematoma volume >15 cm3 and National Institutes of Health Stroke Scale score >1. The patients underwent imaging 3×: within 12 to 24 (T1), 36 to 48 (T2), and 60 to 72 (T3) hours of last seen well on a 3T magnetic resonance imaging system. Three-dimensional anatomic, multigradient echo and 2-dimensional diffusion tensor images were obtained. Hematoma and edema volumes were calculated, and the distribution of coagulation was measured by dynamic changes in the susceptibilities and fractional anisotropy within the hematoma. RESULTS: Using a coagulated blood phantom, we demonstrated a linear relationship between the percentage coagulation and susceptibility (R2=0.91) with a positive red blood cell stain of the clot. The quantitative susceptibility maps showed a significant increase in hematoma susceptibility (T1, 0.29±0.04 parts per millions; T2, 0.36±0.04 parts per millions; T3, 0.45±0.04 parts per millions; P<0.0001). A concomitant increase in fractional anisotropy was also observed with time (T1, 0.40±0.02; T2, 0.45±0.02; T3, 0.47±0.02; P<0.05). CONCLUSIONS: This quantitative neuroimaging study of coagulation within the hematoma has the potential to improve patient management, such as safe resumption of anticoagulants, the need for reversal agents, the administration of alteplase to resolve the clot, and the need for surgery.

Mechanism of Action of KL-50, a Candidate Imidazotetrazine for the Treatment of Drug-Resistant Brain Cancers.

Aberrant DNA repair is a hallmark of cancer, and many tumors display reduced DNA repair capacities that sensitize them to genotoxins. Here, we demonstrate that the differential DNA repair capacities of healthy and transformed tissue may be exploited to obtain highly selective chemotherapies. We show that the novel N3-(2-fluoroethyl)imidazotetrazine "KL-50" is a selective toxin toward tumors that lack the DNA repair protein O6-methylguanine-DNA-methyltransferase (MGMT), which reverses the formation of O6-alkylguanine lesions. We establish that KL-50 generates DNA interstrand cross-links (ICLs) by a multistep process comprising DNA alkylation to generate an O6-(2-fluoroethyl)guanine (O6FEtG) lesion, slow unimolecular displacement of fluoride to form an N1,O6-ethanoguanine (N1,O6EtG) intermediate, and ring-opening by the adjacent cytidine. The slow rate of N1,O6EtG formation allows healthy cells expressing MGMT to reverse the initial O6FEtG lesion before it evolves to N1,O6EtG, thereby suppressing the formation of toxic DNA-MGMT cross-links and reducing the amount of DNA ICLs generated in healthy cells. In contrast, O6-(2-chloroethyl)guanine lesions produced by agents such as lomustine and the N3-(2-chloroethyl)imidazotetrazine mitozolomide rapidly evolve to N1,O6EtG, resulting in the formation of DNA-MGMT cross-links and DNA ICLs in healthy tissue. These studies suggest that careful consideration of the rates of chemical DNA modification and biochemical DNA repair may lead to the identification of other tumor-specific genotoxic agents.

Structure Elucidation of Secondary Metabolites: Current Frontiers and Lingering Pitfalls.

Analytical methods allow for the structure determination of submilligram quantities of complex secondary metabolites. This has been driven in large part by advances in NMR spectroscopic capabilities, including access to high-field magnets equipped with cryogenic probes. Experimental NMR spectroscopy may now be complemented by remarkably accurate carbon-13 NMR calculations using state-of-the-art DFT software packages. Additionally, microED analysis stands to have a profound effect on structure elucidation by providing X-ray-like images of microcrystalline samples of analytes. Nonetheless, lingering pitfalls in structure elucidation remain, particularly for isolates that are unstable or highly oxidized. In this Account, we discuss three projects from our laboratory that highlight nonoverlapping challenges to the field, with implications for chemical, synthetic, and mechanism of action studies. We first discuss the lomaiviticins, complex unsaturated polyketide natural products disclosed in 2001. The original structures were derived from NMR, HRMS, UV-vis, and IR analysis. Owing to the synthetic challenges presented by their structures and the absence of X-ray crystallographic data, the structure assignments remained untested for nearly two decades. In 2021, the Nelson group at Caltech carried out microED analysis of (-)-lomaiviticin C, leading to the startling discovery that the original structure assignment of the lomaiviticins was incorrect. Acquisition of higher-field (800 MHz 1H, cold probe) NMR data as well as DFT calculations provided insights into the basis for the original misassignment and lent further support to the new structure identified by microED. Reanalysis of the 2001 data set reveals that the two structure assignments are nearly indistinguishable, underscoring the limitations of NMR-based characterization. We then discuss the structure elucidation of colibactin, a complex, nonisolable microbiome metabolite implicated in colorectal cancer. The colibactin biosynthetic gene cluster was detected in 2006, but owing to colibactin's instability and low levels of production, it could not be isolated or characterized. We used a combination of chemical synthesis, mechanism of action studies, and biosynthetic analysis to identify the substructures in colibactin. These studies, coupled with isotope labeling and tandem MS analysis of colibactin-derived DNA interstrand cross-links, ultimately led to a structure assignment for the metabolite. We then discuss the ocimicides, plant secondary metabolites that were studied as agents against drug-resistant P. falciparum. We synthesized the core structure of the ocimicides and found significant discrepancies between our experimental NMR spectroscopic data and that reported for the natural products. We determined the theoretical carbon-13 NMR shifts for 32 diastereomers of the ocimicides. These studies indicated that a revision of the connectivity of the metabolites is likely needed. We end with some thoughts on the frontiers of secondary metabolite structure determination. As modern NMR computational methods are straightforward to execute, we advocate for their systematic use in validating the assignments of novel secondary metabolites.

Assessing survival in non-small cell lung cancer brain metastases after stereotactic radiosurgery: before and after the start of the targetable mutation era.

PURPOSE: Targeted treatment options for non-small cell lung cancer (NSCLC) brain metastases (BMs) may be combined with stereotactic radiosurgery (SRS) to optimize survival. We assessed patient outcomes after SRS for NSCLC BMs, identifying survival trajectories associated with targetable mutations. METHODS: In this retrospective time-dependent analysis, we analyzed median overall survival of patients who received ≥ 1 SRS courses for BM from NSCLC from 2001 to 2021. We compared survival of patients with and without targetable mutations based on clinical variables and treatment. RESULTS: Among the 213 patients included, 87 (40.8%) had targetable mutations-primarily EGFR (22.5%)-and 126 (59.2%) did not. Patients with targetable mutations were more often female (63.2%, p <.001) and nonsmokers (58.6%, p <.001); had higher initial lung-molGPA (2.0 vs. 1.5, p <.001) and lower cumulative tumor volume (3.7 vs. 10.6 cm3, p <.001); and received more concurrent (55.2% vs. 36.5%, p =.007) and total (median 3 vs. 2, p <.001) systemic therapies. These patients had lower mortality rates (74.7% vs. 91.3%, p <.001) and risk (HR 0.298 [95%CI 0.190-0.469], p <.001) and longer median overall survival (20.2 vs. 7.4 months, p <.001), including survival ≥ 3 years (p =.001). Survival was best predicted by SRS with tumor resection in patients with non-targetable mutations (HR 0.491 [95%CI 0.318-757], p =.001) and by systemic therapy with SRS for those with targetable mutations (HR 0.124 [95%CI 0.013-1.153], p =.067). CONCLUSION: The presence of targetable mutations enhances survival in patients receiving SRS for NSCLC BM, particularly when used with systemic therapies. Survival for patients without targetable mutations was longest with SRS and surgical resection. These results inform best practices for managing patients with NSCLC BM based on driver mutation status.

Roflumilast foam 0.3% for adolescent and adult patients with seborrheic dermatitis: A randomized, double-blinded, vehicle-controlled, phase 3 trial.

BACKGROUND: The topical phosphodiesterase 4 inhibitor roflumilast has been studied in several dermatologic conditions. OBJECTIVE: Roflumilast foam 0.3% is being investigated as a topical treatment for seborrheic dermatitis (SD). METHODS: In this phase 3, double-blinded trial, patients with SD were randomly assigned (2:1 ratio) to once-daily roflumilast foam 0.3% or vehicle foam for 8 weeks. The primary efficacy outcome was Investigator Global Assessment (IGA) Success at week 8, defined as IGA of 0 (Clear) or 1 (Almost Clear) plus ≥2-point improvement from baseline. Safety was also assessed. RESULTS: 79.5% of roflumilast-treated and 58.0% of vehicle-treated patients met the primary endpoint (P < .001); statistically significant differences in IGA Success also favored roflumilast at week 2 (roflumilast: 43.0%; vehicle: 25.7%; P < .001) and week 4 (roflumilast: 73.1%; vehicle: 47.1%; P < .001). Roflumilast was well-tolerated with a low rate of treatment-emergent adverse events. LIMITATIONS: Study limitations include the 8-week treatment period for this chronic condition. CONCLUSIONS: Once-daily roflumilast foam was superior to vehicle in leading to IGA of Clear or Almost Clear plus ≥2-point improvement from baseline at 8 weeks in patients with SD. Longer trials are needed to determine durability and safety of roflumilast foam in SD.

Associations between Rat Infestations and Mental Health Vary by Gender, Race, and Income in Chicago.

Rats are an understudied stressor for people in urban environments around the world but the effects may not be distributed equally among residents. In this study, we examined associations between residential rat sightings and mental health in Chicago, where rat complaints are the highest of any American city. We examined how this relationship varied by frequency of rat sightings, race, ethnicity, income, home ownership, and gender and explored potential psychosocial pathways (e.g., feelings about the home) between rat sightings and mental distress. We conducted a randomized household survey along an income gradient in 2021 and asked about depressive symptoms in the past week (i.e., Center for Epidemiologic Studies Depression scale), frequency of rat sightings in/around the home, perceptions of rats, neighborhood conditions, and socio-demographic characteristics. We used logistic regression to assess relationships among these variables for our entire sample and for specific demographics using stratified models. Respondents (n = 589; 409 complete cases) who saw rats in/around the home daily/almost daily had 5.5 times higher odds of reporting high depressive symptoms relative to respondents who saw rats less frequently after accounting for socio-demographics and neighborhood conditions. This relationship was significant for men and respondents with lower incomes or race or ethnicity other than white. Our results show that rat infestations should be considered a threat to mental health among urban residents. Increased mental health support for residents living in rat-infested housing may improve public health in cities.

Intramolecular Oxyalkylation of Unactivated Alkenes.

The synthesis of cyclopropanes by the cyclization of allylic diazoesters is well-known. In prior studies toward the sesquiterpenoid euonyminol, we attempted to carry out an intramolecular cyclopropanation of an allylic diazoester containing an electronically-unbiased alkene embedded in a 6-oxa-bicyclo[3.2.1]-oct-3-ene skeleton. We obtained exclusively a product arising from 1,2-addition of oxygen and carbon (oxyalkylation) to the alkene. While oxyalkylation products have been reported when electron-rich alkenes (e.g. enol ethers) are employed, examples derived from electronically-unbiased alkenes are rare. Here, we establish that the oxyalkylation is general for a range of 6-oxa-bicyclo[3.2.1]-oct-3-ene substrates and show that these products form competitively in the cyclization of simpler α-diazo ß-ketoesters. Our data suggest increasing charge separation in the transition state for the addition promotes the oxyalkylation pathway.

Gut γδ T cells as guardians, disruptors, and instigators of cancer.

Colorectal cancer is the third most common cancer worldwide with nearly 2 million cases per year. Immune cells and inflammation are a critical component of colorectal cancer progression, and they are used as reliable prognostic indicators of patient outcome. With the growing appreciation for immunology in colorectal cancer, interest is growing on the role γδ T cells have to play, as they represent one of the most prominent immune cell populations in gut tissue. This group of cells consists of both resident populations-γδ intraepithelial lymphocytes (γδ IELs)-and transient populations that each has unique functions. The homeostatic role of these γδ T cell subsets is to maintain barrier integrity and prevent microorganisms from breaching the mucosal layer, which is accomplished through crosstalk with enterocytes and other immune cells. Recent years have seen a surge in discoveries regarding the regulation of γδ IELs in the intestine and the colon with particular new insights into the butyrophilin family. In this review, we discuss the development, specialities, and functions of γδ T cell subsets during cancer progression. We discuss how these cells may be used to predict patient outcome, as well as how to exploit their behavior for cancer immunotherapy.

Finding activity through rigidity: syntheses of natural products containing tricyclic bridgehead carbon centers.

Covering: up to 2022Tricyclic bridgehead carbon centers (TBCCs) are a synthetically challenging substructure found in many complex natural products. Here we review the syntheses of ten representative families of TBCC-containing isolates, with the goal of outlining the strategies and tactics used to install these centers, including a discussion of the evolution of the successful synthetic design. We provide a summary of common strategies to inform future synthetic endeavors.

Microprobes for Label-Free Detection of Short Tandem Repeats: An Insight into Alleviating Secondary Structure Effects.

Overgrowth of short tandem repeat sequences in our genes can cause various neurodegenerative disorders. Such repeat sequences are ideal targets for the label-free electrochemical detection of such potential expansions. However, their length- and sequence-dependent secondary structures may interfere with the interfacial charge transfer of a detection platform, making them complex targets. In addition, the gene contains sporadic repeats that may result in false-positive signals. Therefore, it is necessary to design a platform capable of mitigating these effects and ultimately enhancing the specificity of tandem repeats. Here, we analyzed three different backbones of nucleic acid microprobes [DNA, peptide nucleic acid, and lock-nucleic acid (LNA)] to detect in vitro transcribed RNA carrying CAG repeats, which are associated with Huntington's disease, based on the charge-transfer resistance of the interface. We found that the LNA microprobe can distinguish lengths down to the attomolar concentration level and alleviate the effect of secondary structures and sporadic repeats in the sequence, thus distinguishing the "tandem repeats" specifically. Additionally, the control experiments conducted with and without Mg2+ demonstrated the LNA microprobe to perform better in the presence of the divalent cation. The results suggest that the LNA-based platform may eventually lead to the development of a reliable and straightforward biosensor for genetic neurodegenerative disorders.

Fragment Coupling Approach to Diaporthein B.

Pimarane diterpenes are produced by a diverse array of plants, fungi, and bacteria. Many members of this family possess antimicrobial and antiproliferative activities. The pimarane diterpenes are characterized by a tricyclic carbon scaffold comprising three fused six-membered rings and at least three quaternary centers. Here, we describe two convergent, fragment-based strategies toward the synthesis of diaporthein B (3), one of the most highly oxidized pimarane diterpenes. The first approach provided access to the tricyclic carbon scaffold of the target and featured a highly diastereoselective fragment coupling, a novel carbonylative Stille cross-coupling to directly access an α-hydroxyketone from a vinyl iodide, and a tandem aldol cyclization-deprotection cascade. The second route utilized a diastereoselective 1,4-addition of a silyloxyfuran to an unsaturated ketone, followed by an epoxidation-ring opening sequence, to access a highly oxidized intermediate containing two elaborated cyclohexane rings. The chemistry developed herein may ultimately be useful in an eventual synthesis of this class of natural products.

Advanced Materials for Energy-Water Systems: The Central Role of Water/Solid Interfaces in Adsorption, Reactivity, and Transport.

The structure, chemistry, and charge of interfaces between materials and aqueous fluids play a central role in determining properties and performance of numerous water systems. Sensors, membranes, sorbents, and heterogeneous catalysts almost uniformly rely on specific interactions between their surfaces and components dissolved or suspended in the water-and often the water molecules themselves-to detect and mitigate contaminants. Deleterious processes in these systems such as fouling, scaling (inorganic deposits), and corrosion are also governed by interfacial phenomena. Despite the importance of these interfaces, much remains to be learned about their multiscale interactions. Developing a deeper understanding of the molecular- and mesoscale phenomena at water/solid interfaces will be essential to driving innovation to address grand challenges in supplying sufficient fit-for-purpose water in the future. In this Review, we examine the current state of knowledge surrounding adsorption, reactivity, and transport in several key classes of water/solid interfaces, drawing on a synergistic combination of theory, simulation, and experiments, and provide an outlook for prioritizing strategic research directions.

Gas and Propane Combustion from Stoves Emits Benzene and Increases Indoor Air Pollution.

Exposure pathways to the carcinogen benzene are well-established from tobacco smoke, oil and gas development, refining, gasoline pumping, and gasoline and diesel combustion. Combustion has also been linked to the formation of nitrogen dioxide, carbon monoxide, and formaldehyde indoors from gas stoves. To our knowledge, however, no research has quantified the formation of benzene indoors from gas combustion by stoves. Across 87 homes in California and Colorado, natural gas and propane combustion emitted detectable and repeatable levels of benzene that in some homes raised indoor benzene concentrations above well-established health benchmarks. Mean benzene emissions from gas and propane burners on high and ovens set to 350 °F ranged from 2.8 to 6.5 µg min-1, 10 to 25 times higher than emissions from electric coil and radiant alternatives; neither induction stoves nor the food being cooked emitted detectable benzene. Benzene produced by gas and propane stoves also migrated throughout homes, in some cases elevating bedroom benzene concentrations above chronic health benchmarks for hours after the stove was turned off. Combustion of gas and propane from stoves may be a substantial benzene exposure pathway and can reduce indoor air quality.