Recent progress in the applications of presynaptic dopaminergic positron emission tomography imaging in parkinsonism.

Nowadays, presynaptic dopaminergic positron emission tomography, which assesses deficiencies in dopamine synthesis, storage, and transport, is widely utilized for early diagnosis and differential diagnosis of parkinsonism. This review provides a comprehensive summary of the latest developments in the application of presynaptic dopaminergic positron emission tomography imaging in disorders that manifest parkinsonism. We conducted a thorough literature search using reputable databases such as PubMed and Web of Science. Selection criteria involved identifying peer-reviewed articles published within the last 5 years, with emphasis on their relevance to clinical applications. The findings from these studies highlight that presynaptic dopaminergic positron emission tomography has demonstrated potential not only in diagnosing and differentiating various Parkinsonian conditions but also in assessing disease severity and predicting prognosis. Moreover, when employed in conjunction with other imaging modalities and advanced analytical methods, presynaptic dopaminergic positron emission tomography has been validated as a reliable in vivo biomarker. This validation extends to screening and exploring potential neuropathological mechanisms associated with dopaminergic depletion. In summary, the insights gained from interpreting these studies are crucial for enhancing the effectiveness of preclinical investigations and clinical trials, ultimately advancing toward the goals of neuroregeneration in parkinsonian disorders.

Identification of the cytochrome P450s responsible for the biosynthesis of two types of aporphine alkaloids and their de novo biosynthesis in yeast.

Aporphine alkaloids have diverse pharmacological activities; however, our understanding of their biosynthesis is relatively limited. Previous studies have classified aporphine alkaloids into two categories based on the configuration and number of substituents of the D-ring and have proposed preliminary biosynthetic pathways for each category. In this study, we identified two specific cytochrome P450 enzymes (CYP80G6 and CYP80Q5) with distinct activities toward (S)-configured and (R)-configured substrates from the herbaceous perennial vine Stephania tetrandra, shedding light on the biosynthetic mechanisms and stereochemical features of these two aporphine alkaloid categories. Additionally, we characterized two CYP719C enzymes (CYP719C3 and CYP719C4) that catalyzed the formation of the methylenedioxy bridge, an essential pharmacophoric group, on the A- and D-rings, respectively, of aporphine alkaloids. Leveraging the functional characterization of these crucial cytochrome P450 enzymes, we reconstructed the biosynthetic pathways for the two types of aporphine alkaloids in budding yeast (Saccharomyces cerevisiae) for the de novo production of compounds such as (R)-glaziovine, (S)-glaziovine, and magnoflorine. This study provides key insight into the biosynthesis of aporphine alkaloids and lays a foundation for producing these valuable compounds through synthetic biology.

Metabolomics study of dietary Pleurotus eryngii ß-type glycosidic polysaccharide on colitis induced by dextran sodium sulfate in mice - Exploration for the potential metabolic indicators in urine and serum.

Pleurotus eryngii, an edible mushroom recognized for its potent polysaccharides, demonstrates significant regulatory effects on metabolic processes. ß-glucan (WPEP) derived from P. eryngii has been noted for its therapeutic potential, exhibiting notable benefits in alleviating colonic inflammation and restructuring gut microbiota in mice treated with dextran sodium sulfate (DSS). This study focuses on utilizing DSS-induced colitis mice to explore the efficacy and underlying mechanisms of WPEP in ameliorating colitis, employing a metabolomics approach analyzing urine and serum. The findings reveal that WPEP administration effectively regulates metabolic imbalances in DSS mice, impacting purine metabolism, pentose and glucuronic acid interconversion, amino acid metabolism, primary bile acid biosynthesis, citric acid cycle, and lipid metabolism. Furthermore, WPEP demonstrates a capacity to modulate colitis by regulating diverse metabolic pathways, consequently influencing intestinal barrier integrity, motility, inflammation, oxidative stress, and immunity. These insights suggest that WPEP is a promising food component for managing inflammatory bowel diseases.

A pH ultra-sensitive hydrated iridium oxyhydroxide films electrochemical sensor for label-free detection of Vibrio parahaemolyticus.

Vibrio parahaemolyticus (V. parahaemolyticus) is a major foodborne pathogen, which can cause serious foodborne illnesses like diarrhoea. Rapid on-site detection of foodborne pathogens is an ideal way to respond to foodborne illnesses. Herein, we provide an electrochemical sensor for rapid on-site detection. This sensor utilized a pH-sensitive metal-oxide material for the concurrent isothermal amplification and label-free detection of nucleic acids. Based on a pH-sensitive hydrated iridium oxide oxyhydroxide film (HIROF), the electrode transforms the hydrogen ion compound generated during nucleic acid amplification into potential, so as to achieve a real-time detection. The results can be transmitted to a smartphone via Bluetooth. Moreover, HIROF was applied in nucleic acid device detection, with a super-Nernst sensitivity of 77.6 mV/pH in the pH range of 6.0-8.5, and the sensitivity showed the best results so far. Detection of V. parahaemolyticus by this novel method showed a detection limit of 1.0×103 CFU/mL, while the time consumption was only 30 min, outperforming real-time fluorescence loop-mediated isothermal amplification (LAMP). Therefore, the characteristics of compact, portable, and fast make the sensor more widely used in on-site detection.

One-pot electrochemical detection of foodborne pathogen based on in situ nucleic acid amplification and wash-free assay.

A signal amplification electrochemical biosensor chip was developed to integrate loop-mediated isothermal amplification (LAMP) based on in situ nucleic acid amplification and methyl blue (MB) serving as the hybridization redox indicator for sensitive and selective foodborne pathogen detection without a washing step. The electrochemical biosensor chip was designed by a screen-printed carbon electrode modified with gold nanoparticles (Au NPs) and covered with polydimethylsiloxane membrane to form a microcell. The primers of the target were immobilized on the Au NPs by covalent attachment for in situ amplification. The electroactive MB was used as the electrochemical signal reporter and embedded into the double-stranded DNA (dsDNA) amplicons generated by LAMP. Differential pulse voltammetry was introduced to survey the dsDNA hybridization with MB, which differentiates the specifically electrode-unbound and -bound labels without a washing step. Pyrene as the back-filling agent can further improve response signaling by reducing non-specific adsorption. This method is operationally simple, specific, and effective. The biosensor showed a detection linear range of 102-107 CFU mL-1 with the limit of detection of 17.7 CFU mL-1 within 40 min. This method showed promise for on-site testing of foodborne pathogens and could be integrated into an all-in-one device.

Quantitative assessment of preoperative brain development in pediatric congenital heart disease patients by synthetic MRI.

OBJECTIVES: This study investigated the quantitative assessment and application of Synthetic MRI (SyMRI) for preoperative brain development in children with congenital heart disease (CHD). METHODS: Forty-three CHD patients aged 2-24 months were prospectively included in the observation group, and 43 healthy infants were included in the control group. The SyMRI scans were processed by postprocessing software to obtain T1, T2, and PD maps. The values of T1, T2, and PD in different brain regions were compared with the scores of the five ability areas of the Gesell Development Scale by Pearson correlation analysis. RESULTS: In the observation group, the T1 values of the posterior limb of the internal capsule (PLIC), Optic radiation (PTR), cerebral peduncle, centrum semiovale, occipital white matter, temporal white matter, and dentate nucleus were greater than those in the control group. In the observation group, the T2 values of the PLIC, PTR, frontal white matter, occipital white matter, temporal white matter, and dentate nucleus were greater than those in the control group. Pearson correlation analysis revealed that the observation group had significantly lower Development Scale scores. In the observation group, the T2 value of the splenium of the corpus callosum was significantly positively correlated with the personal social behavior score. The AUCs for diagnosing preoperative brain developmental abnormalities in children with CHD using T1 values of the temporal white matter and dentate nucleus were both greater than 0.60. CONCLUSIONS: Quantitative assessment using SyMRI can aid in the early detection of preoperative brain development abnormalities in children with CHD. CRITICAL RELEVANCE STATEMENT: T1 and T2 relaxation values from SyMRI can be considered as a quantitative imaging marker to detect abnormalities, allowing for early clinical evaluation and timely intervention, thereby reducing neurodevelopmental disorders in these children. KEY POINTS: T1 and T2 relaxation values by SyMRI are related to myelin development. Evaluated development quotient markers were lower in the observation compared to the control group. SyMRI can act as a reference indicator for brain development in CHD children.

Relationships between apolipoprotein E and insulin resistance in patients with obstructive sleep apnoea: a large-scale cross-sectional study.

BACKGROUND: Obstructive sleep apnoea (OSA) is commonly associated with insulin resistance (IR) and dyslipidaemia. Apolipoprotein E (APOE) plays important roles in lipid metabolism. The study aimed to disentangle the multifactorial relationships between IR and APOE based on a large-scale population with OSA. METHODS: A total of 5,591 participants who underwent polysomnography for OSA diagnosis were finally enrolled. We collected anthropometric, fasting biochemical and polysomnographic data for each participant. Linear regression analysis was performed to evaluate the relationships between APOE, IR, and sleep breathing-related parameters. Logistic regression, restricted cubic spline (RCS) and mediation analyses were used to explore relationships between APOE and IR in patients with OSA. RESULTS: Increasing OSA severity was associated with greater obesity, more obvious dyslipidaemia, and higher levels of APOE and IR. APOE was positively correlated with the apnoea-hypopnoea index (AHI), oxygen desaturation index (ODI) and microarousal index (MAI) even after adjusting for age, sex, body mass index, and smoking and drinking levels (ß = 0.107, ß = 0.102, ß = 0.075, respectively, all P < 0.001). The risks of IR increased from the first to fourth quartiles of APOE (odds ratio (OR) = 1.695, 95% CI: 1.425-2.017; OR = 2.371, 95% confidence interval (CI): 2.009-2.816; OR = 3.392, 95% CI: 2.853-4.032, all P < 0.001) after adjustments. RCS analysis indicated non-linear and dose response relationships between APOE, AHI, ODI, MAI and insulin resistance. Mediation analyses showed that HOMA-IR explained 9.1% and 10% of the association between AHI, ODI and APOE. The same trends were observed in men, but not in women. CONCLUSIONS: This study showed that APOE is a risk factor for IR; moreover, IR acts as a mediator between OSA and APOE in men. APOE, IR, and OSA showed non-linear and multistage relationships. Taken together, these observations revealed the complex relationships of metabolic disorders in patients with OSA, which could lead to the development of new treatment modalities and a deeper understanding of the systemic impact of OSA.

Melatonin mediates intestinal barrier dysfunction and systemic inflammation in moderate-severe OSA patients.

BACKGROUND: Intestinal barrier dysfunction and systemic inflammation are common in obstructive sleep apnoea (OSA). We aimed to investigate the role of melatonin, an anti-inflammatory mediator, in mediating the relationships between OSA, intestinal barrier dysfunction and systemic inflammation. METHODS: Two hundred and thirty-five male participants who complained with sleep problems and underwent whole night polysomnography at our sleep centre between 2017 and 2018 were enrolled. Polysomnographic data, anthropometric measurements and biochemical indicators were collected. Serum melatonin, intestinal barrier function biomarker zonula occludens-1 (ZO-1) and inflammatory biomarkers C-reactive protein (CRP) with lipopolysaccharide (LPS) were detected. Spearman's correlation analysis assessed the correlations between sleep parameters, melatonin and biomarkers (ZO-1, LPS and CRP). Mediation analysis explored the effect of OSA on intestinal barrier dysfunction and systemic inflammation in moderate-severe OSA patients. RESULTS: As OSA severity increased, serum melatonin decreased, whereas ZO-1, LPS and CRP increased. Spearman's correlation analysis showed that serum melatonin was significantly negatively correlated with ZO-1 (r = -0.19, p < .05) and LPS (r = -0.20, p < .05) in the moderate-OSA group; serum melatonin was significantly negatively correlated with ZO-1 (r = -0.46, p < .01), LPS (r = -0.35, p < .01) and CPR (r = -0.30, p < .05) in the severe-OSA group. Mediation analyses showed melatonin explain 36.12% and 35.38% of the effect of apnoea-hypopnea index (AHI) on ZO-1 and LPS in moderate to severe OSA patients. CONCLUSIONS: Our study revealed that melatonin may be involved in mediating intestinal barrier dysfunction and systemic inflammation in moderate-to-severe OSA patients.

Effects of tonsillectomy and adenoidectomy on the immune system.

Surgical removal of the tonsils and adenoids, important immune organs, is a frequent and recurrent class of surgery, and currently, there is no consensus on the effects these surgical procedures may have on the immune system. Here, we examine individual studies on tonsillectomy, adenoidectomy, and adenotonsillectomy, discuss their postoperative humoral and cellular immune changes, and explore their effects on the incidence of related diseases. There is evidence that these three surgeries have no negative effects on humoral immunity; however, there has been contrary results. Furthermore, these procedures seem to have no significant effects on cellular immunity, although tonsil and adenoid removal can cause an increased incidence of certain illnesses, especially infectious diseases. Based on this comprehensive review, we conclude that the removal of tonsils and adenoids does not negatively affect cellular and humoral immunity. However, surgery may lead to an increased incidence of related infectious diseases. This finding may inform the surgeon's decision to perform the procedure in a clinical setting.

Enzyme purification and sustained enzyme activity for pharmaceutical biocatalysis by fusion with phase-separating intrinsically disordered protein.

In recent decades, biocatalysis has emerged as an important alternative to chemical catalysis in pharmaceutical manufacturing. Biocatalysis is attractive because enzymatic cascades can synthesize complex molecules with incredible selectivity, yield, and in an environmentally benign manner. Enzymes for pharmaceutical biocatalysis are typically used in their unpurified state, since it is time-consuming and cost-prohibitive to purify enzymes using conventional chromatographic processes at scale. However, impurities present in crude enzyme preparations can consume substrate, generate unwanted byproducts, as well as make the isolation of desired products more cumbersome. Hence, a facile, nonchromatographic purification method would greatly benefit pharmaceutical biocatalysis. To address this issue, here we have captured enzymes into membraneless compartments by fusing enzymes with an intrinsically disordered protein region, the RGG domain from LAF-1. The RGG domain can undergo liquid-liquid phase separation, forming liquid condensates triggered by changes in temperature or salt concentration. By centrifuging these liquid condensates, we have successfully purified enzyme-RGG fusions, resulting in significantly enhanced purity compared to cell lysate. Furthermore, we performed enzymatic reactions utilizing purified fusion proteins to assay enzyme activity. Results from the enzyme assays indicate that enzyme-RGG fusions purified by the centrifugation method retain enzymatic activity, with greatly reduced background activity compared to crude enzyme preparations. Our work focused on three different enzymes-a kinase, a phosphorylase, and an ATP-dependent ligase. The kinase and phosphorylase are components of the biocatalytic cascade for manufacturing molnupiravir, and we demonstrated facile co-purification of these two enzymes by co-phase separation. To conclude, enzyme capture by RGG tagging promises to overcome difficulties in bioseparations and biocatalysis for pharmaceutical synthesis.

Nanopore sequencing demonstrates the roles of spermatozoal DNA N6-methyladenine in mediating transgenerational lipid metabolism disorder induced by excessive folate consumpton.

Increased consumption of folic acid is prevalent due to its beneficial effects, but growing evidence emphasizes the side effects pointing to excessive dietary folate intake. The effects of excessive paternal folic acid consumption on offspring and its transgenerational inheritance mechanism have not been elucidated. We hypothesize that excessive folic acid consumption will alter sperm DNA N6-methyladenine (6mA) and 5-methylcytosine (5mC) methylation and heritably influence offspring metabolic homeostasis. Here, we fed roosters either folic acid-control or folic acid-excess diet throughout life. Paternal chronic folic acid excessive supplementation increased hepatic lipogenesis and lipid accumulation but reduced lipolysis both in the roosters and their offspring, which was further confirmed to be induced by one-carbon metabolism inhibition and gene expression alteration associated with the Peroxisome proliferator-activated receptor pathway. Based on the spermatozoal genome-wide DNA methylome identified by Nanopore sequencing, multi-omics association analysis of spermatozoal and hepatic DNA methylome, transcriptome, and metabolome suggested that differential spermatozoal DNA 6mA and 5mC methylation could be involved in regulating lipid metabolism-related gene expression in offspring chickens. This model suggests that sperm DNA N6-methyladenine and 5-methylcytosine methylation were involved in epigenetic transmission and that paternal dietary excess folic acid leads to hepatic lipid accumulation in offspring.

N2O recovery from wastewater and flue gas via microbial denitrification: Processes and mechanisms.

Nitrous oxide (N2O) is increasingly regarded as a significant greenhouse gas implicated in global warming and the depletion of the ozone layer, yet it is also recognized as a valuable resource. This paper comprehensively reviews innovative microbial denitrification techniques for recovering N2O from nitrogenous wastewater and flue gas. Critical analysis is carried out on cutting-edge processes such as the coupled aerobic-anoxic nitrous decomposition operation (CANDO) process, semi-artificial photosynthesis, and the selective utilization of microbial strains, as well as flue gas absorption coupled with heterotrophic/autotrophic denitrification. These processes are highlighted for their potential to facilitate denitrification and enhance the recovery rate of N2O. The review integrates feasible methods for process control and optimization, and presents the underlying mechanisms for N2O recovery through denitrification, primarily achieved by suppressing nitrous oxide reductase (Nos) activity and intensifying competition for electron donors. The paper concludes by recognizing the shortcomings in existing technologies and proposing future research directions, with an emphasis on prioritizing the collection and utilization of N2O while considering environmental sustainability and economic feasibility. Through this review, we aim to inspire interest in the recovery and utilization of N2O, as well as the development and application of related technologies.

Soluble CXCL16 is a prognostic biomarker associated with rapidly progressive interstitial lung disease complicated with dermatomyositis.

OBJECTIVES: Rapidly progressive interstitial lung disease (RPILD) in patients with dermatomyositis (DM) significantly impacts prognosis, leading to high mortality rates. Although several indicators have been demonstrated to strongly correlate with the risk of developing RPILD, their clinical utility still needs to be investigated. The objective of this study was to investigate the clinical significance of soluble CXCL16 (sCXCL16) in DM patients complicated with RPILD. METHODS: Serum sCXCL16 was measured by enzyme-linked immunosorbent assay in 96 patients with DM and 55 matching healthy donors. Correlations between sCXCL16 levels and clinical features, laboratory examinations and the predictive value of baseline sCXCL16 level for RPILD were analysed. RESULTS: The serum sCXCL16 levels were significantly higher in patients with DM (n = 96, 3.264 ± 1.516 ng/mL) compared with healthy donors (n = 55, 1.781 ± 0.318 ng/mL), especially in DM complicated with RPILD (n = 31, 4.441 ± 1.706 ng/mL). The sCXCL16 levels were positively correlated with levels of serum ferritin, C reactive protein, erythrocyte sedimentation rate, lactate dehydrogenase, hydroxybutyrate dehydrogenase, and negatively correlated with peripheral lymphocytes percentage, but showed no correlation with levels of anti-melanoma differentiation-associated gene 5 antibody, Krebs von den Lungen-6 or creatine kinase. Multivariable analysis showed that elevated sCXCL16 was an independent prognostic factor for poor prognosis of RPILD in patients with DM. The 2-year survival rate was significantly lower in patients with high sCXCL16 level than in those with low sCXCL16 level. CONCLUSION: A higher serum sCXCL16 level was identified as a predictive biomarker of RPILD in patients with DM, and closely associated with poor prognosis.

Detection of sulphur(II) of carbon dots synthesized from Gardenia residue.

The detection of anions using carbon dots (CDs) has received less attention compared to cations. Therefore, the present study aimed to develop a fluorescence sensor based on carbon dots (CDs) capable of detecting S2- in real water samples. The CDs were successfully prepared from the residues of a traditional Chinese herb, Gardenia, which emitted green photoluminescence (PL) under ultraviolet light irradiation. The as-prepared CDs were quasi-spherical in shape and ranged in size from 10 to 30 nm. Different detailed analyses proved that the CDs had good morphology, various functional groups, high water solubility, great optical features, and excellent stability under diverse environmental conditions. The ion detection showed that only Ag+ had the strongest fluorescence quenching effect on the CDs, however, the addition of S2- could recover their fluorescence. Based on these results, an "off-on" fluorescence sensor was achieved to selectively detect the concentration of S2- in real water samples with a limit of detection (LOD) of 39 µM, which further expanded the application of residues from traditional Chinese herbal medicine.

From waste to strength: Tailor-made enzyme activation design transformation of denatured soy meal into high-performance all-biomass adhesive.

Given the severe protein denaturation and self-aggregation during the high-temperature desolubilization, denatured soy meal (DSM) is limited by its low reactivity, high viscosity, and poor water solubility. Preparing low-cost and high-performance adhesives with DSM as the key feedstock is still challenging. Herein, this study reveals a double-enzyme co-activation method targeting DSM with the glycosidic bonds in protein-carbohydrate complexes and partial amide bonds in protein, increasing the protein dispersion index from 10.2 % to 75.1 % improves the reactivity of DSM. The green crosslinker transglutaminase (TGase) constructs a robust adhesive isopeptide bond network with high water-resistant bonding strength comparable to chemical crosslinkers. The adhesive has demonstrated high dry/wet shear strength (2.56 and 0.93 MPa) for plywood. After molecular recombination by enzyme strategy, the adhesive had the proper viscosity, high reactivity, and strong water resistance. This research showcases a novel perspective on developing a DSM-based adhesive and blazes new avenues for changes in protein structural function and adhesive performance.

l-Carnosine loaded on carboxymethyl cellulose hydrogels for promoting wound healing.

Wound management remains a challenge in clinical practice. Nowadays, patients have an increasing demand for wound repair with enhanced speed and quality; therefore, there is a great need to seek therapeutic strategies that can promote rapid and effective wound healing. In this study, we developed a carboxymethyl cellulose hydrogel loaded with l-carnosine (CRN@hydrogel) for potential application as a wound dressing. In vitro experiments confirmed that CRN@hydrogel can release over 80% of the drug within 48 h and demonstrated its favorable cytocompatibility and blood compatibility, thus establishing its applicability for safe utilization in clinical practice. Using a rat model, we found that this hydrogel could promote and accelerate wound healing more effectively. These results indicate that the novel hydrogel can serve as an efficient therapeutic strategy for wound treatment.

Gut microbiome changes associated with chronic pancreatitis and pancreatic cancer: A systematic review and Meta-analysis.

BACKGROUND: The study of changes in the microbiome in chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDAC) holds significant potential for developing noninvasive diagnostic tools as well as innovative interventions to alter the progression of diseases. This systematic review and meta-analysis aimed to analyze in detail the taxonomic and functional characteristics of the gut microbiome in patients with CP and PDAC. METHODS: Two researchers conducted a systematic search across public databases to gather all published research up to June 2023. Diversity and gut microbiota composition are the main outcomes we focus on. RESULTS: This meta-analysis included 14 studies, involving a total of 1511 individuals in the PDAC (n=285), CP (n=342), and control (n=649) groups. Our results show a significant difference in the composition of gut microbiota between PDAC/CP patients compared to healthy controls (HC), as evidenced by a slight decrease in α-diversity, including Shannon (SMD=-0.33; P=0.002 and SMD=-0.59; P<0.001, respectively) and a statistically significant ß-diversity (P<0.05). The pooled results showed that at the phylum level, the proportion of Firmicutes was lower in PDAC and CP patients than in HC patients. At the genus level, more than two studies demonstrated that 4 genera were significantly increased in PDAC patients compared to HC (e.g., Escherichia-Shigella and Veillonella). CP patients had an increase in 4 genera (e.g., Escherichia-Shigella and Klebsiella) and a decrease in 8 genera (e.g., Coprococcus and Bifidobacterium) compared to HC. Functional/metabolomics results from various studies also showed differences between PDAC/CP patients and HC. In addition, this study found no significant differences in gut microbiota between PDAC and CP patients. CONCLUSIONS: Current evidence suggests changes in gut microbiota is associated with PDAC/CP, commonly reflected by a reduction in beneficial species and an increase in the pathogenic species. Further studies are needed to confirm these findings and explore therapeutic possibilities.

Fetal liver CD34+ contain human immune and endothelial progenitors and mediate solid tumor rejection in NOG mice.

BACKGROUND: Transplantation of CD34+ hematopoietic stem and progenitor cells (HSPC) into immunodeficient mice is an established method to generate humanized mice harbouring a human immune system. Different sources and methods for CD34+ isolation have been employed by various research groups, resulting in customized models that are difficult to compare. A more detailed characterization of CD34+ isolates is needed for a better understanding of engraftable hematopoietic and potentially non-hematopoietic cells. Here we have performed a direct comparison of CD34+ isolated from cord blood (CB-CD34+) or fetal liver (FL-CD34+ and FL-CD34+CD14-) and their engraftment into immunocompromised NOD/Shi-scid Il2rgnull (NOG) mice. METHODS: NOG mice were transplanted with either CB-CD34+, FL-CD34+ or FL-CD34+CD14- to generate CB-NOG, FL-NOG and FL-CD14--NOG, respectively. After 15-20 weeks, the mice were sacrificed and human immune cell reconstitution was assessed in blood and several organs. Liver sections were pathologically assessed upon Haematoxylin and Eosin staining. To assess the capability of allogenic tumor rejection in CB- vs. FL-reconstituted mice, animals were subcutaneously engrafted with an HLA-mismatched melanoma cell line. Tumor growth was assessed by calliper measurements and a Luminex-based assay was used to compare the cytokine/chemokine profiles. RESULTS: We show that CB-CD34+ are a uniform population of HSPC that reconstitute NOG mice more rapidly than FL-CD34+ due to faster B cell development. However, upon long-term engraftment, FL-NOG display increased numbers of neutrophils, dendritic cells and macrophages in multiple tissues. In addition to HSPC, FL-CD34+ isolates contain non-hematopoietic CD14+ endothelial cells that enhance the engraftment of the human immune system in FL-NOG mice. We demonstrate that these CD14+CD34+ cells are capable of reconstituting Factor VIII-producing liver sinusoidal endothelial cells (LSEC) in FL-NOG. However, CD14+CD34+ also contribute to hepatic sinusoidal dilatation and immune cell infiltration, which may culminate in a graft-versus-host disease (GVHD) pathology upon long-term engraftment. Finally, using an HLA-A mismatched CDX melanoma model, we show that FL-NOG, but not CB-NOG, can mount a graft-versus-tumor (GVT) response resulting in tumor rejection. CONCLUSION: Our results highlight important phenotypical and functional differences between CB- and FL-NOG and reveal FL-NOG as a potential model to study hepatic sinusoidal dilatation and mechanisms of GVT.

A DNA-Modularized STING Agonist with Macrophage-Selectivity and Programmability for Enhanced Anti-Tumor Immunotherapy.

The activation of cyclic GMP-AMP (cGAMP) synthase (cGAS) and its adaptor, stimulator of interferon genes (STING), is known to reprogram the immunosuppressive tumor microenvironment for promoting antitumor immunity. To enhance the efficiency of cGAS-STING pathway activation, macrophage-selective uptake, and programmable cytosolic release are crucial for the delivery of STING agonists. However, existing polymer- or lipid-based delivery systems encounter difficulty in integrating multiple functions meanwhile maintaining precise control and simple procedures. Herein, inspired by cGAS being a natural DNA sensor, a modularized DNA nanodevice agonist (DNDA) is designed that enable macrophage-selective uptake and programmable activation of the cGAS-STING pathway through precise self-assembly. The resulting DNA nanodevice acts as both a nanocarrier and agonist. Upon local administration, it demonstrates the ability of macrophage-selective uptake, endosomal escape, and cytosolic release of the cGAS-recognizing DNA segment, leading to robust activation of the cGAS-STING pathway and enhanced antitumor efficacy. Moreover, DNDA elicits a synergistic therapeutic effect when combined with immune checkpoint blockade. The study broadens the application of DNA nanotechnology as an immune stimulator for cGAS-STING activation.