Unique Kinetics of the Human Milk Antibody Response to JYNNEOS Vaccine for Prevention of Monkey Pox: A Case Study.

Background: JYNNEOS is a nonreplicating modified vaccinia Ankara vaccine currently licensed to prevent monkeypox infection, and its milk immunogenicity remains unstudied. Objective: Investigate the human milk immunogenicity of the JYNNEOS vaccine in one individual and examine the milk for evidence of vaccine components. Methods: Immunogenicity of milk and plasma samples were tested by Luminex assays against Vaccinia antigens, and vaccine components were tested using PCR and sandwich ELISA. Results: Plasma antibody (Ab) response increased up to 3.7-fold in immunoglobulin G (IgG) titer and 1.4-fold in IgA compared with baseline, confirming vaccine immunogenicity in this participant 2 weeks post dose 2. Specific plasma IgG remained 1.2- to 1.7-fold above baseline 12 weeks post dose 2, while IgA returned to baseline levels. Notably, the milk response exhibited unique kinetics, particularly for IgA. Milk IgA against all three antigens increased 0.9- to 2.2-fold 2 weeks post dose 2, reaching a peak titer increase of 1.1- to 2.7-fold at 12 weeks post dose 2. Secretory (s) Ab levels increased to 1.1- to 2-fold at 2 weeks post dose 2 and reached a peak of 2- to 3.2-fold increase at the 12-week time point. Importantly, IgA and sAb responses in milk exhibited correlation, suggesting most milk IgA was sIgA. Notably, no vaccine components (VACV protein or DNA) were detected in the milk samples. Conclusion: These data suggest that the milk Ab response to this intradermal (ID) VACV-based vaccine is distinct from that observed systemically, indicating a unique mucosal immune response and highlighting its potential to elicit protective long-lasting sIgA. This case report provides strong evidence for inclusion of this vaccine platform in future studies of maternal vaccines aimed to elicit a protective milk Ab response.

Associations between SARS-CoV-2 Infection or COVID-19 Vaccination and Human Milk Composition: A Multi-Omics Approach.

BACKGROUND: The risk of contracting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) via human milk-feeding is virtually nonexistent. Adverse effects of coronavirus disease 2019 (COVID-19) vaccination for lactating individuals are not different from the general population, and no evidence has been found that their infants exhibit adverse effects. Yet, there remains substantial hesitation among this population globally regarding the safety of these vaccines. OBJECTIVES: Herein, we aimed to determine if compositional changes in milk occur following SARS-CoV-2 infection or COVID-19 vaccination, including any evidence of vaccine components. METHODS: An extensive multiomics approach was taken using a subset of milk samples obtained as part of our broad studies examining the effects on milk of SARS-CoV-2 infection and COVID-19 vaccination. RESULTS: We found that compared with unvaccinated individuals, SARS-CoV-2 infection was associated with significant compositional differences in 67 proteins, 385 lipids, and 13 metabolites. In contrast, COVID-19 vaccination was not associated with any changes in lipids or metabolites, although it was associated with changes in 13 or fewer proteins. Compositional changes in milk differed by vaccine. Changes following vaccination were greatest after 1-6 h for the mRNA-based Moderna vaccine (8 changed proteins), 3 d for the mRNA-based Pfizer (4 changed proteins), and adenovirus-based Johnson and Johnson (13 changed proteins) vaccines. Proteins that changed after both natural infection and Johnson and Johnson vaccine were associated mainly with systemic inflammatory responses. In addition, no vaccine components were detected in any milk sample. CONCLUSIONS: Together, our data provide evidence of only minimal changes in milk composition because of COVID-19 vaccination, with much greater changes after natural SARS-CoV-2 infection.

Responses of biomarkers, joint effect and drilosphere bacterial communities to antimony (III and/or V) contamination.

Contamination of soils with antimony (Sb) is becoming increasingly severe and widespread, and the associated ecological risks cannot be ignored. To evaluate how different Sb forms affected the earthworm Eisenia fetida in soil, the biomarker response index (BRI), effect addition index (EAI), and microbial diversity were characterized after single and joint application of Sb(III) and Sb(V). The results showed that Sb(III) was better enriched by earthworms than Sb(V). The metallothionein (MT) content in earthworms increased under Sb stress, and the superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST) activities also showed an increasing trend, suggesting waken-up antioxidant capacity. Severe alterations for health status were observed under combined treatment. Additionally, the EAI indicated that Sb(III) and Sb(V) had synergistic and antagonistic effects at low and high concentrations, respectively. The bacterial populations in the drilosphere (gut and burrow lining) appeared to be more susceptible to Sb contamination than in the non-drilosphere, their specific microecology may be an important factor in soil Sb migration and transformation. The abundance of Actinobacteria exhibited a significant decrease with increasing concentrations of single Sb(III) and Sb(V), while the abundance of Bacteroidia increased. The correlation heatmap showed that Sphingobacterium faecium was highly tolerant to Sb. These results provide not only an important basis for the ecological risk assessment of Sb in the soil environment but also new insights into the altered drilosphere bacterial communities under Sb stress.

Preparation of straw/PLA composites with excellent flame retardancy based on deep eutectic solvent sulfonation.

There have been numerous studies on flame retardant modification of natural fiber/PLA composite materials due to the demand for applications. However, the existing flame retardant modification methods mostly involve adding flame retardants, which have a negative impact on the mechanical properties. Based on this, this study aims to introduce sulfonic groups into the cellulose of straw fibers via modification with a sulfamic acid-based deep eutectic solvent (SDES), thereby achieving flame retardance without affecting the inherent mechanical properties of the composite material. The performance enhancement of DS/PLA is manifested in the following specific aspects: the LOI reaches 36.53 %, the thermal stability is improved from 7.8 % of the residual carbon of PS/PLA to 38.4 %, and the tensile modulus is increased by 69.5 %. The preparation scheme for straw/PLA composite materials in this study is simple, economical, and efficient, and the flame retardant performance of the composite material is excellent, providing valuable references for flame retardant modification of natural fiber/plastic composite materials.

Physical literacy and health of Chinese medical students: the chain mediating role of physical activity and subjective well-being.

Background/objective: While Physical Literacy has been highlighted as a determinant in health in recent study, there is a dearth of studies examining its effect on physical health, and there is a little in the way of empirical data linking Physical Literacy to health outcomes. Accordingly, further empirical research is needed to clarify the mechanisms by which Physical Literacy affects physical health. The purpose of this study was to verify the role of medical students' Physical Literacy on Health-related quality of life as well as to explore the chain mediating role of Physical Activity and Subjective Well-being in it. Methods: This study utilized a cross-sectional study design. The Physical Literacy, Health-related Quality of Life, Physical Activity ratings, and Subjective Well-being of students at Shanxi Medical University were all measured using an online survey administered in September 2023. A total of 1968 valid questionnaires were returned. First, descriptive statistics and correlation analysis were performed using SPSS software. Second, PROCESS was used to test the mediating role. Finally, we used structural equation modeling (Amos) to test the model fit. Results: There is a significant correlation between all variables. After mediation effects analysis, we found that there were three indirect pathways of physical literacy on health-related quality of life: a single mediating effect of physical activity, a single mediating effect of subjective well-being, and a chained mediating effect of physical activity-subjective well-being. Conclusion: The mediating role of physical activity and subjective well-being on the relationship between physical literacy and health-related quality of life has been confirmed. Our research results support the integration of physical literacy into physical education teaching and the modification of curriculum content by physical education teachers as part of efforts to enhance students' physical activity levels, subjective well-being levels, and overall health. This study provides a new perspective for intervention in improving the health of medical students.

Multiple cropping effectively increases soil bacterial diversity, community abundance and soil fertility of paddy fields.

BACKGROUND: Crop diversification is considered as an imperative approach for synchronizing the plant nutrient demands and soil nutrient availability. Taking two or more crops from the same field in one year is considered as multiple cropping. It improves the diversity and abundance of soil microbes, thereby improving the growth and yield of crops. Therefore, the present study was conducted to explore the effects of different multiple winter cropping on soil microbial communities in paddy fields. In this study, eight rice cropping patterns from two multiple cropping systems with three different winter crops, including Chinese milk vetch (CMV), rape, and wheat were selected. The effects of different multiple winter cropping on soil microbial abundance, community structure, and diversity in paddy fields were studied by 16 S rRNA high-throughput sequencing and real-time fluorescence quantitative polymerase chain reaction (PCR). RESULTS: The results showed that different multiple winter cropping increased the operational taxonomic units (OTUs), species richness, and community richness index of the bacterial community in 0 ~ 20 cm soil layer. Moreover, soil physical and chemical properties of different multiple cropping patterns also affected the diversity and abundance of microbial bacterial communities. The multiple cropping increased soil potassium and nitrogen content, which significantly affected the diversity and abundance of bacterial communities, and it also increased the overall paddy yield. Moreover, different winter cropping changed the population distribution of microorganisms, and Proteobacteria, Acidobacteria, Nitrospira, and Chloroflexi were identified as the most dominant groups. Multiple winter cropping, especially rape-early rice-late rice (TR) andChinese milk vetch- early rice-late rice (TC) enhanced the abundance of Proteobacteria, Acidobacteria, and Actinobacteria and decreased the relative abundance of Verrucomicrobia and Euryarchaeota. CONCLUSION: In conclusion, winter cropping of Chinese milk vetch and rape were beneficial to improve the soil fertility, bacteria diversity, abundance and rice yield.

Netrin-1-engineered endothelial cell exosomes induce the formation of pre-regenerative niche to accelerate peripheral nerve repair.

The formation of vascular niche is pivotal during the early stage of peripheral nerve regeneration. Nevertheless, the mechanisms of vascular niche in the regulation of peripheral nerve repair remain unclear. Netrin-1 (NTN1) was found up-regulated in nerve stump after peripheral nerve injury (PNI). Herein, we demonstrated that NTN1-high endothelial cells (NTN1+ECs) were the critical component of vascular niche, fostering angiogenesis, axon regeneration, and repair-related phenotypes. We also found that NTN1+EC-derived exosomes (NTN1 EC-EXO) were involved in the formation of vascular niche as a critical role. Multi-omics analysis further verified that NTN1 EC-EXO carried a low-level expression of let7a-5p and activated key pathways associated with niche formation including focal adhesion, axon guidance, phosphatidylinositol 3-kinase-AKT, and mammalian target of rapamycin signaling pathway. Together, our study suggested that the construction of a pre-regenerative niche induced by NTN1 EC-EXO could establish a beneficial microenvironment for nerve repair and facilitate functional recovery after PNI.

Gasdermin D silencing alleviates airway inflammation and remodeling in an ovalbumin-induced asthmatic mouse model.

Emerging evidence demonstrates that pyroptosis has been implicated in the pathogenesis of asthma. Gasdermin D (GSDMD) is the pyroptosis executioner. The mechanism of GSDMD in asthma remains unclear. The aim of this study was to elucidate the potential role of GSDMD in asthmatic airway inflammation and remodeling. Immunofluorescence staining was conducted on airway epithelial tissues obtained from both asthma patients and healthy controls (HCs) to evaluate the expression level of N-GSDMD. ELISA was used to measure concentrations of cytokines (IL-1ß, IL-18, IL-17A, and IL-10) in serum samples collected from asthma patients and healthy individuals. We demonstrated that N-GSDMD, IL-18, and IL-1ß were significantly increased in samples with mild asthma compared with those from the controls. Then, wild type and Gsdmd-knockout (Gsdmd-/-) mice were used to establish asthma model. We performed histopathological staining, ELISA, and flow cytometry to explore the function of GSDMD in allergic airway inflammation and tissue remodeling in vivo. We observed that the expression of N-GSDMD, IL-18, and IL-1ß was enhanced in OVA-induced asthma mouse model. Gsdmd knockout resulted in attenuated IL-18, and IL-1ß production in both bronchoalveolar lavage fluid (BALF) and lung tissue in asthmatic mice. In addition, Gsdmd-/- mice exhibit a significant reduction in airway inflammation and remodeling, which might be associated with reduced Th17 inflammatory response and M2 polarization of macrophages. Further, we found that GSDMD knockout may improve asthmatic airway inflammation and remodeling through regulating macrophage adhesion, migration, and macrophage M2 polarization by targeting Notch signaling pathway. These findings demonstrate that GSDMD deficiency profoundly alleviates allergic inflammation and tissue remodeling. Therefore, GSDMD may serve as a potential therapeutic target against asthma.

Real time monitoring peripheral nerve function with ICG and BDA-ICG by NIR-II fluorescence imaging.

Neuroanatomical tract tracers are important for studying axoplasmic transport and the complex interconnections of the nervous system. Though traditional fluorescent tracers are widely used, they have several prominent drawbacks when imaging, including low resolutions and low tissue penetrations and inability to be supervised dynamically within a long peripheral nerve during the long term. Here, we explored the potential of ICG as a neural tracer for axoplasmic transport and for the first time demonstrated that ICG could be used to detect transport function within peripheral nerve by near-infrared region II (NIR-II) imaging. On basis of this finding, a novel bi-directional neural tracer biotinylated dextran amine-indocyanine green (BDA-ICG) was prepared and characterized with better long-term stability and higher nerve-to-background ratio than ICG in vivo, and successfully imaged the injured peripheral nerve from the healthy one within 24 h. Our results show that BDA-ICG are promising neural tracers and clinically available dyes with NIR-II emission tail characteristics as ICG.

Peripheral nervous system lymphatic vessels: A simple delivery route to promote nerve regeneration.

The structural and functional features of lymphatic vessels in the peripheral nervous system (pLVs) is still unclear. Here, we clarify the existence of pLVs in rats, PROX1-EGFP transgenic mice and human, and exhibit a clear three-dimensional structure for helping understand its structural features. Moreover, two specific phenotypes of lymphatics endothelial cells (Rnd1Hi LECs and Ccl21Hi LECs) in peripheral nerves are well characterized by single-cell sequencing. Subsequently, the ability of trans-lymphatic delivery to peripheral nerves via pLVs has been dynamically demonstrated. After peripheral nerve injury (PNI), extensive lymphangiogenesis occurs in the lesion area and further enhances the efficiency of retrograde lymphatic-nerve transport. In PNI animal models, subcutaneously footpad-injected exosomes are efficiently delivered to sciatic nerve via pLVs which can promote nerve regeneration. The trans-lymphatic delivery to peripheral nerves via pLVs can subtly bypass BNB which provides an easy and alternative delivery route for PNI treatment.

The effects of Massa Medicata Fermentata on the digestive function and intestinal flora of mice with functional dyspepsia.

Introduction: The purpose of this study was to identify the chemical components of Massa Medicata Fermentata (MMF) in different fermentation methods, analyze its regulatory effects on gastrointestinal propulsion and intestinal flora in mice with food accumulation, and further explore its mechanism of action in the treatment of dyspepsia. Methods: The chemical compositions of three kinds of MMF were identified using the UPLC-Q- Exactive Orbitrap mass spectrometer. A model of spleen deficiency and food accumulation in mice was established. The gastric emptying rate and intestinal propulsion rate were calculated, serum gastrin concentration and cholinesterase activity were measured, and 16S rRNA microbial detection was performed in different groups of mouse feces. Results: The results showed that a total of 95 chemical components were identified from the three MMF extracts, 62 of which were the same, but there were differences in flavonoids and their glycosides, organic acids, and esters. MMF, PFMMF, and commercial MMF could all significantly improve the gastric emptying rate, intestinal propulsion rate, and GAS concentration in the serum of model mice; PFMMF has a better effect, while there was no significant difference in cholinesterase activity among the groups (p > 0.05). The 16S rRNA sequencing results showed that the MMF and PFMMF could increase the content of beneficial bacteria Bacteroidetes and decrease the pathogenic bacteria Verrucomicrobia in the intestines of model mice, while the commercial MMF could not. Discussion: Studies suggest that MMF has a variety of possible mechanisms for improving food accumulation and treating gastrointestinal dyspepsia, which provides reference value for the quality evaluation and clinical application of MMF.

Recent Advances in Nanomaterials for the Treatment of Acute Kidney Injury.

Acute kidney injury (AKI) is a serious clinical syndrome with high morbidity, elevated mortality, and poor prognosis, commonly considered a "sword of Damocles" for hospitalized patients, especially those in intensive care units. Oxidative stress, inflammation, and apoptosis, caused by the excessive production of reactive oxygen species (ROS), play a key role in AKI progression. Hence, the investigation of effective and safe antioxidants and inflammatory regulators to scavenge overexpressed ROS and regulate excessive inflammation has become a promising therapeutic option. However, the unique physiological structure and complex pathological alterations in the kidneys render traditional therapies ineffective, impeding the residence and efficacy of most antioxidant and anti-inflammatory small molecule drugs within the renal milieu. Recently, nanotherapeutic interventions have emerged as a promising and prospective strategy for AKI, overcoming traditional treatment dilemmas through alterations in size, shape, charge, and surface modifications. This Review succinctly summarizes the latest advancements in nanotherapeutic approaches for AKI, encompassing nanozymes, ROS scavenger nanomaterials, MSC-EVs, and nanomaterials loaded with antioxidants and inflammatory regulator. Following this, strategies aimed at enhancing biocompatibility and kidney targeting are introduced. Furthermore, a brief discussion on the current challenges and future prospects in this research field is presented, providing a comprehensive overview of the evolving landscape of nanotherapeutic interventions for AKI.

Photoactive rhodamine-based photosensitizer eliminates Staphylococcus aureus via superoxide radical photosensitization.

Due to the antibiotics abuse, bacterial infection has become one of the leading causes of human death worldwide. Novel selective antimicrobial agents are urgently needed, with the hope of maintaining the balance of the microbial environment. Photo-activated chemotherapeutics have shown great potential to eliminate bacteria with appealing spatiotemporal selectivity. In this work, we reported the structural modification to enhance the triplet excited state property of Rhodamine B, synthesizing a rhodamine-based photosensitizer RBPy. Upon light activation, RBPy exhibited much stronger photosensitization ability than the parent compound Rhodamine B both in solution and in bacteria. Importantly, RBPy can selectively inactivate Staphylococcus aureus and inhibit biofilm formation with high biocompatibility. This work provides a new strategy to develop rhodamine-based photoactive chemotherapeutics for antimicrobial photodynamic therapy.

In vivo antiviral efficacy of LCTG-002, a pooled, purified human milk secretory IgA product, against SARS-CoV-2 in a murine model of COVID-19.

Immunoglobulin A (IgA) is the most abundant antibody (Ab) in human mucosae, with secretory form (sIgA) being dominant and uniquely stable. sIgA is challenging to produce recombinantly but is naturally found in human milk, which could be considered a global resource for this biologic, justifying its development as a mucosal therapeutic. Presently, SARS-CoV-2 was utilized as a model mucosal pathogen, and methods were developed to efficiently extract human milk sIgA from donors who were naïve to SARS-CoV-2 or had recovered from infection that elicited high-titer anti-SARS-CoV-2 Spike sIgA in their milk (pooled to make LCTG-002). Mass spectrometry determined that proteins with a relative abundance of 1% or greater were all associated with sIgA. Western blot demonstrated that all batches consisted predominantly of sIgA. Compared to control IgA, LCTG-002 demonstrated significantly higher Spike binding (mean endpoint of 0.87 versus 5.87). LCTG-002 was capable of blocking the Spike receptor-binding domain - angiotensin-converting enzyme 2 (ACE2) interaction with significantly greater potency compared to control (mean LCTG-002 IC50 154ug/mL versus 50% inhibition not achieved for control), and exhibited significant neutralization activity against Spike-pseudotyped virus infection (mean LCTG-002 IC50 49.8ug/mL versus 114.5ug/mL for control). LCTG-002 was tested for its capacity to reduce viral lung burden in K18+hACE2 transgenic mice inoculated with SARS-CoV-2. LCTG-002 significantly reduced SARS-CoV-2 titers compared to control when administered at 0.25 mg/day or 1 mg/day, with a maximum TCID50 reduction of 4.9 logs. This innovative study demonstrates that LCTG-002 is highly pure and efficacious in vivo, supporting further development of milk-derived, polyclonal sIgA therapeutics.

A new application of nano-selenium: rescue of CK2 and mitochondria from oxidative stress to prevent cardiac hypertrophy.

Background: Excessive reactive oxygen species (ROS) and subsequent mitochondrial dysfunction are pivotal in initiating cardiac hypertrophy. To explore nano-selenium's (SeNP's) preventive potential against this condition, the authors evaluated chemically synthesized chitosan-SeNPs and biosynthesized Bacillus cereus YC-3-SeNPs in an angiotensin II (Ang II)-induced cardiac hypertrophy model. Methods: This investigation encompassed ROS measurement, mitochondrial membrane potential analysis, transmission electron microscopy, gene and protein expression analyses, protein carbonylation assays, serum antioxidant quantification and histological staining. Results: SeNPs effectively countered Ang II-induced cardiac hypertrophy by reducing ROS, restoring mitochondrial and protein kinase 2α (CK2-α) function, activating antioxidant pathways and enhancing serum antioxidant levels. Conclusion: This finding underscores SeNPs' role in attenuating Ang II-induced myocardial hypertrophy both in vitro and in vivo.

Enlargement of the heart is called cardiac hypertrophy; this is caused by too many reactive oxygen species, which are compounds that damage the mitochondria of cells. The mitochondria provide energy to cells and their disruption can cause a significantly negative effect on cells and the tissues and organs cells make up. Selenium is a type of metal that must be consumed in small amounts to stay healthy; it has antioxidant effects, meaning it can stop reactive oxygen species and potentially prevent cardiac hypertrophy. Nano-selenium (SeNP), consisting of tiny, spherical particles containing selenium, may be a more effective way of delivering selenium as an antioxidant to prevent cardiac hypertrophy. SeNPs were made synthetically and from a type of bacterium called Bacillus cereus; both SeNPs demonstrated antioxidant effects in heart cells taken from chicken embryos and live chickens. These results suggest that SeNPs could be developed into medication to combat cardiac hypertrophy.

Fluorescence imaging of peripheral nerve function and structure.

Peripheral nerve injuries are common and can cause catastrophic consequences. Although peripheral nerves have notable regenerative capacity, full functional recovery is often challenging due to a number of factors, including age, the type of injury, and delayed healing, resulting in chronic disorders that cause lifelong miseries and significant financial burdens. Fluorescence imaging, among the various techniques, may be the key to overcome these restrictions and improve the prognosis because of its feasibility and dynamic real-time imaging. Intraoperative dynamic fluorescence imaging allows the visualization of the morphological structure of the nerve so that surgeons can reduce the incidence of medically induced injury. Axoplasmic transport-based neuroimaging allows the visualization of the internal transport function of the nerve, facilitating early, objective, and accurate assessment of the degree of regenerative repair, allowing early intervention in patients with poor recovery, thereby improving prognosis. This review briefly discusses peripheral nerve fluorescent dyes that have been reported or could potentially be employed, with a focus on their role in visualizing the nerve's function and anatomy.

In Situ Twistronics: A New Platform Based on Superlubricity.

Twistronics, an emerging field focused on exploring the unique electrical properties induced by twist interface in graphene multilayers, has garnered significant attention in recent years. The general manipulation of twist angle depends on the assembly of van der Waals (vdW) layered materials, which has led to the discovery of unconventional superconductivity, ferroelectricity, and nonlinear optics, thereby expanding the realm of twistronics. Recently, in situ tuning of interlayer conductivity in vdW layered materials has been achieved based on scanning probe microscope. In this Perspective, the advancements in in situ twistronics are focused on by reviewing the state-of-the-art in situ manipulating technology, discussing the underlying mechanism based on the concept of structural superlubricity, and exploiting the real-time twistronic tests under scanning electron microscope (SEM). It is shown that the real-time manipulation under SEM allows for visualizing and monitoring the interface status during in situ twistronic testing. By harnessing the unique tribological properties of vdW layered materials, this novel platform not only enhances the fabrication of twistronic devices but also facilitates the fundamental understanding of interface phenomena in vdW layered materials. Moreover, this platform holds great promise for the application of twistronic-mechanical systems, providing avenues for the integration of twistronics into various mechanical frameworks.

Substrate DNA Promoting Binding of Mycobacterium tuberculosis MtrA by Facilitating Dimerization and Interpretation of Affinity by Minor Groove Width.

In order to deepen the understanding of the role and regulation mechanisms of prokaryotic global transcription regulators in complex processes, including virulence, the associations between the affinity and binding sequences of Mycobacterium tuberculosis MtrA have been explored extensively. Analysis of MtrA 294 diversified 26 bp binding sequences revealed that the sequence similarity of fragments was not simply associated with affinity. The unique variation patterns of GC content and periodical and sequential fluctuation of affinity contribution curves were observed along the sequence in this study. Furthermore, docking analysis demonstrated that the structure of the dimer MtrA-DNA (high affinity) was generally consistent with other OmpR family members, while Arg 219 and Gly 220 of the wing domain interacted with the minor groove. The results of the binding box replacement experiment proved that box 2 was essential for binding, which implied the differential roles of the two boxes in the binding process. Furthermore, the results of the substitution of the nucleotide at the 20th and/or 21st positions indicated that the affinity was negatively associated with the value of minor groove width precisely at the 21st position. The dimerization of the unphosphorylated MtrA facilitated by a low-affinity DNA fragment was observed for the first time. However, the proportion of the dimer was associated with the affinity of substrate DNA, which further suggested that the affinity was actually one characteristic of the stability of dimers. Based on the finding of 17 inter-molecule hydrogen bonds identified in the interface of the MtrA dimer, including 8 symmetric complementary ones in the conserved α4-ß5-α5 face, we propose that hydrogen bonds should be considered just as important as salt bridges and the hydrophobic patch in the dimerization. Our comprehensive study on a large number of binding fragments with quantitative affinity values provided new insight into the molecular mechanism of dimerization, binding specificity and affinity determination of MtrA and clues for solving the puzzle of how global transcription factors regulate a large quantity of target genes.

In Vivo Antiviral Efficacy of LCTG-002, a Pooled, Purified Human Milk Secretory IgA product, Against SARS-CoV-2 in a Murine Model of COVID-19.

Immunoglobulin A (IgA) is the most abundant antibody (Ab) in human mucosal compartments including the respiratory tract, with the secretory form of IgA (sIgA) being dominant and uniquely stable in these environments. sIgA is naturally found in human milk, which could be considered a global resource for this biologic, justifying the development of human milk sIgA as a dedicated airway therapeutic for respiratory infections such as SARS-CoV-2. In the present study, methods were therefore developed to efficiently extract human milk sIgA from donors who were either immunologically naïve to SARS-CoV-2 (pooled as a control IgA) or had recovered from a PCR-confirmed SARS-CoV-2 infection that elicited high-titer anti-SARS-CoV-2 Spike sIgA Abs in their milk (pooled together to make LCTG-002). Mass spectrometry determined that proteins with a relative abundance of 1.0% or greater were all associated with sIgA. None of the proteins exhibited statistically significant differences between batches. Western blot demonstrated all batches consisted predominantly of sIgA. Compared to control IgA, LCTG-002 demonstrated significantly higher binding to Spike, and was also capable of blocking the Spike - ACE2 interaction in vitro with 6.3x greater potency compared to control IgA (58% inhibition at ∼240ug/mL). LCTG-002 was then tested in vivo for its capacity to reduce viral burden in the lungs of K18+hACE2 transgenic mice inoculated with SARS-CoV-2. LCTG-002 was demonstrated to significantly reduce SARS-CoV-2 titers in the lungs compared to control IgA when administered at either 250ug/day or 1 mg/day, as measured by TCID50, plaque forming units (PFU), and qRT-PCR, with a maximum reduction of 4.9 logs. This innovative study demonstrates that LCTG-002 is highly pure, efficacious, and well tolerated in vivo, supporting further development of milk-derived, polyclonal sIgA therapeutics against SARS-CoV-2 and other mucosal infections.

Sirtuin1 inhibits calcium oxalate crystal-induced kidney injury by regulating TLR4 signaling and macrophage-mediated inflammatory activation.

Sirtuin1 (Sirt1) activation significantly attenuated calcium oxalate (CaOx) crystal deposition and renal inflammatory injury by regulating renal immune microenvironment. Here, to elucidate the molecular mechanism underlying the therapeutic effects of Sirt1 on macrophage related inflammation and tubular epithelial cells (TECs) necrosis, we constructed a macrophage and CaOx monohydrate (COM)-stimulated tubular cell co-culture system to mimic immune microenvironment in kidney and established a mouse model of CaOx nephrocalcinosis in wild-type and myeloid-specific Sirt1 knockout mice. Target prediction analyses of Gene Expression Omnibus Datasets showed that only miR-34b-5p is regulated by lipopolysaccharides and upregulated by SRT1720 and targets the TLR4 3'-untranslated region. In vitro, SRT1720 suppressed TLR4 expression and M1 macrophage polarization and decreased reactive oxygen species (ROS) production and mitochondrial damage in COM-stimulated TECs by targeting miR-34b-5p. Mechanically, Sirt1 promoted miR-34b-5p expression by suppressing the tri-methylation of H3K27, which directly bound to the miR-34b-5p promoter and abolished the miR-34b-5p transcription. Furthermore, loss of Sirt1 aggravated CaOx nephrocalcinosis-induced inflammatory and oxidative kidney injury, while AgomiR-34b reversed these effects. Therefore, our data suggested that Sirt1 inhibited TLR4 signaling and M1 macrophage polarization and decreased inflammatory and oxidative injury of TECs in vitro and in vivo.