Toxin-Enabled "On-Demand" Liposomes for Enhanced Phototherapy to Treat and Protect against Methicillin-Resistant Staphylococcus aureus Infection.

An effective therapeutic strategy against methicillin-resistant Staphylococcus aureus (MRSA) that does not promote further drug resistance is highly desirable. While phototherapies have demonstrated considerable promise, their application toward bacterial infections can be limited by negative off-target effects to healthy cells. Here, a smart targeted nanoformulation consisting of a liquid perfluorocarbon core stabilized by a lipid membrane coating is developed. Using vancomycin as a targeting agent, the platform is capable of specifically delivering an encapsulated photosensitizer along with oxygen to sites of MRSA infection, where high concentrations of pore-forming toxins trigger on-demand payload release. Upon subsequent near-infrared irradiation, local increases in temperature and reactive oxygen species effectively kill the bacteria. Additionally, the secreted toxins that are captured by the nanoformulation can be processed by resident immune cells to promote multiantigenic immunity that protects against secondary MRSA infections. Overall, the reported approach for the on-demand release of phototherapeutic agents into sites of infection could be applied against a wide range of high-priority pathogens.

γ-Secretase Inhibitor Alleviates Acute Airway Inflammation of Allergic Asthma in Mice by Downregulating Th17 Cell Differentiation.

T helper 17 (Th17) cells play an important role in the pathogenesis of allergic asthma. Th17 cell differentiation requires Notch signaling. γ-Secretase inhibitor (GSI) blocks Notch signaling; thus, it may be considered as a potential treatment for allergic asthma. The aim of this study was to evaluate the effect of GSI on Th17 cell differentiation in a mouse model of allergic asthma. OVA was used to induce mouse asthma model in the presence and absence of GSI. GSI ameliorated the development of OVA-induced asthma, including suppressing airway inflammation responses and reducing the severity of clinical signs. GSI also significantly suppressed Th17-cell responses in spleen and reduced IL-17 levels in serum. These findings suggest that GSI directly regulates Th17 responses through a Notch signaling-dependent pathway in mouse model of allergic asthma, supporting the notion that GSI is a potential therapeutic agent for the treatment of allergic asthma.

Dietary glutamine supplementation improves both Th1 and Th17 responses via CARD11-mTORC1 pathway in murine model of atopic dermatitis.

Glutamine (GLN) is considered an immunomodulatory nutrient, while caspase recruitment domain 11 (CARD11) is a susceptibility locus for atopic dermatitis (AD). T-cell antigen receptor (TCR)-stimulated GLN uptake requires CARD11. However, the specific pathogenesis of AD via GLN uptake remains unclear. This study aimed to elucidate the association between dietary GLN supplementation and the CARD11 pathway in the pathogenesis of AD, focusing on T helper type 1 (Th1) and Th17 cell expression in AD. Herein, wild-type (WT) mice with house dust mite epidermal-sensitized skin exhibited increased expression of interferon-gamma (IFN-gamma) and interleukin (IL)-17, whereas CARD11 deficiency impaired Th1 and Th17 responses at the same site. CARD11 is a key mediator of Th1 and Th17 expression in AD. Additionally, we suppressed mammalian target of rapamycin complex 1 (mTORC1) signaling, downstream of CARD11, to underscore the critical role of CARD11 in mediating Th1 and Th17 expression in AD. Further, dietary supplementation of GLN to CARD11-/- mice restored Th1 and Th17 responses, whereas inflammatory expression was reduced in WT mice, and p-CARD11 expression and mTORC1 signaling activity were increased in JPM50.6 cells and CARD11-/- mice. Upon inhibiting the GLN transporter, alanine-serine-cysteine transporter carrier 2 (ASCT2), we observed that the Th1 and Th17 response in AD was reduced. Conclusively, ASCT2-mediated GLN uptake improves the expression of Th1 and Th17 cells via CARD11-mTORC1 signaling pathway in AD, suggesting the potential of glutamine supplementation for AD treatment.

Red Blood Cell Membrane-Coated Nanoparticles Enable Incompatible Blood Transfusions.

Blood transfusions save lives and improve health every day. Despite the matching of blood types being stricter than it ever has been, emergency transfusions among incompatible blood types are still inevitable in the clinic when there is a lack of acceptable blood types for recipients. Here to overcome this, a counter measure nanoplatform consisting of a polymeric core coated by a red blood cell (RBC) membrane is developed. With A-type or B-type RBC membrane camouflaging, the nanoplatform is capable of specifically capturing anti-A or anti-B IgM antibodies within B-type or A-type whole blood, thereby decreasing the corresponding IgM antibody levels and then allowing the incompatible blood transfusions. In addition to IgM, the anti-RBC IgG antibody in a passive immunization murine model can likewise be neutralized by this nanoplatform, leading to prolonged circulation time of incompatible donor RBCs. Noteworthily, nanoplatform made by expired RBCs (>42 days stored hypothermically) and then subjected to lyophilization does not impair their effect on antibody neutralization. Most importantly, antibody-captured RBC-NP do not exacerbate the risk of inflammation, complement activation, and coagulopathy in an acute hemorrhagic shock murine model. Overall, this biomimetic nanoplatform can safely neutralize the antibody to enable incompatible blood transfusion.

Bioinformatics analysis of ferroptosis-related gene AKR1C3 as a potential biomarker of asthma and its identification in BEAS-2B cells.

Ferroptosis is a newly discovered type of cell death and has recently been shown to be associated with asthma. However, the relationship between them at the genetic level has not been elucidated via informatics analysis. In this study, bioinformatics analyses are conducted using asthma and ferroptosis datasets to identify candidate ferroptosis-related genes using the R software. Weighted gene co-expression network analysis is performed to identify co-expressed genes. Protein-protein interaction networks, the Kyoto encyclopedia of genes and genomes, and gene ontology enrichment analysis are used to identify the potential functions of the candidate genes. We experimentally validate the results of our analysis using small interfering RNAs and plasmids to silence and upregulate the expression of the candidate gene in human bronchial epithelial cells (BEAS-2B). The ferroptosis signature levels are examined. Bioinformatics analysis of the asthma dataset GDS4896 shows that the level of the aldo-keto reductase family 1 member C3 (AKR1C3) gene in the peripheral blood of patients with severe therapy-resistant asthma and controlled persistent mild asthma (MA) is significantly upregulated. The AUC values for asthma diagnosis and MA are 0.823 and 0.915, respectively. The diagnostic value of AKR1C3 is verified using the GSE64913 dataset. The gene module of AKR1C3 is evident in MA and functions through redox reactions and metabolic processes. Ferroptosis indicators are downregulated by the overexpression of AKR1C3 and upregulated by silencing AKR1C3. The ferroptosis-related gene AKR1C3 can be used as a diagnostic biomarker for asthma, particularly for MA, and regulates ferroptosis in BEAS-2B cells.

Allergen immunotherapy combined with Notch pathway inhibitors improves HDM-induced allergic airway inflammation and inhibits ILC2 activation.

Introduction: Group 2 innate lymphoid cells (ILC2s) play a crucial role in house dust mite (HDM)-induced allergic inflammation, and allergen immunotherapy (AIT) holds promise for treating the disease by reducing the frequency of ILC2s. Despite significant progress in AIT for allergic diseases, there remains a need to improve the control of allergic symptoms. Methods: We investigated the synergistic effect of the Notch signaling pathway and subcutaneous immunotherapy (SCIT) in treating allergic airway inflammation in mice and their impact on the ratio of ILC2s in lung tissues. This was achieved by establishing the HDM-induced airway allergic disorders (HAAD) model and SCIT model. Additionally, we conducted in vitro investigations into the effect of the Notch signaling pathway on the secretory function of activated ILC2s using fluorescence-activated cell sorting. Furthermore, we explored the coactivation of the Notch signaling pathway with SCIT in vitro by sorting ILC2s from the lung tissues of mice after SCIT modeling. Results: Previously, our group demonstrated that Notch signaling pathway inhibitors can reduce allergic airway inflammation in mice. Notch signaling induces lineage plasticity of mature ILC2s. In this study, we showed that AIT alleviates allergic airway inflammation and suppresses the frequency of ILC2s induced by HDM. Interestingly, AIT combined with a γ-secretase inhibitor (GSI), an inhibitor of the Notch signaling pathway, significantly inhibited the frequency of ILC2s, reduced airway inflammation, and suppressed Th2-type responses in a mouse model. Furthermore, lung ILC2s from HDM-challenged mice with or without AIT were treated with GSI in vitro, and we found that GSI dramatically reduced the secretion of type 2 inflammatory factors in ILC2s. Discussion: These findings suggest that Notch signaling pathway inhibitors can be used as adjuvant therapy for AIT and may hold potential treatment value in the cooperative control of allergic airway inflammation during early AIT.

Molecular mechanism of interleukin-17A regulating airway epithelial cell ferroptosis based on allergic asthma airway inflammation.

Interleukin-17A (IL-17A) levels are elevated in patients with asthma. Ferroptosis has been identified as the non-apoptotic cell death type associated with asthma. Data regarding the relation of ferroptosis with asthma and the effect of IL-17A on modulating ferroptosis in asthma remain largely unclear. The present work focused on investigating the role of IL-17A in allergic asthma-related ferroptosis and its associated molecular mechanisms using public datasets, clinical samples, human bronchial epithelial cells, and an allergic asthma mouse model. We found that IL-17A was significantly upregulated within serum in asthma cases. Adding IL-17A significantly increased ferroptosis within human bronchial epithelial cells (BEAS-2B). In ovalbumin (OVA)-induced allergic asthmatic mice, IL-17A regulated and activated lipid peroxidation induced ferroptosis, whereas IL-17A knockdown effectively inhibited ferroptosis in vivo by protection of airway epithelial cells via the xCT-GSH-GPX4 antioxidant system and reduced airway inflammation. Mouse mRNA sequencing results indicated that the tumor necrosis factor (TNF) pathway was the differential KEGG pathway in the OVA group compared to healthy controls and the OVA group compared to the IL-17A knockout OVA group. We further used N-acetylcysteine (TNF inhibitor) to inhibit the TNF signaling pathway, which was found to protect BEAS-2B cells from IL-17A induced lipid peroxidation and ferroptosis damage. Our findings reveal a novel mechanism for the suppression of ferroptosis in airway epithelial cells, which may represent a new strategy for the use of IL-17A inhibitors against allergic asthma.

Doxorubicin Detoxification in Healthy Organs Improves Tolerability to High Drug Doses for Enhanced Antitumor Therapy.

With its well-documented toxicity, the use of doxorubicin (Dox) for cancer treatment requires trade-offs between safety and effectiveness. This limited use of Dox also hinders its functionality as an immunogenic cell death inducer, thus impeding its usefulness for immunotherapeutic applications. Here, we develop a biomimetic pseudonucleus nanoparticle (BPN-KP) by enclosing GC-rich DNA within erythrocyte membrane modified with a peptide to selectively target healthy tissue. By localizing treatment to organs susceptible to Dox-mediated toxicity, BPN-KP acts as a decoy that prevents the drug from intercalating into the nuclei of healthy cells. This results in significantly increased tolerance to Dox, thereby enabling the delivery of high drug doses into tumor tissue without detectable toxicity. By lessening the leukodepletive effects normally associated with chemotherapy, dramatic immune activation within the tumor microenvironment was also observed after treatment. In three different murine tumor models, high-dose Dox with BPN-KP pretreatment resulted in significantly prolonged survival, particularly when combined with immune checkpoint blockade therapy. Overall, this study demonstrates how targeted detoxification using biomimetic nanotechnology can help to unlock the full potential of traditional chemotherapeutics.

Vaginal Epithelial Cell Membrane-Based Phototherapeutic Decoy Confers a "Three-in-One" Strategy to Treat against Intravaginal Infection of Candida albicans.

Phototherapy is an effective strategy to control Candida albicans (C. albicans) infection without raising the concern of drug resistance. Despite its effectiveness, a higher dose of phototherapeutic power is required for C. albicans elimination compared to bacteria that have to be used, which is readily accompanied by off-target heat and toxic singlet oxygen to damage normal cells, thus limiting its usefulness for antifungal applications. Here to overcome this, we develop a "three-in-one" biomimetic nanoplatform consisting of an oxygen-dissolved perfluorocarbon camouflaged by a photosensitizer-loaded vaginal epithelial cell membrane. With a cell membrane coating, the nanoplatform is capable of specifically binding with C. albicans at the superficial or deep vaginal epithelium, thereby centering the phototherapeutic agents on C. albicans. Meanwhile, the cell membrane coating endows the nanoplatform to competitively protect healthy cells from candidalysin-medicated cytotoxicity. Upon candidalysin sequestration, pore-forming on the surface of the nanoplatform accelerates release of the preloaded photosensitizer and oxygen, resulting in enhanced phototherapeutic power for improved anti-C. albicans efficacy under near-infrared irradiation. In an intravaginal C. albicans-infected murine model, treatment with the nanoplatform leads to a significantly decreased C. albicans burden, particularly when leveraging candidalysin for further elevated phototherapy and C. albicans inhibition. Also, the same trends hold true when using the nanoplatform to treat the clinical C. albicans isolates. Overall, this biomimetic nanoplatform can target and bind with C. albicans and simultaneously neutralize the candidalysin and then transform such toxins that are always considered a positive part in driving C. albicans infection with the power of enhancing phototherapy for improved anti-C. albicans efficacy.

Bacterial Toxin-Responsive Biomimetic Nanobubbles for Precision Photodynamic Therapy against Bacterial Infections.

With few options available for the effective treatment of multidrug-resistant bacteria, photodynamic therapy (PDT) has emerged as a promising therapeutic strategy that does not promote the development of antibiotic resistance. Unfortunately, the beneficial bactericidal effect of PDT is oftentimes accompanied by the uncontrollable production of reactive oxygen species. To overcome this issue, a pore-forming toxin (PFT)-responsive biomimetic nanobubble is designed, which is constructed by co-encapsulating a perfluorocarbon nanoemulsion and a photosensitizer within the red blood cell membrane. It is shown that PFTs derived from three pathogens, including methicillin-resistant Staphylococcus aureus (MRSA), group A Streptococcus (GAS), and Listeria monocytogenes (LM), can be effectively absorbed by the nanobubble. Upon toxin absorption, the formation of pores on the nanobubble surface allows the accelerated release of oxygen dissolved inside the nanoemulsion along with the photosensitizer, thus resulting in enhanced PDT and bactericidal efficacy. In three skin infection models, treatment with the nanobubbles results in significantly decreased lesion formation and reduced inflammation. In addition to oxygen, the platform can be used to deliver nitric oxide in a bacterial toxin-dependent manner. Overall, biomimetic nanobubbles may work as a broad gas delivery system that is capable of responding to a variety of PFT-based stimuli for precision PDT.

Anti-Dll4 Antibody Inhibits the Differentiation of Th17 Cells in Asthmatic Mice.

T helper 17 (Th17) cells play an important role in allergic asthma, and the Notch ligand Delta-like ligand (Dll)4 has been reported to direct the differentiation of Th17 cells. In this study, experimental animals were divided into five groups (control group, asthma group, physiological saline group, anti-Dll4 antibody group, and immunoglobulin G group). The study aimed to explore the effect of anti-Dll4 antibody on the differentiation of Th17 cell in asthmatic mice. Dll4 protein expressions were performed by immunohistochemical imaging. The proportion of Th17 cells in mouse spleen-isolated CD4+ T cells were measured by flow cytometry. The protein expression of Th17 transcription factor retinoid-related orphan nuclear receptor (RORγt) was detected by Western blotting. Interleukin (IL)-17 levels in serum were measured by enzyme-linked immunosorbent assay (ELISA). The study found that the expression of Dll4 in lung tissue from the asthma group significantly increased compared with the anti-Dll4 antibody group. The ratio of Th17 cells in CD4+ T cells was significantly downregulated, and the protein expression of RORγt in spleen significantly reduced in the anti-Dll4 antibody group compared with the asthma group. Moreover, the IL-17 level in serum from the anti-Dll4 antibody group significantly reduced compared with the asthma group. These results suggested that anti-Dll4 antibody could inhibit the differentiation of Th17 cells in asthmatic mice.