The gut protist Tritrichomonas arnold restrains virus-mediated loss of oral tolerance by modulating dietary antigen-presenting dendritic cells.

Loss of oral tolerance (LOT) to gluten, driven by dendritic cell (DC) priming of gluten-specific T helper 1 (Th1) cell immune responses, is a hallmark of celiac disease (CeD) and can be triggered by enteric viral infections. Whether certain commensals can moderate virus-mediated LOT remains elusive. Here, using a mouse model of virus-mediated LOT, we discovered that the gut-colonizing protist Tritrichomonas (T.) arnold promotes oral tolerance and protects against reovirus- and murine norovirus-mediated LOT, independent of the microbiota. Protection was not attributable to antiviral host responses or T. arnold-mediated innate type 2 immunity. Mechanistically, T. arnold directly restrained the proinflammatory program in dietary antigen-presenting DCs, subsequently limiting Th1 and promoting regulatory T cell responses. Finally, analysis of fecal microbiomes showed that T. arnold-related Parabasalid strains are underrepresented in human CeD patients. Altogether, these findings will motivate further exploration of oral-tolerance-promoting protists in CeD and other immune-mediated food sensitivities.

Can Microbes Boost Tregs to Suppress Food Sensitivities?

Food sensitivities are on the rise worldwide. Peripheral induced regulatory T cells (pTreg cells) play a central role in oral tolerance to dietary antigens and can contribute to preventing the onset of immune-mediated food sensitivities. Here, we discuss the potential of microbial-derived products in promoting pTreg cell proliferation for re-establishing oral tolerance in immune-mediated food sensitivities.

Purification and Identification of Peptides from Hydrilla verticillata (Linn. f.) Royle with Cytoprotective and Antioxidative Effect against H2O2-Treated HepG2 Cells.

Antioxidant peptides were purified from Hydrilla verticillata (Linn. f.) Royle (HVR) protein hydrolysate by ultrafiltration, gel filtration chromatography, and semipreparative reversed-phase HPLC and identified by UPLC-ESI-MS/MS. Therein, TCLGPK and TCLGER were selected to be synthesized, and they displayed desirable radical-scavenging activity to ABTS (99.20 ± 0.56-99.20 ± 0.43%), DPPH (97.32 ± 0.59-97.56 ± 0.97%), hydroxyl radical (54.32 ± 1.27-70.42 ± 2.01%), and superoxide anion (42.93 ± 1.46-52.62 ± 1.11%) at a concentration of 0.96 µmol/mL. They possessed a cytoprotective effect against H2O2-induced oxidative stress in HepG2 cells in a dose-dependent manner. 1.6 µmol/mL of the two peptides could perfectly protect HepG2 cells from H2O2-induced injury. The TCLGPK exhibited higher antioxidant activity and cytoprotective effect than TCLGER. Western blot and molecular docking results indicated that the two peptides achieved antioxidant ability and cytoprotective effect by combining with Kelch-like ECH-associated protein 1 (Keap1) to activate the Keap1-nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response elements signaling pathway, leading to the activity and expression of the related antioxidases in the pathway significantly up-regulating and the intracellular reactive oxygen species level, lipid peroxidation, and cell apoptosis rate significantly down-regulating.

Antibiotic-free ocular sterilization while suppressing immune response to protect corneal transparency in infectious keratitis treatment.

Clinical guidelines for infectious keratitis treatment require that anti-inflammatory drugs can only be used after infection elimination, which causes irreversible inflammatory damage to the cornea. In this work, photodynamic metal organic frameworks (PCN-224) were used as drug carrier to load Pt NPs with catalase-like activity and anti-inflammatory drug (Dexamethasone, DXMS) for endogenous oxygen generation and reduced corneal damage, respectively. The photodynamic therapy (PDT) effect was greatly enhanced in bacteria elimination and bacterial biofilms removal through catalysis of overexpressed hydrogen peroxide (H2O2, ∼8.0 and 31.0 µM in bacterial solution and biofilms, respectively) into oxygen by Pt NPs. More importantly, the cationic liposome modified PCN-224@Pt@DXMS@Liposomes (PPDL NPs) greatly enhanced the adhesion to negatively charged ocular surface and penetration into corneal barrier and bacterial biofilms. Both in vitro cell viability test and in vivo eye irritation tests proved good biocompatibility of PPDL NPs under 660 nm laser irradiation. Furthermore, PDT of PPDL NPs in rapid bacteria killing was verified through infectious keratitis animal model. The superior bactericidal effect of antibacterial materials could largely replace the bactericidal effect of the immune system. It is worth mentioning that this simultaneous sterilization and anti-inflammation treatment mode is a new exploration against the clinical treatment guidelines.

Advancing the precision management of inflammatory bowel disease in the era of omics approaches and new technology.

There is great heterogeneity among inflammatory bowel disease (IBD) patients in terms of pathogenesis, clinical manifestation, response to treatment, and prognosis, which requires the individualized and precision management of patients. Many studies have focused on prediction biomarkers and models for assessing IBD disease type, activity, severity, and prognosis. During the era of biologics, how to predict the response and side effects of patients to different treatments and how to quickly recognize the loss of response have also become important topics. Multiomics is a promising area for investigating the complex network of IBD pathogenesis. Integrating numerous amounts of data requires the use of artificial intelligence.

A Novel "Inside-Out" Intraocular Nanomedicine Delivery Mode for Nanomaterials' Biological Effect Enhanced Choroidal Neovascularization Occlusion and Microenvironment Regulation.

Photodynamic therapy (PDT) is commonly used in choroidal neovascularization (CNV) treatment due to the superior light transmittance of the eye. However, PDT often leads to surrounding tissue damage and further microenvironmental deterioration, including exacerbated hypoxia, inflammation, and secondary neovascularization. In this work, Pt nanoparticles (NPs) and Au NPs decorated zeolitic imidazolate framework-8 nanoplatform is developed to load indocyanine green for precise PDT and microenvironment amelioration, which can penetrate the internal limiting membrane through Müller cells endocytosis and target to CNV by surface-grafted cyclo(Arg-Gly-Asp-d-Phe-Lys) after intravitreal injection. The excessive H2 O2 in the CNV microenvironment is catalyzed by catalase-like Pt NPs for hypoxia relief and enhanced PDT occlusion of neovascular. Meanwhile, Au NPs show significant anti-inflammatory and anti-angiogenesis properties in regulating macrophages and blocking vascular endothelial growth factor (VEGF). Compared with verteporfin treatment, the mRNA expressions of hypoxia-inducible factor-1α and VEGF in the nanoplatform group are downregulated by 90.2% and 81.7%, respectively. Therefore, the nanoplatform realizes a comprehensive CNV treatment effect based on the high drug loading capacity and biosafety. The CNV treatment mode developed in this work provides a valuable reference for treating other diseases with similar physiological barriers that limit drug delivery and similar microenvironment.

Gut microbiota composition in patients with advanced malignancies experiencing immune-related adverse events.

Introduction: The gut microbiota is implicated in the occurrence and severity of immune-related adverse events (irAEs), but the role it plays as well as its causal relationship with irAEs has yet to be established. Methods: From May 2020 to August 2021, 93 fecal samples were prospectively collected from 37 patients with advanced thoracic cancers treated with anti-PD-1 therapy, and 61 samples were collected from 33 patients with various cancers developing different irAEs. 16S rDNA amplicon sequencing was performed. Antibiotic-treated mice underwent fecal microbiota transplantation (FMT) with samples from patients with and without colitic irAEs. Results: Microbiota composition was significantly different in patients with and without irAEs (P=0.001) and with and without colitic-type irAEs (P=0.003). Bifidobacterium, Faecalibacterium, and Agathobacter were less abundant and Erysipelatoclostridium more abundant in irAE patients, while Bacteroides and Bifidobacterium were less abundant and Enterococcus more abundant in colitis-type irAE patients. Major butyrate-producing bacteria were also less abundant in patients with irAEs than those without (P=0.007) and in colitic vs. non-colitic irAE patients (P=0.018). An irAE prediction model had an AUC of 86.4% in training and 91.7% in testing. Immune-related colitis was more common in colitic-irAE-FMT (3/9) than non-irAE-FMT mice (0/9). Conclusions: The gut microbiota is important in dictating irAE occurrence and type, especially for immune-related colitis, possibly by modulating metabolic pathways.

Dynamic gut microbiota changes in patients with advanced malignancies experiencing secondary resistance to immune checkpoint inhibitors and immune-related adverse events.

Background: Immune checkpoint inhibitors (ICIs) have been a breakthrough in cancer immunotherapy, but secondary resistance (SR) and immune-related adverse events (irAEs) are significant clinical dilemmas. Although the gut microbiota is associated with ICI efficacy and irAEs, the knowledge of longitudinal gut microbiota dynamics during SR and irAE development is still quite limited. Methods: This was a prospective observational cohort study of cancer patients initially receiving anti-programmed cell death-1 (PD-1) treatment between May 2020 and October 2022. Clinical information was collected to evaluate therapy response and AEs. Patients were divided into a secondary resistance (SR) group, a non-secondary resistance (NSR) group, and an irAE group. Fecal samples were longitudinally obtained from baseline across multiple timepoints and analyzed with 16S rRNA sequencing. Results: Thirty-five patients were enrolled, and 29 were evaluable. After a median follow-up of 13.3 months, NSR patients had a favorable progression-free survival (PFS) compared with SR (457.9 IQR 241.0-674.0 days vs. 141.2 IQR 116.9-165.4 days, P=0.003) and irAE patients (457.9 IQR 241.0-674.0 days vs. 269.9, IQR 103.2-436.5 days, P=0.053). There were no significant differences in the microbiota between groups at baseline. Several previously reported beneficial microbiomes for ICI efficacy including Lachnospiraceae, Ruminococcaceae, Agathobacter, and Faecalibacterium showed decreasing trends as secondary resistance developed, yet not achieved significance (P>0.05). Significant changes in butyrate-producing bacteria were also presented in the SR cohort (P=0.043) with a decreasing trend upon secondary resistance occurrence (P=0.078). While the abundance of IgA-coated bacteria was stable in the SR cohort, there was a temporary decrease upon ICI treatment initiation and reestablishment after continuation of ICI treatment in the NSR cohort (primary ICI response: 0.06, IQR 0.04-0.10; durable ICI response: 0.11, IQR 0.07-0.14; P=0.042). Bacteroides contributed most to the difference between baseline and irAE occurrence, which decreased after irAE occurrence (Baseline: 0.10 IQR 0.07-0.36; irAE occurrence: 0.08 IQR 0.06-0.12) and was restored upon irAE remission to a comparable level as baseline (irAE remission: 0.10 IQR 0.09-0.18). Conclusions: The development of SR and irAEs is related to the longitudinal dynamics of the intestinal microbiota. The investigation into the preventative and protective effects of enteric microbe manipulation strategies is further required.

Novel biomarker panel for the diagnosis and prognosis assessment of sepsis based on machine learning.

Background: The authors investigated a panel of novel biomarkers for diagnosis and prognosis assessment of sepsis using machine learning (ML) methods. Methods: Hematological parameters, liver function indices and inflammatory marker levels of 332 subjects were retrospectively analyzed. Results: The authors constructed sepsis diagnosis models and identified the random forest (RF) model to be the most optimal. Compared with PCT (procalcitonin) and CRP (C-reactive protein), the RF model identified sepsis patients at an earlier stage. The sepsis group had a mortality rate of 36.3%, and the RF model had greater predictive ability for the 30-day mortality risk of sepsis patients. Conclusion: The RF model facilitated the identification of sepsis patients and showed greater accuracy in predicting the 30-day mortality risk of sepsis patients.