BACKGROUND: Regulatory dendritic cell (DCreg) subset exhibits a unique capacity for inducing immune tolerance among the variety subsets of dendritic cells (DCs) within gut-associated lymphoid tissues (GALTs). Fms-like tyrosine kinase 3 ligand (FLT3L) is involved in the differentiation of DCregs and the subsequent expansion of regulatory T-cells (Tregs) mediated by DCregs, though the precise mechanism remains poorly understood. This study aimed to explore the expansion mechanism of Treg induced by DCreg and the role of FLT3L in this process. METHODS: DCregs were distinguished from other DC subsets isolated from GALTs of BALB/c mice through a mixed lymphocyte reaction assay. The functions and mechanisms by which FLT3L promoted Treg expansion via DCregs were investigated in vitro through co-culture experiments involving DCregs and either CD4 + CD25 - T-cells or CD4 + CD25 + T-cells. Additionally, an in vivo experiment was conducted using a dextran sulfate sodium (DSS)-induced colitis model in mice. RESULTS: CD103 + CD11b + DC exhibited DCreg-like functionality and was identified as DCreg for subsequent investigation. Analysis of Foxp3 + Treg percentages within a co-culture system of CD4 + CD25 - T-cells and DCregs, with or without FLT3L, demonstrated the involvement of the FLT3/FLT3L axis in driving the differentiation of precursor T-cells into Foxp3 + Tregs induced by DCregs. Cell migration and co-culture assays revealed that the FLT3/FLT3L axis enhanced DCreg migration toward Tregs via the Rho pathway. Additionally, it was observed that DCregs could promote Treg proliferation through the Notch pathway, as inhibition of Notch signaling by DAPT (N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester) suppressed Treg expansion within the co-culture system of DCregs and CD4 + T-cells or CD4 + CD25 + T-cells. Furthermore, the FLT3/FLT3L axis influenced JAG1 expression in DCregs, indirectly modulating Treg expansion. In vivo experiments further established that FLT3L promoted DCreg expansion and restored Treg balance in DSS-induced colitis models, thereby ameliorating colitis symptoms in mice. CONCLUSION The FLT3/FLT3L axis is integral to the maintenance of DCreg function in Treg expansion.
Animals ; T-Lymphocytes, Regulatory/immunology* ; Dendritic Cells/immunology* ; Mice ; Mice, Inbred BALB C ; Membrane Proteins/metabolism* ; Receptors, Notch/metabolism* ; Lymphoid Tissue/metabolism* ; Signal Transduction/physiology* ; Coculture Techniques ; Flow Cytometry

OBJECTIVE: To design and construct a graphene oxide (GO)/silver nitrate (Ag₃PO₄)/chitosan (CS) composite coating for rapidly killing bacteria and preventing postoperative infection in implant surgery. METHODS: GO/Ag₃PO₄ composites were prepared by ion exchange method, and CS and GO/Ag₃PO₄ composites were deposited on medical titanium (Ti) sheets successively. The morphology, physical image, photothermal and photocatalytic ability, antibacterial ability, and adhesion to the matrix of the materials were characterized. RESULTS: The GO/Ag₃PO₄ composites were successfully prepared by ion exchange method and the heterogeneous structure of GO/Ag₃PO₄ was proved by morphology phase test. The heterogeneous structure formed by Ag₃PO₄ and GO reduced the band gap from 1.79 eV to 1.39 eV which could be excited by 808 nm near-infrared light. The photothermal and photocatalytic experiments proved that the GO/Ag₃PO₄/CS coating had excellent photothermal and photodynamic properties. In vitro antibacterial experiments showed that the antibacterial rate of the GO/Ag₃PO₄/CS composite coating against Staphylococcus aureus reached 99.81% after 20 minutes irradiation with 808 nm near-infrared light. At the same time, the composite coating had excellent light stability, which could provide stable and sustained antibacterial effect. CONCLUSION GO/Ag₃PO₄/CS coating can be excited by 808 nm near infrared light to produce reactive oxygen species, which has excellent antibacterial activity under light.
Chitosan ; Silver Nitrate ; Titanium ; Anti-Bacterial Agents/pharmacology* ; Coloring Agents

background The lead isotope ratios (LIR) differ among different sourced samples. Previous domestic and oversea studies on source tracing by LIR in human blood or urine mainly focused on the comparison of blood or urine samples from the same or different individuals, while few comparisons between biological and environmental samples, and the reported relative standard deviations (RSDs) of the main LIR (^207/206Pb and ^208/206Pb) fluctuate widely from 0.3% to 1%. Objective To optimize inductively coupled plasma mass spectrometry (ICP-MS), obtain a better RSD, and determine LIRs of human blood, urine, and related environmental samples. Methods The ICP-MS was optimized for operating conditions and parameters according to the sensitivity and RSD of LIR. The study subjects were 40 lead-exposed workers in a lead-acid battery factory and 2 lead poisoned children in a hospital. The samples included 40 blood and 40 urine samples from the workers before shift, 4 dust samples and 2 water samples in the workplace on the same day before shift, 2 blood and 3 urine samples from the children before hospital admission due to lead-poisoning, and 4 urine samples after medical treatment. After heating and acid digestion, the LIR (^207/206Pb and ^208/206Pb) of biological and environmental samples were determined by the optimized ICP-MS method. t-test and two-dimensional traceability graphics were adopted to analyze the detection results. Results The calibrated RSDs of the LIR (^207/206Pb and ^208/206Pb) of lead isotope standard solution were 0.11% and 0.08% respectively, and the NIST-SRM-981 actual values were 0.91531±0.00097 and 2.1670±0.0017, respectively. When the total concentration of lead was greater than 5 μg·L⁻¹, the RSD of each isotope ratio was stable gradually; when the total concentration of lead was between 10-80 μg·L⁻¹, the RSD was below 0.20%. There were statistically significant differences in the blood and urine LIR (^207/206Pb and ^208/206Pb) of the lead-exposed workers (t=5.831, P<0.001; t=21.021, P<0.001), the LIR (^207/206Pb and ^208/206Pb) between workplace dust samples and workers’ urine samples (t=−6.879, P=0.038; t=12.521, P<0.001), and the ^208/206Pb between workplace dust samples and workers’ blood samples (t=−10.46, P<0.001), except the ^207/206Pb between workplace dust samples and workers’ blood samples (t=−0.12, P=0.912). In the patients afflicted with lead poisoning, the projection points of LIR of blood and urine samples from the same individual were not at the same level in the two-dimensional model, nor was the LIR of urine samples before and after medical treatment of the same individual. Conclusion The optimized ICP-MS can control the RSD of main LIR (^207/206Pb and ^208/206Pb) below 0.20%. There are differences in the LIR distributions of different samples.

OBJECTIVE: To investigate the changes in diversity, relative abundance and distribution of intestinal flora in patients with chronic rhinosinusitis and nasal polyps (CRSwNP) using high-throughput sequencing technology identify the intestinal flora significantly related to pathogenesis and progression of CRSwNP. METHODS: Ten patients with CRSwNP hospitalized in the Department of Otolaryngology-Head and Neck Surgery of Guangdong Provincial People's Hospital were selected as the case group with 10 healthy volunteers recruited in the same period as the control group. Fecal genomic DNA extraction kit was used to extract the DNA in the fecal samples, and the DNA fragment length was measured and quantified. The V3 and V4 highly variable regions of the 16S rDNA gene of prokaryotes were amplified followed by library construction, Illumina MiSeq sequencing, sequence alignment and species identification analysis. The relative abundance, diversity and distribution characteristics of the intestinal flora were analyzed, and the relevant metabolic pathways were predicted. RESULTS: Compared with the control group, the patients with CRSwNP had significant changes in the overall structure of the intestinal flora, highlighted by increased abundance of Saccharopolyspora and decreased contents of , , and . Among the metabolic pathways predicted to be associated with CRSwNP, 9 showed significant changes in patients with CRSwNP as compared with the control group ( < 0.05). CONCLUSIONS Patients with CRSwNP have significant changes in the structural characteristics of intestinal flora related with multiple metabolic pathways, and these changes may play an important role in the development of chronic rhinosinusitis.

Objective:To study the effect of immune regulation of the rat Leydig cells in testis infection.Methods:UU was injected into the bladders of rats,which mimics the ascending infection pathway,while using culture medium injection as control.After 1,2,3 w respectively,the rats were sacrificed to observe the pathological alterations in testis by histological examination.Leydig cell were also separated from testis,the comparation of levels of IL-1,IL-6,TGF-?,Fas and FasL mRNA expression among control and UU infected groups was made by RT-PCR.Results:Compared with control,in UU infected group,the levels of IL-1,IL-6,TGF-? increased,the level of Fas decreased,the level of FasL increased.Conclusion:Leydig cell can play the role of immune regulation,with the expressing changes of IL-1,IL-6,TGF-?,Fas and FasL in the infection of testis in rat.