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 explore the therapeutic effect of human umbilical cord-derived mesenchymal stem cells(hUC-MSCs)in mouse model of allergic lung inflammation.METHODS hUC-MSCs were isolated and cultured from umbilical cord of healthy neonates.The expression of MSC cell surface markers were assessed by flow cytometry in the fifth generation of hUC-MSCs.Mice were sensitized by intraperitoneal injection of ovalbumin and challenged via inhalation of aerosolized ovalbumin to establish an allergic airway inflammation model.The same dose of normal saline was used in the control group.After 14 days of nebulization,lung tissues and bronchoalveolar lavage fluid(BALF)were collected from the mice.Hematoxylin and eosin staining and Luminex multiplex assay were performed to assess the levels of allergic inflammation.Lung tissues were minced,homogenized,and digested into single-cell suspensions for cell culture.hUC-MSCs or human nasal epithelial cells were co-cultured with mouse lung cells at a ratio of 1:5 or 1:10(cell number ratio).After 18 hours,the supernatants were collected,and Luminex multiplex assay was performed to assess the expression of inflammatory cytokines interleukin-5(IL-5)and IL-6.RESULTS Cultured hUC-MSCs showed an elongated spindle-shaped morphology.The positive markers CD105,CD73,and CD90 showed positive rates of>95%respectively,while the negative markers CD45,CD34,and CD11b exhibited positive rates of<2%respectively.Compared with the controls,the allergic mice showed significant infiltration of eosinophils in the peribronchial regions of lung tissues,and increased expression levels of IL-5(P<0.01)and IL-6(P<0.05)in BALF.Compared with the control group,mouse lung cells co-cultured with hUC-MSCs significantly decreased the levels of IL-5 and IL-6 in the supernatant(both P<0.05 in 1∶5 group and 1∶10 group).CONCLUSION Co-culture with hUC-MSCs can significantly ameliorate allergic inflammation in lung tissue of mouse model,indicating the therapeutic potential of hUC-MSCs in airway allergic inflammation.

Objective　To explore the effect of Mp1p on host macrophages through transcriptomics combined with metabolomics. Methods Firstly, a THP-1 macrophage strain (THP-1-Mp1p+) stably expressing Mp1p was constructed using lentivirus. Secondly, using high-throughput RNA sequencing (RNA Seq) technology, the expression level of intracellular mRNA was detected in transcriptomics analysis to determine differentially expressed genes; In metabolomics analysis, metabolite identification was performed through database comparison, and pathway analysis was performed on differential metabolites to reveal potential mechanisms of action. Finally, the results of metabolomics and transcriptomics were combined for analysis, and differential metabolites and genes were analyzed to further elucidate the mechanism of action of Mp1p on macrophages. Results Transcriptome analysis showed that, compared with the negative control group, the THP-1-Mp1p+ group had a total of 1 180 differentially expressed genes (DEGs), with 345 upregulated genes and 835 downregulated genes. GO enrichment analysis of DEGs showed that there were 135 differentially expressed genes, including 105 in biological processes (BP), 28 in cellular components (CC), and 2 in molecular functions (MF). The KEGG analysis results showed that the effect of Mp1p on THP-1 macrophages was highly correlated with the TNF pathway. The metabolomic analysis found that both the blank control group and the THP-1-Mp1p+ macrophage group achieved good separation between QC samples in both positive and negative ion modes. The threshold for significant differential metabolites was set at: VIP≥1 and T-test P<0.05, resulting in the identification of 488 differential metabolites, with 230 in the positive ion mode and 258 in the negative ion mode. Pathway enrichment analysis of the identified metabolites pointed to significant enrichment in metabolic pathways. The combined analysis confirmed that the tumor necrosis factor signaling pathway, interleukin-17 signaling pathway, and NF-kappaB signaling pathway were important metabolic pathways involved. Conclusions The virulence factor Mp1p may affect host macrophages by modulating the tumor necrosis factor signaling pathway, interleukin-17 signaling pathway, and NF-kappaB signaling pathway. The findings contribute to a better understanding of the mechanisms of action of Mp1p and may offer potential directions for the selection of relevant diagnostic and therapeutic targets in the future.

Objectives:Fenofibric acid is extracted from the widely used hypolipemic fenofibrate,nowadays being approved for marketing around numerous nations and regions,nonetheless not in China.Present trial evaluated the efficacy and safety in the Chinese hypertriglyceridemia population. Methods:This is a multi-center,randomized,double-blind,placebo-controlled phase Ⅲ clinical trial.Patients from 3 different cohorts,including severe hypertriglyceridemia(HTG),moderate HTG and mixed-dyslipidemia(MD),were randomized at 1:1 ratio to receive fenofibric acid 135 mg or placebo daily for 12 weeks.The primary endpoint was the percentage change of triglyceridemia(TG)from baseline at week 12.Secondary endpoints were the percentage changes of other blood lipid indexes.At the same time,the incidence of medical adverse events was observed. Results:Among the three cohorts of patients with severe HTG(n=52),moderate HTG(n=23)and MD(n=52),the TG levels in the fenofibric acid-treated group decreased by(49.12±29.19)%,(49.95±25.19)%and(49.79±19.28)%,respectively from baseline to 12 weeks,while the corresponding placebo groups decreased by(18.88±40.69)%,(8.11±29.86)%and increased by(10.42±73.04)%,respectively from baseline to 12 weeks.The differences between treatment and placebo groups were statistically significant(P<0.017 for severe HTG cohort,P<0.05 for moderate and MD cohort).The high-density lipoprotein cholesterol(HDL-C)in the fenofibric acid-treated group increased by(25.51±21.45)%,(24.55±24.73)%,and(23.60±27.38)%,and the placebo group increased by(1.91±20.42)%,(2.40±9.32)%and(7.13±19.12)%,respectively,the differences between the two groups were statistically significant(all P<0.05).In the fenofibric acid group,adverse events with incidence>5%included upper respiratory tract infection(10.9%),abdominal pain(6.3%),and increased serum creatinine levels(6.3%),rates of adverse events were similar between the two groups(P>0.05). Conclusions:Fenofibric acid can significantly reduce triglycerides and elevate HDL-C levels safely in Chinese patients with severe to moderate HTG without statin or MD patients on top of statin therapy.

Objective:To explore the ability of sequential immunization regimen inducing neutralizing antibodies against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) Wuhan-Hu1 and Omicron variants in mice.Methods:Groups of 6-8-week-old BALB/c mice were primed with two doses of Wuhan-Hu-1 inactivated vaccine, and then boosted with Omicron or Wuhan-Hu-1 inactivated vaccine, respectively. Binding antibodies were tested by enzyme linked immunosorbent assay; and neutralizing antibodies against Wuhan-Hu1 and Omicron variants were analyzed by vesicular stomatitis virus pseudovirus assay system; SARS-CoV-2 specific cellular immune responses were quantified by enzyme-linked immunosorbent spot assay.Results:IgG antibodies against Wuhan-Hu1, Delta and Omicron RBD were enhanced after the second dose of Wuhan-Hu1 inactivated vaccine. Compared with Wuhan-Hu1 inactivated vaccine, the group boosted with Omicron inactivated vaccine improved Wu-RBD and Omic-RBD specific IgG antibodies 1.41 and 1.26 times, and serum neutralizing antibodies against BA.1, BA.2, BA.4/5 and BF.7 were elevated 4.5, 3.4, 12.1 and 6.5 folds, respectively, by sequential immunization. After booster immunization with inactivated Wuhan-Hu1 or Omicron vaccines, Wu-RBD IgA titer was significantly higher than that of one dose inactivated Wuhan-Hu1 vaccine ( P=0.005 7, P=0.006 1). Conclusions:Neutralizing antibodies against Omicron variants were enhanced by sequential immunization with Omicron inactivated vaccine. Specific IgA was significantly enhanced after the third dose of inactivated vaccine.

Objective:To automatically synthesize Al 18F-1, 4, 7-triazacyclononane-1, 4, 7-triacetic acid (NOTA)-fibroblast activation protein inhibitor (FAPI)-04, perform PET/CT imaging in vivo, and evaluate its diagnostic efficacy on tumors. Methods:Al 18F-NOTA-FAPI-04 was produced in All-in-one automatic synthesis module and its quality control was conducted by high performance liquid chromatography (HPLC) equipped with a radioactive detector. Al 18F-NOTA-FAPI-04 PET/CT imaging was performed in normal BALB/c mice ( n=3) and 4T1 breast cancer models ( n=3) to determine its biodistribution. Then Al 18F-NOTA-FAPI-04 and 18F-FDG PET/CT imaging were performed in a hepatocellular carcinoma patient (male, 51 years old). Results:The synthesis time of Al 18F-NOTA-FAPI-04 was about 35 min, and the radiochemical yield was (25.2±1.9)% (attenuation correction, n=3). The product was colorless transparent solution with pH value of 7.0-7.5, and the specific activity was (46.11±3.07) GBq/μmol (attenuation correction, n=3). The radiochemical purity was above 99.0% and was still above 98.0% at room temperature after 6 h. PET/CT imaging in mice showed that physiological uptake of Al 18F-NOTA-FAPI-04 was mainly in biliary system and bladder, and Al 18F-NOTA-FAPI-04 highly concentrated in tumor xenografts. PET/CT imaging in the patient showed that Al 18F-NOTA-FAPI-04 obtained high tumor background ratio (TBR) values of 4.1, 8.9, 5.4, 4.8, 2.2 in parasternal lymph nodes, anterior diaphragmatic lymph nodes, hilar lymph nodes, pancreaticoduodenal ligament lymph nodes, abdominal aortic lymph nodes, respectively, while TBR values were 1.0, 2.8, 5.0, 2.1, 1.1 by 18F-FDG. Conclusions:Al 18F-NOTA-FAPI-04 can be synthesized with short time, high radiochemical yield and good stability using All-in-one module. Al 18F-NOTA-FAPI-04 PET/CT imaging has high contrast and excellent diagnostic efficacy on tumors.

Objective To explore the effect of budesonide suspension for inhalation in the treatment of childhood asthma and its influence on growth and development in 1-2 years. Methods The 68 children with asthma admitted to our hospital from October 2016 to January 2017 were selected. Every patient had acute attacks and received continued medication. 34 patients treated with salbutamol sulfate inhaled aerosol were used as the control group. 34 patients treated with budesonide suspension combined with salbutamol sulfate aerosol were classified as the observation group. The interleukin-6 (IL-6), tumor necrosis factor-α(TNF-α), high-sensitivity-C-reactive protein (hs-CRP), maximum respiratory flow, IS maximum expiratory volume, regulatory B cell ratio, wheezing disappearance time, shortness of breath relief time, wet rales disappearing time, cough disappearing time, and the two year follow-up indicators of growth and development were compared. Results After medication, IL-6, TNF-α, hs-CRP, regulatory B cell ratio, wheezing disappearance time, shortness of breath relief time, moist rales disappearance time, and cough disappearance time were lower in the observation group(P<0.05). The maximum respiratory flow and IS maximum expiratory volume in the observation group were higher than those in the control group (P<0.05). The GH level, height, and weight obtained from two year follow up in the observation group were lower than those in the control group (P<0.05). Conclusion Budesonide suspension combined with salbutamol sulfate aerosol inhalation therapy can alleviate the inflammatory reaction, improve the lung function and immune function of children, and accelerate the disappearance of clinical symptoms, but it will affect the growth and development of children to a certain extent.

Multi-modal therapeutics are emerging for simultaneous diagnosis and treatment of cancer. Polymeric carriers are often employed for loading multiple drugs due to their versatility and controlled release of these drugs in response to a tumor specific microenvironment. A theranostic nanomedicine was designed and prepared by complexing a small gadolinium chelate, conjugating a chemotherapeutic drug PTX through a cathepsin B-responsive linker and covalently bonding a fluorescent probe pheophorbide a (Ppa) with a branched glycopolymer. The branched prodrug-based nanosystem was degradable in the tumor microenvironment with overexpressed cathepsin B, and PTX was simultaneously released to exert its therapeutic effect. The theranostic nanomedicine, branched glycopolymer-PTX-DOTA-Gd, had an extended circulation time, enhanced accumulation in tumors, and excellent biocompatibility with significantly reduced gadolinium ion (Gd

Liver fibrosis can progress to liver cirrhosis and end-stage liver disease, which may lead to poor prognosis. In addition to pathological angiogenesis and hepatic sinusoid remodeling, hepatic lymphangiogenesis also plays an important role in the progression of liver fibrosis. This article briefly describes lymphatic vessel markers and their expression in the liver, introduces the role of lymphangiogenesis in liver fibrosis, and reviews the role of liver macrophages (Kupffer cells) and lymphatic endothelial cells in lymphangiogenesis. It is pointed out lymphangiogenesis may become a potential target for the intervention of liver fibrosis, which plays an important role in the early treatment and reversal of liver fibrosis and the prevention of liver cirrhosis and end-stage liver disease.

Objective To investigate the effectiveness and safety of esophageal covered stent for the treatment of esophagogastric cervical anastomotic fistula. Methods Retrospective analysis of clinical and imaging data of patients with esophageal and gastric anastomotic neck fistula treated by esophageal membrane stent implantation in the Affiliated Tumor Hospital of Zhengzhou University from July 2015 to June 2018. Twenty‐one cases, 15 males and 6 females were enrolled. All patients showed fistula after esophagogastrostomy for esophageal carcinoma. All the fistulas were located in the cervical segment of esophagus and were diagnosed as anastomotic fistula 2 to 13 days after surgery. The length of esophagus residue, the position and size of the fistula were measured by esophagography. We retrospectively analyzed the data of patients with cervical anastomotic fistula treated with esophageal covered stent. Patients were followed up for more than 6 months by review and telephone follow‐up. Results In the 21 patients, 19 (90.5%) were successfully implanted stents at one time, and 2 (9.5%) were placed at a lower position. The esophageal stent was implanted for 10 to 60 days (31±19) days, and the stent was successfully removed after the fistula healed, with a procedure time of 6 to 23 minutes. No recurrence of fistula was found during follow‐up. Four patients had anastomotic scar stenosis, and eating smoothly after balloon dilatation. Conclusion Esophageal covered stent implantation is a safe and effective technique for gastroesophageal cervical anastomotic fistula.