Background . The role of miR‐223‐3p in dendritic cells (DCs) is unknown. This study is aimed at investigating the effect of miR‐223‐3p on the antigen uptake and presentation capacities of DCs and the underlying molecular mechanism. Methods . FITC‐OVA antigen uptake and cell surface markers in bone marrow‐derived DCs (BMDCs) were analyzed by flow cytometry. BMDCs were transfected with the miR‐223‐3p mimic or inhibitor. Cytokine levels were determined by ELISA. CD4+ T cell differentiation was determined by mixed lymphocyte culture assay. Results . OVA treatment significantly downregulated miR‐223‐3p in BMDCs. The miR‐223‐3p mimic significantly inhibited OVA‐induced antigen uptake and surface expression of MHC‐II on BMDCs ( P < 0.01). The miR‐223‐3p mimic increased TGF‐ β 1 production in OVA‐treated DCs ( P < 0.01). Mixed lymphocyte reaction showed that the miR‐223‐3p mimic significantly promoted Treg cell differentiation. In addition, the miR‐223‐3p mimic significantly upregulated CD103 in DCs, indicating the promotion of tolerogenic DCs. The miR‐223‐3p mimic downregulated Rhob protein in OVA‐induced DCs. Rhob knockdown significantly suppressed the ability of FITC‐OVA endocytosis ( P < 0.01) and surface MHC‐II molecule expression ( P < 0.01) in BMDCs, promoting promoted Treg cell differentiation. Mannose receptor (MR) knockdown significantly upregulated miR‐223‐3p, downregulated Rhob protein in OVA‐treated DCs, inhibited the FITC‐OVA endocytosis and surface MHC‐II expression in BMDCs, and promoted Treg cell differentiation (all P < 0.01). Conclusion . These data suggest that miR‐223‐3p has an inhibitory effect on the antigen uptake and presentation capacities of BMDCs and promotes Treg cell differentiation, which is, at least partially, through targeting MR signaling and Rhob.

Original Article Hesperetin ameliorates glioblastoma by inhibiting proliferation, inducing apoptosis, and suppressing metastasis Qian Cheng, Lianzhi Mao, Hongxiang Huang, Longguang Tang, Hongyan Jiang, Yufei Zhang, Qingchun Mu

Background: MiR-146a has been shown to negatively regulate innate immune, inflammatory response and antiviral pathway, however, its role in the tolerogenic responses remains largely unknown. This study aimed to investigate the role of miR-146a in the OVA-induced allergic inflammation of dendritic cells (DCs). Methods: Bone marrow-derived DCs (BMDCs) were treated with OVA (100 µg/ml) for 24 h. MiR-146a expressions were assessed by quantitative RT-PCR. BMDCs were transfected with miR-146a mimics or inhibitor. Cell surface markers were analyzed by flow cytometry. Cytokine levels were determined by ELISA assay. Mixed lymphocyte culture assay was adopted to assess CD4 + T-cell differentiation. The 3ʹ UTR luciferase reporter assay was utilized to determine the miRNA target sequence. Results: OVA treatment significantly up-regulated miR-146a in BMDCs in a dose- and time-dependent manner. In the OVA-treated DCs, overexpression of miR-146a (mimics transfection) down-regulated the surface markers (CD80, CD86) and increased production of anti-inflammatory cytokines TGF-β1 and IL-10 but decreased pro-inflammatory cytokine IL-12. MiR-146a overexpression promoted immature DC to induce regulatory T cells (Treg) differentiation. By contrast, transfection of miR-146a inhibitor into DC exhibited the opposite trends. Notch1 was a direct target of miR-146a, and Notch1 knock-down induced similar effects as miR-146a mimics transfection in BMDCs. Moreover, the effect of miR-146a inhibitor on OVA-induced DC was attenuated by Notch1 knock-down. Conclusion: miRNA-146a promoted tolerogenic properties of DCs, at least partially, through targeting Notch1 signaling.

Symptoms of coronavirus disease 2019 (COVID-19) range from asymptomatic to severe pneumonia and death. A deep understanding of the variation of biological characteristics in severe COVID-19 patients is crucial for the detection of individuals at high risk of critical condition for the clinical management of the disease. Herein, by profiling the gene expression spectrum deduced from DNA coverage in regions surrounding transcriptional start site in plasma cell-free DNA (cfDNA) of COVID-19 patients, we deciphered the altered biological processes in the severe cases and demonstrated the feasibility of cfDNA in measuring the COVID-19 progression. The up- and downregulated genes in the plasma of severe patient were found to be closely related to the biological processes and functions affected by COVID-19 progression. More importantly, with the analysis of transcriptome data of blood cells and lung cells from control group and cases with severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection, we revealed that the upregulated genes were predominantly involved in the viral and antiviral activity in blood cells, reflecting the intense viral replication and the active reaction of immune system in the severe patients. Pathway analysis of downregulated genes in plasma DNA and lung cells also demonstrated the diminished adenosine triphosphate synthesis function in lung cells, which was evidenced to correlate with the severe COVID-19 symptoms, such as a cytokine storm and acute respiratory distress. Overall, this study revealed tissue involvement, provided insights into the mechanism of COVID-19 progression, and highlighted the utility of cfDNA as a noninvasive biomarker for disease severity inspections.