Astrocyte-derived extracellular vesicles inhibit the abnormal activation of immune function in neonatal mice with hypoxic-ischemic brain damage by carrying miR-124-3p.

OBJECTIVE: Hypoxic-ischemic brain damage (HIBD) is among the leading causes of neonatal death worldwide. miR-124-3p can be utilized as a potential diagnostic and prognostic biomarker for perinatal asphyxia and HI encephalopathy in newborns. This study investigated the protective effect and mechanism of miR-124-3p in astrocyte-derived extracellular vesicles (ADEVs) in HIBD. METHODS: The neonatal mouse model of HIBD was established. Astrocytes were transfected with the miR-124-3p inhibitor, followed by isolation and identification of ADEVs (ADEVs + inhi miR). HIBD mice were injected with ADEVs or ADEVs + inhi miR through the lateral ventricle, and neurological function was evaluated based on the modified neurological severity score (mNSS). The infarct volume of mice and the morphological modifications of neurons were observed by TTC staining and hematoxylin-eosin staining. The contents of SOD, GSH-Px, CAT, and MDA in the hippocampus were measured. The neuronal apoptosis, the activation of MPO+ neutrophils, NK cells, and CD3+ cells in CA1 region of the hippocampus was determined by means of TUNEL staining and immunofluorescence. RESULTS: ADEVs alleviated HIBD in neonatal mice. ADEVs could intrinsically protect mice from HIBD by reducing oxidative stress and apoptosis in hippocampal tissue. ADEVs inhibited the positive expression of MPO+ neutrophils, NK cells, and CD3+ cells in HIBD neonatal mice. ADEVs inhibited the hippocampal immune cells by delivering miR-124-3p in neonatal HIBD mice. CONCLUSION: ADEVs can inhibit the abnormal activation of immune function in HIBD by delivering miR-124-3p, thereby eliciting a protective effect on brain damage in neonatal mice.

Clinical and psychological status analysis of children and parents infected with familial aggregation omicron variant in Shanghai in parent-child ward.

Aims: To analyze the clinical characteristics, treatment outcomes and sleep psychological problems of children and parents infected with familial aggregation Omicron variants under a parent-child ward treatment mode to provide a theoretical reference for the diagnosis and comprehensive treatment of Omicron variant strains. Methods: The clinical data of 225 children and 230 adult family members admitted were retrospectively collected and analyzed to investigate their clinical characteristics and response to treatments. Results: The proportion of infected adults and children was the same, and the proportion of children with mild disease was higher than that of adults, but the clinical symptoms were milder. The clinical symptoms of fever, nausea, vomiting and wheezing in children were significantly higher than in adults (P < 0.05). In addition, dry pharynx, pharynx itching and pharyngeal pain were lower than in adults (P < 0.05). The time of turning negative in the moderate group was longer than in the mild group, and the time of turning negative in the unvaccinated group was higher than in the vaccinated group (P < 0.05). The Cycle Threshold Value (Ct value) of Open Reading Frame 1ab (ORF1ab) and Nucleocapsid protein (N) gene of children were higher adults. The increase in the rate of Ct value of ORF1ab and N gene in adults treated with Traditional Chinese Medicine (TCM) was significantly higher than in those who underwent symptomatic treatment (P < 0.01). Based on the Children's Sleep Habits Questionnaire (CSHQ)score, we found varying levels of sleep problems in sleeping habits, latency and anxiety, night awakenings and abnormal sleep at all ages (P < 0.05). In the adult group, those with Self-Rating Scale of Sleep (SRSS) scores ≥3 accounted for more than 50% of adults with insomnia, sleep deprivation, sleep instability and early awakening. The proportion of adults with anxiety and depression was 21.3% and 16.4%. Conclusion: Infections in children and adults during this pandemic were mainly associated with familial aggregation infections, and their clinical symptoms were mainly located in the upper respiratory tract. With comprehensive treatment, children became negative faster, vaccination led to faster recovery, and although some patients experienced sleeping and psychological issues, all patients had good prognoses following comprehensive diagnosis under a parent-child ward treatment mode.

[Clinical features of children and their family members with family clusters of SARS-CoV-2 Omicron variant infection in Shanghai, China: an analysis of 380 cases]. / 上海380例家庭聚集性感染Omicronå˜å¼‚æ ªçš„å„¿ç«¥åŠå ¶å®¶å±žä¸´åºŠç‰¹å¾åˆ†æž.

OBJECTIVES: To study the clinical features and prognosis of children and their family members with family clusters of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infection under the admission mode of parent-child ward. METHODS: A retrospective analysis was performed on the medical data of 190 children and 190 family members with SARS-CoV-2 Omicron variant infection who were admitted to Shanghai Sixth People's Hospital, the designated hospital for coronavirus disease 2019 (COVID-19), April 8 to May 10, 2022. RESULTS: Both the child and adult groups were mainly mild COVID-19, and the proportion of mild cases in the child group was higher than that in the adult group (P<0.05). Respiratory symptoms were the main clinical manifestations in both groups. Compared with the adult group, the child group had higher incidence rates of fever, abdominal pain, diarrhea, and wheezing (P<0.05) and lower incidence rates of nasal obstruction, runny nose, cough, dry throat, throat itching, and throat pain (P<0.05). Compared with the child group, the adult group had higher rates of use of Chinese patent drugs, traditional Chinese medicine decoction, recombinant interferon spray, cough-relieving and phlegm-eliminating drugs, and nirmatrelvir/ritonavir tablets (P<0.05). Compared with the adult group, the child group had a lower vaccination rate of SARS-CoV-2 vaccine (30.5% vs 71.1%, P<0.001) and a shorter duration of positive SARS-CoV-2 nucleic acid (P<0.05). The patients with mild COVID-19 had a shorter duration of positive SARS-CoV-2 nucleic acid than those with common COVID-19 in both groups (P<0.05). The patients with underlying diseases had a longer duration of positive SARS-CoV-2 nucleic acid than those without such diseases in both groups (P<0.05). CONCLUSIONS: Both children and adults with family clusters of SARS-CoV-2 Omicron variant infection manifest mainly mild COVID-19. Despite lower vaccination rate of SARS-CoV-2 vaccine in children, they have rapid disease recovery, with a shorter duration of positive SARS-CoV-2 nucleic acid than adults, under the admission mode of parent-child ward.

An Antigen-Presenting and Apoptosis-Inducing Polymer Microparticle Prolongs Alloskin Graft Survival by Selectively and Markedly Depleting Alloreactive CD8+ T Cells.

Selectively depleting the pathogenic T cells is a fundamental strategy for the treatment of allograft rejection and autoimmune disease since it retains the overall immune function of host. The concept of killer artificial antigen-presenting cells (KaAPCs) has been developed by co-coupling peptide-major histocompatibility complex (pMHC) multimer and anti-Fas monoclonal antibody (mAb) onto the polymeric microparticles (MPs) to induce the apoptosis of antigen-specific T cells. But little information is available about its in vivo therapeutic potential and mechanism. In this study, polyethylenimine (PEI)-coated poly lactic-co-glycolic acid microparticle (PLGA MP) was fabricated as a cell-sized scaffold to covalently co-couple H-2Kb-Ig dimer and anti-Fas mAb for the generation of alloantigen-presenting and apoptosis-inducing MPs. Intravenous infusions of the biodegradable KaAPCs prolonged the alloskin graft survival for 43 days in a single MHC-mismatched murine model, depleted the most of H-2Kb-alloreactive CD8+ T cells in peripheral blood, spleen, and alloskin graft in an antigen-specific manner and anti-Fas-dependent fashion. The cell-sized KaAPCs circulated throughout vasculature into liver, kidney, spleen, lymph nodes, lung, and heart, but few ones into local allograft at early stage, with a retention time up to 36 h in vivo. They colocalized with CD8+ T cells in secondary lymphoid organs while few ones contacted with CD4+ T cells, B cells, macrophage, and dendritic cells, or internalized by phagocytes. Importantly, the KaAPC treatment did not significantly impair the native T cell repertoire or non-pathogenic immune cells, did not obviously suppress the overall immune function of host, and did not lead to visible organ toxicity. Our results strongly document the high potential of PLGA MP-based KaAPCs as a novel antigen-specific immunotherapy for allograft rejection and autoimmune disorder. The in vivo mechanism of alloinhibition, tissue distribution, and biosafety were also initially characterized, which will facilitate its translational studies from bench to bedside.

A biodegradable killer microparticle to selectively deplete antigen-specific T cells in vitro and in vivo.

The specific eradication of pathogenic T cells for the treatment of allograft rejections and autoimmune disorders without impairment of overall immune function is a fundamental goal. Here, cell-sized poly(lactic-co-glycolic acid) microparticles (PLGA MPs) were prepared as a scaffold to co-display the peptide/major histocompatibility complex (pMHC, target antigen) and anti-Fas monoclonal antibody (apoptosis-inducing molecule) for the generation of biodegradable killer MPs. Ovalbumin (OVA) antigen-targeted killer MPs significantly depleted OVA-specific CD8+ T cells in an antigen-specific manner, both in vitro and in OT-1 mice. After intravenous administration, the killer MPs predominantly accumulated in the liver, lungs, and gut of OT-1 mice with a retention time of up to 48 hours. The killing effects exerted by killer MPs persisted for 4 days after two injections. Moreover, the H-2Kb alloantigen-targeted killer MPs were able to eliminate low-frequency alloreactive T cells and prolong alloskin graft survival for 41.5 days in bm1 mice. Our data indicate that PLGA-based killer MPs are capable of specifically depleting pathogenic T cells, which highlights their therapeutic potential for treating allograft rejection and autoimmune disorders.

Antigen-specific killer polylactic-co-glycolic acid (PLGA) microspheres can prolong alloskin graft survival in a murine model.

BACKGROUND: The strategy of specifically depleting antigen-specific T cells can potentially be used for the treatment of allograft rejection and autoimmunity because it does not suppress the overall immune systems. METHODS: In this study, we generated killer polylactic-co-glycolic acid (PLGA) microspheres by covalently coupling major histocompatibility complex (MHC) class I antigens and apoptosis-inducing anti-Fas monoclonal antibody (mAb) onto PLGA microspheres. A modified double-emulsion method was used for the preparation of cell-sized PLGA microspheres. H-2K(b)/peptide monomers were generated in-house and analyzed through flow cytometry. The killer PLGA microspheres were administered intravenously into BALB/c mice (H-2K(d)) that had previously been grafted with skin squares from C57BL/6 mice (H-2K(b)). Tumor cell challenge and third-party mixed lymphocyte culture were used to assess the general immune functions of host. RESULTS: The alloskin graft survival was prolonged by 4 days. The killer PLGA microspheres could specifically deplete the H-2K(b) alloantigen-reactive CD8(+) T cells that infiltrated into the alloskin graft but not CD4(+) T cells, without impairment of host overall immune function. CONCLUSIONS: Here, we initially report that PLGA microspheres, which have been widely used as medicine-delivering carriers, were used to prepare antigen-specific killer complexes and treat allograft rejection. Our data highlight the therapeutic potential of this biocompatible and biodegradable antigen-specific killer effector for the treatment of allograft rejection and autoimmune disease.