Concomitant inhibition of PPARγ and mTORC1 induces the differentiation of human monocytes into highly immunogenic dendritic cells

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Production of tetravalent dengue virus envelope protein domain III based antigens in lettuce chloroplasts and immunologic analysis for future oral vaccine development

Dengue fever is a mosquito (Aedes aegypti) ‐transmitted viral disease that is endemic in more than 125 countries around the world. There are four serotypes of the dengue virus (DENV 1‐4) and a safe and effective dengue vaccine must provide protection against all four serotypes. To date, the first vaccine, Dengvaxia (CYD‐TDV), is available after many decades’ efforts, but only has moderate efficacy. More effective and affordable vaccines are hence required. Plants offer promising vaccine production platforms and food crops offer additional advantages for the production of edible human and animal vaccines, thus eliminating the need for expensive fermentation, purification, cold storage and sterile delivery. Oral vaccines can elicit humoural and cellular immunity via both the mucosal and humoral immune systems. Here, we report the production of tetravalent EDIII antigen (EDIII‐1‐4) in stably transformed lettuce chloroplasts. Transplastomic EDIII‐1‐4‐expressing lettuce lines were obtained and homoplasmy was verified by Southern blot analysis. Expression of EDIII‐1‐4 antigens was demonstrated by immunoblotting, with the EDIII‐1‐4 antigen accumulating to 3.45% of the total protein content. Immunological assays in rabbits showed immunogenicity of EDIII‐1‐4. Our in vitro gastrointestinal digestion analysis revealed that EDIII‐1‐4 antigens are well protected when passing through the oral and gastric digestion phases but underwent degradation during the intestinal phase. Our results demonstrate that lettuce chloroplast engineering is a promising approach for future production of an affordable oral dengue vaccine.     

碱性羟胺、弱碱和乙酸水解奇异变形杆菌LPS抗原及其活性的影响

采用碱性羟胺、弱碱、乙酸水解奇异变形杆菌LPS抗原,研究不同方式对小鼠活性的影响。检测结果表明,与水解前对比三种方式均能降低LPS抗原内毒素含量,即从2 500×104EU/mL降低至(250~2.5)×104EU/mL;热源性检测表明对家兔体温几乎无影响;但免疫原性结果表明ED50 LPSED50 Acid-LPS+Al(OH)3ED50 Alkaline-LPS+Al(OH)ED350 HA-LPS+Al(OH),3毒性结果为LD50 HA-LPSLD50 Alkaline-LPSLD50 LPSLD50 Acid-LPS。因此,经过乙酸(体积分数2%)或0.1 mol/L弱碱(体积分数2%)水解,能够显著降低内毒素含量及热源性,并保持其生物活性,使之成为有效的候选疫苗组分,用于预防或治疗大面积烧伤及术前或术后感染。     

碳离子辐射诱导的远隔效应

放射治疗诱导的远隔效应能够抑制非辐射区域内肿瘤的生长，目前已有临床和临床前研究表明，常规放疗射线（X射线、γ射线）能够诱导远隔效应的发生，但是对于其发生的机理以及碳离子诱导的远隔效应研究较少。与常规放疗射线相比，碳离子束具有高传能线密度、高相对生物效应、低氧增强比以及复杂DNA损伤等优势，并且具有激活肿瘤细胞更强免疫原性的潜力。本文综述了常规放疗以及碳离子放射治疗诱导的远隔效应及其机理，为寻找更有效的癌症放疗方法提供参考。     

A randomised double-blind clinical trial of two yellow fever vaccines prepared with substrains 17DD and 17D-213/77 in children nine-23 months old

This randomised, double-blind, multicentre study with children nine-23 months old evaluated the immunogenicity of yellow fever (YF) vaccines prepared with substrains 17DD and 17D-213/77. YF antibodies were tittered before and 30 or more days after vaccination. Seropositivity and seroconversion were analysed according to the maternal serological status and the collaborating centre. A total of 1,966 children were randomised in the municipalities of the states of Mato Grosso do Sul, Minas Gerais and São Paulo and blood samples were collected from 1,714 mothers. Seropositivity was observed in 78.6% of mothers and 8.9% of children before vaccination. After vaccination, seropositivity rates of 81.9% and 83.2%, seroconversion rates of 84.8% and 85.8% and rates of a four-fold increase over the pre-vaccination titre of 77.6% and 81.8% were observed in the 17D-213/77 and 17DD subgroups, respectively. There was no association with maternal immunity. Among children aged 12 months or older, the seroconversion rates of 69% were associated with concomitant vaccination against measles, mumps and rubella. The data were not conclusive regarding the interference of maternal immunity in the immune response to the YF vaccine, but they suggest interference from other vaccines. The failures in seroconversion after vaccination support the recommendation of a booster dose in children within 10 years of the first dose.     

Anxa2- and Ctsd-knockout CHO cell lines to diminish the risk of contamination with host cell proteins

Chinese hamster ovary (CHO) cells have been used as host cells in the production of a range of recombinant therapeutic proteins, including monoclonal antibodies and Fc-fusion proteins. Host cell proteins (HCP) represent impurities that must be removed from therapeutic formulations because of their potential risks for immunogenicity. While the majority of HCP impurities are effectively removed in typical downstream purification processes, clearance of a small population of HCP remains challenging. In this study, we knocked out the Anxa2 and Ctsd genes to assess the feasibility of knockout approaches for diminishing the risk of contamination with HCP. Using the CRISPR/Cas9 system, Anxa2-, and Ctsd-knockout CHO cell lines were successfully established, and we confirmed the complete elimination of the corresponding HCP in cell lysates. Importantly, all knockout cell lines showed similar growth and viability to those of the wild-type control during 8 days of cultivation. Thus, knockout of unrequired genes can reduce contamination with HCP in the production of recombinant therapeutic proteins.