Immunogenicity and protective efficacy of adenoviral and subunit RSV vaccines based on stabilized prefusion F protein in pre-clinical models

Respiratory Syncytial Virus (RSV) remains a leading cause of severe respiratory disease for which no licensed vaccine is available. We have previously described the derivation of an RSV Fusion protein (F) stabilized in its prefusion conformation (preF) as vaccine immunogen and demonstrated superior immunogenicity in naive mice of preF versus wild type RSV F protein, both as protein and when expressed from an Ad26 vaccine vector. Here we address the question if there are qualitative differences between the two vaccine platforms for induction of protective immunity. In naïve mice, both Ad26.RSV.preF and preF protein induced humoral responses, whereas cellular responses were only elicited by Ad26.RSV.preF. In RSV pre-exposed mice, a single dose of either vaccine induced cellular responses and strong humoral responses. Ad26-induced RSV-specific cellular immune responses were detected systemically and locally in the lungs. Both vaccines showed protective efficacy in the cotton rat model, but Ad26.RSV.preF conferred protection at lower virus neutralizing titers in comparison to RSV preF protein. Factors that may contribute to the protective capacity of Ad26.RSV.preF elicited immunity are the induced IgG2a antibodies that are able to engage Fcγ receptors mediating Antibody Dependent Cellular Cytotoxicity (ADCC), and the induction of systemic and lung resident RSV specific CD8 + T cells. These data demonstrate qualitative improvement of immune responses elicited by an adenoviral vector based vaccine encoding the RSV preF antigen compared to the subunit vaccine in small animal models which may inform RSV vaccine development.     

Circulating angiotensin converting enzyme 2 and COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has triggered a widespread outbreak since December 2019. The SARS-CoV-2 infection-related illness has been dubbed the coronavirus disease 2019 (COVID-19) by the World Health Organization. Asymptomatic and subclinical infections, a severe hyper-inflammatory state, and mortality are all examples of clinical signs. After attaching to the angiotensin converting enzyme 2 (ACE2) receptor, the SARS-CoV-2 virus can enter cells through membrane fusion and endocytosis. In addition to enabling viruses to cling to target cells, the connection between the spike protein (S-protein) of SARS-CoV-2 and ACE2 may potentially impair the functionality of ACE2. Blood pressure is controlled by ACE2, which catalyzes the hydrolysis of the active vasoconstrictor octapeptide angiotensin (Ang) II to the heptapeptide Ang-(1-7) and free L-Phe. Additionally, Ang I can be broken down by ACE2 into Ang-(1-9) and metabolized into Ang-(1-7). Numerous studies have demonstrated that circulating ACE2 (cACE2) and Ang-(1-7) have the ability to restore myocardial damage in a variety of cardiovascular diseases and have anti-inflammatory, antioxidant, anti-apoptotic, and anti-cardiomyocyte fibrosis actions. There have been some suggestions for raising ACE2 expression in COVID-19 patients, which might be used as a target for the creation of novel treatment therapies. With regard to this, SARS-CoV-2 is neutralized by soluble recombinant human ACE2 (hrsACE2), which binds the viral S-protein and reduces damage to a variety of organs, including the heart, kidneys, and lungs, by lowering Ang II concentrations and enhancing conversion to Ang-(1-7). This review aims to investigate how the presence of SARS-CoV-2 and cACE2 are related. Additionally, there will be discussion of a number of potential therapeutic approaches to tip the ACE/ACE-2 balance in favor of the ACE-2/Ang-(1-7) axis.     

Role and mechanism of angiotensin-converting enzyme 2 in acute lung injury in coronavirus disease 2019

Coronavirus disease 2019 is a major threat to public health globally. Though its pathogenesis has not been fully elucidated, angiotensin-converting enzyme 2 (ACE2) has been recently identified as a receptor for the entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into the cell. Here, we aimed to clarify the potential role of ACE2 in SARS-CoV-2-induced acute lung injury and its underlying mechanism. As a receptor for coronavirus, ACE2 mediates the entry of SARS-CoV-2 into cells in a similar way as for severe acute respiratory syndrome coronavirus (SARS-CoV). The high binding affinity of SARS-CoV-2 to ACE2 correlates with its efficient spread among humans. On the other hand, ACE2 negatively regulates the renin-angiotensin-aldosterone system (RAAS) primarily by converting angiotensin II to angiotensin 1–7, which exerts a beneficial effect on coronavirus-induced acute lung injury. Human recombinant ACE2 has been considered as a potential therapy for SARS-CoV-2 by blocking virus entry and redressing the imbalance of RAAS in SARS-CoV-2 infection. The level of ACE2 expression can be upregulated by treatment with an ACE inhibitor (ACEI) or angiotensin Ⅱ type 1 receptor blocker (ARB). To date, no evidence shows that ACEIs or ARBs increase the susceptibility and mortality of patients infected with SARS-CoV-2, and hence, it is not advisable to discontinue such drugs in patients with cardiovascular disease.     

中药调节黏膜免疫系统用于防治COVID-19的思路探索

机体免疫功能低下患者,极易出现新型冠状病毒感染,与中医所说正气不足、邪毒侵扰一致。目前集中在抗病毒药物研发是必须的,但对于调节机体免疫系统制剂的研究也较为迫切。黏膜组织是人体免疫系统的一道重要屏障,具有独特功能和结构的独立免疫体系,是机体抵抗感染的第一道防线,与外界抗原(比如食物、共生菌、病毒等)直接接触。其在抵抗病毒、抗感染方面,黏膜免疫(如呼吸道黏膜、肠道黏膜等)起着极其重要的作用,可以消灭外来病原微生物或其他外来抗原,不至于病毒侵入机体组织而对机体造成损伤。中药通过黏膜免疫系统发挥治疗作用的研究报道日益增多,该文拟针对黏膜免疫系统与新型冠状病毒肺炎(COVID-19)的关系以及中药的干预机制展开探讨,以期为COVID-19的防治提供可借鉴的研究方法与治疗思路。     

活体大蒜及离体蒜苗对连作当归胁迫的影响

目的:通过活体大蒜(garlic)及离体蒜苗(garlic sprout)挥发物对当归(Angelica sinensis)的化感效应,探索大蒜挥发性物质对连作当归存在的化感效应,为当归大蒜间作模式缓解连作当归胁迫提供一定的理论依据。方法:试验通过对当归各生长指标及叶片保护酶系统的测定分析,讨论当归在活体大蒜及离体蒜苗挥发物的影响作用下对连作胁迫、无连作胁迫环境的适应性及抗性生长发育机制。结果:整体分析,连作胁迫条件下离体蒜苗对当归幼苗化感效应处理(DC2)下的当归生长指标、叶片保护酶活性较当归单作(CK1)整体提高17. 51%,48. 34%;连作茬口种植活体蒜苗与当归间作处理(LC2)下的当归生长指标、叶片保护酶活性较当归单作(CK2)整体提高16. 63%,36. 65%;即离体蒜苗挥发物较活体大蒜缓解当归连作胁迫作用更显著。结论:无论有无连作障碍胁迫,适当浓度的活体大蒜及离体蒜苗挥发物对当归生长指标及叶片保护酶活性均表现为明显的化感促进作用,其化感促进作用在有连作胁迫条件下表现更显著,因而间作大蒜对当归连作障碍胁迫有一定的缓解作用。     

基于网络药理学和分子对接技术的抗病毒颗粒治疗新型冠状病毒肺炎（COVID-19）的潜在物质基础研究

目的通过网络药理学及分子对接技术探寻抗病毒颗粒治疗新型冠状病毒肺炎(COVID-19)的潜在物质基础。方法借助TCMSP检索抗病毒颗粒中板蓝根、连翘、石膏、知母、芦根、地黄、广藿香、石菖蒲、郁金的化学成分和作用靶点。通过Uni Prot数据库查询靶点对应的基因,进而运用Cytoscape3.6.1构建药材-化合物-靶点(基因)网络,通过DAVID进行基因本体(GO)功能富集分析和KEGG通路富集分析,预测其作用机制,将药材-化合物-靶点网络中排名前15的成分与新型冠状病毒(SARS-Co V-2)3CL水解酶进行分子对接,同时将比枯枯灵、木犀草素、槲皮素与血管紧张素转化酶Ⅱ(ACE2)进行分子对接。结果药材-化合物-靶点(基因)网络包含药材8个、化合物75个、靶点255个。GO功能富集分析得到GO条目161个(P0.05),其中生物过程(BP)条目65个,细胞组成(CC)条目36个,分子功能(MF)条目60个。KEGG通路富集筛选得到131条信号通路(P0.05)。分子对接结果显示抗病毒颗粒中比枯枯灵、木犀草素、槲皮素等核心活性化合物与SARS-Co V-23CL水解酶的亲和力与临床推荐化学药相似。结论抗病毒颗粒中的活性化合物比枯枯灵、木犀草素、槲皮素等能通过与ACE2结合作用于PTGS2、HSP90AB1、PTGS1等靶点调节多条信号通路,从而可能发挥对COVID-19的治疗作用。     

光强对野菊生理生化特性的影响

通过分析光强对野菊生长及生理生化特性的影响,揭示适于野菊生长的光照强度,为野菊种植提供参考依据。分别在100%,80%,60%,40%,20%全自然光强水平下种植野菊,生长旺盛期测定野菊相关生长,光合色素含量、光合参数、荧光参数等光合生理及保护酶系统指标,采取透射电镜技术观察叶绿体超微结构。结果表明:野菊叶片在80%以上全自然光强下出现不同程度发黄现象,株高和茎粗在60%全自然光强达到最大值,60%以上全自然光强下野菊分枝数显著增加;光合色素含量和净光合速率均与光强负相关,光合参数与叶绿素荧光参数则随光强下降呈先上升后下降趋势,60%全自然光强下野菊气孔导度、胞间CO2浓度、蒸腾速率、水分利用效率及PSⅡ实际光化学量子产量等生理指标均处于最高水平;60%~80%全自然光强下野菊叶绿体结构无明显异常,全自然光强下基质片层破碎,20%~40%全自然光强下叶绿体数量、淀粉粒数量与体积均明显降低;随光强下降,SOD与CAT活性呈下降趋势,POD活性呈先上升后下降趋势,MDA含量呈上升趋势。综上,野菊在20%~100%全自然光强下均能生长,但在60%全自然光强下生长最佳。     

Clinical Course of Patients With Worsening Heart Failure With Reduced Ejection Fraction

Background

Epidemiology of patients with worsening heart failure and reduced ejection fraction (HFrEF) in the real-world setting is not well described.

反相高效液相色谱法分析纤溶酶纯度的方法研究

目的 建立纤溶酶反相高效液相色谱纯度测定方法。方法 采用SHISEIDO CAPCELL PAK C₁₈ SG300（250 mm×4.6 mm，5 μm），以0.1%三氟乙酸溶液-乙腈（95：5）为流动相A，以0.08%三氟乙酸溶液-乙腈（20：80）为流动相B，进行梯度洗脱，体积流量为0.7 mL·min^-1，检测波长280 nm，柱温40℃。参照2020年版《中国药典》四部9101药品质量标准分析方法验证指导原则进行专属性、检测限、耐用性考察。应用所建立的方法和分子排阻色谱法对3批样品纯度进行检测。结果 建立的反相色谱法专属性强，检测限为0.01%，耐用性强。对3批样品进行检测，质量分数在93.5%~96.9%，结果准确。结论 建立反相色谱法测定纤溶酶纯度，分辨率更高、重现性更好，可进行更好的质量控制。