Preferential infection of human Ad5-specific CD4 T cells by HIV in Ad5 naturally exposed and recombinant Ad5-HIV vaccinated individuals

Efficacy trials of adenovirus 5-vectored candidate HIV vaccines [recombinant Ad5 (rAd5)-HIV] were halted for futility due to lack of vaccine efficacy and unexpected excess HIV infections in the vaccine recipients. The potential immunologic basis for these observations is unclear. We comparatively evaluated the HIV susceptibility and phenotypes of human CD4 T cells specific to Ad5 and CMV, two viruses that have been used as HIV vaccine vectors. We show that Ad5-specific CD4 T cells, either induced by natural Ad5 exposure or expanded by rAd5 vaccination, are highly susceptible to HIV in vitro and are preferentially lost in HIV-infected individuals compared with CMV-specific CD4 T cells. Further investigation demonstrated that Ad5-specific CD4 T cells selectively display a proinflammatory Th17-like phenotype and express macrophage inflammatory protein 3α and α4β7 integrin, suggestive of gut mucosa homing potential of these cells. Analysis of HIV p24 and cytokine coexpression using flow cytometry revealed preferential infection of IL-17- and IL-2-producing, Ad5-specific CD4 T cells by HIV in vitro. Our data suggest a potential mechanism explaining the excess HIV infections in vaccine recipients after rAd5-HIV vaccination and highlight the importance of testing the HIV susceptibility of vaccine-generated, vector and insert-specific CD4 T cells in future HIV vaccine studies.Adenovirus serotype 5 (Ad5) has been used as an HIV vaccine viral vector, and the candidate HIV vaccines based on Ad5 vectors [recombinant Ad5 (rAd5)-HIV] have been intensively studied (1–5). However, development of efficacious rAd5-HIV vaccines in humans has been unsuccessful to date, despite the vaccines eliciting potent cellular immune responses. Notably, the Step trial that evaluated the Merck rAd5-HIV vaccines demonstrated no vaccine efficacy and was halted due to unexpected excess HIV infections in men who have sex with men in the vaccine arm (2, 5). The Phambili study testing the same Merck rAd5 vaccines in South Africans with heterosexual risk of HIV infection was also terminated early, and a higher HIV infection rate, albeit detected more distant from vaccination, was observed in rAd5-vaccinated individuals (3). Similarly, immunization of rhesus monkeys with replication-defective rAd5 vaccine (Merck-type) was consistent with the results of the Step trial and suggested greater risk of simian immunodeficiency virus (SIV) infection in vaccinated monkeys (6). More recently, the HVTN505 study of a different rAd5 vaccine, given with a DNA prime, was also terminated early for futility; at the time of study closure there was a nonsignificant excess of infections in the vaccine arm that seemed to diminish with time (4). The potential immunologic basis for the rAd5-associated excess HIV infection in vaccine recipients is unknown.CD4 T cells are major cellular targets by HIV for infection in vivo. Studies focusing on early immunologic events during HIV transmission revealed that virtually all initially infected cells at mucosal sites are CD4 T cells (7). Therefore, occurrence of HIV acquisition in vaccinated individuals most likely involves early exposure and infection of vulnerable CD4 T cells by HIV. Our group and others have shown that human CD4 T cells specific to different antigens demonstrate differential susceptibilities to HIV (8, 9). Because vector-specific CD4 T cells are elicited by recombinant viral vector vaccines, it should be highly informative for future HIV vaccine design to investigate whether vector antigen-specific CD4 T cells induced by a given viral vectored HIV vaccine are particularly resistant or susceptible to HIV infection. For example, in contrast to rAd5-HIV vaccines, the rhesus CMV-based SIV vaccine did not cause increase in SIV infection and was shown to stringently control SIV in vaccinated monkeys (10).A carboxyfluorescein succinimidyl ester (CFSE)-based proliferation assay used to model T-cell antigen specificity has been adapted to determine the susceptibility of antigen-specific CD4 T cells to HIV and the associated phenotypes (8). In this study we comparatively investigated human CD4 T cells specific to Ad5 and CMV, using cell samples from Ad5/CMV naturally exposed, HIV-uninfected and -infected subjects, as well as from a phase I HIV vaccine trial that evaluated a DNA prime rAd5 boost regimen (11). We found that human Ad5-specific CD4 T cells are substantially more susceptible to HIV in vitro and are preferentially lost in HIV-infected individuals compared with CMV-specific CD4 T cells. Flow cytometric and microarray analyses revealed remarkable phenotypic differences between Ad5 and CMV-specific CD4 T cells. Our data suggest that the greater HIV susceptibility of Ad5-specific CD4 T cells may pose a potential risk in HIV vaccine trials.     

重组病毒载体疫苗的研究进展

重组病毒载体疫苗的原理是将外源基因插入病毒基因组以构建重组病毒,免疫机体后在体内表达相应蛋白并诱导特异性免疫应答。该类疫苗具有载体种类多、插入片段长、能同时诱导体液免疫和细胞免疫等优势,能克服灭活疫苗的效力维持时间短和减毒活疫苗回复突变的弊端。此文综述了重组病毒载体疫苗的最新研究进展,为将来的研究提供参考。     

Potential for Bacillus thuringiensis and Other Bacterial Toxins as Biological Control Agents to Combat Dipteran Pests of Medical and Agronomic Importance

The control of dipteran pests is highly relevant to humans due to their involvement in the transmission of serious diseases including malaria, dengue fever, Chikungunya, yellow fever, zika, and filariasis; as well as their agronomic impact on numerous crops. Many bacteria are able to produce proteins that are active against insect species. These bacteria include Bacillus thuringiensis, the most widely-studied pesticidal bacterium, which synthesizes proteins that accumulate in crystals with insecticidal properties and which has been widely used in the biological control of insects from different orders, including Lepidoptera, Coleoptera, and Diptera. In this review, we summarize all the bacterial proteins, from B. thuringiensis and other entomopathogenic bacteria, which have described insecticidal activity against dipteran pests, including species of medical and agronomic importance.     

Oncolytic adenoviruses: a game changer approach in the battle between cancer and the immune system.

Introduction: Oncolytic adenoviruses are among the most studied oncolytic viruses because of their tumor selectivity, safety, and transgene-delivery capability. With a growing number of different immunotherapies against cancer, the extraordinary immunogenicity of the adenovirus has emerged as a differentiating strength. Enabling T-cell related therapies with oncolytic adenoviruses appears a promising approach due to its inherent ability to elicit responses from the adaptive immune compartment.

Areas covered: These viruses have successfully enhanced both adoptive T-cell therapies and immune-checkpoint therapies. Oncolytic viruses induce several effects at the tumor and on the systemic level that help to circumvent current limitations of T-cells and related therapies, such as T-cell trafficking, tumor immune suppressivity and antigen spreading.

Expert opinion: Taking into account the multitude of possibilities of treating cancer with immunotherapies, learning to optimize the combinations and administration strategies of these drugs, could lead to durable responses in patients with currently incurable cancers.     

克隆IN-1重组单链抗体基因与促进中枢神经再生的研究

目的利用基因工程技术,对IgMG型的IN-1的基因进行改良,以得到IN-1重组单链抗体(scFv)cDNA基因片段为促使受损的中枢神经再生和治疗弥漫性轴索损伤开辟一个崭新途径。方法宿主菌为大肠杆菌DH5a,克隆质粒为pUC18。参照genebank中发表的IN-1抗体的轻链重链序列,重新设计适于在大肠杆菌中表达的目的基因片段,将该基因双链分成35个小片段合成,经退火、复性连接成目的片段后,克隆到经过BamHI和HindIII双酶切的克隆载体pUC18中,并转化大肠杆菌DH5a,抽提重组子pUC18/744进行克隆PCR、酶切鉴定及测序分析。结果测序结果证明获得的基因序列与实验设计仅差一个碱基。结论正确设计并合成了IN-1重组单链抗体(IN-1-scFv)的cDNA,为深入研究其生物活性奠定了基础,也为应用抗体工程治疗弥漫性轴索损伤开创了一个新思路。     

基于软信息的结构化转换

随着文本信息（软信息）对多传感器信息融合的影响不断加深,如何形成一个有效的软信息结构化转换模型,给予计算机和传感器更多可融合的结构化软信息,成为了一个重要的任务。针对软信息结构化问题,即文本表示问题,首先对文本分类技术中向量空间模型的TF IDF权重进行研究;然后针对其结构化有效性方面的不足,通过引入事件全局权重和信息增益对TF IDF权重进行特征项关于文本主旨的信息及特征项在文本类间的分布信息补充、完善和实现软信息的结构化表示;最后通过实验验证了该改进方法对软信息结构化转换的可行性和有效性。     

慢病毒载体介导的人磷脂磷酸水解酶3基因在人脐带间充质干细胞中的表达

目的 体外分离和培养人脐带间充质干细胞（umbilical cord mesenchymal stem cell,UC-MSCs）,并将含有人磷脂磷酸水解酶3（human lipid phosphate phosphatases 3,hLPP3）的慢病毒载体转染UC-MSCs,探讨hLPP-3在UC-MSCs中的表达.方法 从脐带中分离单细胞,经细胞形态学、流式细胞仪（FACS）检测、细胞分化潜能判定,鉴定UC-MSCs的生物学特性.同时将hLPP-3基因克隆入慢病毒载体,包装出病毒上清,以不同拷贝数转染UC-MSCs,用免疫印迹和实时定量PCR技术分别测定不同转染组hLPP-3的蛋白及mRNA表达水平.结果 成功在体外分离和培养了UC-MSCs,并诱导其向脂肪、骨、软骨细胞分化.流式细胞仪检测结果显示脐带MSC表达CD90、CD73及CD105,而不表达CD14、CD34、CD45、CD19、HLA-DR、CD11b及CD106蛋白.用含hLPP-3-GFP融合基因的慢病毒载体转染UC-MSCs,实时定量PCR检测发现,hLPP-3的mRNA转录水平与转染拷贝数有关,转染拷贝数越高,hLPP-3的表达量越高;转染后1个月,免疫印迹发现hLPP-3-GFP依然维持高表达.结论 成功地在体外分离和培养了UC-MSC,并用含有hLPP-3基因的慢病毒载体转染UC-MSCs,通过转染拷贝数在一定水平上调控了UC-MSC中hLPP-3 mRNA的转录水平和蛋白表达量.     

Solid lipid nanoparticles for applications in gene therapy: a review of the state of the art

Importance of the field: Gene therapy represents a new paradigm in the prevention and treatment of many inherited and acquired diseases, including genetic disorders, such as cystic fibrosis, haemophilia and many somatic diseases, such as tumours, neurodegenerative diseases and viral infections, such as AIDS.

Areas covered in this review: Among a large array of non-viral transfection agents used for in-vitro applications, cationic SLNs are the topic of this review, being recently proposed as an alternative carrier for DNA delivery, due to many technological advantages such as large-scale production from substances generally recognized as safe, good storage stability and possibility of steam sterilization and lyophilisation.

What the reader will gain: The authors give some information on the knowledge of intracellular trafficking and SLNs-DNA complex chemical-physical properties reported until now in the literature.

Take home message: The future success of cationic SLNs for administration of genetic material will depend on their ability to efficiently cross the physiological barriers, selectively targeting a specific cell type in vivo and expressing therapeutic genes.