Interferon is the first line of innate defense against viruses infection. Interferon α1b is a major antiviral subtype of interferon family. SARS-CoV-2 have evolved several mechanisms to block interferon induction. Interferon α1b, has been approved for the antiviral clinical use for many years, showing strong in vitro antiviral activity against SARS-CoV-2. Preliminary clinical studies including type I interferon have showed critical positive efficiency on COVID-19 treatment and prevention. A clinical trial with a larger cohort of infected patients that are randomized to treatment with interferon-alpha or to a placebo is ongoing.
Breaking out in Wuhan, China at the end of year 2019, coronavirus disease 2019 (COVID-19) rapidly spread around the world. It was listed as a “public health emergency of international concern” by WHO and has caused incalculable damage to human health and economic development. Humans are generally susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the coronavirus that causes COVID-19. In the lack of specific drugs and treatments, vaccination is the most effective and economical way to prevent and control COVID-19. At present, the vaccines against SARS-CoV-2 are being developed in many countries, which work together to cope with the epidemic. This paper mainly reviews the research advances in the vaccines against SARS-CoV-2, i.e., inactivated vaccine, viral vector vaccine, genetic engineering recombinant subunit vaccine, and nucleic acid vaccine.
Viral infection-related diseases pose a serious threat to human health. Current antiviral therapies cannot cure some diseases caused by chronic viral infections, such as AIDS and hepatitis B. Therefore, new treatment methods are urgently needed. Gene-editing technology that can directly target genetic material may become a powerful tool against viruses. As a new programmable nuclease-mediated gene-editing technology, the CRISPR/Cas9 system has been successfully applied to the research of a variety of human-related diseases due to its high editing efficiency, simple operation, low cost, and wide application range. It also provides new technical means for the research of viral infection-related diseases and the development of new treatment methods. The mechanism of the CRISPR/Cas9 system and the latest advances in the treatment of common human viral infection-related diseases were reviewed in the article.
Self-amplifying mRNA vaccine is a versatile vaccine platform developed from alphavirus expression vector in which the viral replication genes are intact but those viral structural genes are replaced with antigen genes derived from pathogens. These vaccines have emerged as ideal modalities for rapid vaccine design, avoiding the problem of pathogen culture, reversion to pathogenicity and pre-existing immunity. Numerous studies demonstrated that these vaccines could be employed to induce humoral and cellular immune responses in human, mice, rabbits, pigs, avian and even fish. During the past years, focus has been on the use of recombinant single vectored self-replicating mRNA derived from the genome backbone of Sindbis virus, Semliki forest virus, and Venezuelan equine encephalitis virus. Now trans-amplifying RNA and nucleotide modified trans-amplifying RNA vaccines have come into focus as promising next-generation technology platforms for vaccine development. An overview of recent advance in self-replicating RNA vaccines developed from alphavirus expression vectors was presented, with an emphasis on current state of SAM vaccine approaches against emerging infectious diseases, such as influenza A virus, SARS-CoV-2, and ZIKA virus, and provide perspectives on the future of this technology platform.
Objective: Preparation of positive quality control products with good thermal stability, resistance to RNase attack and full monitoring for RT-PCR detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods: The MS2 phage coat protein CP (including the PAC site) gene sequence and the mature enzyme protein A gene sequence (including the ribosome binding site) were amplified and inserted into the plasmid pET28a to construct the universal recombinant vector pET28a/CP-A. Synthesize a specific nucleic acid sequence containing ORF1ab gene, N gene and E gene of SARS-Cov-2, and insert it into the downstream of the PAC site, which is named pET28a/CP-A.The recombinant protein is expressed through the prokaryotic expression system, and purified by ammonium sulfate and gel filtration chromatography. The purified protein is physically characterized by electron microscopy and dynamic light scattering. The formed armor RNA is digested with omnipotent nuclease, and its thermal stability is verified by fluorescent RT-PCR. Results: A recombinant vector containing the MS2 bacteriophage coat protein gene, the mature enzyme protein gene and exogenous nucleic acid was successfully constructed. VLPs was efficiently expressed in the form of soluble protein at 25℃ and IPTG at 0.3mmol /L for 14h. After purification, The VLPs were observed under transmission electron microscopy in uniform shape and size,with a diameter of about 23-28nm. The VLPs were digested with Benzonase nuclease, and detected by RT-PCR, which confirmed that they formed armor RNA that encapsulated the target gene. The armor RNA can exist stably at 37℃ for 10-15 days under sterile conditions. Conclusion: In vitro, the armor RNA encapsulating foreign target sequence prepared by self-assembly of MS2 phage coat protein and mature enzyme protein has good thermal stability and can monitor the entire detection process. It can be used as a qualitative or quantitative quality control product for the detection of SARS-CoV-2 by RT-PCR.
Fed-batch culture has been one of main bioprocesses for monoclonal antibody (mAb) production by Chinese hamster ovary (CHO) cells. It has been reported that environmental parameters like temperature and pH and nutritional ingredients are key factors that can influence cell growth, carbon and/or nitrogen source metabolism and foreign protein expression in CHO cell suspension culture. Objective: Effects of culture process parameters (temperature and pH) on cell growth and anti-CD20 antibody expression by CHO cells were investigated based on design of experiment (DOE), and a fed-batch strategy was successfully developed to improve anti-CD20 antibody expression level with amino acid supplementation. The results show that temperature was a key factor for anti-CD20 antibody expression: 35℃was the optimal temperature with an increased cell density and target mAb yield. However, the impact of pH on mAb production by CHO cells was not significant and there were no interaction between pH and temperature. The optimal culture conditions were 35℃ and pH7.0 according to the analysis of DOE predictive profiler. In addition, it found that residual concentrations of tyrosine and cysteine in culture was below 0.1mmol/L at late stage of cultivation process under the optimal culture condition. As such, additional 1.5mmol/L tyrosine and 1mmol/L cysteine were fed on day 2, led to an increase in anti-CD20 antibody titer by 24.1% and no changes in glycosylation of anti-CD20 antibody.
Objective: To construct a ZmCen gene expressing vector using CRISPR/Cas9 system and analyze its effect on growth and development in maize after transformation. Methods: A sgRNA in the first exon of ZmCen gene was designed targeting it. The sgRNA was inserted into the pOMS01-Cas9-ZmCen-sgRNA vector, and its transgenic lines B104 were obtained via Agrobacterium-mediated transformation, subcultured, induced and differentiated into seedlings. The T0 and T1 generations genomic DNA was amplified and analyzed, and the plants were phenotype comparison screening. Results: The ZmCen expressing vector was successfully constructed. The genomic DNA of T0 and T1 generations was detected by PCR and sequenced. The mutagenesis frequency for ZmCen was 20.13% and 64.52% in T0 and T1 transgenic lines, respectively. The frequency of homozygous deletion mutation was 5% in T1 transgenic lines. Sequence analysis showed that base substitutions, insertions, or deletions occurred near the editing target of the ZmCen gene. Compared with the wild-type phenotype, it was found that the T1 generation plants of ZmCen mutant showed incomplete male inflorescence phenotype, while the male inflorescence of homozygous mutant plants was sterility. Conclusion: The ZmCen gene was succeed editing by CRISPR/Cas9 technical in maize, and the successful construction of ZmCen mutants lays a foundation for the related-genes study of maize male organ development.
Base editing is a precise genome editing technique based on the CRISPR/Cas system. Base editing use cytosine deaminases or adenine deaminases to perform base editing, and achieve base substitutions, respectively. Base editor, engineered by fusing the Cas9 nikase (Cas9n) with a cytidine deaminase enzyme is guided by a sgRNA to the target site. The position is the single base 4-7 of the target distance from the end of the sgRNA site motif (protospacer adjacent motif, PAM) sequence for editing.Without cutting doublestrand DNAs, base editor can precisely mediate the direct conversion of cytidine to thymineor or guanine to adenine. Therefore the base editing history, composition, working principle, and technology developments were briefly described.
Cancer is still a major problem threatening human health in recent years. With the development of medicine, besides the traditional methods of cancer treatment: surgery, radiotherapy, chemotherapy, immunotherapy can also be used. At present, cancer immunotherapy has been widely concerned, but there are many limitations in its application. For example, PD-1 / PD-L1 inhibitors are found to have acquired drug resistance in the process of application. Therefore, cellular immunotherapy (chimeric antigen receptor T cell, CAR-T) emerges as the times require, becoming a new treatment method to make up for the defects of immune checkpoint inhibitors (ICIs) and monoclonal antibody drugs. Through briefly introduces the emergence and application of CAR-T immunity therapy and the research progress on TME related targets, providing certain ideas for the follow-up research.
As a biomimetic material of mussel, polydopamine can be formed spontaneously by dopamine in alkaline environment. Because of its good adhesion properties and histocompatibility, it has a wide range of applications in life sciences and other fields. Surface modification of the material with polydopamine can not only protect the material from external corrosion such as strong oxidants, acids and alkalis, but also give the material new functions through surface modification, making it play a better role in various fields. The preparation principle, biological properties of polydopamine and its application in tissue engineering (bone tissue, cartilage tissue, dural tissue, blood vessel tissue, ear tissue) in recent years are reviewed, in order to provide reference for the follow-up study of polydopamine as a tissue engineering adhesive material.
Organoids are driven by stem cells in vitro to form multicellular three-dimensional structures with the micro-anatomical and self-renewing characteristics of the source organs. Organoids produce organ-specific cell types that can reproduce part of the function and spatial structure of the corresponding organs. They promote the development of life medicine research and have shown broad application prospects in cancer basic and clinical research, regenerative medicine and other fields. This review summarizes the research progress of organoids in recent years, including introducing its construction process and culture system and expounding its advantages and disadvantages as an in vitro research model, which provides a reference for scientific research and application based on organoids.
As a by-product of grain processing, bran phenolic substances have important nutritional characteristics and pharmacological effects. However, most phenols in bran exist in the form of binding state, with low biological accessibility. There is a challenge to realize the effective release of phenolic substances in bran and improve the bioavailability. The nutritional characteristics and existing forms of bran phenolic compounds, as well as the research progress of enzymatic degradation, microbial fermentation and other biological treatment strategies in improving the biological accessibility of phenols were reviewed. Explore the interaction and mechanism of the mixed strain system and the relationship between the structural changes of the pretreated bran and the degradation efficiency. All these researches will provide a theoretical basis for the high value-added utilization of bran and the development of related functional foods.
Gene therapy is an approach treating certain diseases by transferring therapeutic genetic material to target cells. Gene therapy may provide the possibility of “one-time” cure paving the way as an important treatment armamentarium in near future. However, challenges subsuming long-term efficacy and safety data, accessibility, and regulatory policy forgene therapy need to be addressed. The review will start with basic concept and history, to discuss current status and future prospects of gene therapy.
Objective: Based on the analysis of macro data, the industrial development and patent situations of the Shanghai biomedical industry are revealed, corresponding suggestions are proposed. Methods: By comparing the biomedical industry and patent data of several provinces and cities in China, Shanghai biomedical industry development situation, economic contribution and patent layout are specifically analyzed. Results: The industrial spatial pattern with Yangtze River Delta and Bohai Rim as the core region, Pearl River Delta and Sichuan-Chongqing as the fast-growing region has been formed. The Pudong New Area occupies a leading position in the Shanghai biomedical industry, and that universities, research institutes are the main body of patent applications. Conclusion: Shanghai should optimize the industry carrying space, strengthen the concentration of development factors, deepen the advancement from “point breakthrough” to “chain innovation”, build a biomedical agglomeration, and accelerate the implementation of technological R&D and industrialization.
