Preparation and immunogenicity evaluation of recombinant influenza hemagglutinin trimer vaccine / 中华微生物学和免疫学杂志

Objective:To prepare a recombinant hemagglutinin trimer (HA-Tri) vaccine against influenza viruses and to study its immunogenicity in a mouse model.Methods:A stable CHO cell line that could express HA-Tri was constructed. Western blot, single radial immunodiffusion, protein particle size detection and N-glycosylation site analysis were performed for qualitative and quantitative analysis of the recombinant protein. According to the different treatment conditions such as dosage and adjuvant, BALB/c mice were divided into 11 groups and subjected to consistent immunization procedures. Serum neutralizing antibody titers were measured on 56 d after the first immunization to evaluate the immunogenicity of HA-Tri.Results:The constructed CHO cells could secret and express HA-Tri proteins. The HA-Tri proteins were biologically active and capable of forming precipitation rings in the single radial immunodiffusion. The particle size of HA-Tri was approximately 18.79 nm and 10 N-glycosylation sites were detected, including high mannose, complex glycoforms and heterozygous glycoforms. After prime-boost immunization, there was no statistically significant difference in the titers of neutralizing antibodies induced in mice by 3.75 μg of HA-Tri in combination with RFH01 adjuvant and 15 μg of monovalent vaccine stock solution ( P=0.431 2, U=36). Serum antibody titers in the HA-Tri+ RFH01 groups were higher than those in the corresponding HA-Tri groups without RFH01 adjuvant, and the highest titer was induced in the 15 μg HA-Tri+ RFH01 group, which was 1 280. Conclusions:The recombinant HA-Tri protein was successfully prepared. HA-Tri in combination with RFH01 adjuvant could induce humoral immune responses against influenza viruses in BALB/c mice, which would provide reference for the development of influenza virus recombinant subunit vaccines.

Single chain antibody fragment display systems: a review / 生物工程学报

Single chain antibody fragment (scFv) is a small molecule composed of a variable region of heavy chain (VH) and a variable region of light chain (VL) of an antibody, and these two chains are connected by a flexible short peptide. scFv is the smallest functional fragment with complete antigen-binding activity, which contains both the antibody-recognizing site and the antigen-binding site. Compared with other antibodies, scFv has the advantages of small molecular weight, strong penetration, low immunogenicity, and easy expression. Currently, the most commonly used display systems for scFv mainly include the phage display system, ribosome display system, mRNA display system, yeast cell surface display system and mammalian cell display system. In recent years, with the development of scFv in the field of medicine, biology, and food safety, they have also attracted much attention in the sectors of biosynthesis and applied research. This review summarizes the advances of scFv display systems in recent years in order to facilitate scFv screening and application.

Transformation Models for Characterization of Cancer Driver Genes / 中国生物化学与分子生物学报

The development of cancer is a complex process. Although many genetic and epigenetic alterations are detected in cancer cells, only small proportion of these alterations may function as cancer drivers. Because it is difficult to directly characterize driver factors in human body, alternative research models have continuously been developed. In the early stage from 1915 to 1980s, genetic activation of proto-oncogenes and inactivation of tumor suppressor genes were often characterized using various carcinogenicity tests, including animal tumor induction models, malignant transformation of normal human cells/tissues/organs cultured in vitro or transplanted into immuno-defected mice. Since 1990 to now, gene transfection and knockout technologies were frequently used to characterize cancer driver genes. Currently, 2-dimensional (2D) or 3-dimensional (3D) cell culture and organoid are also employed to test carcinogenicity of environmental factors and driver genes. In this review, we summarized the main models of malignant transformation and their advantages and disadvantages.

Progress in application of genetically engineered mice exposed to cigarette smoke in research on drug targets and pathogenesis of COPD / 中国药理学通报

Chronic obstructive pulmonary disease (COPD) is a common illness of respiratory system, seriously threatening human life and health. Emergence and development of COPD are results of inter-actions between genes and pathogenic factors. The combination of cigarette smoking exposure and genetically engineered mice is able to make similar biological effects of special genes under pathogenic condition of cigarette smoke exposure. The article summarizes the method practice on study of drug targets, inflammation and immune in COPD, analyzes the results of these studies, and describes the basic process of the method, aiming to provide reference for research on pathogenesis and drugs of COPD.

Exploration of an integrated competency development model for undergraduates training by participating the international Genetic Engineering Machine Competition / 生物工程学报

Starting from participating the high-level professional competition, our school has built a talent training system with the spirit of "biomaker" and an innovative practical ability training system. Such system takes the interest of student as the starting point, and relies on the strong scientific research and teaching infrastructure. The programme gives full play to students' initiatives and enhances the scientific research literacy and comprehensive ability of undergraduates majoring in biotechnology. It is an effective exploration of the traditional university education model and meets the urgent demand for innovative talents training in the era of rapid development of life sciences.

Animal models of human atherosclerosis: current progress

Atherosclerosis retains the leading position among the causes of global morbidity and mortality worldwide, especially in the industrialized countries. Despite the continuing efforts to investigate disease pathogenesis and find the potential points of effective therapeutic intervention, our understanding of atherosclerosis mechanisms remains limited. This is partly due to the multifactorial nature of the disease pathogenesis, when several factors so different as altered lipid metabolism, increased oxidative stress, and chronic inflammation act together leading to the formation and progression of atherosclerotic plaques. Adequate animal models are currently indispensable for studying these processes and searching for novel therapies. Animal models based on rodents, such as mice and rats, and rabbits represent important tools for studying atherosclerosis. Currently, genetically modified animals allow for previously unknown possibilities in modelling the disease and its most relevant aspects. In this review, we describe the recent progress made in creating such models and discuss the most important findings obtained with them to date.

Generation of human monoclonal antibody Fab fragment to Zika Virus by Phage Display Technology / 中华实验和临床病毒学杂志

Objective@#In this study, phage display technology was used to construct the human anti-Zika virus(ZIKV), phage antibody library and to obtain and express the monoclonal antibody. The aim was to master the preparation and expression of human phage antibody library screening method for highly specific antibodies.@*Methods@#The whole blood samples of Zika patients were collected and the lymphocytes were isolated. The RT-PCR method was used to amplify the antibody light chain and heavy chain Fab gene from lymphocyte Ig mRNA. The pComb3H system was used to construct the gene with genetic diversity Preparation of human anti-ZIKV phage antibody library. The purified antibody library was screened by using the purified ZIKV and the obtained ZIKV E protein antigen.@*Results@#The monoclonal antibody Fab fragment gene was successfully obtained for the ZIKV E protein antigen. The gene can be efficiently expressed in Escherichia coli.@*Conclusions@#According to the sequence analysis, this study showed that the monoclonal antibody was a new human genetically engineered antibody against ZIKV, which laid the foundation for the early diagnosis of ZIKV, and obtain a specific monoclonal antibody to ZIKV for human treatment of ZIKV infection.

Mouse models of breast cancer in preclinical research / 한국실험동물학회지

Breast cancer remains the second leading cause of cancer death among woman, worldwide, despite advances in identifying novel targeted therapies and the development of treating strategies. Classification of clinical subtypes (ER+, PR+, HER2+, and TNBC (Triple-negative)) increases the complexity of breast cancers, which thus necessitates further investigation. Mouse models used in breast cancer research provide an essential approach to examine the mechanisms and genetic pathway in cancer progression and metastasis and to develop and evaluate clinical therapeutics. In this review, we summarize tumor transplantation models and genetically engineered mouse models (GEMMs) of breast cancer and their applications in the field of human breast cancer research and anti-cancer drug development. These models may help to improve the knowledge of underlying mechanisms and genetic pathways, as well as creating approaches for modeling clinical tumor subtypes, and developing innovative cancer therapy.

Bringing scientific research education closer to undergraduates through International Genetically Engineered Machine competition / 生物工程学报

In recent years, the International Genetically Engineered Machine (iGEM) competition has experienced rapid global development. In 2017 alone, the number of iGEM teams registered around the globe reached an unprecedented 313, with 98 iGEM teams from China having enrolled in the competition and obtained outstanding results. In contrast to the many college students' innovation projects and scientific research training programs in China, iGEM's organization mode is focused on student-centered research learning. Moreover, it achieved a rich educational effect, embodying a new educational idea, which gives it great significance for the extracurricular scientific research training of undergraduates in Chinese universities. In this article, we took Peking University's participation in the iGEM competition as a starting point. The first part introduces the background and general situation of the iGEM competition. The second part reproduces the general procedure of one iGEM season and organization of Peking University's team. The third part compares iGEM's organization mode with those of other undergraduate research training courses and discusses them in detail. The fourth part sums up the experience with iGEM activities as well as explains its effect on developing the research capacity of undergraduate students as well as inspiring them to organize an undergraduate scientific research competition. This article aims to provide a reference for the organization of iGEM activities in domestic universities and for the reform of undergraduate education.

Preface for special column on iGEM (2018) / 生物工程学报

Themed in synthetic biology, supplemented with multiple inter-disciplines, International Genetically Engineered Machine (iGEM)Competition provides with a most influential and dynamic platform for young minds in the field of biology. Many college and high school teams not only achieved excellent results in this competition, but got academic breakthrough achievements as well in recent years. Hence, we launch this iGEM special editorial column, featured in latest domestic iGEM research projects. Simultaneously, we discuss, in this special issue, about the progress of iGEM in China, and its inspiration on development of research skills and scientific competence of collegiate students.

Effects of Shkbp1 deletion on mouse T lymphocyte subsets / 中国比较医学杂志

Objective Shkbp is also called Shkbp1,can competitively inhibit binding CIN85 and c-Cbl,thereby blocking the epidermal growth factor receptor (EGFR) endocytosis and degradation,to play a role in tumor promotion.This study aims to explore the changes in blood cell classification and T cell subsets in blood,bone marrow,and spleen in Shkbp1-deletion (Shkbp-1-/-) mice.Methods Shkbp-1-/-transgenic mice were identified by PCR genotyping.Blood cell classification was performed using an automatic classification system.Flow cytometry was used to detect the T lymphocyte subsets in the blood,bone marrow,and spleen of Shkbp-1-/-and control mice.Results Routine blood examination showed that neutrophils and eosinophils tended to increase and showing significant differences,and there was no significant difference in lymphocytes.The flow cytometry results showed that there was a decrease of CD4+CD8+ double positive cells and increase of bone marrow CD3+ and CD4+ cells in the control group.However,there was a decreasing trend of CD3+,CD4+,CD8+,and CD4+CD8+ cells in the spleen tissues.Conclusions Shkbp1 is involved in the maturation and differentiation of blood cells,and affects the number of immune cells.This study lays a foundation for the study of how Shkbp1 is involved in the differentiation of blood cells.

Research progress in animal models of cholangiocarcinoma / 上海交通大学学报（医学版）

Cholangiocarcinoma (CCA) is a malignant neoplasm derived from cholangiocytes. The incidence of CCA is only lower than that of hepatocellular carcinoma and ranked the second in liver malignant cancers. The prognosis of CCA patients is poor and most patients will die within a few months after diagnosis. CCA is related to various risk factors, including primary sclerosing cholangitis, cirrhosis, certain chemical agents and liver fluke. Establishment of proper animal models of CCA can not only be helpful for understanding the mechanisms of incidence and development, but also lay a solid foundation for developing novel treatment strategies. Common animal models of CCA include carcinogen-induced models, implantation models, operation models, and genetically engineered models.

Effect of P-selectin Deletion on Intestinal Tumorigenesis in 15,24-week-old ApcMin/+ Mice / 中山大学学报(医学科学版)

[Objective] To investigate the effect of P-selectin on the intestinal tumorigenesis in the 15,24-week-old ApcMin/+ mice.[Methods] Male ApcMin/+ mice were mated with female P-selectin knockout (P-sel-/-) mice to generate AMin/+Ps-/-mice.The diameters and numbers of the intestinal tumors in the intestines of ApcMin/+ and AM/+ps-/-mice were measured using an inverted microscope.The tumor volumes were measured using the following equation:volume =0.52 × (length × width2).[Results] There were no significant difference between the volume and number of intestinal tumor in 15-week-old ApcMin/+ mice and 15-week-old A+ P-mice.The volume and number of intestinal tumor were significantly increased in 24-week-old A+P-mice compared to 24-weekold ApcMin/+ mice.P-selectin deletion significantly prolonged the survival time of ApcMin/+ mice.[Conclusions] P-selectin deletion promotes the intestinal tumorigenesis in the 24-week-old ApcMin/+ mice.

Reproductive performance of genetically engineered mice housed in different housing systems / 한국실험동물학회지

The genetically engineered mice require special husbandry care and are mainly housed in Individually Ventilated Cage (IVC) systems and Static Micro Isolator Cages (SMIC) to minimize the risk for spreading undesirable microorganisms. However, the static micro isolation cage housing like SMIC are being replaced with IVC systems in many facilities due to a number of benefits like a higher density housing in limited space, better protection from biohazards and allergens and decreased work load due to decreased frequency of cage changing required in this system. The purpose of this study was to examine the reproductive performance of genetically engineered mice housed in individually ventilated cages (IVC) and Static Micro Isolator Cages (SMIC). When the B6C3-Tg (APPswe, PSEN1dE9) 85Dbo/Mmjax transgenic mice were housed in these two housing systems, the number of litters per dam, number of pups born per dam and number of pups weaned per dam were found to be slightly higher in the IVC as compared to the SMIC but the difference was not significant (P<0.05). In case of Growth Associated Protein 43 (GAP-43) knockout mice, the number of litters born per dam and the number of pups born per dam were marginally higher in the IVC as compared to those housed in SMIC but the difference was not significant (P<0.05). Only the number of pups weaned per dam were found to be significantly higher as compared to those housed in the SMIC system at P<0.05.

Targeted suppression of Act1 in the macrophages ameliorates experimental ulcerative colitis in mice induced by dextran sodium sulfate / 中国实验动物学报

Objective To investigate the role of macrophage?derived Act1 (nuclear factor kappa B activator 1) in the inflammatory bowel disease. Methods Genetically engineered mice carrying targeted suppression of Act1 in the mac?rophages (Anti?Act1) were used for the dextran sodium sulfate (DSS)?induced ulcerative colitis. The severity of colitis was assessed by weight loss, stool consistency, fecal blood index, colorectal length and H&E histology. The infiltration of CD45 + leukocytes and CD68 + macrophages in the inflammatory intestine was observed by immunohistochemical staining and expression levels of mRNA for inflammatory cytokines in colon tissues were analyzed by RT?qPCR. Results As com?pared with C57 mice, the anti?Act1 mice exhibited less severe acute colitis following DSS treatment, with reduced CD45 +leukocyte and CD68 + macrophage infiltrates in the colon tissue. Inflamed colons of the anti?Act1 mice expressed lower mR?NA levels of TNF?α, IL?1βand IL?6. Conclusions Targeted suppression of Act1 in the macrophages ameliorates dextran sodium sulfate?induced intestinal inflammation.

Current research in animal models of dry age-related macular degeneration / 中华实验眼科杂志

Age-related macular degeneration (AMD) is the leading cause of the irreversible vision loss in population over 55 years of age.With the increasingly serious problem of aging,the prevalence of AMD is rising year by year.However,as the pathogenesis of dry AMD is largely unknown,the effective therapy still is lack.Given that there was a lack of proper animal models,it brought about obstacles to researches about molecular mechanism underlying dry AMD.Nowadays,lots of murine models of dry AMD have been established and developed,which provide suitable tools for relevant researches.But,different dry AM D models show varied pathogenesis features,and a reasonable choice of models is very important for different studies.The characteristics of different dry models were reviewed in this article.

Extracting Extra-Telomeric Phenotypes from Telomerase Mouse Models

Telomerase reverse transcriptase (TERT) is the protein component of telomerase and combined with an RNA molecule, telomerase RNA component, forms the telomerase enzyme responsible for telomere elongation. Telomerase is essential for maintaining telomere length from replicative attrition and thus contributes to the preservation of genome integrity. Although diverse mouse models have been developed and studied to prove the physiological roles of telomerase as a telomere-elongating enzyme, recent studies have revealed non-canonical TERT activities beyond telomeres. To gain insights into the physiological impact of extra-telomeric roles, this review revisits the strategies and phenotypes of telomerase mouse models in terms of the extra-telomeric functions of telomerase.

Genetically Engineered Mouse Models for Drug Development and Preclinical Trials

Drug development and preclinical trials are challenging processes and more than 80% to 90% of drug candidates fail to gain approval from the United States Food and Drug Administration. Predictive and efficient tools are required to discover high quality targets and increase the probability of success in the process of new drug development. One such solution to the challenges faced in the development of new drugs and combination therapies is the use of low-cost and experimentally manageable in vivo animal models. Since the 1980's, scientists have been able to genetically modify the mouse genome by removing or replacing a specific gene, which has improved the identification and validation of target genes of interest. Now genetically engineered mouse models (GEMMs) are widely used and have proved to be a powerful tool in drug discovery processes. This review particularly covers recent fascinating technologies for drug discovery and preclinical trials, targeted transgenesis and RNAi mouse, including application and combination of inducible system. Improvements in technologies and the development of new GEMMs are expected to guide future applications of these models to drug discovery and preclinical trials.

Progress in models of pancreatic cancer / 国际外科学杂志

Pancreatic cancer is a highly malignant tumor. Animal models of pancreatic cancer included xenograft models, carcinogen induced models, genetically engineered models. Xenograft models are relatively reliable and feasible, but the growth pattern is different between serve immunodeficienct animals and human beings. Carcinogens induced models simulated the environmental factors to reconstruct the development of pancreatic cancer. But carcinogens could have other biological effects. Genetically engineered models could make the occurrence of pancreatic cancer at the molecular level. But it is difficult to control the transgenic product accurately. No model could meet all the needs of different experiments. It is important to choose a suitable animal model in different experiments.

The Ecological Safety of Genetically Modified Microorganisms / 环境与健康杂志

The worldwide situation of genetically engineered microorganisms (GEMs) being released into environment was presented in the present review. The studies on impacts of GEMs on environments were introduced. The regulations of biosafety and application of GEMs were briefly addressed.