Targeting lentiviral vectors to primordial germ cells(PGCs):An efficient strategy for generating transgenic chickens

Recent advances in avian transgenic studies highlight the possibility of utilizing lentiviral vectors as tools to generate transgenic chickens. However, low rates of gonadal chimerism and germ line transmission efficiency still limit the broad usage of this method in creating transgenic chickens. In this study, we implemented a simple strategy using modified lentiviral vectors targeted to chicken primordial germ cells(PGCs) to generate transgenic chickens. The lentiviral vectors were pseudotyped with a modified Sindbis virus envelope protein(termed M168) and conjugated with an antibody specific to PGC membrane proteins. We demonstrated that these optimized M168-pseudotyped lentiviral vectors conjugated with SSEA4 antibodies successfully targeted transduction of PGCs in vitro and in vivo. Compared with the control, 50.0%–66.7% of chicken embryos expressed green fluorescent protein(GFP) in gonads transduced by the M168-pseudotyped lentivirus. This improved the targeted transduction efficiency by 30.0%–46.7%. Efficient chimerism of exogenous genes was also observed. This targeting technology could improve the efficiency of germ line transmission and provide greater opportunities for transgenic poultry studies.

Pseudotyped lentiviral vectors:Ready for translation into targeted cancer gene therapy?

Gene therapy holds great promise for curing cancer by editing the deleterious genes of tumor cells,but the lack of vector systems for efficient delivery of genetic material into specific tumor sites in vivo has limited its full therapeutic potential in cancer gene therapy.Over the past two decades,increasing studies have shown that lentiviral vectors(LVs)modified with different glycoproteins from a donating virus,a process referred to as pseudotyping,have altered tropism and display cell-type specificity in transduction,leading to selective tumor cell killing.This feature of LVs together with their ability to enable high efficient gene delivery in dividing and non-dividing mammalian cells in vivo make them to be attractive tools in future cancer gene therapy.This review is intended to summarize the status quo of some typical pseudotypings of LVs and their applications in basic anti-cancer studies across many malignancies.The opportunities of translating pseudotyped LVs into clinic use in cancer therapy have also been discussed.

Isolation and cultivation of murine hematopoietic stem cells and expression of hFIX mediated by recombinant lentiviral vectors in vitro

Hematopoietic stem cells(HSCs)are an attractive target for gene therapy,especially for inherited blood diseases.Moreover,recombinant lentiviral vectors are considered to be prospective in HSCs gene therapy for the high efficiency of infection.In this study,murine mononuclear cells(MNCs)were isolated from bone marrow and cultured in suspension,and then Lin−CD117+HSCs were isolated by immunomagnetic beads.During culturing,cells and colonies increased in HSCs supplied with cytokines while no change was observed in the control group without cytokines.FUXW recombinant lentiviral vectors were produced by calcium phosphate-mediated transient cotransfection infected MNCs from ICR and C57 mice.The hFIX expressions were 41.7±4.2 ng/mL and 34.5±6.6 ng/mL in supernatant on 7d.The hFIX expressions of HSCs infected by FUXW recombinant lentiviral vectors were 46.6±5.7 ng/mL(with cytokines)and 33.3±4.8 ng/mL(without cytokines)in supernatant on 7d.Results indicate that recombinant lentiviral vectors can infect murine MNCs and Lin−CD117+HSCs efficiently,and expression of the transgene can be improved when supplied with cytokines.

Recent advances in lentiviral vectors for gene therapy

Lentiviral vectors(LVs), derived from human immunodeficiency virus, are powerful tools for modifying the genes of eukaryotic cells such as hematopoietic stem cells and neural cells. With the extensive and in-depth studies on this gene therapy vehicle over the past two decades, LVs have been widely used in both research and clinical trials. For instance, third-generation and selfinactive LVs have been used to introduce a gene with therapeutic potential into the host genome and achieve targeted delivery into specific tissue. When LVs are employed in leukemia, the transduced T cells recognize and kill the tumor B cells;in β-thalassemia, the transduced CD34^(+) cells express normal β-globin;in adenosine deaminase-deficient severe combined immunodeficiency, the autologous CD34^(+) cells express adenosine deaminase and realize immune reconstitution. Overall, LVs can perform significant roles in the treatment of primary immunodeficiency diseases, hemoglobinopathies, B cell leukemia, and neurodegenerative diseases. In this review, we discuss the recent developments and therapeutic applications of LVs. The safe and efficient LVs show great promise as a tool for human gene therapy.

Recombinant HIV to kill latent reservoir cells: a hypothetical therapeutic strategy

Latency is the pivotal factor that governs the long-term pathogenecity and persistence of HIV-1 infection.It is also the primary impediment to cure and successful treatment,resulting in patient death.Latency of HIV-1 infection promotes failure of the conventional antiretroviral therapy(ART).Cessation of ART immediately leads to viral reactivation and attainment of viral load in peripheral circulation.ART comes with severe side effects and is ineffective at treating latent infection.To eliminate latent infection,alternate therapeutic strategies such as Shock and Kill,Block and Lock,gene editing and vaccination have been proposed.Although these strategies have experimentally been proven successful,they possess major limitations.Hence,in this hypothesis,an alternate therapeutic strategy has been proposed to solve the threat of HIV-latency.The proposed model encompasses the generation and administration of recombinant HIV-1 particles whose genomes having pro-apoptotic gene,tBid,will activate apoptotic cell death pathways after infecting only the latent cells,thereby removing latent HIV host cells from patients’bodies.

Protective effects of ciliary neurotrophic factor on the retinal ganglion cells by injure of hydrogen peroxide

AIM: To explore the effect of ciliary neurotrophic factor(CNTF) on retinal ganglion cell(RGC)-5 induced by hydrogen peroxide(H_2O_2). METHODS: After cell adherence, RGC-5 culture medium was changed to contain different concentrations of H_2O_2 from50 to 150 μmol/L at four time points(0.5, 1, 1.5 and 2 h) to select the concentration and time point for H_2O_2 induced model. Two different ways of interventions for injured RGC-5 cells respectively were CNTF as an addition in the culture medium or recombinant lentiviral plasmid carrying CNTF gene transfecting bone mesenchymal stem cells(BMSCs) for co-culture with RGC-5. RESULTS: Compared to the control group, H_2O_2 led to RGC-5 death closely associated with concentrations and action time of H_2O_2 and we chose 125 μmol/L and 2 h to establish the H_2O_2-induced model. While CNTF inhibited the loss of RGC-5 cells obviously with a dose-dependent survival rate. Nevertheless two administration routes had different survival rate yet higher rate in recombinant lentiviral plasmid group but there were no statistically significant differences. CONCLUSION: Both the two administration routes of CNTF have effects on RGC-5 cells induced by H_2O_2. If their own advantages were combined, there may be a better administration route.

Expression of human adrenomedullin gene in gastric adenocarcinoma and construction and identification of adrenomedullin overexpression vector and adrenomedullin-shRNA vector

Background:To explore the expression of adrenomedullin in gastric adenocarcinoma tissues,and to construct a eukaryotic expression vector that effectively overexpresses adrenomedullin gene and a short hairpin RNA eukaryotic expression vector that effectively inhibits adrenomedullin gene.This study lays the foundation for exploring the impact of adrenomedullin on solid tumors.Methods:A total of 60 samples of gastric adenocarcinoma tissues and adjacent tissues were collected.Immunohistochemical staining was used to verify the expression of adrenomedullin in gastric adenocarcinoma and the adjacent tissues.According to the adrenomedullin gene sequence in the National Center for Biotechnology Information and the design principle of the small interfering RNA target sequence,design and construct three specific short hairpin RNA expression vectors targeting the adrenomedullin gene mRNA and one homology using the lentiviral vector KLPO.1.The negative control vector,RT-PCR and Western blotting methods were used to detect the expression of the adrenomedullin gene,and the expression vector with the best inhibitory effect was selected.The eukaryotic expression vector pcDNA3 was used to construct an overexpression vector containing the full length of the adrenomedullin cDNA.RT-PCR and Western blotting methods were used to detect the expression of the adrenomedullin gene.Results:The PLKO.1-adrenomedullin with the best inhibitory effect and the human adrenomedullin gene overexpression vector pcDNA-adrenomedullin were successfully constructed and screened.Conclusion:Adrenomedullin is highly expressed in gastric cancer,and effectively inhibiting the expression of adrenomedullin in gastric cancer may have certain value in the treatment of gastric cancer.

Understanding the role of transmembrane 9 superfamily member 1 in bladder cancer pathogenesis

In this editorial we comment on the article by Wei et al,published in the recent issue of the World Journal of Clinical Oncology.The authors investigated the role of Transmembrane 9 superfamily member 1(TM9SF1)protein in bladder cancer(BC)carcinogenesis.Lentiviral vectors were used to achieve silencing or overexpression of TM9SF1 gene in three BC cell lines.These cell lines were then subject to cell counting kit 8,wound-healing assay,transwell assay,and flow cytometry.Proliferation,migration,and invasion of BC cells were increased in cell lines subjected to TM9SF1 overexpression.TM9SF1 silencing inhibited proliferation,migration and invasion of BC cells.The authors conclude that TM9SF1 may be an oncogene in bladder cancer pathogenesis.

Lentivector-mediated RNAi efficiently downregulatesexpression of murine cdk4 gene in vitro

In order to explore the role of cyclin-dependent kinase 4(cdk4)in neurodegenerative diseases,lentiviral-delivered RNA interference(RNAi)was used to silence the expression of the murine cdk4 gene in vitro.Three cdk4-shRNAs of mouse and a negative sequence were designed.After synthesis and annealing,double strand oligonucleo-tides were cloned into a linearized pSIH1-H1-copGFP shRNA vector.It was confirmed by polymerase chain reaction(PCR)and sequencing that three pairs of cdk4-shRNAs and a negative shRNA were correctly inserted into the pSIH1-H1-copGFP vector.The above recombi-nants were transfected by lipofectamine into BV-2 cells.The gene silencing efficacy rates of the 3 targets were compared by Western blotting.The cdk4-siRNA2 was the most effective in silencing cdk4.The optimized pSIH1-cdk4-siRNA2 and pSIH-negative-siRNA were co-transfected into 293T cells with the lentiviral packaging plasmids respectively.The culture supernatant was har-vested and condensed at the 24th and 48th h after transfection.Interference efficiency of the lentivirus expressing cdk4-siRNA was determined by reverse transcriptase-PCR(RT-PCR)and Western blotting in BV-2 cells.Lentivector-mediated RNAi could efficiently down-regulate the expression of the murine cdk4 gene in vitro,which provides a potential tool for studying and treating cdk4-related diseases.