ABSTRACT
Objective To seek an optimal method for the separation,culture of mouse embryonic germ cells (EGCs) in vitro,and to observe the influence of Activated Schwann cells (ASCs)-derived neurotrophins on the differentiation capability of mouse EGCs into neurogenic cells.Methods The gonadal ridges and a few abdominal tissues of the 11-day postcoitum (dpc) mouse embryos were isolated and disaggregated by 0.125％ trypsin-0.02％ EDTA,followed by culture of the mouse EGCs on mouse embryonic fibroblast (MEF) feeders.Monoclonal formation of the mouse EGCs was observed,and the staining of stage specificity embryo antigen-1 (SSEA-1),alkaline phosphatase (AKP),periodic acid-Schiff staining (PAS) were applied to identify the mouse EGCs.Two groups were divided as followed:mouse EGCs+basic medium (control group) and mouse EGCs+ASCs (experimental group).Immunofluorescence (NeuN,MBP,GFAP)analysis was used to evaluate the neurogenic differentiation of mouse EGCs and then to calculate the statistical positive rates of cell staining.All experimental results were analyzed statistically.Results (1) Identification ofmouse EGCs:Mouse EGCs were characterized by a dome-shaped colony containing a large nucleus and a relatively small amount of cytoplasm.All mouse EGCs were positive staining of SSEA-1,AKP,and PAS;(2)The neural induction of mouse EGCs:After one week induction,there were few round or oval cells with long axon-like processes migrating from the edge of the EGCs clones.3 weeks later,the neurogenic-like cells increased quickly.The results of immunofluorescence (NeuN,MBP,GFAP)staining demonstrated that mouse EGCs could differentiate into neurogenic cells under the influence of ASCs.The positive rate of cell staining was significant.Conclusion In this study,a simple,economical method was applied to successfully separate the mouse EGCs in vitro; mouse EGCs can differentiate into neurogenic cells under the influence of ASCs-derived neurotrophins.
ABSTRACT
The envelope protein(Env) of lentiviruses such as HIV,SIV,FIV and EIAV is larger than that of other retroviruses.The Chinese EIAV attenuated vaccine is based on Env and has helped to successfully control this virus,demonstrating that envelope is crucial for vaccine.We compared Env variation of the four kinds of lentiviruses.Phylogenetic analysis showed that the evolutionary relationship of Env between HIV and SIV was the closest and they appeared to descend from a common ancestor,and the relationship of HIV and EIAV was the furthest.EIAV had the shortest Env length and the least number of potential N-linked glycosylation sites(PNGS) as well as glycosylation density compared to various immunodeficiency viruses.However,HIV had the longest Env length and the most PNGS.Moreover,the alignment of HIV and SIV showed that PNGS were primarily distributed within extracellular membrane protein gp120 rather than transmembrane gp41.It implies that the size difference among these viruses is associated with a lentivirus specific function and also the diversity of env.There are low levels of modification of glycosylation sites of Env and selection of optimal protective epitopes might be useful for development of an effective vaccine against HIV/AIDS.
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The ubiquitin-like modifier bISG15 is an antiviral protein found in fetal bovine lung (FBL) cells.Bovine Herpesvirus 1(BHV-1),which is a viral pathogen of cattle,can infect FBL cells and induce cytopathic effects.Real-time PCR assays showed that BHV- 1 's infection could repress the basal or inducible transcription of bISG15 in FBL cells.It demonstrates that this repression effect depends on BHV-1 viral infection and new protein synthesis.Our previous work showed that bIRF-3 was the key factor in the stimulation of bISG 15 in FBL cells,so the effect of BHV-1 viral protein on bIRF-3 activating the promoter of bISG15 was confirmed.The luciferase assay showed the BHV-1 viral protein bICP0 inhibited the activation of bISG15 promoter stimulated by bIRF-3.Taken together,our work suggested that BHV-I had some molecular mechanism to resist the cellular bISG15'santiviral functions.
ABSTRACT
Perinatal transmission of Human immunodeficiency virus(HIV),also called mother-to-child transmission(MTCT),accounts for 90% of infections in infants worldwide and occurs in 30%-45% of children born to untreated HIV-1 infected mothers.Among HIV-1 infected mothers,some viruses are transmitted from mothers to their infants while others are not.The relationship between virologic properties and the pathogenesis caused by HIV-1 remains unclear.Previous studies have demonstrated that one obvious source of selective pressure in the perinatal transmission of HIV-1 is maternal neutralizing antibodies.Recent studies have shown that viruses which are successfully transmitted to the child have growth advantages over those not transmitted,when those two viruses are grown together.Furthermore,the higher fitness is determined by the gp120 protein of the virus envelope.This suggests that the selective transmission of viruses with higher fitness occurred exclusively,regardless of transmission routes.There are many factors contributing to the selective transmission and HIV replicative fitness is an important one that should not be neglected.This review summarizes current knowledge of the role of HIV replicative fitness in HIV MTCT transmission and the determinants of viral fitness upon MTCT.
ABSTRACT
Objective To observe the effect of treating acute spinal cord injury in rats by transplantation of autologous activated Schwann cells(AASCs). Methods Unilateral saphenous nerves were ligated directly, free it and culture Schwann cells 1 week later using the tissue clot method. Nerve growth factor(NGF) and brain-derived neurotrophic factor(BDNF) in medium were detected in different periods. 90 female Wistar rats[(200?30) g] were randomly assigned to 3 different study groups as follows: control group A(n=30): 20% DMEM injection; research group B(n=30): autologous Schwann cells(ASCs) transplantation; research group C (n=30): AASCs transplantation. The cells were purified before transplantion to the injuried T10 spinal cord site of rats (New York University type weight drop apparatus, NYU). The recoveries of the lower extremity were observed using Basso-Beattie-Bresnahan(BBB) locomotor scoring system and somatosensory evoked potential and motor evoked potentials(SEP & MEP). And then observe the coticospinal tract(CST) using the biotinylated dextran amine(BDA) tracing. Results BBB score was higher in research group than the control group 4 weeks after injury, the statistical difference was significant(P