Expression and significance of HBV genes and their antigens in human primary intrahepatic cholangiocarcinoma

AIM To explore the etiology and pathogenesis of human primary intrahepatic cholangiocarcinoma, the expression of HBV genes and HBV-antigens was detected in the cancerous tissue and its surrounding hepatic tissues.METHODS HBV-antigens were detected by immunohistochemical technique and HBV genes were examined with in situ hybridization.RESULTS In 20 cases of cholangiocarcinoma, the positive detection rate of HBxAg, pre-S1, pre-S2, HBsAg and HBcAg was 75%, 40%, 40%, 10% and 0%, respectively, and in the surrounding hepatic tissues of 19 cases the positive rates were 84.2%, 47.9%, 47.9%, 31.6% and 31.6%. Among 40 cases of cholangiocarcinoma, the positive rate of HBV-DNA, x gene, pre-s gene, s gene and s gene fell on 77.5%, 70.0%, 47.5%, 40% and 42.5%, respectively, and of the surrounding hepatic tissues in 33 cases, 87.9%, 84.8%, 63.6%, 69.7% and 66.7%.CONCLUSION The development of human primary intrahepatic cholangiocarcinoma bears a close relationship with chronic persistent HBV infection. Particularly, the x gene of HBV and its protein (HBxAg) might play an important role in pathogenesis of hepatic carcinoma.A large number of studies indicate a close relationship between human primary hepatocellular carcinoma and hepatitis B virus (HBV) infection, which is considered generally as an important factor in the development of hepatic carcinoma[1,2]. In human primary hepatic carcinoma, hepatocellular carcinoma is more frequently encountered, while intrahepatic cholangiocarcinoma (ChC), including hepatocholangiocarcinoma (HChC), is relatively less, being 8%-10%[3]. For a long time, the etiology and pathogenesis of intrahepatic cholangiocarcinoma have been unclear. A few reports considered it to be related to infestation with clonorchiasis sinensis[4,5], but never involved with HBV infection. We used immunohistochemical technique and in situ hybridization methods to detect HBV genes and their -related antigens in the tissues of intrahepatic cholangiocarcinoma and its surrounding hepatic tissues for the purpose of exploring the etiology and pathogenesis of intrahepatic cholangiocarcinoma.

Sequencing of PCR amplified HBV DNA pre-c and c regions in 2.2.15 cells and antiviral action by targeted antisense oligonucleotide directed against sequence

AIM To study the specific inhibition of HBV gene expression by liver-targeting antisense oligonucleotide (ASON) directed against pre-c and c regious in a sequence-specific manner.METHODS According to the result of direct sequencing of PCR amplified products, a 16-mer phosphorothioate analogue of the antisense oligonucleotide (PS-ASOn) directed against the HBV U5-like region was synthesized and then linked with one live-targeting ligand, the galactosylated poly-L-lysine. Their effect on the expression of HBV gene was observed using the 2.2.15 cells.RESULTS HBV DNA in the 2.2.15 cells was from HBV with surface antigen subtype ayw1 by sequencing so that antisense oligonucleotides could bind specifically to the target sequence through base piring. Under the same experimental conditions, the inhibitory rates of PS-ASON to HBsAg and HBeAg were 70% and 58% at a concentration of 10μmol/L, while by ligand-PS-ASON they were 96% and 82%, the amount of HBV DNA in cultured supernatant and cells was reduced significantly. An unrelated sequence oligonucleotide showed no effectiveness. All the oligonucleotides had no cytotoxicity.CONCLUSION Antisense oligonucleotides complexed by the liver-targeting ligand can be targeted to cells via asialoglycoprotein receptors, resulting in supecific inhibition of HBV gene expression and replication.

Differentially expressed genes in hepatocellular carcinoma induced by woodchuck hepatitis B virus in mice

INTRODUCTIONHepatocellular carcinoma(HCC)is one of the major causes of death in the word.The mechanism of carcinogenesis is unknown,although it is widely accepted that HBV and HCV are clsely related to liver cancer[1-5[1-5].Previously,a variety of studies have described the differences in gene expression which distinguished tumor from nontumor[6-11].Cloning of the genes,especially the genes associated with HBV and HCV,is still very important to account for the development of liver cancer.

Fibrinogen-like protein 2 fibroleukin expression and its correlation with disease progression in murine hepatitis virus type 3-induced fulminant hepatitis and in patients with severe viral hepatitis B

AIM： To evaluate the expression of fibrinogenlike protein 2 （fgl2） and its correlation with disease progression in both mice and patients with severe viral hepatitis. METHODS： Balb/cJ or A/J mice were infected intraperitoneally （ip） with 100 PFU of murine hepatitis virus type 3 （MHV-3）, liver and serum were harvested at 24, 48, and 72 h post infection for further use. Liver tissues were obtained from 23 patients with severe acute chronic （AOC） hepatitis B and 13 patients with mild chronic hepatitis B. Fourteen patients with mild chronic hepatitis B with cirrhosis and 4 liver donors served as normal controls. In addition, peripheral blood mononuciear cells （PBMC） were isolated from 30 patients （unpaired） with severe AOC hepatitis B and 10 healthy volunteers as controls. Procoagulant activity representing functional prothrombinase activity in PBMC and white blood cells was also assayed. A polyclonal antibody against fgl2 was used to detect the expression of both mouse and human fgl2 protein in liver samples as well as in PBMC by immunohistochemistry staining in a separate set of studies. Alanine aminotransferase （ALT） and total bilirubin （TBil） in serum were measured to assess the severity of liver injury.RESULTS： Histological changes were found in liver sections 12-24 h post MHV-3 infection in Balb/cJ mice. In association with changes in liver histology, marked elevations in serum ALT and TBil were observed. House fgl2 （mfgl2） protein was detected in the endothelium of intrahepatic veins and hepatic sinusoids within the liver 24 h after MHV-3 infection. Liver tissues from the patients with severe AOC hepatitis B had classical pathological features of acute necroinflammation. Human fgl2 （hfgl2） was detected in 21 of 23 patients （91.30%） with severe AOC hepatitis B, while only 1 of 13 patients （7.69%） with mild chronic hepatitis B and cirrhosis had hfgl2 mRNA or protein expression. Twenty-eight of thirty patients （93.33%） with severe AOC hepatitis B and 1 of 10 with mild chronic hepatitis B had detectable hfgl2 expression in PBMC. No hfgl2 expression was found either in the liver tissue or in the PBMC from normal donors. There was a positive correlation between hfgl2 expression and the severity of the liver disease as indicated by the levels of TBil. PCA significantly increased in PBMC in patients with severe AOC hepatitis B. CONCLUSION： The molecular and cellular results reported here in both mice and patients with severe viral hepatitis suggest that virus-induced hfgl2 prothrombinase/fibroleukin expression and the coagulation activity associated with the encoded fgl2 protein play a pivotal role in initiating severe hepatitis. The measurement of hfgl2/fibroleukin expression in PBMC may serve as a useful marker to monitor the severity of AOC hepatitis B and a target for therapeutic intervention.

RNAi,a new therapeutic strategy against viral infection

RNA interference (RNAi) is an adaptive defense mechanism triggered by double-stranded RNA (dsRNA). It is a powerful reverse genetic tool that has been widely employed to silence gene expression in mammalian and human cells.RNAi-based gene therapies, especially in viral diseases have become more and more interesting and promising. Recently,small interfering RNA (siRNA) can be used to protect host from viral infection, inhibit the expression of viral antigen and accessory genes, control the transcription and replication of viral genome, hinder the assembly of viral particles, and display influences in virus-host interactions. In this review, we attempt to present recent progresses of this breakthrough technology in the above fields and summarize the possibilities of siRNA-based drugs.

Inhibitory effects of Shuanghuanglian injection on nuclear factor-kappa B expression in mice with viral encephalitis in a time-and dose-dependent manner

Previous studies have confirmed that the anti-virus effects of Shuanghuanglian injection may be associated with nuclear factor-kappa B activity. This study observed nuclear factor-kappa B expression in mice with viral encephalitis, and showed significant decreases in nuclear factor-kappa B protein and mRNA levels following Shuanghuanglian injection. The inhibitory effect was more significant with prolonged intervention duration and increased treatment dose. These findings verify that Shuanghuanglian injection plays a therapeutic role in viral encephalitis by reducing expression of nuclear factor-kappa B in a time- and dose-dependent manner.

Applying a highly specific and reproducible cDNA RDA method to clone garlic up-regulated genes in human gastric cancer cells

AIM: To develop and optimize cDNA representational difference analysis (cDNA RDA) method and to identify and clone garlic up-regulated genes in human gastric cancer (HGC) cells. METHODS: We performed cDNA RDA method by using abundant double-stranded cDNA messages provided by two self-constructed cDNA libraries (Allitridi-treated and paternal HGC cell line BGC823 cells cDNA libraries respectively). Bam H I and Xho I restriction sites harbored in the library vector were used to select representations. Northern and Slot blots analyses were employed to identify the obtained difference products. RESULTS: Fragments released from the cDNA library vector after restriction endonuclease digestion acted as good marker indicating the appropriate digestion degree for library DNA. Two novel expressed sequence tags (ESTs) and a recombinant gene were obtained. Slot blots result showed a 8-fold increase of glia-derived nexin/protease nexin 1 (GDN/PN1) gene expression level and 4-fold increase of hepatitis B virus x-interacting protein (XIP) mRNA level in BGC823 cells after Allitridi treatment for 72h. CONCLUSION: Elevated levels of GDN/PN1 and XIP mRNAs induced by Allitridi provide valuable molecular evidence for elucidating the garlic's efficacies against neurodegenerative and inflammatory diseases. Isolation of a recombinant gene and two novel ESTs further show cDNA RDA based on cDNA libraries to be a powerful method with high specificity and reproducibility in cloning differentially expressed genes.

Relationship between HBV genotypes and anti-viral therapeutic efficacy of interferon-alpha

BACKGROUND: Much evidence demonstrates that the genotypes of hepatitis B virus (HBV) present differences in pathogenicity and outcomes owing to differences in genetic structure. This study aimed to investigate the influences of HBV genotypes on the anti-viral therapeutic efficacy of interferon-alpha (IFN-alpha) in chronic hepatitis B patients, and to determine the relationship between HBV genotypes and levels of viral replication or gene variations. METHODS: The chronic hepatitis B patients who were treated with IFN-alpha were selected randomly. Anti-viral therapeutic efficacy was monitored in these patients. The HBV genotypes were detected by PCR microplate hybridization ELISA. The levels of serum HBV-DNA were determined by fluorescence quantitative PCR. HBV gene variation at pre-C and basic core promoter (BCP) regions were assayed by gene chip technology. RESULTS: Genotypes B and C were predominant in 94 chronic hepatitis B patients. A, E and F genotypes were not found in these patients. The HBV-DNA levels of genotype C and mixed genotypes were significantly higher than those of genotype B. The response to IFN-alpha in patients with genotype B was markedly better than in those with genotypes C and D, and the complete response to IFN-alpha was only observed in genotype B. The response to IFN-alpha in patients with mixed genotypes was the least sensitive. The negative transition of HBeAg was correlated with variations in the HBV pre-C and BCP regions in patients with partial or no response to IFN-alpha. The variation rates of HBV pre-C and BCP regions were clearly higher in genotype C than in genotype B. CONCLUSIONS: The results suggest that HBV genotype is correlated with the serum levels of HBV-DNA, HBV gene variations and therapeutic efficacy of IFN-alpha. The regular detection of HBV genotypes in the clinic will be of benefit for disease prognosis and planning of anti-viral therapeutic strategies.

MicroRNA-regulated viral vectors for gene therapy

Safe and effective gene therapy approaches require targeted tissue-specific transfer of a therapeutic transgene.Besides traditional approaches, such as transcriptional and transductional targeting, micro RNA-dependent posttranscriptional suppression of transgene expression has been emerging as powerful new technology to increase the specificity of vector-mediated transgene expression. Micro RNAs are small non-coding RNAs and often expressed in a tissue-, lineage-, activation- or differentiation-specific pattern. They typically regulate gene expression by binding to imperfectly complementary sequences in the 3' untranslated region(UTR) of the m RNA. To control exogenous transgene expression, tandem repeats of artificial micro RNA target sites are usually incorporated into the 3' UTR of the transgene expression cassette, leading to subsequent degradation of transgene m RNA in cel s expressing the corresponding micro RNA. This targeting strategy, first shown for lentiviral vectors in antigen presenting cells, has now been used for tissue-specific expression of vector-encoded therapeutic transgenes, to reduce immune response against the transgene, to control virus tropism for oncolytic virotherapy, to increase safety of live attenuated virus vaccines and to identify and select cell subsets for pluripotent stem cell therapies, respectively. This review provides an introduction into the technical mechanism underlying micro RNA-regulation, highlights new developments in this field and gives an overview of applications of micro RNA-regulated viral vectors for cardiac, suicide gene cancer and hematopoietic stem cell therapy, as well as for treatment of neurological and eye diseases.

Surface Modification of Biomimetic PLGA-(ASP-PEG) Matrix with RGD-Containing Peptide:a New Non-Viral Vector for Gene Transfer and Tissue Engineering

RGD-containing peptide （ K16-GRGDSPC） , characterized as non-viral gene vectors, was fabricated to modify the surface of PLGA-[ASP- PEG] matrix, which offered the foundation for gene transfer with porous matrix of gene activated later. Peptide was synthesized and matrix was executed into chips A, B and chip C. Chip C was regarded as control. Chips A and B were reacted with cross-linker. Then chip A was reacted with peptide. MS and HPLC were ased to detect the .14W and purity of peptide. Sulphur, existing on the surface of biomaterials, was detected by XPS. The purity of un-reacted peptide in residual solution was detected by a spectrophotometer. HPLC shows that the peptide purity was 94%- 95% , and MS shows that the MW was 2 741. 3307. XPS reveals that the binding energy of sulphur was 164 eV and the ratio of carbon to sulphur （C/S） was 99. 746 ：0. 1014 in reacted chip A. The binding energy of sulphur in reacted chip B was 164 eV and 162 eV, C/ S was 99.574：0.4255, aM there was no sulphur in chip C. Peptide was manufactured and linked to the surface of biomimetic and 3-D matrix, which offered the possibilities for gene transfer and tissue engineering with this new kind of non-viral gene vector.

Cloning and sequence analysis of E2 gene of bovine viral diarrhea virus HB-DCZ strain in Hebei province of China

The objective of this paper was to analyze the E2 genetic characterization of HB-DCZ strain of Bovine viral diaxrhca Virus （BVDV） which wcrc amplified by RT-PCR and isolated from China. The product of PCK was cloned into pMD18-T vector, and then transfected Escherichia Coli JMI00. The recombinant plasmids were amplified by PCR and were sequenced. From the nucleotide sequence of the amplified products, phylogenetie analyses were performed and genotypes or subgenotypes were identified. The results indicated that the E2 gene fragment of HB-DCZ strain contained 1277bp nucleotides, and had 89.4%, 70.7%, 97.6%, 68.9%, 67.2% sequence similarity with Osloss, OregonC24V, Changchun184, ZM195, NADL, respectively. In conclusion, HB-DCZ strain is closely related to BVDV Osloss, Changchun184, and belongs to subgenotype lb.

Antiviral factors and their counteraction by HIV-1: many uncovered and more to be discovered

Extensive studies on HIV-1 have led to the discovery of a variety of structurally and functionally diverse innate defense factors that target various steps of the retroviral replication cycle.Some of them,such as APOBEC3,tetherin,and SERINC5,are well established.Their importance is evident from the fact that HIV-1 uses its accessory proteins Vif,Vpu,and Nef to counteract them.However,the list of antiviral factors is constantly increasing,and accumulating evidence suggests that innate defense mechanisms,which restrict HIV-1 and/or are counteracted by viral proteins,remain to be discovered.These antiviral factors are relevant to diseases other than HIV/AIDS,since they are commonly active against various viral pathogens.In this review,we provide an overview of recently reported antiretroviral factors and viral countermeasures,present the evidence suggesting that more innate defense mechanisms remain to be discovered,and discuss why this is a challenging but rewarding task.

A Viral Expression Vector from Foxtail mosaic virus to Express Green Fluorescent Protein

[Objective]Foxtail mosaic virus(FoMV)infects gramineous and dicotyledonous plants.In this study,we sought to construct a viral vector based on FoMV to express exogenous proteins in plants.[Method]A recombinant viral expression vector was constructed by inserting the promotor of Potato virus X(PVX)and exogenous gene sequences into the 3’non-coding region of the FoMV coat protein gene.[Results]The plasmid pCB301-FoMV-CP-PVXprom-GFP expressed green fluorescent protein in inoculated Nicotiana benthamiana leaves.[Conclusion]A recombinant viral expression vector was constructed successfully.

Correlation of peripheral blood IL-17A gene polymorphism with myocardial injury and MMPs/TIMPs balance in patients with viral myocarditis

Objective:To study the correlation of peripheral blood IL-17A gene polymorphism with myocardial injury and MMPs/TIMPs balance in patients with viral myocarditis.Methods:A total of 80 patients who were diagnosed with viral myocarditis in Dongguan Branch, Yan'an University Affiliated Hospital between September 2014 and September 2017 were selected as the VMC group of the research, and 100 healthy volunteers who received physical examination in Dongguan Branch, Yan'an University Affiliated Hospital during the same period were selected as the control group of the research. The peripheral blood was collected to determine the IL-17A gene rs2275913 locus polymorphism, and serum was collected to determine the contents of myocardial injury and MMPs/TIMPs indexes.Results: The proportion of IL-17A gene GG genotype of VMC group was lower than that of control group and the proportion of GA+AA genotype was higher than that of control group;serum IL-17, CK-MB, cTnI, sFas, MDA, PINP, ICTP, MMP2, MMP9, TIMP1 and TIMP2 contents of VMC group were significantly higher than those of control group, and serum IL-17, CK-MB, cTnI, sFas, MDA, PINP, ICTP, MMP2, MMP9, TIMP1 and TIMP2 contents of patients with GA+AA genotype in VMC group were higher than those of patients with GG genotype.Conclusion: The mutation of the allele G to A in the peripheral blood IL-17A gene rs2275913 locus of patients with viral myocarditis can aggravate myocardial injury and MMPs/TIMPs imbalance.

Fusion Wheat Histone H4 Protein Increases Transfection Efficiency of Non-viral DNA Vector

The lack of efficient and non-toxic gene delivery, preferably with non-viral DNA vectors, is generally regarded as a major limitation for gene therapy. In this study, a wheat histone H4 gene was cloned from Triticum aestivum, sequenced, modified and expressed in E. coli. The wheat histone H4 gene and reconstructed H4TL gene encoded wheat histone H4 and a recombinant protein of 141 amino acids with an approximate molecular weight of 15500. Gel electrophoresis mobility shift assays demonstrated that the purified protein had high affinity for DNA. Most significantly, the complex of plasmid pEGFP/C1 with H4TL was transfected with increased efficiency into MCF-7, HO8910, LNCap, A549 and HeLa cells in vitro. These results demonstrate that the targeting of non-viral vectors to tumor-specific receptors provides a cheap, simple and highly efficient tool for gene delivery.

Cloning of differentially expressed genes in human hepatocellular carcinoma and nontumor liver

INTRODUCTIONThe mechanism of hepatocellular carcinoma(HCC)is still unclear,although some genes have been found to play a role in the transformation of liver cells,and a variety of studies have described differences in gene expression which distinguished tumor from nontumor[1-6].The new genes,especially the functional genes directly related with tumor are still worth being found.The purpose of our study is to find the different genes between human liver tumor and normal tissues using suppression subtractive hybridization.

Viral-mediated gene therapy in pediatric neurological disorders

Background Due to the broad application of next-generation sequencing,the molecular diagnosis of genetic disorders in pediatric neurology is no longer an unachievable goal.However,treatments for neurological genetic disorders in children remain primarily symptomatic.On the other hand,with the continuous evolution of therapeutic viral vectors,gene therapy is becoming a clinical reality.From this perspective,we wrote this review to illustrate the current state regarding viral-mediated gene therapy in childhood neurological disorders.Data sources We searched databases,including PubMed and Google Scholar,using the keywords"adenovirus vector,""lentivirus vector,"and"AAv"for gene therapy,and"immunoreaction induced by gene therapy vectors,""administration routes of gene therapy vectors,"and"gene therapy"with"NCL,""SMA,""DMD,""congenital myopathy,""MPS""leukodystrophy,"or"pediatric metabolic disorders".We also screened the database of ClinicalTrials.gov using the keywords"gene therapy for children"and then filtered the results with the ones aimed at neurological disorders.The time range of the search procedure was from the inception of the databases to the present.Results We presented the characteristics of commonly used viral vectors for gene therapy for pediatric neurological disorders and summarized their merits and drawbacks,the administration routes of each vector,the research progress,and the clinical application status of viral-mediated gene therapy on pediatric neurological disorders.Conclusions Viral-mediated gene therapy is on the brink of broad clinical application.Viral-mediated gene therapy will dramatically change the treatment pattern of childhood neurological disorders,and many children with incurable diseases will meet the dawn of a cure.Nevertheless,the vectors must be optimized for better safety and efficacy.

Hemodialysis bilayer bionic blood vessels developed by the mechanical stimulation of hepatitis B viral X(HBX)genetransfected hepatic stellate cells

Artificial vascular graft(AVG)fistula is widely used for hemodialysis treatment in patients with renal failure.However,it has poor elasticity and compliance,leading to stenosis and thrombosis.The ideal artificial blood vessel for dialysis should replicate the structure and components of a real artery,which is primarily maintained by collagen in the extracellular matrix(ECM)of arterial cells.Studies have revealed that in hepatitis B virus(HBV)-induced liver fibrosis,hepatic stellate cells(HSCs)become hyperactive and produce excessive ECM fibers.Furthermore,mechanical stimulation can encourage ECM secretion and remodeling of a fiber structure.Based on the above factors,we transfected HSCs with the hepatitis B viral X(HBX)gene for simulating the process of HBV infection.Subsequently,these HBX-HSCs were implanted into a polycaprolactonepolyurethane(PCL-PU)bilayer scaffold in which the inner layer is dense and the outer layer consists of pores,which was mechanically stimulated to promote the secretion of collagen nanofiber from the HBX-HSCs and to facilitate crosslinking with the scaffold.We obtained an ECM-PCL-PU composite bionic blood vessel that could act as access for dialysis after decellularization.Then,the vessel scaffold was implanted into a rabbit’s neck arteriovenous fistula model.It exhibited strong tensile strength and smooth blood flow and formed autologous blood vessels in the rabbit’s body.Our study demonstrates the use of human cells to create biomimetic dialysis blood vessels,providing a novel approach for creating clinical vascular access for dialysis.

Non-viral and viral delivery systems for CRISPR-Cas9 technology in the biomedical field

The clustered regularly interspaced short palindromic repeats(CRISPR)-associated protein 9(CRISPR-Cas9) system provides a novel genome editing technology that can precisely target a genomic site to disrupt or repair a specific gene. Some CRISPR-Cas9 systems from different bacteria or artificial variants have been discovered or constructed by biologists, and Cas9 nucleases and single guide RNAs(sgRNA) are the major components of the CRISPR-Cas9 system. These Cas9 systems have been extensively applied for identifying therapeutic targets, identifying gene functions, generating animal models, and developing gene therapies.Moreover, CRISPR-Cas9 systems have been used to partially or completely alleviate disease symptoms by mutating or correcting related genes. However, the efficient transfer of CRISPR-Cas9 system into cells and target organs remains a challenge that affects the robust and precise genome editing activity. The current review focuses on delivery systems for Cas9 mRNA, Cas9 protein, or vectors encoding the Cas9 gene and corresponding sgRNA. Non-viral delivery of Cas9 appears to help Cas9 maintain its on-target effect and reduce off-target effects, and viral vectors for sgRNA and donor template can improve the efficacy of genome editing and homology-directed repair. Safe, efficient, and producible delivery systems will promote the application of CRISPR-Cas9 technology in human gene therapy.

Increasingβ-hexosaminidase A activity using genetically modified mesenchymal stem cells

GM2 gangliosidoses are a group of autosomal-recessive lysosomal storage disorde rs.These diseases result from a deficiency of lysosomal enzymeβ-hexosaminidase A(HexA),which is responsible for GM2 ganglioside degradation.HexA deficiency causes the accumulation of GM2-gangliosides mainly in the nervous system cells,leading to severe progressive neurodegeneration and neuroinflammation.To date,there is no treatment for these diseases.Cell-mediated gene therapy is considered a promising treatment for GM2 gangliosidoses.This study aimed to evaluate the ability of genetically modified mesenchymal stem cells(MSCs-HEXA-HEXB)to restore HexA deficiency in Tay-Sachs disease patient cells,as well as to analyze the functionality and biodistribution of MSCs in vivo.The effectiveness of HexA deficiency cross-correction was shown in mutant MSCs upon intera ction with MSCs-HEXA-HEXB.The results also showed that the MSCs-HEXA-HEXB express the functionally active HexA enzyme,detectable in vivo,and intravenous injection of the cells does not cause an immune response in animals.These data suggest that genetically modified mesenchymal stem cells have the potentials to treat GM2 gangliosidoses.