Production of recombinant adenovirus containing human interlukin-4 gene.
Mojarrad, Majid; Abdolazimi, Yassan; Hajati, Jamshid; Modarressi, Mohammad Hossein
2011-11-01
Recombinant adenoviruses are currently used for a variety of purposes, including in vitro gene transfer, in vivo vaccination, and gene therapy. Ability to infect many cell types, high efficiency in gene transfer, entering both dividing and non dividing cells, and growing to high titers make this virus a good choice for using in various experiments. In the present experiment, a recombinant adenovirus containing human IL-4 coding sequence was made. IL-4 has several characteristics that made it a good choice for using in cancer gene therapy, controlling inflammatory diseases, and studies on autoimmune diseases. In brief, IL-4 coding sequence was amplified by and cloned in pAd-Track-CMV. Then, by means of homologous recombination between recombinant pAd-Track-CMV and Adeasy-1 plasmid in bacteria, recombinant adenovirus complete genome was made and IL-4 containing shuttle vector was incorporated into the viral backbone. After linearization, for virus packaging, viral genome was transfected into HEK-293 cell line. Viral production was conveniently followed with the aid of green fluorescent protein. Recombinant adenovirus produced here, was capable to infecting cell lines and express interlukin-4 in cell. This system can be used as a powerful, easy, and cost benefit tool in various studies on cancer gene therapy and also studies on immunogenetics.
Protection of Non-Human Primates against Rabies with an Adenovirus Recombinant Vaccine
Xiang, Z.Q.; Greenberg, L.; Ertl, H. C.; Rupprecht, C.E.
2014-01-01
Rabies remains a major neglected global zoonosis. New vaccine strategies are needed for human rabies prophylaxis. A single intramuscular immunization with a moderate dose of an experimental chimpanzee adenovirus (Ad) vector serotype SAd-V24, also termed AdC68, expressing the rabies virus glycoprotein, resulted in sustained titers of rabies virus neutralizing antibodies and protection against a lethal rabies virus challenge infection in a non-human primate model. Taken together, these data demonstrate the safety, immunogenicity, and efficacy of the recombinant Ad-rabies vector for further consideration in human clinical trials. PMID:24503087
Production of Recombinant Adenovirus Containing Human Interlukin-4 Gene
Mojarrad, Majid; Abdolazimi, Yassan; Hajati, Jamshid; Modarressi, Mohammad Hossein
2011-01-01
Objective(s) Recombinant adenoviruses are currently used for a variety of purposes, including in vitro gene transfer, in vivo vaccination, and gene therapy. Ability to infect many cell types, high efficiency in gene transfer, entering both dividing and non dividing cells, and growing to high titers make this virus a good choice for using in various experiments. In the present experiment, a recombinant adenovirus containing human IL-4 coding sequence was made. IL-4 has several characteristics that made it a good choice for using in cancer gene therapy, controlling inflammatory diseases, and studies on autoimmune diseases. Materials and Methods In brief, IL-4 coding sequence was amplified by and cloned in pAd-Track-CMV. Then, by means of homologous recombination between recombinant pAd-Track-CMV and Adeasy-1 plasmid in bacteria, recombinant adenovirus complete genome was made and IL-4 containing shuttle vector was incorporated into the viral backbone. After linearization, for virus packaging, viral genome was transfected into HEK-293 cell line. Viral production was conveniently followed with the aid of green fluorescent protein. Results Recombinant adenovirus produced here, was capable to infecting cell lines and express interlukin-4 in cell. Conclusion This system can be used as a powerful, easy, and cost benefit tool in various studies on cancer gene therapy and also studies on immunogenetics. PMID:23493491
Shang, Shu-huan; Zhang, Yu-feng; Shi, Bin; Cheng, Xiang-rong
2008-10-01
To construct a recombinant human platelet-derived growth factor-B (PDGF-B) adenoviral vector and to transfect it into human periodontal ligament stem cells (PDLSC). The recombinant plasmid pAd-PDGF-B was constructed by homologous recombination and confirmed by restriction endonucleases digestion. Recombinant adenovirus was packaged in HEK293 cells. PDLSC were transfected with recombinant adenovirus and PDGF-B expression was confirmed. Expression of collagen type I gene was determined by quantitative analysis of the products of RT-PCR. The cell proliferation was determined with MTT colorimetric assay. The recombinant plasmid pAd-PDGF-B was confirmed by restriction endonucleases digestion. EGFP expression was observed on the third day after transfecting, and the expression of PDGF-B was detected. Immunohistochemical methods revealed that PDGF-B was expressed in PDLSC. Levels of expression of collagen type I gene were increased significantly by transfer of the exogenous PDGF-B gene to PDLSC. At the same time, findings indicated that Ad-PDGF-B stimulated PDLSC proliferation. MTT assay indicated the absorbance of PDLSC by stimulating with Ad-PDGF-B was (0.68 +/- 0.02), P < 0.01. Using the AdEasy system, the human PDGF-B recombinant adenovirus can be rapidly obtained. These results indicate that recombinant adenoviruses encoding PDGF-B transgenes could modulate proliferative activity of PDLSC, enhance the high expression of collagen type I and lay the foundation for periodontal tissue regeneration and dental implant gene therapy.
Cabrera-Mora, Monica; Fonseca, Jairo Andres; Singh, Balwan; Zhao, Chunxia; Makarova, Natalia; Dmitriev, Igor; Curiel, David T.; Blackwell, Jerry; Moreno, Alberto
2016-01-01
An ideal malaria vaccine should target several stages of the parasite life cycle and induce anti-parasite and anti-disease immunity. We have reported a Plasmodium yoelii chimeric multi-stage recombinant protein (PyLPC/RMC), engineered to express several autologous T cell epitopes and sequences derived from the circumsporozoite protein (CSP) and the merozoite surface protein 1 (MSP-1). This chimeric protein elicits protective immunity, mediated by CD4+ T cells and neutralizing antibodies. However, experimental evidence from pre-erythrocytic vaccine candidates and irradiated sporozoites has shown that CD8+ T cells play a significant role in protection. Recombinant viral vectors have been used as a vaccine platform to elicit effective CD8+ T cell responses. The human adenovirus serotype 5 (Ad5) has been tested in malaria vaccine clinical trials with excellent safety profile. Nevertheless, a major concern for the use of Ad5 is the high prevalence of anti-vector neutralizing antibodies in humans, hampering its immunogenicity. To minimize the impact of anti-vector pre-existing immunity we developed a chimeric Ad5/3 vector in which the knob region of Ad5 was replaced with that of Ad3, conferring partial resistance to anti-Ad5 neutralizing antibodies. Furthermore, we implemented heterologous adenovirus/protein immunization regimens which include a single immunization with recombinant Ad vectors. Our data show that immunization with the recombinant Ad5/3 vector induces protective efficacy indistinguishable from that elicited by Ad5. Our study also demonstrate that the dose of the Ad vectors has an impact on the memory profile and protective efficacy. The results support further studies with Ad5/3 for malaria vaccine development. PMID:27574299
Construction of human artificial chromosome vectors by recombineering.
Kotzamanis, George; Cheung, Wing; Abdulrazzak, Hassan; Perez-Luz, Sara; Howe, Steven; Cooke, Howard; Huxley, Clare
2005-05-23
Human artificial chromosomes (HACs) can be formed de novo by transfection of large fragments of cloned alphoid DNA into human HT1080 cells in tissue culture. In order to generate HACs carrying a gene of interest, one can either co-transfect the alphoid DNA and the gene of interest, or one can clone both into a single vector prior to transfection. Here we describe linking approximately 70 kb of alphoid DNA onto a 156-kb BAC carrying the human HPRT gene using Red homologous recombination in the EL350 Escherichia coli host [Lee et al., Genomics 73 (2001) 56-65]. A selectable marker and EGFP marker were then added by loxP/Cre recombination using the arabinose inducible cre gene in the EL350 bacteria. The final construct generates minichromosomes in HT1080 cells and the HPRT gene is expressed. The retrofitting vector can be used to add the approximately 70 kb of alphoid DNA to any BAC carrying a gene of interest to generate a HAC vector. The method can also be used to link any unrelated BAC or PAC insert onto another BAC clone. The EL350 bacteria are an excellent host for building up complex vectors by a combination of homologous and loxP/Cre recombination.
Yan, Ruicheng; Huang, Jiancong; Zhu, Ling; Chang, Lihong; Li, Jingjia; Wu, Xifu; Ye, Jin; Zhang, Gehua
2015-12-01
The optimal multiplicity of infection (MOI) of the recombinant adenovirus Ad-Rad50-GFP carrying a mutant Rad50 gene expression region on the cell growth of nasopharyngeal carcinoma and the viral amplification efficiency of CNE1 cell infected by this adenovirus were studied. The biological titer of Ad-Rad50-GFP was measured by end point dilution method. The impact of recombinant adenoviral vector transfection on the growth of CNE1 cells was observed by cell growth curve. Transfection efficacy of recombinant adenoviral vector was observed and calculated through fluorescence microscope. The expression f mutant Rad50 in the Ad-Rad50-GFP transfected CNE1 cells with optimal MOI was detected by Western Blot after transfection. The biological titer of Ad-Rad50-GFP was 1.26 x 10¹¹ pfu/ml. CNE1 cell growth was not influenced significantly as they were transfected by recombinant adenoviral vector with MOI less than 50. Transfection efficacy of recombinant adenoviral vector was most salient at 24 hours after transfection, with the high expression of mutant Rad50, and the efficiency still remained about 70% after 72 hours. Recombinant adenoviral vector Ad-Rad50-GFP could transfect CNE1 cells as well as result in the expression of mutant Rad50 in CNE1 cells effectively. MOI = 50 was the optimal multiplicity of infection of CNE1 cells transfected by recombinant adenoviral vector Ad-Rad50-GFP.
Recombinant human Tat-Hsp70-2: A tool for neuroprotection.
Cappelletti, Pamela; Binda, Elisa; Tunesi, Marta; Albani, Diego; Giordano, Carmen; Molla, Gianluca; Pollegioni, Loredano
2017-10-01
Human Hsp70-2 is a chaperone expressed mainly in the nervous system. Up to now, no study has reported on the recombinant expression of this important human chaperone. Herein, we describe the successful purification and characterization of recombinant human Hsp70-2 in Escherichia coli in both the full-length and the chimeric protein containing the protein transduction domain corresponding to the trans-activator of transcription (Tat) from HIV. Under optimized conditions, the Tat-Hsp70-2 was expressed in a soluble form and purified by two chromatographic steps (in a 3.6 mg/L fermentation broth yield): recombinant Tat-Hsp70-2 was folded and showed ATPase activity. In contrast, the full-length recombinant protein was only expressed in the form of inclusion bodies and thus was purified following a refolding procedure. The refolded Hsp70-2 protein was inactive and the protein conformation slightly altered as compared to the corresponding Tat-fused variant. The Tat-Hsp70-2 protein (100 nM), when added to human neuroblastoma SH-SY5Y cells subjected to hydrogen peroxide or 6-hydroxydopamine stress, partially protected from the deleterious effect of these treatments. This work describes an approach for the functional expression of human Tat-Hsp70-2 that provides sufficient material for detailed structure-function studies and for testing its ability to protect neuroblastoma cells from oxidative stress. Copyright © 2016 Elsevier Inc. All rights reserved.
Protection of non-human primates against rabies with an adenovirus recombinant vaccine
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xiang, Z.Q.; Greenberg, L.; Ertl, H.C., E-mail: ertl@wistar.upenn.edu
Rabies remains a major neglected global zoonosis. New vaccine strategies are needed for human rabies prophylaxis. A single intramuscular immunization with a moderate dose of an experimental chimpanzee adenovirus (Ad) vector serotype SAd-V24, also termed AdC68, expressing the rabies virus glycoprotein, resulted in sustained titers of rabies virus neutralizing antibodies and protection against a lethal rabies virus challenge infection in a non-human primate model. Taken together, these data demonstrate the safety, immunogenicity, and efficacy of the recombinant Ad-rabies vector for further consideration in human clinical trials. - Highlights: • Pre-exposure vaccination with vaccine based on a chimpanzee derived adenovirus protectsmore » against rabies. • Protection is sustained. • Protection is achieved with single low-dose of vaccine given intramuscularly. • Protection is not affected by pre-existing antibodies to common human serotypes of adenovirus.« less
Age-Dependent Recombination Rates in Human Pedigrees
Hussin, Julie; Roy-Gagnon, Marie-Hélène; Gendron, Roxanne; Andelfinger, Gregor; Awadalla, Philip
2011-01-01
In humans, chromosome-number abnormalities have been associated with altered recombination and increased maternal age. Therefore, age-related effects on recombination are of major importance, especially in relation to the mechanisms involved in human trisomies. Here, we examine the relationship between maternal age and recombination rate in humans. We localized crossovers at high resolution by using over 600,000 markers genotyped in a panel of 69 French-Canadian pedigrees, revealing recombination events in 195 maternal meioses. Overall, we observed the general patterns of variation in fine-scale recombination rates previously reported in humans. However, we make the first observation of a significant decrease in recombination rates with advancing maternal age in humans, likely driven by chromosome-specific effects. The effect appears to be localized in the middle section of chromosomal arms and near subtelomeric regions. We postulate that, for some chromosomes, protection against non-disjunction provided by recombination becomes less efficient with advancing maternal age, which can be partly responsible for the higher rates of aneuploidy in older women. We propose a model that reconciles our findings with reported associations between maternal age and recombination in cases of trisomies. PMID:21912527
Xu, Kun; Song, Yufeng; Dai, Lianpan; Zhang, Yongli; Lu, Xuancheng; Xie, Yijia; Zhang, Hangjie; Cheng, Tao; Wang, Qihui; Huang, Qingrui; Bi, Yuhai; Liu, William J; Liu, Wenjun; Li, Xiangdong; Qin, Chuan; Shi, Yi; Yan, Jinghua; Zhou, Dongming; Gao, George F
2018-03-15
The recent outbreak of Zika virus (ZIKV) has emerged as a global health concern. ZIKV can persist in human semen and be transmitted by sexual contact, as well as by mosquitoes, as seen for classical arboviruses. We along with others have previously demonstrated that ZIKV infection leads to testis damage and infertility in mouse models. So far, no prophylactics or therapeutics are available; therefore, vaccine development is urgently demanded. Recombinant chimpanzee adenovirus has been explored as the preferred vaccine vector for many pathogens due to the low preexisting immunity against the vector among the human population. Here, we developed a ZIKV vaccine based on recombinant chimpanzee adenovirus type 7 (AdC7) expressing ZIKV M/E glycoproteins. A single vaccination of AdC7-M/E was sufficient to elicit potent neutralizing antibodies and protective immunity against ZIKV in both immunocompetent and immunodeficient mice. Moreover, vaccinated mice rapidly developed neutralizing antibody with high titers within 1 week postvaccination, and the elicited antiserum could cross-neutralize heterologous ZIKV strains. Additionally, ZIKV M- and E-specific T cell responses were robustly induced by AdC7-M/E. Moreover, one-dose inoculation of AdC7-M/E conferred mouse sterilizing immunity to eliminate viremia and viral burden in tissues against ZIKV challenge. Further investigations showed that vaccination with AdC7-M/E completely protected against ZIKV-induced testicular damage. These data demonstrate that AdC7-M/E is highly effective and represents a promising vaccine candidate for ZIKV control. IMPORTANCE Zika virus (ZIKV) is a pathogenic flavivirus that causes severe clinical consequences, including congenital malformations in fetuses and Guillain-Barré syndrome in adults. Vaccine development is a high priority for ZIKV control. In this study, to avoid preexisting anti-vector immunity in humans, a rare serotype chimpanzee adenovirus (AdC7) expressing the ZIKV M
Processing of human cytomegalovirus glycoprotein B in recombinant adenovirus-infected cells.
Marshall, G S; Fenger, D P; Stout, G G; Knights, M E; Hunt, L A
1996-07-01
Intracellular processing of human cytomegalovirus (HCMV) glycoprotein B (gB; gpUL55) expressed by a recombinant adenovirus (Ad-gB) was studied in human A549 cells as processing events could affect immunogenicity when such viruses are used as live-recombinant vaccines. Cleavage of [35S]methionine-labelled gp13O into gp93 and gp55 reached a maximum after a 3 h chase. Cleavage was completely inhibited by brefeldin A, suggesting that processing normally occurs as a late Golgi or post-Golgi event. Uncleaved gp 130 remained completely sensitive to endo-beta-N-acetylglucosaminidase H (Endo-H) in untreated cells following long chase periods, indicating high-mannose oligosaccharides at all of the 18 N-linked glycosylation sites (Asn-X-Ser/Thr) and retention in the endoplasmic reticulum. Endo-H analysis of gp55 from swainsonine-treated and untreated cells was consistent with glycosylation at all three potential sites, with two oligosaccharides remaining sensitive to Endo-H and one being processed to Endo-H resistance. The heavily glycosylated N-terminal gp93 subunit was not detected by [35S]methionine-labelling but was easily detected along with gp55 after labelling with [3H]mannose. No cleavage of gp 130 was observed in analogous pulse-chase radiolabelling of Ad-gB-infected human fibroblasts, even though these cells are permissive for HCMV replication and can process the native gB molecule. Processing of gB in recombinant adenovirus-infected A549 cells was generally similar to that previously reported for native gB in HCMV-infected fibroblasts.
Zhang, Xi; Si, Ying-Jian; Chen, Xing-Hua; Liu, Yao; Gao, Li; Gao, Lei; Peng, Xian-Gui; Wang, Qing-Yu
2008-06-01
This study was aimed to investigate the effect of vcam-1 gene-modified human umbilical cord blood derived stromal cells (CBDSCs) on hematopoietic regulation so as to establish the experimental foundation for further study. The target gene vcam-1 was cloned into the shuttle plasmid with the report gene GFP. The recombinant shuttle plasmid was transformed into BJ5183 bacteria to recombine with backbone vector pAdeasy-l, and the recombinant adenoviral vector ad-vcam-1-gfp was confirmed after transfection with CBDSCs. The results indicated that two fragments of about 9 kb and 2 kb were obtained after digestion of recombinant plasmid pAdTrack-vcam-1 with NotIand XhoI, and single fragment of 600 bp was obtained after amplification with PCR; two fragments of about 31 kb and 4 kb were obtained after digestion of recombinant plasmid pad-vcam-1-gfp with PacI, which suggested a successful homologous recombination. The expression of vcam-1 gene in ad-vcam-1-gfp transfected CBDSCs could be detected by immunocytochemistry, RT-PCR and fluorescent microscopy. It is concluded that the recombinant adenoviral vector ad-vcam-1-gfp has been constructed successfully, and the expression of vcam-1 is up-regulated in CBDSCs transfected by gene ad-vcam-1-gfp.
Heterologous mitochondrial DNA recombination in human cells.
D'Aurelio, Marilena; Gajewski, Carl D; Lin, Michael T; Mauck, William M; Shao, Leon Z; Lenaz, Giorgio; Moraes, Carlos T; Manfredi, Giovanni
2004-12-15
Inter-molecular heterologous mitochondrial DNA (mtDNA) recombination is known to occur in yeast and plants. Nevertheless, its occurrence in human cells is still controversial. To address this issue we have fused two human cytoplasmic hybrid cell lines, each containing a distinct pathogenic mtDNA mutation and specific sets of genetic markers. In this hybrid model, we found direct evidence of recombination between these two mtDNA haplotypes. Recombinant mtDNA molecules in the hybrid cells were identified using three independent experimental approaches. First, recombinant molecules containing genetic markers from both parental alleles were demonstrated with restriction fragment length polymorphism of polymerase chain reaction products, by measuring the relative frequencies of each marker. Second, fragments of recombinant mtDNA were cloned and sequenced to identify the regions involved in the recombination events. Finally, recombinant molecules were demonstrated directly by Southern blot using appropriate combinations of polymorphic restriction sites and probes. This combined approach confirmed the existence of heterogeneous species of recombinant mtDNA molecules in the hybrid cells. These findings have important implications for mtDNA-related diseases, the interpretation of human evolution and population genetics and forensic analyses based on mtDNA genotyping.
Bayesian Inference of Shared Recombination Hotspots Between Humans and Chimpanzees
Wang, Ying; Rannala, Bruce
2014-01-01
Recombination generates variation and facilitates evolution. Recombination (or lack thereof) also contributes to human genetic disease. Methods for mapping genes influencing complex genetic diseases via association rely on linkage disequilibrium (LD) in human populations, which is influenced by rates of recombination across the genome. Comparative population genomic analyses of recombination using related primate species can identify factors influencing rates of recombination in humans. Such studies can indicate how variable hotspots for recombination may be both among individuals (or populations) and over evolutionary timescales. Previous studies have suggested that locations of recombination hotspots are not conserved between humans and chimpanzees. We made use of the data sets from recent resequencing projects and applied a Bayesian method for identifying hotspots and estimating recombination rates. We also reanalyzed SNP data sets for regions with known hotspots in humans using samples from the human and chimpanzee. The Bayes factors (BF) of shared recombination hotspots between human and chimpanzee across regions were obtained. Based on the analysis of the aligned regions of human chromosome 21, locations where the two species show evidence of shared recombination hotspots (with high BFs) were identified. Interestingly, previous comparative studies of human and chimpanzee that focused on the known human recombination hotspots within the β-globin and HLA regions did not find overlapping of hotspots. Our results show high BFs of shared hotspots at locations within both regions, and the estimated locations of shared hotspots overlap with the locations of human recombination hotspots obtained from sperm-typing studies. PMID:25261696
Bayesian inference of shared recombination hotspots between humans and chimpanzees.
Wang, Ying; Rannala, Bruce
2014-12-01
Recombination generates variation and facilitates evolution. Recombination (or lack thereof) also contributes to human genetic disease. Methods for mapping genes influencing complex genetic diseases via association rely on linkage disequilibrium (LD) in human populations, which is influenced by rates of recombination across the genome. Comparative population genomic analyses of recombination using related primate species can identify factors influencing rates of recombination in humans. Such studies can indicate how variable hotspots for recombination may be both among individuals (or populations) and over evolutionary timescales. Previous studies have suggested that locations of recombination hotspots are not conserved between humans and chimpanzees. We made use of the data sets from recent resequencing projects and applied a Bayesian method for identifying hotspots and estimating recombination rates. We also reanalyzed SNP data sets for regions with known hotspots in humans using samples from the human and chimpanzee. The Bayes factors (BF) of shared recombination hotspots between human and chimpanzee across regions were obtained. Based on the analysis of the aligned regions of human chromosome 21, locations where the two species show evidence of shared recombination hotspots (with high BFs) were identified. Interestingly, previous comparative studies of human and chimpanzee that focused on the known human recombination hotspots within the β-globin and HLA regions did not find overlapping of hotspots. Our results show high BFs of shared hotspots at locations within both regions, and the estimated locations of shared hotspots overlap with the locations of human recombination hotspots obtained from sperm-typing studies. Copyright © 2014 by the Genetics Society of America.
Ledgerwood, J E; Costner, P; Desai, N; Holman, L; Enama, M E; Yamshchikov, G; Mulangu, S; Hu, Z; Andrews, C A; Sheets, R A; Koup, R A; Roederer, M; Bailer, R; Mascola, J R; Pau, M G; Sullivan, N J; Goudsmit, J; Nabel, G J; Graham, B S
2010-12-16
Ebola virus causes irregular outbreaks of severe hemorrhagic fever in equatorial Africa. Case mortality remains high; there is no effective treatment and outbreaks are sporadic and unpredictable. Studies of Ebola virus vaccine platforms in non-human primates have established that the induction of protective immunity is possible and safety and human immunogenicity has been demonstrated in a previous Phase I clinical trial of a 1st generation Ebola DNA vaccine. We now report the safety and immunogenicity of a recombinant adenovirus serotype 5 (rAd5) vaccine encoding the envelope glycoprotein (GP) from the Zaire and Sudan Ebola virus species, in a randomized, placebo-controlled, double-blinded, dose escalation, Phase I human study. Thirty-one healthy adults received vaccine at 2×10(9) (n=12), or 2×10(10) (n=11) viral particles or placebo (n=8) as an intramuscular injection. Antibody responses were assessed by ELISA and neutralizing assays; and T cell responses were assessed by ELISpot and intracellular cytokine staining assays. This recombinant Ebola virus vaccine was safe and subjects developed antigen specific humoral and cellular immune responses. Published by Elsevier Ltd.
USDA-ARS?s Scientific Manuscript database
Replication-defective recombinant adenovirus 5 (rAd5) vectors carrying foot-and-mouth disease virus (FMDV) transgenes elicit a robust immune response to FMDV challenge in cattle; however vaccine function mechanisms are incompletely understood. Recent efforts addressing critical interactions of rAd5 ...
The remarkable frequency of human immunodeficiency virus type 1 genetic recombination.
Onafuwa-Nuga, Adewunmi; Telesnitsky, Alice
2009-09-01
The genetic diversity of human immunodeficiency virus type 1 (HIV-1) results from a combination of point mutations and genetic recombination, and rates of both processes are unusually high. This review focuses on the mechanisms and outcomes of HIV-1 genetic recombination and on the parameters that make recombination so remarkably frequent. Experimental work has demonstrated that the process that leads to recombination--a copy choice mechanism involving the migration of reverse transcriptase between viral RNA templates--occurs several times on average during every round of HIV-1 DNA synthesis. Key biological factors that lead to high recombination rates for all retroviruses are the recombination-prone nature of their reverse transcription machinery and their pseudodiploid RNA genomes. However, HIV-1 genes recombine even more frequently than do those of many other retroviruses. This reflects the way in which HIV-1 selects genomic RNAs for coencapsidation as well as cell-to-cell transmission properties that lead to unusually frequent associations between distinct viral genotypes. HIV-1 faces strong and changeable selective conditions during replication within patients. The mode of HIV-1 persistence as integrated proviruses and strong selection for defective proviruses in vivo provide conditions for archiving alleles, which can be resuscitated years after initial provirus establishment. Recombination can facilitate drug resistance and may allow superinfecting HIV-1 strains to evade preexisting immune responses, thus adding to challenges in vaccine development. These properties converge to provide HIV-1 with the means, motive, and opportunity to recombine its genetic material at an unprecedented high rate and to allow genetic recombination to serve as one of the highest barriers to HIV-1 eradication.
Widjojoatmodjo, Myra N; Bogaert, Lies; Meek, Bob; Zahn, Roland; Vellinga, Jort; Custers, Jerome; Serroyen, Jan; Radošević, Katarina; Schuitemaker, Hanneke
2015-10-05
RSV is an important cause of lower respiratory tract infections in children, the elderly and in those with underlying medical conditions. Although the high disease burden indicates an urgent need for a vaccine against RSV, no licensed RSV vaccine is currently available. We developed an RSV vaccine candidate based on the low-seroprevalent human adenovirus serotypes 26 and 35 (Ad26 and Ad35) encoding the RSV fusion (F) gene. Single immunization of mice with either one of these vectors induced high titers of RSV neutralizing antibodies and high levels of F specific interferon-gamma-producing T cells. A Th1-type immune response was indicated by a high IgG2a/IgG1 ratio of RSV-specific antibodies, strong induction of RSV-specific interferon-gamma and tumor necrosis factor-alpha cytokine producing CD8 Tcells, and low RSV-specific CD4 T-cell induction. Both humoral and cellular responses were increased upon a boost with RSV-F expressing heterologous adenovirus vector (Ad35 boost after Ad26 prime or vice versa). Both single immunization and prime-boost immunization of cotton rats induced high and long-lasting RSV neutralizing antibody titers and protective immunity against lung and nasal RSV A2 virus load up to at least 30 weeks after immunization. Cotton rats were also completely protected against challenge with a RSV B strain (B15/97) after heterologous prime-boost immunization. Lungs from vaccinated animals showed minimal damage or inflammatory infiltrates post-challenge, in contrast to animals vaccinated with formalin-inactivated virus. Our results suggest that recombinant human adenoviral Ad26 and Ad35 vectors encoding the RSV F gene have the potential to provide broad and durable protection against RSV in humans, and appear safe to be investigated in infants. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
Can indirect tests detect a known recombination event in human mtDNA?
White, Daniel James; Gemmell, Neil John
2009-07-01
Whether human mitochondrial DNA (mtDNA) recombines sufficiently to influence its evolution, evolutionary analysis, and disease etiology, remains equivocal. Overall, evidence from indirect studies of population genetic data suggests that recombination is not occurring at detectable levels. This may be explained by no, or low, recombination or, alternatively, current indirect tests may be incapable of detecting recombination in human mtDNA. To investigate the latter, we have tested whether six well-established indirect tests of recombination could detect recombination in a human mtDNA data set, in which its occurrence had been empirically confirmed. Three showed statistical evidence for recombination (r(2) vs. distance, the Homoplasy test, Neighborhood Similarity Score), and three did not (D' vs. distance, Max Chi Squared, Pairwise Homoplasy Index). Possible reasons for detection failure are discussed. Further, evidence from earlier studies suggesting a lack of recombination in mtDNA in humans is reconsidered, taking into account the appropriateness of the tests used, based on our new findings.
Effectiveness of Recombinant Human Growth Hormone for Pharyngocutaneous Fistula Closure
Sari, Murat; Midi, Ahmet; Yumusakhuylu, Ali Cemal; Findik, Ozan; Binnetoglu, Adem
2015-01-01
Objectives In laryngeal cancer, which comprises 25% of head and neck cancer, chemotherapy has come into prominence with the increase in organ-protective treatments. With such treatment, salvage surgery has increased following recurrence; the incidence of pharyngocutaneous fistula has also increased in both respiratory and digestive system surgery. We investigated the effects of recombinant human growth hormone on pharyngocutaneous fistula closure in Sprague-Dawley rats, based on an increase in amino acid uptake and protein synthesis for wound healing, an increase in mitogenesis, and enhancement of collagen formation by recombinant human growth hormone. Methods This study was experimental animal study. Forty Sprague-Dawley rats were separated into two groups, and pharyngoesophagotomy was performed. The pharyngoesophagotomy was sutured with vicryl in both groups. Rats in group 1 (control group) received no treatment, while those in group 2 were administered a subcutaneous injection of recombinant human growth hormone daily. On day 14, the pharynx, larynx, and upper oesophagus were excised and examined microscopically. Results Pharyngocutaneous fistula exhibited better closure macroscopically in the recombinant human growth hormone group. There was a significant difference in collagen formation and epithelisation in the recombinant human growth hormone group compared to the control group. Conclusion This study is believed to be the first in which the effect of recombinant human growth hormone on pharyngocutaneous fistula closure was evaluated, and the findings suggest the potential of use of growth hormone for treatment of pharyngocutaneous fistula. PMID:26622960
Effectiveness of Recombinant Human Growth Hormone for Pharyngocutaneous Fistula Closure.
Kucuk, Nurten; Sari, Murat; Midi, Ahmet; Yumusakhuylu, Ali Cemal; Findik, Ozan; Binnetoglu, Adem
2015-12-01
In laryngeal cancer, which comprises 25% of head and neck cancer, chemotherapy has come into prominence with the increase in organ-protective treatments. With such treatment, salvage surgery has increased following recurrence; the incidence of pharyngocutaneous fistula has also increased in both respiratory and digestive system surgery. We investigated the effects of recombinant human growth hormone on pharyngocutaneous fistula closure in Sprague-Dawley rats, based on an increase in amino acid uptake and protein synthesis for wound healing, an increase in mitogenesis, and enhancement of collagen formation by recombinant human growth hormone. This study was experimental animal study. Forty Sprague-Dawley rats were separated into two groups, and pharyngoesophagotomy was performed. The pharyngoesophagotomy was sutured with vicryl in both groups. Rats in group 1 (control group) received no treatment, while those in group 2 were administered a subcutaneous injection of recombinant human growth hormone daily. On day 14, the pharynx, larynx, and upper oesophagus were excised and examined microscopically. Pharyngocutaneous fistula exhibited better closure macroscopically in the recombinant human growth hormone group. There was a significant difference in collagen formation and epithelisation in the recombinant human growth hormone group compared to the control group. This study is believed to be the first in which the effect of recombinant human growth hormone on pharyngocutaneous fistula closure was evaluated, and the findings suggest the potential of use of growth hormone for treatment of pharyngocutaneous fistula.
Genetic Recombination between Human and Animal Parasites Creates Novel Strains of Human Pathogen
Gibson, Wendy; Peacock, Lori; Ferris, Vanessa; Fischer, Katrin; Livingstone, Jennifer; Thomas, James; Bailey, Mick
2015-01-01
Genetic recombination between pathogens derived from humans and livestock has the potential to create novel pathogen strains, highlighted by the influenza pandemic H1N1/09, which was derived from a re-assortment of swine, avian and human influenza A viruses. Here we investigated whether genetic recombination between subspecies of the protozoan parasite, Trypanosoma brucei, from humans and animals can generate new strains of human pathogen, T. b. rhodesiense (Tbr) responsible for sleeping sickness (Human African Trypanosomiasis, HAT) in East Africa. The trait of human infectivity in Tbr is conferred by a single gene, SRA, which is potentially transferable to the animal pathogen Tbb by sexual reproduction. We tracked the inheritance of SRA in crosses of Tbr and Tbb set up by co-transmitting genetically-engineered fluorescent parental trypanosome lines through tsetse flies. SRA was readily transferred into new genetic backgrounds by sexual reproduction between Tbr and Tbb, thus creating new strains of the human pathogen, Tbr. There was no evidence of diminished growth or transmissibility of hybrid trypanosomes carrying SRA. Although expression of SRA is critical to survival of Tbr in the human host, we show that the gene exists as a single copy in a representative collection of Tbr strains. SRA was found on one homologue of chromosome IV in the majority of Tbr isolates examined, but some Ugandan Tbr had SRA on both homologues. The mobility of SRA by genetic recombination readily explains the observed genetic variability of Tbr in East Africa. We conclude that new strains of the human pathogen Tbr are being generated continuously by recombination with the much larger pool of animal-infective trypanosomes. Such novel recombinants present a risk for future outbreaks of HAT. PMID:25816228
Genetic recombination between human and animal parasites creates novel strains of human pathogen.
Gibson, Wendy; Peacock, Lori; Ferris, Vanessa; Fischer, Katrin; Livingstone, Jennifer; Thomas, James; Bailey, Mick
2015-03-01
Genetic recombination between pathogens derived from humans and livestock has the potential to create novel pathogen strains, highlighted by the influenza pandemic H1N1/09, which was derived from a re-assortment of swine, avian and human influenza A viruses. Here we investigated whether genetic recombination between subspecies of the protozoan parasite, Trypanosoma brucei, from humans and animals can generate new strains of human pathogen, T. b. rhodesiense (Tbr) responsible for sleeping sickness (Human African Trypanosomiasis, HAT) in East Africa. The trait of human infectivity in Tbr is conferred by a single gene, SRA, which is potentially transferable to the animal pathogen Tbb by sexual reproduction. We tracked the inheritance of SRA in crosses of Tbr and Tbb set up by co-transmitting genetically-engineered fluorescent parental trypanosome lines through tsetse flies. SRA was readily transferred into new genetic backgrounds by sexual reproduction between Tbr and Tbb, thus creating new strains of the human pathogen, Tbr. There was no evidence of diminished growth or transmissibility of hybrid trypanosomes carrying SRA. Although expression of SRA is critical to survival of Tbr in the human host, we show that the gene exists as a single copy in a representative collection of Tbr strains. SRA was found on one homologue of chromosome IV in the majority of Tbr isolates examined, but some Ugandan Tbr had SRA on both homologues. The mobility of SRA by genetic recombination readily explains the observed genetic variability of Tbr in East Africa. We conclude that new strains of the human pathogen Tbr are being generated continuously by recombination with the much larger pool of animal-infective trypanosomes. Such novel recombinants present a risk for future outbreaks of HAT.
Human cells: new platform for recombinant therapeutic protein production.
Swiech, Kamilla; Picanço-Castro, Virgínia; Covas, Dimas Tadeu
2012-07-01
The demand for recombinant therapeutic proteins is significantly increasing. There is a constant need to improve the existing expression systems, and also developing novel approaches to face the therapeutic proteins demands. Human cell lines have emerged as a new and powerful alternative for the production of human therapeutic proteins because this expression system is expected to produce recombinant proteins with post translation modifications more similar to their natural counterpart and reduce the potential immunogenic reactions against nonhuman epitopes. Currently, little information about the cultivation of human cells for the production of biopharmaceuticals is available. These cells have shown efficient production in laboratory scale and represent an important tool for the pharmaceutical industry. This review presents the cell lines available for large-scale recombinant proteins production and evaluates critically the advantages of this expression system in comparison with other expression systems for recombinant therapeutic protein production. Copyright © 2012 Elsevier Inc. All rights reserved.
Population-specific recombination sites within the human MHC region.
Lam, T H; Shen, M; Chia, J-M; Chan, S H; Ren, E C
2013-08-01
Genetic rearrangement by recombination is one of the major driving forces for genome evolution, and recombination is known to occur in non-random, discreet recombination sites within the genome. Mapping of recombination sites has proved to be difficult, particularly, in the human MHC region that is complicated by both population variation and highly polymorphic HLA genes. To overcome these problems, HLA-typed individuals from three representative populations: Asian, European and African were used to generate phased HLA haplotypes. Extended haplotype homozygosity (EHH) plots constructed from the phased haplotype data revealed discreet EHH drops corresponding to recombination events and these signatures were observed to be different for each population. Surprisingly, the majority of recombination sites detected are unique to each population, rather than being common. Unique recombination sites account for 56.8% (21/37 of total sites) in the Asian cohort, 50.0% (15/30 sites) in Europeans and 63.2% (24/38 sites) in Africans. Validation carried out at a known sperm typing recombination site of 45 kb (HLA-F-telomeric) showed that EHH was an efficient method to narrow the recombination region to 826 bp, and this was further refined to 660 bp by resequencing. This approach significantly enhanced mapping of the genomic architecture within the human MHC, and will be useful in studies to identify disease risk genes.
Recombinant Human Papillomavirus (HPV) Quadrivalent Vaccine
This page contains brief information about recombinant human papillomavirus (HPV) quadrivalent vaccine and a collection of links to more information about the use of this vaccine, research results, and ongoing clinical trials.
Recombinant Human Papillomavirus (HPV) Nonavalent Vaccine
This page contains brief information about recombinant human papillomavirus (HPV) nonavalent vaccine and a collection of links to more information about the use of this vaccine, research results, and ongoing clinical trials.
Recombinant Human Papillomavirus (HPV) Bivalent Vaccine
This page contains brief information about recombinant human papillomavirus (HPV) bivalent vaccine and a collection of links to more information about the use of this vaccine, research results, and ongoing clinical trials.
How good are indirect tests at detecting recombination in human mtDNA?
White, Daniel James; Bryant, David; Gemmell, Neil John
2013-07-08
Empirical proof of human mitochondrial DNA (mtDNA) recombination in somatic tissues was obtained in 2004; however, a lack of irrefutable evidence exists for recombination in human mtDNA at the population level. Our inability to demonstrate convincingly a signal of recombination in population data sets of human mtDNA sequence may be due, in part, to the ineffectiveness of current indirect tests. Previously, we tested some well-established indirect tests of recombination (linkage disequilibrium vs. distance using D' and r(2), Homoplasy Test, Pairwise Homoplasy Index, Neighborhood Similarity Score, and Max χ(2)) on sequence data derived from the only empirically confirmed case of human mtDNA recombination thus far and demonstrated that some methods were unable to detect recombination. Here, we assess the performance of these six well-established tests and explore what characteristics specific to human mtDNA sequence may affect their efficacy by simulating sequence under various parameters with levels of recombination (ρ) that vary around an empirically derived estimate for human mtDNA (population parameter ρ = 5.492). No test performed infallibly under any of our scenarios, and error rates varied across tests, whereas detection rates increased substantially with ρ values > 5.492. Under a model of evolution that incorporates parameters specific to human mtDNA, including rate heterogeneity, population expansion, and ρ = 5.492, successful detection rates are limited to a range of 7-70% across tests with an acceptable level of false-positive results: the neighborhood similarity score incompatibility test performed best overall under these parameters. Population growth seems to have the greatest impact on recombination detection probabilities across all models tested, likely due to its impact on sequence diversity. The implications of our findings on our current understanding of mtDNA recombination in humans are discussed.
How Good Are Indirect Tests at Detecting Recombination in Human mtDNA?
White, Daniel James; Bryant, David; Gemmell, Neil John
2013-01-01
Empirical proof of human mitochondrial DNA (mtDNA) recombination in somatic tissues was obtained in 2004; however, a lack of irrefutable evidence exists for recombination in human mtDNA at the population level. Our inability to demonstrate convincingly a signal of recombination in population data sets of human mtDNA sequence may be due, in part, to the ineffectiveness of current indirect tests. Previously, we tested some well-established indirect tests of recombination (linkage disequilibrium vs. distance using D′ and r2, Homoplasy Test, Pairwise Homoplasy Index, Neighborhood Similarity Score, and Max χ2) on sequence data derived from the only empirically confirmed case of human mtDNA recombination thus far and demonstrated that some methods were unable to detect recombination. Here, we assess the performance of these six well-established tests and explore what characteristics specific to human mtDNA sequence may affect their efficacy by simulating sequence under various parameters with levels of recombination (ρ) that vary around an empirically derived estimate for human mtDNA (population parameter ρ = 5.492). No test performed infallibly under any of our scenarios, and error rates varied across tests, whereas detection rates increased substantially with ρ values > 5.492. Under a model of evolution that incorporates parameters specific to human mtDNA, including rate heterogeneity, population expansion, and ρ = 5.492, successful detection rates are limited to a range of 7−70% across tests with an acceptable level of false-positive results: the neighborhood similarity score incompatibility test performed best overall under these parameters. Population growth seems to have the greatest impact on recombination detection probabilities across all models tested, likely due to its impact on sequence diversity. The implications of our findings on our current understanding of mtDNA recombination in humans are discussed. PMID:23665874
Human recombinant lysosomal enzymes produced in microorganisms.
Espejo-Mojica, Ángela J; Alméciga-Díaz, Carlos J; Rodríguez, Alexander; Mosquera, Ángela; Díaz, Dennis; Beltrán, Laura; Díaz, Sergio; Pimentel, Natalia; Moreno, Jefferson; Sánchez, Jhonnathan; Sánchez, Oscar F; Córdoba, Henry; Poutou-Piñales, Raúl A; Barrera, Luis A
2015-01-01
Lysosomal storage diseases (LSDs) are caused by accumulation of partially degraded substrates within the lysosome, as a result of a function loss of a lysosomal protein. Recombinant lysosomal proteins are usually produced in mammalian cells, based on their capacity to carry out post-translational modifications similar to those observed in human native proteins. However, during the last years, a growing number of studies have shown the possibility to produce active forms of lysosomal proteins in other expression systems, such as plants and microorganisms. In this paper, we review the production and characterization of human lysosomal proteins, deficient in several LSDs, which have been produced in microorganisms. For this purpose, Escherichia coli, Saccharomyces cerevisiae, Pichia pastoris, Yarrowia lipolytica, and Ogataea minuta have been used as expression systems. The recombinant lysosomal proteins expressed in these hosts have shown similar substrate specificities, and temperature and pH stability profiles to those produced in mammalian cells. In addition, pre-clinical results have shown that recombinant lysosomal enzymes produced in microorganisms can be taken-up by cells and reduce the substrate accumulated within the lysosome. Recently, metabolic engineering in yeasts has allowed the production of lysosomal enzymes with tailored N-glycosylations, while progresses in E. coli N-glycosylations offer a potential platform to improve the production of these recombinant lysosomal enzymes. In summary, microorganisms represent convenient platform for the production of recombinant lysosomal proteins for biochemical and physicochemical characterization, as well as for the development of ERT for LSD. Copyright © 2015 Elsevier Inc. All rights reserved.
Producing recombinant human milk proteins in the milk of livestock species.
Bösze, Zsuzsanna; Baranyi, Mária; Whitelaw, C Bruce A
2008-01-01
Recombinant human proteins produced by the mammary glands of genetically modified transgenic livestock mammals represent a special aspect of milk bioactive components. For therapeutic applications, the often complex posttranslational modifications of human proteins should be recapitulated in the recombinant products. Compared to alternative production methods, mammary gland production is a viable option, underlined by a number of transgenic livestock animal models producing abundant biologically active foreign proteins in their milk. Recombinant proteins isolated from milk have reached different phases of clinical trials, with the first marketing approval for human therapeutic applications from the EMEA achieved in 2006.
High-Resolution Patterns of Meiotic Recombination across the Human Major Histocompatibility Complex
Cullen, Michael; Perfetto, Stephen P.; Klitz, William; Nelson, George; Carrington, Mary
2002-01-01
Definitive characteristics of meiotic recombination events over large (i.e., >1 Mb) segments of the human genome remain obscure, yet they are essential for establishing the haplotypic structure of the genome and for efficient mapping of complex traits. We present a high-resolution map of recombination at the kilobase level across a 3.3-Mb interval encompassing the major histocompatibility complex (MHC). Genotyping of 20,031 single sperm from 12 individuals resulted in the identification and fine mapping of 325 recombinant chromosomes within genomic intervals as small as 7 kb. Several principal characteristics of recombination in this region were observed: (1) rates of recombination can differ significantly between individuals; (2) intense hot spots of recombination occur at least every 0.8 Mb but are not necessarily evenly spaced; (3) distribution in the location of recombination events can differ significantly among individuals; (4) between hot spots, low levels of recombination occur fairly evenly across 100-kb segments, suggesting the presence of warm spots of recombination; and (5) specific sequence motifs associate significantly with recombination distribution. These data provide a plausible model for recombination patterns of the human genome overall. PMID:12297984
Variation in recombination rate may bias human genetic disease mapping studies.
Boyle, A Susannah; Noor, Mohamed A F
2004-11-01
The availability of the human genome sequence and variability information (as from the International HapMap project) will enhance our ability to map genetic disorders and choose targets for therapeutic intervention. However, several factors, such as regional variation in recombination rate, can bias conclusions from genetic mapping studies. Here, we examine the impact of regional variation in recombination rate across the human genome. Through computer simulations and literature surveys, we conclude that genetic disorders have been mapped to regions of low recombination more often than expected if such diseases were randomly distributed across the genome. This concentration in low recombination regions may be an artifact, and disorders appearing to be caused by a few genes of large effect may be polygenic. Future genetic mapping studies should be conscious of this potential complication by noting the regional recombination rate of regions implicated in diseases.
Shirakawa, T; Gotoh, A; Gardner, T A; Kao, C; Zhang, Z J; Matsubara, S; Wada, Y; Hinata, N; Fujisawa, M; Hanioka, K; Matsuo, M; Kamidono, S
2000-01-01
Benign prostatic hyperplasia (BPH) is the most common proliferative disease affecting men. Numerous minimally invasive technologies are being developed or are currently in use to obviate the need for transurethral surgery. The goal of the present study was to develop a novel molecular based approach for the treatment of BPH using recombinant p53 adenoviral vector. The over-expression of wt-p53 can cause cell apoptosis or cell growth arrest, thus preventing the uncontrolled cell proliferation underlying BPH pathophysiology. Ad-CMV-p53, a replication-deficient recombinant adenovirus containing cytomegalovirus promoter driving p53 gene, was used. Human prostate stromal (PS) cells were evaluated for apoptosis (TUNEL assay), mRNA levels of key cell cycle regulators influencing apoptosis (p-53, Bax and Bcl-2) using quantitative RT-PCR and cytotoxicity after Ad-CMV-p53. Ad-CMV-p53 was unilaterally injected into rat ventral prostates and growth inhibition was measured by prostate weight 3 weeks after injection. In vitro exposure to Ad-CMV-p53 significantly inhibited the proliferation of PS cells, induced mRNA over-expression of both wt-p53 and Bax, and increased the proportion of apoptotic cells. A 30% decrease in average prostate weight was demonstrated in rodents after Ad-CMV-p53 injection. The results suggest that further investigation of molecular gene therapy with recombinant wt-p53 adenovirus for the treatment of BPH is warranted.
Ng, Elizabeth S; Davis, Richard; Stanley, Edouard G; Elefanty, Andrew G
2008-01-01
In order to promote the uniform and reproducible differentiation of human embryonic stem cells (HESCs) in response to exogenously added growth factors, we have developed a method (spin embryoid bodies (EBs)) that uses a recombinant protein-based, animal product-free medium in which HESCs are aggregated by centrifugation to form EBs. In this protocol we describe the formulation of this medium, denoted APEL (Albumin Polyvinylalcohol Essential Lipids), and its use in spin EB differentiation of HESCs. We also describe a more economical variant, BPEL (Bovine Serum Albumin (BSA) Polyvinylalchohol Essential Lipids), in which BSA replaces the recombinant human albumin. The integration of a medium that includes only defined and recombinant components with a defined number of cells to initiate EB formation results in a generally applicable, robust platform for growth factor-directed HESC differentiation.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yasuda, Kaori; Endo, Mariko; Ikushiro, Shinichi
Highlights: •We produce 25-hydroxyvitamin D in the recombinant yeast expressing human CYP2R1. •Vitamin D2 is produced in yeast from endogenous ergosterol with UV irradiation. •We produce 25-hydroxyvitamin D2 in the recombinant yeast without added substrate. -- Abstract: CYP2R1 is known to be a physiologically important vitamin D 25-hydroxylase. We have successfully expressed human CYP2R1 in Saccharomyces cerevisiae to reveal its enzymatic properties. In this study, we examined production of 25-hydroxylated vitamin D using whole recombinant yeast cells that expressed CYP2R1. When vitamin D{sub 3} or vitamin D{sub 2} was added to the cell suspension of CYP2R1-expressing yeast cells in amore » buffer containing glucose and β-cyclodextrin, the vitamins were converted into their 25-hydroxylated products. Next, we irradiated the cell suspension with UVB and incubated at 37 °C. Surprisingly, the 25-hydroxy vitamin D{sub 2} was produced without additional vitamin D{sub 2}. Endogenous ergosterol was likely converted into vitamin D{sub 2} by UV irradiation and thermal isomerization, and then the resulting vitamin D{sub 2} was converted to 25-hydroxyvitamin D{sub 2} by CYP2R1. This novel method for producing 25-hydroxyvitamin D{sub 2} without a substrate could be useful for practical purposes.« less
Validation of biological activity testing procedure of recombinant human interleukin-7.
Lutsenko, T N; Kovalenko, M V; Galkin, O Yu
2017-01-01
Validation procedure for method of monitoring the biological activity of reсombinant human interleukin-7 has been developed and conducted according to the requirements of national and international recommendations. This method is based on the ability of recombinant human interleukin-7 to induce proliferation of T lymphocytes. It has been shown that to control the biological activity of recombinant human interleukin-7 peripheral blood mononuclear cells (PBMCs) derived from blood or cell lines can be used. Validation characteristics that should be determined depend on the method, type of product or object test/measurement and biological test systems used in research. The validation procedure for the method of control of biological activity of recombinant human interleukin-7 in peripheral blood mononuclear cells showed satisfactory results on all parameters tested such as specificity, accuracy, precision and linearity.
Quinn, Kylie M.; Costa, Andreia Da; Yamamoto, Ayako; Berry, Dana; Lindsay, Ross W.B.; Darrah, Patricia A.; Wang, Lingshu; Cheng, Cheng; Kong, Wing-Pui; Gall, Jason G.D.; Nicosia, Alfredo; Folgori, Antonella; Colloca, Stefano; Cortese, Riccardo; Gostick, Emma; Price, David A.; Gomez, Carmen E.; Esteban, Mariano; Wyatt, Linda S.; Moss, Bernard; Morgan, Cecilia; Roederer, Mario; Bailer, Robert T.; Nabel, Gary J.; Koup, Richard A.; Seder, Robert A.
2013-01-01
Recombinant adenoviral vectors (rAds) are the most potent recombinant vaccines for eliciting CD8+ T cell-mediated immunity in humans; however, prior exposure from natural adenoviral infection can decrease such responses. Here we show low seroreactivity in humans against simian- (sAd11, sAd16), or chimpanzee-derived (chAd3, chAd63) compared to human-derived (rAd5, rAd28, rAd35) vectors across multiple geographic regions. We then compared the magnitude, quality, phenotype and protective capacity of CD8+ T cell responses in mice vaccinated with rAds encoding SIV Gag. Using a dose range (1 × 107 to 109 PU), we defined a hierarchy among rAd vectors based on the magnitude and protective capacity of CD8+ T cell responses, from most to least as: rAd5 and chAd3, rAd28 and sAd11, chAd63, sAd16, and rAd35. Selection of rAd vector or dose could modulate the proportion and/or frequency of IFNγ+TNFα+IL-2+ and KLRG1+CD127- CD8+ T cells, but strikingly ~30–80% of memory CD8+ T cells co-expressed CD127 and KLRG1. To further optimise CD8+ T cell responses, we assessed rAds as part of prime-boost regimens. Mice primed with rAds and boosted with NYVAC generated Gag-specific responses that approached ~60% of total CD8+ T cells at peak. Alternatively, priming with DNA or rAd28 and boosting with rAd5 or chAd3 induced robust and equivalent CD8+ T cell responses compared to prime or boost alone. Collectively, these data provide the immunologic basis for using specific rAd vectors alone or as part of prime-boost regimens to induce CD8+ T cells for rapid effector function or robust long-term memory, respectively. PMID:23390298
Ha, Jang-Ho; Kim, Ha-Neul; Moon, Ki-Beom; Jeon, Jae-Heung; Jung, Dai-Hyun; Kim, Su-Jung; Mason, Hugh S; Shin, Seo-Yeon; Kim, Hyun-Soon; Park, Kyung-Mok
2017-07-01
Responding to the need for recombinant acidic fibroblast growth factor in the pharmaceutical and cosmetic industries, we established a scalable expression system for recombinant human aFGF using transient and a DNA replicon vector expression in Nicotiana benthamiana . Recombinant human-acidic fibroblast growth factor was recovered following Agrobacterium infiltration of N. benthamiana . The optimal time point at which to harvest recombinant human acidic fibroblast growth factor expressing leaves was found to be 4 days post-infiltration, before necrosis was evident. Commassie-stained SDS-PAGE gels of His-tag column eluates, concentrated using a 10 000 molecular weight cut-off column, showed an intense band at the expected molecular weight for recombinant human acidic fibroblast growth factor. An immunoblot confirmed that this band was recombinant human acidic fibroblast growth factor. Up to 10 µg recombinant human-acidic fibroblast growth factor/g of fresh leaves were achieved by a simple affinity purification protocol using protein extract from the leaves of agroinfiltrated N. benthamiana . The purified recombinant human acidic fibroblast growth factor improved the survival rate of UVB-irradiated HaCaT and CCD-986sk cells approximately 89 and 81 %, respectively. N. benthamiana -derived recombinant human acidic fibroblast growth factor showed similar effects on skin cell proliferation and UVB protection compared to those of Escherichia coli -derived recombinant human acidic fibroblast growth factor. Additionally, N. benthamiana- derived recombinant human acidic fibroblast growth factor increased type 1 procollagen synthesis up to 30 % as well as reduced UVB-induced intracellular reactive oxygen species generation in fibroblast (CCD-986sk) cells.UVB is a well-known factor that causes various types of skin damage and premature aging. Therefore, the present study demonstrated that N. benthamiana -derived recombinant human acidic fibroblast growth factor
Bacterial RecA Protein Promotes Adenoviral Recombination during In Vitro Infection
Lee, Jeong Yoon; Lee, Ji Sun; Materne, Emma C.; Rajala, Rahul; Ismail, Ashrafali M.; Seto, Donald; Dyer, David W.
2018-01-01
ABSTRACT Adenovirus infections in humans are common and sometimes lethal. Adenovirus-derived vectors are also commonly chosen for gene therapy in human clinical trials. We have shown in previous work that homologous recombination between adenoviral genomes of human adenovirus species D (HAdV-D), the largest and fastest growing HAdV species, is responsible for the rapid evolution of this species. Because adenovirus infection initiates in mucosal epithelia, particularly at the gastrointestinal, respiratory, genitourinary, and ocular surfaces, we sought to determine a possible role for mucosal microbiota in adenovirus genome diversity. By analysis of known recombination hot spots across 38 human adenovirus genomes in species D (HAdV-D), we identified nucleotide sequence motifs similar to bacterial Chi sequences, which facilitate homologous recombination in the presence of bacterial Rec enzymes. These motifs, referred to here as ChiAD, were identified immediately 5′ to the sequence encoding penton base hypervariable loop 2, which expresses the arginine-glycine-aspartate moiety critical to adenoviral cellular entry. Coinfection with two HAdV-Ds in the presence of an Escherichia coli lysate increased recombination; this was blocked in a RecA mutant strain, E. coli DH5α, or upon RecA depletion. Recombination increased in the presence of E. coli lysate despite a general reduction in viral replication. RecA colocalized with viral DNA in HAdV-D-infected cell nuclei and was shown to bind specifically to ChiAD sequences. These results indicate that adenoviruses may repurpose bacterial recombination machinery, a sharing of evolutionary mechanisms across a diverse microbiota, and unique example of viral commensalism. IMPORTANCE Adenoviruses are common human mucosal pathogens of the gastrointestinal, respiratory, and genitourinary tracts and ocular surface. Here, we report finding Chi-like sequences in adenovirus recombination hot spots. Adenovirus coinfection in the
Evidence of reduced recombination rate in human regulatory domains.
Liu, Yaping; Sarkar, Abhishek; Kheradpour, Pouya; Ernst, Jason; Kellis, Manolis
2017-10-20
Recombination rate is non-uniformly distributed across the human genome. The variation of recombination rate at both fine and large scales cannot be fully explained by DNA sequences alone. Epigenetic factors, particularly DNA methylation, have recently been proposed to influence the variation in recombination rate. We study the relationship between recombination rate and gene regulatory domains, defined by a gene and its linked control elements. We define these links using expression quantitative trait loci (eQTLs), methylation quantitative trait loci (meQTLs), chromatin conformation from publicly available datasets (Hi-C and ChIA-PET), and correlated activity links that we infer across cell types. Each link type shows a "recombination rate valley" of significantly reduced recombination rate compared to matched control regions. This recombination rate valley is most pronounced for gene regulatory domains of early embryonic development genes, housekeeping genes, and constitutive regulatory elements, which are known to show increased evolutionary constraint across species. Recombination rate valleys show increased DNA methylation, reduced doublestranded break initiation, and increased repair efficiency, specifically in the lineage leading to the germ line. Moreover, by using only the overlap of functional links and DNA methylation in germ cells, we are able to predict the recombination rate with high accuracy. Our results suggest the existence of a recombination rate valley at regulatory domains and provide a potential molecular mechanism to interpret the interplay between genetic and epigenetic variations.
Bioinformatic Analysis of the Human Recombinant Iduronate 2-Sulfate Sulfatase
Morales-Álvarez, Edwin D.; Rivera-Hoyos, Claudia M.; Landázuri, Patricia; Poutou-Piñales, Raúl A.; Pedroza-Rodríguez, Aura M.
2016-01-01
Mucopolysaccharidosis type II is a human recessive disease linked to the X chromosome caused by deficiency of lysosomal enzyme Iduronate 2-Sulfate Sulfatase (IDS), which leads to accumulation of glycosaminoglycans in tissues and organs. The human enzyme has been expressed in Escherichia coli and Pichia pastoris in attempt to develop more successful expression systems that allow the production of recombinant IDS for Enzyme Replacement Therapy (ERT). However, the preservation of native signal peptide in the sequence has caused conflicts in processing and recognition in the past, which led to problems in expression and enzyme activity. With the main object being the improvement of the expression system, we eliminate the native signal peptide of human recombinant IDS. The resulting sequence showed two modified codons, thus, our study aimed to analyze computationally the nucleotide sequence of the IDSnh without signal peptide in order to determine the 3D structure and other biochemical properties to compare them with the native human IDS (IDSnh). Results showed that there are no significant differences between both molecules in spite of the two-codon modifications detected in the recombinant DNA sequence. PMID:27335624
Termini of human chromosomes display elevated rates of mitotic recombination.
Cornforth, M N; Eberle, R L
2001-01-01
The strand-specific in situ hybridization technique of CO-FISH was used to probe telomeres of human mitotic cells in order to determine the spontaneous frequency of crossover. This approach allowed the detection of recombinational crossovers occurring anywhere along the length of individual chromosomes, including reciprocal events taking place between sister chromatids. Although the process of sister chromatid exchange (SCE) is the most prominent type of recombination in somatic mammalian cells, our results show that SCEs accounted for less than a third of the recombinational events revealed by CO-FISH. It is concluded that chromosomal regions near the termini of chromosome arms undergo extraordinarily high rates of spontaneous recombination, producing terminal crossovers whose small size precludes detection by standard cytogenetic methods. That similar results were observed for transformed epithelial cells, as well as primary fibroblasts, suggests that the phenomenon is a common characteristic of human cells. These findings are noteworthy because, although telomeric and subtelomeric DNA is known to be preferentially involved in certain types of recombination, the tips of somatic mammalian chromosomes have not previously been identified as preferred sites for crossover. Implications of these results are discussed in terms of limitations imposed on CO-FISH for its proposed use in directional hybridization mapping.
Geng, Zhirong; Song, Xiaoli; Xing, Zhi; Geng, Jinlong; Zhang, Sichun; Zhang, Xinrong; Wang, Zhilin
2009-05-01
The effects of Se(IV) on the structure and function of recombinant human arsenic (+3 oxidation state) methyltransferase (AS3MT) purified from the cytoplasm of Escherichia coli were studied. The coding region of human AS3MT complementary DNA was amplified from total RNA extracted from HepG2 cell by reverse transcription PCR. Soluble and active human AS3MT was expressed in the E. coli with a Trx fusion tag under a lower induction temperature of 25 degrees C. Spectra (UV-vis, circular dichroism, and fluorescence) were first used to probe the interaction of Se(IV) and recombinant human AS3MT and the structure-function relationship of the enzyme. The recombinant human AS3MT had a secondary structure of 29.0% alpha-helix, 23.9% beta-pleated sheet, 17.9% beta-turn, and 29.2% random coil. When Se(IV) was added, the content of the alpha-helix did not change, but that of the beta-pleated sheet increased remarkably in the conformation of recombinant human AS3MT. Se(IV) inhibited the enzymatic methylation of inorganic As(III) in a concentration-dependent manner. The IC(50) value for Se(IV) was 2.38 muM. Double-reciprocal (1/V vs. 1/[inorganic As(III)]) plots showed Se(IV) to be a noncompetitive inhibitor of the methylation of inorganic As(III) by recombinant human AS3MT with a K (i) value of 2.61 muM. We hypothesized that Se(IV) interacts with the sulfhydryl group of cysteine(s) in the structural residues rather than the cysteines of the active site (Cys156 and Cys206). When Se(IV) was combined with cysteine(s) in the structural residues, the conformation of recombinant human AS3MT changed and the enzymatic activity decreased. Considering the quenching of tryptophan fluorescence, Cys72 and/or Cys226 are deduced to be primary targets for Se(IV).
Turner, Mallory A; Middha, Sumit; Hofherr, Sean E; Barry, Michael A
2015-12-01
Our understanding of adenovirus (Ad) biology is largely extrapolated from human species C Ad5. Most humans are immune to Ad5, so lower-seroprevalence viruses like human Ad6 and Ad26 are being tested as therapeutic vectors. Ad6 and Ad26 differ at the DNA level by 34%. To better understand how this might impact their biology, we examined the life cycle of the two viruses in human lung cells in vitro. Both viruses infected A549 cells with similar efficiencies, executed DNA replication with identical kinetics within 12 h, and began killing cells within 72 h. While Ad6-infected cells remained adherent until death, Ad26-infected cells detached within 12 h of infection but remained viable. Next-generation sequencing (NGS) of mRNA from infected cells demonstrated that viral transcripts constituted 1% of cellular mRNAs within 6 h and 8 to 16% within 12 h. Quantitative PCR and NGS revealed the activation of key early genes at 6 h and transition to late gene activation by 12 h by both viruses. There were marked differences in the balance of E1A and E1B activation by the two viruses and in the expression of E3 immune evasion mRNAs. Ad6 was markedly more effective at suppressing major histocompatibility complex class I (MHC I) display on the cell surface and in evading TRAIL-mediated apoptosis than was Ad26. These data demonstrate shared as well as divergent life cycles in these genetically distant human adenoviruses. An understanding of these differences expands the knowledge of alternative Ad species and may inform the selection of related Ads for therapeutic development. A burgeoning number of adenoviruses (Ads) are being harnessed as therapeutics, yet the biology of these viruses is generally extrapolated from Ad2 and Ad5. Here, we are the first to compare the transcriptional programs of two genetically distant Ads by mRNA next-generation sequencing (NGS). Species C Ad6 and Ad26 are being pursued as lower-seroprevalence Ad vectors but differ at the DNA level by 34%. Head
Genetic recombination as a major cause of mutagenesis in the human globin gene clusters.
Borg, Joseph; Georgitsi, Marianthi; Aleporou-Marinou, Vassiliki; Kollia, Panagoula; Patrinos, George P
2009-12-01
Homologous recombination is a frequent phenomenon in multigene families and as such it occurs several times in both the alpha- and beta-like globin gene families. In numerous occasions, genetic recombination has been previously implicated as a major mechanism that drives mutagenesis in the human globin gene clusters, either in the form of unequal crossover or gene conversion. Unequal crossover results in the increase or decrease of the human globin gene copies, accompanied in the majority of cases with minor phenotypic consequences, while gene conversion contributes either to maintaining sequence homogeneity or generating sequence diversity. The role of genetic recombination, particularly gene conversion in the evolution of the human globin gene families has been discussed elsewhere. Here, we summarize our current knowledge and review existing experimental evidence outlining the role of genetic recombination in the mutagenic process in the human globin gene families.
Recombination or mutational hot spots in human mtDNA?
Innan, Hideki; Nordborg, Magnus
2002-07-01
Awadalla, Eyre-Walker, and Maynard Smith (1999) recently argued that there might be recombination in human mitochondrial DNA (mtDNA). Their claim was based on their observation of decaying linkage disequilibrium (LD) as a function of physical distance. Their study was much criticized, and follow-up studies have failed to find any evidence for recombination. We argue that the criticisms levied, even if correct, could not possibly explain the findings of Awadalla, Eyre-Walker, and Maynard Smith (1999). Nonetheless, the test proposed by Awadalla, Eyre-Walker, and Maynard Smith (1999 ) is not robust because recombination is not the only explanation for decay of LD. We show that such a pattern can be caused by mutational hot spots as well. However, a closer look at the data suggests that the pattern observed was not caused by mutational hot spots but rather by chance. Thus, there appears to be no evidence for recombination in the mtDNA polymorphism data. In conclusion, we discuss the possibility of detecting recombination in mtDNA and the implications of its existence.
Nieminen, Mikko; Tuuri, Timo; Savilahti, Harri
2010-10-01
Human embryonic stem cells are pluripotent cells derived from early human embryo and retain a potential to differentiate into all adult cell types. They provide vast opportunities in cell replacement therapies and are expected to become significant tools in drug discovery as well as in the studies of cellular and developmental functions of human genes. The progress in applying different types of DNA recombination reactions for genome modification in a variety of eukaryotic cell types has provided means to utilize recombination-based strategies also in human embryonic stem cells. Homologous recombination-based methods, particularly those utilizing extended homologous regions and those employing zinc finger nucleases to boost genomic integration, have shown their usefulness in efficient genome modification. Site-specific recombination systems are potent genome modifiers, and they can be used to integrate DNA into loci that contain an appropriate recombination signal sequence, either naturally occurring or suitably pre-engineered. Non-homologous recombination can be used to generate random integrations in genomes relatively effortlessly, albeit with a moderate efficiency and precision. DNA transposition-based strategies offer substantially more efficient random strategies and provide means to generate single-copy insertions, thus potentiating the generation of genome-wide insertion libraries applicable in genetic screens. 2010 Elsevier Inc. All rights reserved.
Major psychological factors affecting acceptance of gene-recombination technology.
Tanaka, Yutaka
2004-12-01
The purpose of this study was to verify the validity of a causal model that was made to predict the acceptance of gene-recombination technology. A structural equation model was used as a causal model. First of all, based on preceding studies, the factors of perceived risk, perceived benefit, and trust were set up as important psychological factors determining acceptance of gene-recombination technology in the structural equation model. An additional factor, "sense of bioethics," which I consider to be important for acceptance of biotechnology, was added to the model. Based on previous studies, trust was set up to have an indirect influence on the acceptance of gene-recombination technology through perceived risk and perceived benefit in the model. Participants were 231 undergraduate students in Japan who answered a questionnaire with a 5-point bipolar scale. The results indicated that the proposed model fits the data well, and showed that acceptance of gene-recombination technology is explained largely by four factors, that is, perceived risk, perceived benefit, trust, and sense of bioethics, whether the technology is applied to plants, animals, or human beings. However, the relative importance of the four factors was found to vary depending on whether the gene-recombination technology was applied to plants, animals, or human beings. Specifically, the factor of sense of bioethics is the most important factor in acceptance of plant gene-recombination technology and animal gene-recombination technology, and the factors of trust and perceived risk are the most important factors in acceptance of human being gene-recombination technology.
Yang, Bin; Wang, Jianwu; Tang, Bo; Liu, Yufang; Guo, Chengdong; Yang, Penghua; Yu, Tian; Li, Rong; Zhao, Jianmin; Zhang, Lei; Dai, Yunping; Li, Ning
2011-03-16
There is great potential for using transgenic technology to improve the quality of cow milk and to produce biopharmaceuticals within the mammary gland. Lysozyme, a bactericidal protein that protects human infants from microbial infections, is highly expressed in human milk but is found in only trace amounts in cow milk. We have produced 17 healthy cloned cattle expressing recombinant human lysozyme using somatic cell nuclear transfer. In this study, we just focus on four transgenic cattle which were natural lactation. The expression level of the recombinant lysozyme was up to 25.96 mg/L, as measured by radioimmunoassay. Purified recombinant human lysozyme showed the same physicochemical properties, such as molecular mass and bacterial lysis, as its natural counterpart. Moreover, both recombinant and natural lysozyme had similar conditions for reactivity as well as for pH and temperature stability during in vitro simulations. The gross composition of transgenic and non-transgenic milk, including levels of lactose, total protein, total fat, and total solids were not found significant differences. Thus, our study not only describes transgenic cattle whose milk offers the similar nutritional benefits as human milk but also reports techniques that could be further refined for production of active human lysozyme on a large scale.
Yang, Bin; Wang, Jianwu; Tang, Bo; Liu, Yufang; Guo, Chengdong; Yang, Penghua; Yu, Tian; Li, Rong; Zhao, Jianmin; Zhang, Lei; Dai, Yunping; Li, Ning
2011-01-01
Background There is great potential for using transgenic technology to improve the quality of cow milk and to produce biopharmaceuticals within the mammary gland. Lysozyme, a bactericidal protein that protects human infants from microbial infections, is highly expressed in human milk but is found in only trace amounts in cow milk. Methodology/Principal Findings We have produced 17 healthy cloned cattle expressing recombinant human lysozyme using somatic cell nuclear transfer. In this study, we just focus on four transgenic cattle which were natural lactation. The expression level of the recombinant lysozyme was up to 25.96 mg/L, as measured by radioimmunoassay. Purified recombinant human lysozyme showed the same physicochemical properties, such as molecular mass and bacterial lysis, as its natural counterpart. Moreover, both recombinant and natural lysozyme had similar conditions for reactivity as well as for pH and temperature stability during in vitro simulations. The gross composition of transgenic and non-transgenic milk, including levels of lactose, total protein, total fat, and total solids were not found significant differences. Conclusions/Significance Thus, our study not only describes transgenic cattle whose milk offers the similar nutritional benefits as human milk but also reports techniques that could be further refined for production of active human lysozyme on a large scale. PMID:21436886
Toro, Haroldo; van Ginkel, Frederik W.; Tang, De-chu C.; Schemera, Bettina; Rodning, Soren; Newton, Joseph
2010-01-01
SUMMARY Protective immunity to avian influenza (AI) virus can be elicited in chickens by in ovo or intramuscular vaccination with replication-competent adenovirus (RCA)-free human recombinant adenovirus serotype 5 (Ad5) encoding AI virus H5 (AdTW68.H5) or H7 (AdCN94.H7) hemagglutinins. We evaluated bivalent in ovo vaccination with AdTW68.H5 and AdCN94.H7 and determined that vaccinated chickens developed robust hemagglutination inhibition (HI) antibody levels to both H5 and H7 AI strains. Additionally, we evaluated immune responses of 1-day-old chickens vaccinated via spray with AdCN94.H7. These birds showed increased immunoglobulin A responses in lachrymal fluids and increased interleukin-6 expression in Harderian gland–derived lymphocytes. However, specific HI antibodies were not detected in the sera of these birds. Because pigs might play a role as a “mixing vessel” for the generation of pandemic influenza viruses we explored the use of RCA-free adenovirus technology to immunize pigs against AI virus. Weanling piglets vaccinated intramuscularly with a single dose of RCA-free AdTW68.H5 developed strong systemic antibody responses 3 wk postvaccination. Intranasal application of AdTW68.H5 in piglets resulted in reduced vaccine coverage, i.e., 33% of pigs (2/6) developed an antibody response, but serum antibody levels in those successfully immunized animals were similar to intramuscularly vaccinated animals. PMID:20521636
Pan, Fan; Yang, Wende; Li, Wei; Yang, Xiao-Yan; Liu, Shuhao; Li, Xin; Zhao, Xiaoxu; Ding, Hui; Qin, Li; Pan, Yunlong
2017-07-01
Several studies have revealed the potential of normalizing tumor vessels in anti-angiogenic treatment. Recombinant human endostatin is an anti-angiogenic agent which has been applied in clinical tumor treatment. Our previous research indicated that gold nanoparticles could be a nanoparticle carrier for recombinant human endostatin delivery. The recombinant human endostatin-gold nanoparticle conjugates normalized vessels, which improved chemotherapy. However, the mechanism of recombinant human endostatin-gold nanoparticle-induced vascular normalization has not been explored. Anterior gradient 2 has been reported to be over-expressed in many malignant tumors and involved in tumor angiogenesis. To date, the precise efficacy of recombinant human endostatin-gold nanoparticles on anterior gradient 2-mediated angiogenesis or anterior gradient 2-related signaling cohort remained unknown. In this study, we aimed to explore whether recombinant human endostatin-gold nanoparticles could normalize vessels in metastatic colorectal cancer xenografts, and we further elucidated whether recombinant human endostatin-gold nanoparticles could interrupt anterior gradient 2-induced angiogenesis. In vivo, it was indicated that recombinant human endostatin-gold nanoparticles increased pericyte expression while inhibit vascular endothelial growth factor receptor 2 and anterior gradient 2 expression in metastatic colorectal cancer xenografts. In vitro, we uncovered that recombinant human endostatin-gold nanoparticles reduced cell migration and tube formation induced by anterior gradient 2 in human umbilical vein endothelial cells. Treatment with recombinant human endostatin-gold nanoparticles attenuated anterior gradient 2-mediated activation of MMP2, cMyc, VE-cadherin, phosphorylation of p38, and extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) in human umbilical vein endothelial cells. Our findings demonstrated recombinant human endostatin-gold nanoparticles might normalize
Detection of recombinant human lactoferrin and lysozyme produced in a bitransgenic cow.
Kaiser, Germán G; Mucci, Nicolás C; González, Vega; Sánchez, Lourdes; Parrón, José A; Pérez, María D; Calvo, Miguel; Aller, Juan F; Hozbor, Federico A; Mutto, Adrián A
2017-03-01
Lactoferrin and lysozyme are 2 glycoproteins with great antimicrobial activity, being part of the nonspecific defensive system of human milk, though their use in commercial products is difficult because human milk is a limited source. Therefore, many investigations have been carried out to produce those proteins in biological systems, such as bacteria, yeasts, or plants. Mammals seem to be more suitable as expression systems for human proteins, however, especially for those that are glycosylated. In the present study, we developed a bicistronic commercial vector containing a goat β-casein promoter and an internal ribosome entry site fragment between the human lactoferrin and human lysozyme genes to allow the introduction of both genes into bovine adult fibroblasts in a single transfection. Embryos were obtained by somatic cell nuclear transfer, and, after 6 transferences to recipients, 3 pregnancies and 1 viable bitransgenic calf were obtained. The presence of the vector was confirmed by fluorescent in situ hybridization of skin cells. At 13 mo of life and after artificial induction of lactation, both recombinant proteins were found in the colostrum and milk of the bitransgenic calf. Human lactoferrin concentration in the colostrum was 0.0098 mg/mL and that in milk was 0.011 mg/mL; human lysozyme concentration in the colostrum was 0.0022 mg/mL and that in milk was 0.0024 mg/mL. The molar concentration of both human proteins revealed no differences in protein production of the internal ribosome entry site upstream and downstream protein. The enzymatic activity of lysozyme in the transgenic milk was comparable to that of human milk, being 6 and 10 times higher than that of bovine lysozyme present in milk. This work represents an important step to obtain multiple proteins or enhance single protein production by using animal pharming and fewer regulatory and antibiotic-resistant foreign sequences, allowing the design of humanized milk with added biological value for
Murasugi, Akira
2013-01-01
Midkine is a heparin-binding growth factor that promotes cell growth, survival, and migration. Externally added midkine prevents ventricular remodeling and improves long-term survival after myocardial infarction in the mouse. Preclinical testing of this protein is in progress. Externally added pleiotrophin, a member of the midkine protein family, promotes functional recovery after neural transplantation in rats. Thus, pleiotrophin is also a candidate therapeutic protein. Large amounts of these proteins were obtained by using the heterologous protein expression system of Pichia pastoris, and the recombinant P. pastoris clones were cultured in a controlled fermentor. Intracellular expression yielded about 300 mg/L recombinant human (rh)-midkine, which was extracted, renatured, and purified. From 1 L of the culture, 64 mg of rh-midkine was purified. Secretory expression induced by the midkine secretion signal resulted in about 100 mg of rhmidkine in 1 L of the culture supernatant, but over 70% of the rh-midkine had yeast-specific glycosylation. Three threonyl residues that are targets for glycosylation were substituted with alanyl residues, and nonglycosylated, active rh-midkine was obtained. In secretory expression using α-mating factor prepro-sequence, about 640 mg/L rh-midkine was obtained, but it was partially truncated. Therefore, a protease-deficient host was used, and about 360 mg/L intact rh-midkine was then obtained. The rh-midkine was recovered and purified, with 70% final yield. All purified rh-midkine, regardless of expression method, was able to promote mammalian cell proliferation. In secretory expression of rh-pleiotrophin using α- mating factor prepro-sequence, 260 mg/L rh-pleiotrophin could be secreted. The rh-pleiotrophin was recovered and efficiently purified with 72% final yield.
Ancient Recombination Events between Human Herpes Simplex Viruses
Burrel, Sonia; Boutolleau, David; Ryu, Diane; Agut, Henri; Merkel, Kevin; Leendertz, Fabian H.
2017-01-01
Abstract Herpes simplex viruses 1 and 2 (HSV-1 and HSV-2) are seen as close relatives but also unambiguously considered as evolutionary independent units. Here, we sequenced the genomes of 18 HSV-2 isolates characterized by divergent UL30 gene sequences to further elucidate the evolutionary history of this virus. Surprisingly, genome-wide recombination analyses showed that all HSV-2 genomes sequenced to date contain HSV-1 fragments. Using phylogenomic analyses, we could also show that two main HSV-2 lineages exist. One lineage is mostly restricted to subSaharan Africa whereas the other has reached a global distribution. Interestingly, only the worldwide lineage is characterized by ancient recombination events with HSV-1. Our findings highlight the complexity of HSV-2 evolution, a virus of putative zoonotic origin which later recombined with its human-adapted relative. They also suggest that coinfections with HSV-1 and 2 may have genomic and potentially functional consequences and should therefore be monitored more closely. PMID:28369565
A reanalysis of the indirect evidence for recombination in human mitochondrial DNA.
Piganeau, G; Eyre-Walker, A
2004-04-01
In an attempt to resolve the controversy about whether recombination occurs in human mtDNA, we have analysed three recently published data sets of complete mtDNA sequences along with 10 RFLP data sets. We have analysed the relationship between linkage disequilibrium (LD) and distance between sites under a variety of conditions using two measures of LD, r2 and /D'/. We find that there is a negative correlation between r2 and distance in the majority of data sets, but no overall trend for /D'/. Five out of six mtDNA sequence data sets show an excess of homoplasy, but this could be due to either recombination or hypervariable sites. Two additional recombination detection methods used, Geneconv and Maximum Chi-Square, showed nonsignificant results. The overall significance of these findings is hard to quantify because of nonindependence, but our results suggest a lack of evidence for recombination in human mtDNA.
Hanada, Katsuhiro; Yamaoka, Yoshio
2014-10-01
Helicobacter pylori is a gram-negative pathogenic bacterium that colonises the human stomach. The chronic infection it causes results in peptic ulcers and gastric cancers. H. pylori can easily establish a chronic infection even if the immune system attacks this pathogen with oxidative stress agents and immunoglobulins. This is attributed to bacterial defence mechanisms against these stresses. As a defence mechanism against oxidative stresses, in bacterial genomes, homologous recombination can act as a repair pathway of DNA's double-strand breaks (DSBs). Moreover, homologous recombination is also involved in the antigenic variation in H. pylori. Gene conversion alters genomic structures of babA and babB (encoding outer membrane proteins), resulting in escape from immunoglobulin attacks. Thus, homologous recombination in bacteria plays an important role in the maintenance of a chronic infection. In addition, H. pylori infection causes DSBs in human cells. Homologous recombination is also involved in the repair of DSBs in human cells. In this review, we describe the roles of homologous recombination with an emphasis on the maintenance of a chronic infection. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.
Wang, J; Yang, P; Tang, B; Sun, X; Zhang, R; Guo, C; Gong, G; Liu, Y; Li, R; Zhang, L; Dai, Y; Li, N
2008-12-01
Improvement of the nutritional value of cow milk with transgenic expression of recombinant human alpha-lactalbumin (alpha-LA) has been previously attempted. However, the detailed characterization of the recombinant protein and analysis of the transgenic milk components are not explored yet. Here, we first report production of healthy transgenic cows by somatic cell nuclear transfer, in which expression of up to 1.55 g/L of recombinant human alpha-LA was achieved. The recombinant human alpha-LA was purified from transgenic milk and displayed physicochemical properties similar to its natural counterpart with respect to molecular weight, structure, and regulatory activity for beta-1,4-galactosyltransferase. Additionally, no N-glycosylation was found in the recombinant human alpha-LA, whereas the endogenous bovine alpha-LA was glycosylated at the unusual site (71)Asn-Ile-(73)Cys. Compared with milk from nontransgenic cows, expression of the transgene did not materially alter milk composition, such as fat and protein content. Our research thus provides scientific evidence supporting the feasibility of humanizing cow milk.
International Validation of Two Human Recombinant Estrogen Receptor (ERa) Binding Assays
An international validation study has been successfully completed for 2 competitive binding assays using human recombinant ERa. Assays evaluated included the Freyberger-Wilson (FW) assay using a full length human ER, and the Chemical Evaluation and Research Institute (CERI) assay...
Human recombinant soluble guanylyl cyclase: expression, purification, and regulation
NASA Technical Reports Server (NTRS)
Lee, Y. C.; Martin, E.; Murad, F.
2000-01-01
The alpha1- and beta1-subunits of human soluble guanylate cyclase (sGC) were coexpressed in the Sf9 cells/baculovirus system. In addition to the native enzyme, constructs with hexahistidine tag at the amino and carboxyl termini of each subunit were coexpressed. This permitted the rapid and efficient purification of active recombinant enzyme on a nickel-affinity column. The enzyme has one heme per heterodimer and was readily activated with the NO donor sodium nitroprusside or 3-(5'-hydroxymethyl-2'furyl)-1-benzyl-indazole (YC-1). Sodium nitroprusside and YC-1 treatment potentiated each other in combination and demonstrated a remarkable 2,200-fold stimulation of the human recombinant sGC. The effects were inhibited with 1H-(1,2, 4)oxadiazole(4,3-a)quinoxalin-1one (ODQ). The kinetics of the recombinant enzyme with respect to GTP was examined. The products of the reaction, cGMP and pyrophosphate, inhibited the enzyme. The extent of inhibition by cGMP depended on the activation state of the enzyme, whereas inhibition by pyrophosphate was not affected by the enzyme state. Both reaction products displayed independent binding and cooperativity with respect to enzyme inhibition. The expression of large quantities of active enzyme will facilitate structural characterization of the protein.
Ancient Recombination Events between Human Herpes Simplex Viruses.
Burrel, Sonia; Boutolleau, David; Ryu, Diane; Agut, Henri; Merkel, Kevin; Leendertz, Fabian H; Calvignac-Spencer, Sébastien
2017-07-01
Herpes simplex viruses 1 and 2 (HSV-1 and HSV-2) are seen as close relatives but also unambiguously considered as evolutionary independent units. Here, we sequenced the genomes of 18 HSV-2 isolates characterized by divergent UL30 gene sequences to further elucidate the evolutionary history of this virus. Surprisingly, genome-wide recombination analyses showed that all HSV-2 genomes sequenced to date contain HSV-1 fragments. Using phylogenomic analyses, we could also show that two main HSV-2 lineages exist. One lineage is mostly restricted to subSaharan Africa whereas the other has reached a global distribution. Interestingly, only the worldwide lineage is characterized by ancient recombination events with HSV-1. Our findings highlight the complexity of HSV-2 evolution, a virus of putative zoonotic origin which later recombined with its human-adapted relative. They also suggest that coinfections with HSV-1 and 2 may have genomic and potentially functional consequences and should therefore be monitored more closely. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Lennon, V A; Lambert, E H; Leiby, K R; Okarma, T B; Talib, S
1991-04-01
A synthetic gene encoding the 210 N-terminal residues of the alpha-subunit of the nicotinic acetylcholine receptor (AChR) of human skeletal muscle was cloned into an inducible expression plasmid to produce a fusion protein in high yield in Escherichia coli. Like native human AChR, the recombinant human alpha 1-210 protein induced AChR-binding, AChR-modulating, and AChR-blocking autoantibodies in rats when injected once intradermally as an emulsion in CFA, with Bordetella pertussis vaccine as supplementary adjuvant. The minimum dose of recombinant protein required to induce biochemical signs of experimental autoimmune myasthenia gravis (EAMG) with 100% incidence was 2.2 micrograms. With 6.6 to 22 micrograms, serum levels of autoantibodies were persistent, and clinically apparent EAMG lasted more than a month. Clinical, electrophysiological, and biochemical indices of EAMG induced by doses of 66 micrograms or more were more uniformly severe and persistent, with 33% fatality. Rats receiving a control extract of E. coli containing plasmid without the alpha 1-210 codon insert, with adjuvants, did not develop autoantibodies or signs of EAMG. This highly reproducible new model of EAMG induced by a recombinant human autoantigen should be valuable for testing Ag-specific immunotherapeutic strategies that might be applicable to treating acquired myasthenia gravis in humans.
Briney, Bryan S; Willis, Jordan R; Hicar, Mark D; Thomas, James W; Crowe, James E
2012-09-01
Antibody heavy-chain recombination that results in the incorporation of multiple diversity (D) genes, although uncommon, contributes substantially to the diversity of the human antibody repertoire. Such recombination allows the generation of heavy chain complementarity determining region 3 (HCDR3) regions of extreme length and enables junctional regions that, because of the nucleotide bias of N-addition regions, are difficult to produce through normal V(D)J recombination. Although this non-classical recombination process has been observed infrequently, comprehensive analysis of the frequency and genetic characteristics of such events in the human peripheral blood antibody repertoire has not been possible because of the rarity of such recombinants and the limitations of traditional sequencing technologies. Here, through the use of high-throughput sequencing of the normal human peripheral blood antibody repertoire, we analysed the frequency and genetic characteristics of V(DD)J recombinants. We found that these recombinations were present in approximately 1 in 800 circulating B cells, and that the frequency was severely reduced in memory cell subsets. We also found that V(DD)J recombination can occur across the spectrum of diversity genes, indicating that virtually all recombination signal sequences that flank diversity genes are amenable to V(DD)J recombination. Finally, we observed a repertoire bias in the diversity gene repertoire at the upstream (5') position, and discovered that this bias was primarily attributable to the order of diversity genes in the genomic locus. © 2012 The Authors. Immunology © 2012 Blackwell Publishing Ltd.
NASA Astrophysics Data System (ADS)
Olsen, David; Chang, Robert; Williams, Kim E.; Polarek, James W.
We have developed a recombinant expression system to produce a series of novel recombinant human gelatins that can substitute for animal sourced gelatin preparations currently used in pharmaceutical and nutraceutical applications. This system allows the production of human sequence gelatins, or, if desired, gelatins from any other species depending on the availability of the cloned gene. The gelatins produced with this recombinant system are of defined molecular weight, unlike the animal-sourced gelatins, which consist of numerous polypeptides of varying size. The fermentation and purification process used to prepare these recombinant gelatins does not use any human- or animal-derived components and thus this recombinant material should be free from viruses and agents that cause transmissible spongiform encephalopathies. The recombinant gelatins exhibit lot-to-lot reproducibility and we have performed extensive analytical testing on them. We have demonstrated the utility of these novel gelatins as biological stabilizers and plasma expanders, and we have shown they possess qualities that are important in applications where gel formation is critical. Finally, we provide examples of how our system allows the engineering of these recombinant gelatins to optimize the production process.
Acute effect of infection by adipogenic human adenovirus Ad36
Pasarica, Magdalena; Loiler, Scott; Dhurandhar, Nikhil V.
2009-01-01
Human adenovirus Ad36 is causally and correlatively associated in animals and humans, respectively, with increased adiposity and altered metabolic profile. We inoculated rats with Ad36, UV-inactivated Ad36 or mock-infected. Four-days later, Ad36-infected rats showed 23% greater epididymal fat pad weight and viral mRNA, the viral DNA could also be detected in tissues viz. the liver, brain, and adipose tissue. Intranasal or intra-peritoneal routes of viral inoculations showed similar tissue affinity. Serum cytokine response was remarkably down regulated. Ad36 acutely suppresses systemic immune response and spreads widely. This information will help to determine Ad36 tissue tropism and its metabolic consequences. PMID:18830560
LDSplitDB: a database for studies of meiotic recombination hotspots in MHC using human genomic data.
Guo, Jing; Chen, Hao; Yang, Peng; Lee, Yew Ti; Wu, Min; Przytycka, Teresa M; Kwoh, Chee Keong; Zheng, Jie
2018-04-20
Meiotic recombination happens during the process of meiosis when chromosomes inherited from two parents exchange genetic materials to generate chromosomes in the gamete cells. The recombination events tend to occur in narrow genomic regions called recombination hotspots. Its dysregulation could lead to serious human diseases such as birth defects. Although the regulatory mechanism of recombination events is still unclear, DNA sequence polymorphisms have been found to play crucial roles in the regulation of recombination hotspots. To facilitate the studies of the underlying mechanism, we developed a database named LDSplitDB which provides an integrative and interactive data mining and visualization platform for the genome-wide association studies of recombination hotspots. It contains the pre-computed association maps of the major histocompatibility complex (MHC) region in the 1000 Genomes Project and the HapMap Phase III datasets, and a genome-scale study of the European population from the HapMap Phase II dataset. Besides the recombination profiles, related data of genes, SNPs and different types of epigenetic modifications, which could be associated with meiotic recombination, are provided for comprehensive analysis. To meet the computational requirement of the rapidly increasing population genomics data, we prepared a lookup table of 400 haplotypes for recombination rate estimation using the well-known LDhat algorithm which includes all possible two-locus haplotype configurations. To the best of our knowledge, LDSplitDB is the first large-scale database for the association analysis of human recombination hotspots with DNA sequence polymorphisms. It provides valuable resources for the discovery of the mechanism of meiotic recombination hotspots. The information about MHC in this database could help understand the roles of recombination in human immune system. DATABASE URL: http://histone.scse.ntu.edu.sg/LDSplitDB.
Functional bottlenecks for generation of HIV-1 intersubtype Env recombinants.
Bagaya, Bernard S; Vega, José F; Tian, Meijuan; Nickel, Gabrielle C; Li, Yuejin; Krebs, Kendall C; Arts, Eric J; Gao, Yong
2015-05-23
Intersubtype recombination is a powerful driving force for HIV evolution, impacting both HIV-1 diversity within an infected individual and within the global epidemic. This study examines if viral protein function/fitness is the major constraint shaping selection of recombination hotspots in replication-competent HIV-1 progeny. A better understanding of the interplay between viral protein structure-function and recombination may provide insights into both vaccine design and drug development. In vitro HIV-1 dual infections were used to recombine subtypes A and D isolates and examine breakpoints in the Env glycoproteins. The entire env genes of 21 A/D recombinants with breakpoints in gp120 were non-functional when cloned into the laboratory strain, NL4-3. Likewise, cloning of A/D gp120 coding regions also produced dead viruses with non-functional Envs. 4/9 replication-competent viruses with functional Env's were obtained when just the V1-V5 regions of these same A/D recombinants (i.e. same A/D breakpoints as above) were cloned into NL4-3. These findings on functional A/D Env recombinants combined with structural models of Env suggest a conserved interplay between the C1 domain with C5 domain of gp120 and extracellular domain of gp41. Models also reveal a co-evolution within C1, C5, and ecto-gp41 domains which might explain the paucity of intersubtype recombination in the gp120 V1-V5 regions, despite their hypervariability. At least HIV-1 A/D intersubtype recombination in gp120 may result in a C1 from one subtype incompatible with a C5/gp41 from another subtype.
Combination recombinant simian or chimpanzee adenoviral vectors for vaccine development.
Cheng, Cheng; Wang, Lingshu; Ko, Sung-Youl; Kong, Wing-Pui; Schmidt, Stephen D; Gall, Jason G D; Colloca, Stefano; Seder, Robert A; Mascola, John R; Nabel, Gary J
2015-12-16
Recombinant adenoviral vector (rAd)-based vaccines are currently being developed for several infectious diseases and cancer therapy, but pre-existing seroprevalence to such vectors may prevent their use in broad human populations. In this study, we investigated the potential of low seroprevalence non-human primate rAd vectors to stimulate cellular and humoral responses using HIV/SIV Env glycoprotein (gp) as the representative antigen. Mice were immunized with novel simian or chimpanzee rAd (rSAV or rChAd) vectors encoding HIV gp or SIV gp by single immunization or in heterologous prime/boost combinations (DNA/rAd; rAd/rAd; rAd/NYVAC or rAd/rLCM), and adaptive immunity was assessed. Among the rSAV and rChAd tested, rSAV16 or rChAd3 vector alone generated the most potent immune responses. The DNA/rSAV regimen also generated immune responses similar to the DNA/rAd5 regimen. rChAd63/rChAd3 and rChAd3 /NYVAC induced similar or even higher levels of CD4+ and CD8+ T-cell and IgG responses as compared to rAd28/rAd5, one of the most potent combinations of human rAds. The optimized vaccine regimen stimulated improved cellular immune responses and neutralizing antibodies against HIV compared to the DNA/rAd5 regimen. Based on these results, this type of novel rAd vector and its prime/boost combination regimens represent promising candidates for vaccine development. Published by Elsevier Ltd.
Wang, Shuchao; Sun, Chenglong; Zhang, Shoufeng; Zhang, Xiaozhuo; Liu, Ye; Wang, Ying; Zhang, Fei; Wu, Xianfu; Hu, Rongliang
2015-09-01
The rabies virus (RABV) glycoprotein (G) is responsible for inducing neutralizing antibodies against rabies virus. Development of recombinant vaccines using the G genes from attenuated strains rather than street viruses is a regular practice. In contrast to this scenario, we generated three human adenovirus type 5 recombinants using the G genes from the vaccine strains SRV9 and Flury-LEP, and the street RABV strain BD06 (nrAd5-SRV9-G, nrAd5-Flury-LEP-G, and nrAd5-BD06-G). These recombinants were non-replicative, but could grow up to ~10(8) TCID50/ml in helper HEK293AD cells. Expression of the G protein was verified by immunostaining, quantitative PCR and cytometry. Animal experiments revealed that immunization with nrAd5-BD06-G can induce a higher seroconversion rate, a higher neutralizing antibody level, and a longer survival time after rabies virus challenge in mice when compared with the other two recombinants. Moreover, the expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) was significantly higher in mice immunized with nrAd5-BD06-G, which might also contribute to the increased protection. These results show that the use of street RABV G for non-replicative systems may be an alternative for developing effective recombinant rabies vaccines.
The production of recombinant human erythropoietin.
Inoue, N; Takeuchi, M; Ohashi, H; Suzuki, T
1995-01-01
Erythropoietin (EPO) is the glycoprotein hormone that promotes differentiation of erythroid progenitor cells in bone marrow. The normal kidney produces EPO to maintain erythrocyte for oxygen supply. This hormone activity was found in the serum of anemic animals in the 1890s. Renal failure results in severe anemia because of reduced EPO production, therefore anemia patients expected EPO treatment for long time. However, this was difficult due to the limited amount of EPO. Many researchers have tried to isolate EPO since the 1950s. Finally Miyake and Goldwasser purified highly active EPO from the urine of aplastic anemia patients. Since then, the characteristics and structural information from the purified material accelerated the cloning of the EPO gene. Mammalian cells were essential to produce EPO, because EPO contains 40% carbohydrate that plays some important roles in its activity, stability and biosynthesis. In 1984, two groups succeeded in cloning the EPO gene and expressing this gene in mammalian cells. Recombinant human EPO is currently available for anemia treatment. In this paper, we review production in mammalian cells, molecular characterization, especially carbohydrate moieties, and clinical applications of recombinant EPO.
Production of biologically active recombinant human factor H in Physcomitrella.
Büttner-Mainik, Annette; Parsons, Juliana; Jérôme, Hanna; Hartmann, Andrea; Lamer, Stephanie; Schaaf, Andreas; Schlosser, Andreas; Zipfel, Peter F; Reski, Ralf; Decker, Eva L
2011-04-01
The human complement regulatory serum protein factor H (FH) is a promising future biopharmaceutical. Defects in the gene encoding FH are associated with human diseases like severe kidney and retinal disorders in the form of atypical haemolytic uremic syndrome (aHUS), membranoproliferative glomerulonephritis II (MPGN II) or age-related macular degeneration (AMD). There is a current need to apply intact full-length FH for the therapy of patients with congenital or acquired defects of this protein. Application of purified or recombinant FH (rFH) to these patients is an important and promising approach for the treatment of these diseases. However, neither protein purified from plasma of healthy individuals nor recombinant protein is currently available on the market. Here, we report the first stable expression of the full-length human FH cDNA and the subsequent production of this glycoprotein in a plant system. The moss Physcomitrella patens perfectly suits the requirements for the production of complex biopharmaceuticals as this eukaryotic system not only offers an outstanding genetical accessibility, but moreover, proteins can be produced safely in scalable photobioreactors without the need for animal-derived medium compounds. Transgenic moss lines were created, which express the human FH cDNA and target the recombinant protein to the culture supernatant via a moss-derived secretion signal. Correct processing of the signal peptide and integrity of the moss-produced rFH were verified via peptide mapping by mass spectrometry. Ultimately, we show that the rFH displays complement regulatory activity comparable to FH purified from plasma. © 2010 The Authors. Plant Biotechnology Journal © 2010 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.
Short-term effects of recombinant human growth hormone and feeding on gluconeogenesis in humans
USDA-ARS?s Scientific Manuscript database
After a short-term fast, lactating women have increased rates of glucose production but not gluconeogenesis (GNG) despite relative hypoinsulinemia. We explored the effects of non-insulin-dependent increase in glucose utilization and recombinant human growth hormone (rhGH) on glucose production, glyc...
A novel multi-epitope recombined protein for diagnosis of human brucellosis.
Yin, Dehui; Li, Li; Song, Xiuling; Li, Han; Wang, Juan; Ju, Wen; Qu, Xiaofeng; Song, Dandan; Liu, Yushen; Meng, Xiangjun; Cao, Hongqian; Song, Weiyi; Meng, Rizeng; Liu, Jinhua; Li, Juan; Xu, Kun
2016-05-21
In epidemic regions of the world, brucellosis is a reemerging zoonosis with minimal mortality but is a serious public hygiene problem. Currently, there are various methods for brucellosis diagnosis, however few of them are available to be used to diagnose, especially for serious cross-reaction with other bacteria. To overcome this disadvantage, we explored a novel multi-epitope recombinant protein as human brucellosis diagnostic antigen. We established an indirect enzyme-linked immunosorbent assay (ELISA) based on this recombinant protein. 248 sera obtained from three different groups including patients with brucellosis (146 samples), non-brucellosis patients (82 samples), and healthy individuals (20 samples) were tested by indirect ELISA. To evaluate the assay, a receiver-operating characteristic (ROC) analysis and immunoblotting were carried out using these characterized serum samples. For this test, the area under the ROC curve was 0.9409 (95 % confidence interval, 0.9108 to 0.9709), and a sensitivity of 88.89 % and a specificity of 85.54 % was given with a cutoff value of 0.3865 from this ROC analysis. The Western blot results indicate that it is feasible to differentiate human brucellosis and non-brucellosis with the newly established method based on this recombinant protein. Our results obtained high diagnostic accuracy of the ELISA assay which encourage the use of this novel recombinant protein as diagnostic antigen to implement serological diagnosis of brucellosis.
Recombinant human leptin in women with hypothalamic amenorrhea.
Welt, Corrine K; Chan, Jean L; Bullen, John; Murphy, Robyn; Smith, Patricia; DePaoli, Alex M; Karalis, Aspasia; Mantzoros, Christos S
2004-09-02
Disruptions in hypothalamic-gonadal and other endocrine axes due to energy deficits are associated with low levels of the adipocyte-secreted hormone leptin and may result in hypothalamic amenorrhea. We hypothesized that exogenous recombinant leptin replacement would improve reproductive and neuroendocrine function in women with hypothalamic amenorrhea. Eight women with hypothalamic amenorrhea due to strenuous exercise or low weight were studied for one month before receiving recombinant human leptin and then while receiving treatment for up to three months. Six control subjects with hypothalamic amenorrhea received no treatment and were studied for a mean (+/-SD) of 8.5+/-8.1 months. Luteinizing hormone (LH) pulsatility, body weight, ovarian variables, and hormone levels did not change significantly over time in the controls and during a one-month control period before recombinant leptin therapy in the treated subjects. In contrast, recombinant leptin treatment increased mean LH levels and LH pulse frequency after two weeks and increased maximal follicular diameter, the number of dominant follicles, ovarian volume, and estradiol levels over a period of three months. Three patients had an ovulatory menstrual cycle (P<0.05 for the comparison with an expected rate of spontaneous ovulation of 10 percent); two others had preovulatory follicular development and withdrawal bleeding during treatment (P<0.05). Recombinant leptin significantly increased levels of free triiodothyronine, free thyroxine, insulin-like growth factor 1, insulin-like growth factor-binding protein 3, bone alkaline phosphatase, and osteocalcin but not cortisol, corticotropin, or urinary N-telopeptide. Leptin administration for the relative leptin deficiency in women with hypothalamic amenorrhea appears to improve reproductive, thyroid, and growth hormone axes and markers of bone formation, suggesting that leptin, a peripheral signal reflecting the adequacy of energy stores, is required for normal
Recombinant human prion protein inhibits prion propagation in vitro.
Yuan, Jue; Zhan, Yi-An; Abskharon, Romany; Xiao, Xiangzhu; Martinez, Manuel Camacho; Zhou, Xiaochen; Kneale, Geoff; Mikol, Jacqueline; Lehmann, Sylvain; Surewicz, Witold K; Castilla, Joaquín; Steyaert, Jan; Zhang, Shulin; Kong, Qingzhong; Petersen, Robert B; Wohlkonig, Alexandre; Zou, Wen-Quan
2013-10-09
Prion diseases are associated with the conformational conversion of the cellular prion protein (PrP(C)) into the pathological scrapie isoform (PrP(Sc)) in the brain. Both the in vivo and in vitro conversion of PrP(C) into PrP(Sc) is significantly inhibited by differences in amino acid sequence between the two molecules. Using protein misfolding cyclic amplification (PMCA), we now report that the recombinant full-length human PrP (rHuPrP23-231) (that is unglycosylated and lacks the glycophosphatidylinositol anchor) is a strong inhibitor of human prion propagation. Furthermore, rHuPrP23-231 also inhibits mouse prion propagation in a scrapie-infected mouse cell line. Notably, it binds to PrP(Sc), but not PrP(C), suggesting that the inhibitory effect of recombinant PrP results from blocking the interaction of brain PrP(C) with PrP(Sc). Our findings suggest a new avenue for treating prion diseases, in which a patient's own unglycosylated and anchorless PrP is used to inhibit PrP(Sc) propagation without inducing immune response side effects.
Bioprocess and downstream optimization of recombinant human growth hormone in Pichia pastoris
Azadi, Saeed; Sadjady, Seyed Kazem; Mortazavi, Seyed Alireza; Naghdi, Nasser; Mahboubi, Arash; Solaimanian, Roya
2018-01-01
The methylotrophic yeast Pichia pastoris is a well-established expression host, which is often used in the production of protein pharmaceuticals. This work aimed to evaluate the effect of various concentrations of ascorbic acid in mixed feeding strategy with sorbitol/methanol on productivity of recombinant human growth hormone (r-hGH). The relevant concentration of ascorbic acid (5, 10, or 20 mmol) and 50 g/L sorbitol were added in batch-wise mode to the medium at the beginning of induction phase. The rate of methanol addition was increased stepwise during the first 12 h of production and then kept constant. Total protein and r-hGH concentrations were analyzed and the results compared with sorbitol/methanol feeding using one-way analysis of variance. Moreover, an effective clarification process using activated carbon was developed to remove process contaminants like pigments and endotoxins. Finally, a three-step chromatographic process was applied to purify the product. According to the obtained results, addition of 10 mmol ascorbic acid to sorbitol/methanol co-feeding could significantly increase cell biomass (1.7 fold), total protein (1.14 fold), and r-hGH concentration (1.43 fold). One percent activated carbon could significantly decrease pigments and endotoxins without any significant changes in r-hGH assay. The result of the study concluded that ascorbic acid in combination with sorbitol could effectively enhance the productivity of r-hGH. This study also demonstrated that activated carbon clarification is a simple method for efficient removal of endotoxin and pigment in production of recombinant protein in the yeast expression system. PMID:29853932
[Construction and expression of recombinant human serum albumin-EPO fusion protein].
Huang, Ying-Chun; Gou, Xing-Hua; Han, Lei; Li, De-Hua; Zhao, Lan-Ying; Wu, Qia-Qing
2011-05-01
OBJECTIVE To construct the recombinant plasmid pCI-HLE encoding human serum album-EPO (HSA-EPO) fusion protein and to express it in CHO cell. The cDNA encoding human serum album and EPO were amplified by PCR, and then spliced with the synsitic DNA fragment encoding GS (GGGGS), by overlap PCR extension to form LEPO. After BamH I digestion, the HSA and LEPO was ligated to generate the fusion HSA-EPO gene and was then cloned into the expression vector pCI-neo to generate the recombinant plasmid pCI-HLE. The plasmid pCI-HLE was transfected into CHO cell by liposome protocol. Then, the recombinant cells were screened by G418 and identified by PCR and Western blot. Expression of fusion protein was evaluated by Enzyme Linked Immunosorbent Assay (ELISA). Restrictive enzymes digestion and DNA sequencing revealed that HSA-EPO fusion gene was cloned into expression vector pCI-neo successfully. PCR and Western blot analysis confirmed that the fusion gene was integrated in the genome of CHO cells and expressed successfully. The HSA-EPO production varied from 86 Iu/(mL x 10(6) x 72 h) to 637 IU/(mLx 10(6) x 72 h). The results confirmed that HSA-EPO fusion gene can be expressed in the CHO cells, with EPO immunogenicity, which could serve as foundation for the development of long-lasting recombinant HSA-EPO protein.
Wu, Min; Kwoh, Chee-Keong; Li, Xiaoli; Zheng, Jie
2014-09-11
The regulatory mechanism of recombination is one of the most fundamental problems in genomics, with wide applications in genome wide association studies (GWAS), birth-defect diseases, molecular evolution, cancer research, etc. Recombination events cluster into short genomic regions called "recombination hotspots". Recently, a zinc finger protein PRDM9 was reported to regulate recombination hotspots in human and mouse genomes. In addition, a 13-mer motif contained in the binding sites of PRDM9 is found to be enriched in human hotspots. However, this 13-mer motif only covers a fraction of hotspots, indicating that PRDM9 is not the only regulator of recombination hotspots. Therefore, the challenge of discovering other regulators of recombination hotspots becomes significant. Furthermore, recombination is a complex process. Hence, multiple proteins acting as machinery, rather than individual proteins, are more likely to carry out this process in a precise and stable manner. Therefore, the extension of the prediction of individual trans-regulators to protein complexes is also highly desired. In this paper, we introduce a pipeline to identify genes and protein complexes associated with recombination hotspots. First, we prioritize proteins associated with hotspots based on their preference of binding to hotspots and coldspots. Second, using the above identified genes as seeds, we apply the Random Walk with Restart algorithm (RWR) to propagate their influences to other proteins in protein-protein interaction (PPI) networks. Hence, many proteins without DNA-binding information will also be assigned a score to implicate their roles in recombination hotspots. Third, we construct sub-PPI networks induced by top genes ranked by RWR for various species (e.g., yeast, human and mouse) and detect protein complexes in those sub-PPI networks. The GO term analysis show that our prioritizing methods and the RWR algorithm are capable of identifying novel genes associated with
Recombining overlapping BACs into a single larger BAC.
Kotzamanis, George; Huxley, Clare
2004-01-06
BAC clones containing entire mammalian genes including all the transcribed region and long range controlling elements are very useful for functional analysis. Sequenced BACs are available for most of the human and mouse genomes and in many cases these contain intact genes. However, large genes often span more than one BAC, and single BACs covering the entire region of interest are not available. Here we describe a system for linking two or more overlapping BACs into a single clone by homologous recombination. The method was used to link a 61-kb insert carrying the final 5 exons of the human CFTR gene onto a 160-kb BAC carrying the first 22 exons. Two rounds of homologous recombination were carried out in the EL350 strain of bacteria which can be induced for the Red genes. In the first round, the inserts of the two overlapping BACs were subcloned into modified BAC vectors using homologous recombination. In the second round, the BAC to be added was linearised with the very rare-cutting enzyme I-PpoI and electroporated into recombination efficient EL350 bacteria carrying the other BAC. Recombined BACs were identified by antibiotic selection and PCR screening and 10% of clones contained the correctly recombined 220-kb BAC. The system can be used to link the inserts from any overlapping BAC or PAC clones. The original orientation of the inserts is not important and desired regions of the inserts can be selected. The size limit for the fragments recombined may be larger than the 61 kb used here and multiple BACs in a contig could be combined by alternating use of the two pBACLink vectors. This system should be of use to many investigators wishing to carry out functional analysis on large mammalian genes which are not available in single BAC clones.
Foster, Barbara A.; Gangavarapu, Kalyan J.; Mathew, Grinu; Azabdaftari, Gissou; Morrison, Carl D.; Miller, Austin; Huss, Wendy J.
2013-01-01
Stem cell enrichment provides a tool to examine prostate stem cells obtained from benign and malignant tissue. Functional assays can enrich stem cells based on common stem cell phenotypes, such as high ATP binding cassette (ABC) transporter mediated efflux of Hoechst substrates (side population assay). This functional assay is based upon mechanisms that protect cells from environmental insult thus contributing to the survival and protection of the stem cell population. We have isolated and analyzed cells digested from twelve clinical prostate specimens based on the side population assay. Prostate stem cell properties of the isolated cells were tested by serial recombination with rat urogenital mesenchyme. Recombinants with side population cells demonstrate an increase in the frequency of human ductal growth and the number of glands per recombinant when compared to recombinants with non-side population cells. Isolated cells were capable of prostatic growth for up to three generations in the recombination assay with as little as 125 sorted prostate cells. The ability to reproducibly use cells isolated by fluorescence activated cell sorting from human prostate tissue is an essential step to a better understanding of human prostate stem cell biology. ABC transporter G2 (ABCG2) was expressed in recombinants from side population cells indicating the side population cells have self-renewal properties. Epithelial cell differentiation of recombinants was determined by immunohistochemical analysis for expression of the basal, luminal, and neuroendocrine markers, p63, androgen receptor, prostate specific antigen, and chromogranin A, respectively. Thus, the ABCG2 expressing side population demonstrates multipotency and self-renewal properties indicating stem cells are within this population. PMID:23383057
Meyer, Nuala J; Reilly, John P; Anderson, Brian J; Palakshappa, Jessica A; Jones, Tiffanie K; Dunn, Thomas G; Shashaty, Michael G S; Feng, Rui; Christie, Jason D; Opal, Steven M
2018-01-01
Plasma interleukin-1 beta may influence sepsis mortality, yet recombinant human interleukin-1 receptor antagonist did not reduce mortality in randomized trials. We tested for heterogeneity in the treatment effect of recombinant human interleukin-1 receptor antagonist by baseline plasma interleukin-1 beta or interleukin-1 receptor antagonist concentration. Retrospective subgroup analysis of randomized controlled trial. Multicenter North American and European clinical trial. Five hundred twenty-nine subjects with sepsis and hypotension or hypoperfusion, representing 59% of the original trial population. Random assignment of placebo or recombinant human interleukin-1 receptor antagonist × 72 hours. We measured prerandomization plasma interleukin-1 beta and interleukin-1 receptor antagonist and tested for statistical interaction between recombinant human interleukin-1 receptor antagonist treatment and baseline plasma interleukin-1 receptor antagonist or interleukin-1 beta concentration on 28-day mortality. There was significant heterogeneity in the effect of recombinant human interleukin-1 receptor antagonist treatment by plasma interleukin-1 receptor antagonist concentration whether plasma interleukin-1 receptor antagonist was divided into deciles (interaction p = 0.046) or dichotomized (interaction p = 0.028). Interaction remained present across different predicted mortality levels. Among subjects with baseline plasma interleukin-1 receptor antagonist above 2,071 pg/mL (n = 283), recombinant human interleukin-1 receptor antagonist therapy reduced adjusted mortality from 45.4% to 34.3% (adjusted risk difference, -0.12; 95% CI, -0.23 to -0.01), p = 0.044. Mortality in subjects with plasma interleukin-1 receptor antagonist below 2,071 pg/mL was not reduced by recombinant human interleukin-1 receptor antagonist (adjusted risk difference, +0.07; 95% CI, -0.04 to +0.17), p = 0.230. Interaction between plasma interleukin-1 beta concentration and recombinant human
Hwang, Shen-An; Kruzel, Marian L; Actor, Jeffrey K
2017-02-01
Trehalose 6'6-dimycolate (TDM) is the most abundant glycolipid on the cell wall of Mycobacterium tuberculosis (MTB). TDM is capable of inducing granulomatous pathology in mouse models that resembles those induced by MTB infection. Using the acute TDM model, this work investigates the effect of recombinant human and mouse lactoferrin to reduce granulomatous pathology. C57BL/6 mice were injected intravenously with TDM at a dose of 25 μg·mouse -1 . At day 4 and 6, recombinant human or mouse lactoferrin (1 mg·(100 μL) -1 ·mouse -1 ) were delivered by gavage. At day 7 after TDM injection, mice were evaluated for lung pathology, cytokine production, and leukocyte populations. Mice given human or mouse lactoferrin had reduced production of IL-12p40 in their lungs. Mouse lactoferrin increased IL-6 and KC (CXCL1) in lung tissue. Increased numbers of macrophages were observed in TDM-injected mice given human or mouse lactoferrin. Granulomatous pathology, composed of mainly migrated leukocytes, was visually reduced in mice that received human or mouse lactoferrin. Quantitation of granulomatous pathology demonstrated a significant decrease in mice given human or mouse lactoferrin compared with TDM control mice. This report is the first to directly compare the immune modulatory effects of both heterologous recombinant human and homologous mouse lactoferrin on the development of TDM-induced granulomas.
Kim, Jeong Hwan; Park, Si-Nae; Suh, Hwal
2007-02-28
The purpose of current experiment is the generation of insulin-producing human mesenchymal stem cells as therapeutic source for the cure of type 1 diabetes. Type 1 diabetes is generally caused by insulin deficiency accompanied by the destruction of islet beta-cells. In various trials for the treatment of type 1 diabetes, cell-based gene therapy using stem cells is considered as one of the most useful candidate for the treatment. In this experiment, human mesenchymal stem cells were transduced with AAV which is containing furin-cleavable human preproinsulin gene to generate insulin-producing cells as surrogate beta-cells for the type 1 diabetes therapy. In the rAAV production procedure, rAAV was generated by transfection of AD293 cells. Human mesenchymal stems cells were transduced using rAAV with a various multiplicity of infection. Transduction of recombinant AAV was also tested using beta-galactosidse expression. Cell viability was determined by using MTT assay to evaluate the toxicity of the transduction procedure. Expression and production of Insulin were tested using reverse transcriptase-polymerase chain reaction and immunocytochemistry. Secretion of human insulin and C-peptide from the cells was assayed using enzyme-linked immunosorbent assay. Production of insulin and C-peptide from the test group represented a higher increase compared to the control group. In this study, we examined generation of insulin-producing cells from mesenchymal stem cells by genetic engineering for diabetes therapy. This work might be valuable to the field of tissue engineering for diabetes treatment.
Recombinant Human Insulin in Global Diabetes Management – Focus on Clinical Efficacy
Mbanya, Jean Claude; Sandow, Juergen; Landgraf, Wolfgang
2017-01-01
Abstract Biosynthetic human insulin and insulin analogues are the mainstay of insulin therapy for both type 1 and type 2 diabetes although access to human insulin at affordable prices remains a global issue. The world is experiencing an exponential rise in the prevalence of diabetes presenting an urgent need to establish effective diabetes therapy in countries burdened by inadequate health care budgets, malnutrition and infectious diseases. Recombinant human insulin has replaced animal insulins and animal-based semisynthetic human insulin thereby available in sufficient quantities and at affordable prices able to provide global access to insulin therapy. In many patients, analog insulins can offer additional clinical benefit, although at a considerably higher price thus severely restricting availability in low income countries. The approval process for recombinant human insulins (i.e. biosimilars) and analogue insulins is highly variable in the developing countries in contrast to Europe and in North America, where it is well established within a strict regulatory framework. This review aims to discuss the future access to human insulin therapy in a global context with an ever increasing burden of diabetes and significant economic implications. PMID:29632602
Liu, Wei; Zhou, Yan; Wang, Ziyan; Zhang, Zeqiang; Wang, Qizhi; Su, Weiheng; Chen, Yan; Zhang, Yan; Gao, Feng; Jiang, Chunlai; Kong, Wei
2017-05-01
The high prevalence of herpes simplex virus 2 (HSV-2) infections in humans necessitates the development of a safe and effective vaccine that will need to induce vigorous T-cell responses to control viral infection and transmission. We designed rAd-gD2, rAd-gD2ΔUL25, and rAd-ΔUL25 to investigate whether recombinant replication-defective adenoviruses vaccine could induce specific T-cell responses and protect mice against intravaginal HSV-2 challenge compared with FI-HSV-2. In the present study, recombinant adenovirus-based HSV-2 showed higher reductions in mortality and stronger antigen-specific T-cell responses compared with FI-HSV-2 and the severity of genital lesions in mice immunized with rAd-gD2ΔUL25 was significantly decreased by eliciting IFN-γ-secreting T-cell responses compared with rAd-gD2 and rAd-ΔUL25 groups. Our results demonstrated the immunogenicity and protective efficacy of recombinant adenovirus vaccines in acute HSV-2 infection following intravaginal challenge in mice. © 2017 The Societies and John Wiley & Sons Australia, Ltd.
Rodríguez-López, Alexander; Alméciga-Díaz, Carlos J.; Sánchez, Jhonnathan; Moreno, Jefferson; Beltran, Laura; Díaz, Dennis; Pardo, Andrea; Ramírez, Aura María; Espejo-Mojica, Angela J.; Pimentel, Luisa; Barrera, Luis A.
2016-01-01
Mucopolysaccharidosis IV A (MPS IV A, Morquio A disease) is a lysosomal storage disease (LSD) produced by mutations on N-acetylgalactosamine-6-sulfate sulfatase (GALNS). Recently an enzyme replacement therapy (ERT) for this disease was approved using a recombinant enzyme produced in CHO cells. Previously, we reported the production of an active GALNS enzyme in Escherichia coli that showed similar stability properties to that of a recombinant mammalian enzyme though it was not taken-up by culture cells. In this study, we showed the production of the human recombinant GALNS in the methylotrophic yeast Pichia pastoris GS115 (prGALNS). We observed that removal of native signal peptide and co-expression with human formylglycine-generating enzyme (SUMF1) allowed an improvement of 4.5-fold in the specific GALNS activity. prGALNS enzyme showed a high stability at 4 °C, while the activity was markedly reduced at 37 and 45 °C. It was noteworthy that prGALNS was taken-up by HEK293 cells and human skin fibroblasts in a dose-dependent manner through a process potentially mediated by an endocytic pathway, without any additional protein or host modification. The results show the potential of P. pastoris in the production of a human recombinant GALNS for the development of an ERT for Morquio A. PMID:27378276
Application of Recombinant Proteins for Serodiagnosis of Visceral Leishmaniasis in Humans and Dogs.
Farahmand, Mahin; Nahrevanian, Hossein
2016-07-01
Visceral leishmaniasis (VL) is a zoonotic disease caused by leishmania species. Dogs are considered to be the main reservoir of VL. A number of methods and antigen-based assays are used for the diagnosis of leishmaniasis. However, currently available methods are mainly based on direct examination of tissues for the presence of parasites, which is highly invasive. A variety of serological tests are commonly applied for VL diagnosis, including indirect fluorescence antibody test, enzyme-linked immunosorbent assay (ELISA), dot-ELISA, direct agglutination test, Western-blotting, and immunochromatographic test. However, when soluble antigens are used, serological tests are less specific due to cross-reactivity with other parasitic diseases. Several studies have attempted to replace soluble antigens with recombinant proteins to improve the sensitivity and the specificity of the immunodiagnostic tests. Major technological advances in recombinant antigens as reagents for the serological diagnosis of VL have led to high sensitivity and specificity of these serological tests. A great number of recombinant proteins have been shown to be effective for the diagnosis of leishmania infection in dogs, the major reservoir of L. infantum. Although few recombinant proteins with high efficacy provide reasonable results for the diagnosis of human and canine VL, more optimization is still needed for the appropriate antigens to provide high-throughput performance. This review aims to explore the application of different recombinant proteins for the serodiagnosis of VL in humans and dogs.
Kan, Takanobu; Hiragun, Takaaki; Ishii, Kaori; Hiragun, Makiko; Yanase, Yuhki; Tanaka, Akio; Hide, Michihiro
2015-07-01
We previously identified MGL_1304 secreted by Malassezia globosa as a sweat antigen for patients with atopic dermatitis (AD) and cholinergic urticaria (ChU). However, purifying native MGL_1304 from human sweat or culture supernatant of M. globosa (sup-MGL_1304) is costly and time-consuming. Moreover, recombinant MGL_1304 expressed by using Escherichia coli (TF-rMGL_1304) needs a large chaperon protein and lacks the original glycosylation of yeasts. Thus, we generated a recombinant MGL_1304 by Pichia pastoris (P-rMGL_1304) and investigated its characteristic features. Recombinant MGL_1304 proteins expressed by E. coli and P. pastoris were generated. Properties of these recombinants and native antigens were compared by western blot analysis, histamine release tests (HRT) of patients with AD and ChU, and β-hexosaminidase release tests with RBL-48 cells. P-rMGL_1304-specific IgE in sera of patients with AD were measured by sandwich ELISA. Western blot analysis revealed that IgE of patients with AD bound to all MGL_1304 recombinants and native antigens. The histamine releasing ability of P-rMGL_1304 was 100 times higher than that of TF-rMGL_1304, and was comparable to that of sup-MGL_1304. Degranulation rates of RBL-48 cells, sensitized with sera of patients with AD in response to the stimulation of P-rMGL_1304, were comparable to those of sup-MGL_1304, whereas those of TF-rMGL_1304 were relatively weak. The levels of P-rMGL_1304-specific IgE in sera of patients with AD were correlated with their disease severities. P-rMGL_1304 has an antigenicity comparable to the native antigen, and is more useful than TF-rMGL_1304, especially in HRT and degranulation assay of RBL-48 cells. Copyright © 2015 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.
Deyashiki, Y; Tamada, Y; Miyabe, Y; Nakanishi, M; Matsuura, K; Hara, A
1995-08-01
Human liver cytosol contains multiple forms of 3 alpha-hydroxysteroid dehydrogenase and dihydrodiol dehydrogenase with hydroxysteroid dehydrogenase activity, and multiple cDNAs for the enzymes have been cloned from human liver cDNA libraries. To understand the relationship of the multiple enzyme froms to the genes, a cDNA, which has been reported to code for an isoenzyme of human liver 3 alpha-hydroxysteroid/dihydrodiol dehydrogenase, was expressed in Escherichia coli. The recombinant enzyme showed structural and functional properties almost identical to those of the isoenzyme purified from human liver. In addition, the recombinant isoenzyme efficiently reduced 5 alpha-dihydrotestosterone and 5 beta-dihydrocortisone, the known substrates of human liver 3 alpha-hydroxysteroid dehydrogenase and chlordecone reductase previously purified, which suggests that these human liver enzymes are identical. Furthermore, the steady-state kinetic data for NADP(+)-linked (S)-1-indanol oxidation by the recombinant isoenzyme were consistent with a sequential ordered mechanism in which NADP+ binds first. Phenolphthalein inhibited this isoenzyme much more potently than it did the other human liver dihydrodiol dehydrogenases, and was a competitive inhibitor (Ki = 20 nM) that bound to the enzyme-NADP+ complex.
Berg, Michael G; Adams, Robert J; Gambhira, Ratish; Siracusa, Mark C; Scott, Alan L; Roden, Richard B S; Ketner, Gary
2014-09-01
Immunization with human papillomavirus (HPV) L1 virus-like particles (VLPs) prevents infection with HPV. However, the expense and logistical demands of current VLP vaccines will limit their widespread use in resource-limited settings, where most HPV-induced cervical cancer occurs. Live oral adenovirus vaccines have properties that are well-suited for use in such settings. We have described a live recombinant adenovirus vaccine prototype that produces abundant HPV16 L1 protein from the adenovirus major late transcriptional unit and directs the assembly of HPV16 VLPs in tissue culture. Recombinant-derived VLPs potently elicit neutralizing antibodies in mice. Here, we characterize the immune response to the recombinant after dual oral and intranasal immunization of pigtail macaques, in which the virus replicates as it would in immunized humans. The immunization of macaques induced vigorous humoral responses to adenovirus capsid and nonstructural proteins, although, surprisingly, not against HPV L1. In contrast, immunization elicited strong T-cell responses to HPV VLPs as well as adenovirus virions. T-cell responses arose immediately after the primary immunization and were boosted by a second immunization with recombinant virus. T-cell immunity contributes to protection against a wide variety of pathogens, including many viruses. The induction of a strong cellular response by the recombinant indicates that live adenovirus recombinants have potential as vaccines for those agents. These studies encourage and will inform the continued development of viable recombinant adenovirus vaccines. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
A Butter Aroma Recombinate Activates Human Class-I Odorant Receptors.
Geithe, Christiane; Andersen, Gaby; Malki, Agne; Krautwurst, Dietmar
2015-11-04
With ∼400 olfactory G protein-coupled receptors (GPCR), humans sensitively perceive ∼230 key aroma compounds as best natural agonists of ∼10000 food volatiles. An understanding of odorant coding, thus, critically depends on the knowledge about interactions of key food aroma chemicals and their mixtures with their cognate receptors. Genetically designed test cell systems enable the screening, deorphaning, and characterization of single odorant receptors (OR). This study shows for the food aroma-specific and quantitative butter aroma recombinate, and its single components, specific in vitro class-I OR activity patterns, as well as the activation of selected OR in a concentration-dependent manner. Recently, chemosensory receptors, especially class-I OR, were demonstrated to be expressed on blood leukocytes, which may encounter foodborne aroma compounds postprandially. This study shows that butter aroma recombinate induced chemotaxis of isolated human neutrophils in a defined gradient, and in a concentration-dependent and pertussis toxin-sensitive manner, suggesting at least a GPCR-mediated activation of blood leukocytes by key food odorants.
Yarimkaya, Ali; Apaydin, Berat; Unal, Ethem; Karabicak, Ilhan; Aydogan, Fatih; Uslu, Ezel; Erginoz, Ethem; Artis, Tarik; Eyuboglu, Erhun
2003-12-01
Recombinant human growth hormone and nandrolone phenylpropionate are two different anabolic agents. This study was designed to investigate the effects of these anabolic agents on the healing of ischemic colon anastomosis in rats. Seventy adult male Wistar rats were divided into five groups (n = 14). Group I was the sham laparotomy group. In the other groups, surgical procedures consisting of transsection and anastomosis were made at a distance 3 cm from the peritoneal reflection. Group II was the nonischemic control group. Ischemic colon model was produced in the remaining groups. Group III was the untreated control group. Groups IV and V received recombinant human growth hormone and nandrolone phenylpropionate, respectively. Bursting pressure and hydroxyproline levels were measured on the third and seventh postoperative days to evaluate anastomotic healing. Recombinant human growth hormone increased both collagen deposition and bursting pressure significantly at postoperative Days 3 and 7 compared with the sham and untreated control groups (P < 0.005). When compared with the untreated control, nandrolone phenylpropionate significantly increased collagen deposition at postoperative Days 3 and 7 (P < 0.005) and bursting pressure only at postoperative Day 3 (P < 0.005). Recombinant human growth hormone has more favorable therapeutic effects on the healing of ischemic colonic anastomoses than nandrolone phenylpropionate. Recombinant human growth hormone also improves healing of nonischemic colonic anastomosis.
Mackiewicz, Dorota; de Oliveira, Paulo Murilo Castro; Moss de Oliveira, Suzana; Cebrat, Stanisław
2013-01-01
Recombination is the main cause of genetic diversity. Thus, errors in this process can lead to chromosomal abnormalities. Recombination events are confined to narrow chromosome regions called hotspots in which characteristic DNA motifs are found. Genomic analyses have shown that both recombination hotspots and DNA motifs are distributed unevenly along human chromosomes and are much more frequent in the subtelomeric regions of chromosomes than in their central parts. Clusters of motifs roughly follow the distribution of recombination hotspots whereas single motifs show a negative correlation with the hotspot distribution. To model the phenomena related to recombination, we carried out computer Monte Carlo simulations of genome evolution. Computer simulations generated uneven distribution of hotspots with their domination in the subtelomeric regions of chromosomes. They also revealed that purifying selection eliminating defective alleles is strong enough to cause such hotspot distribution. After sufficiently long time of simulations, the structure of chromosomes reached a dynamic equilibrium, in which number and global distribution of both hotspots and defective alleles remained statistically unchanged, while their precise positions were shifted. This resembles the dynamic structure of human and chimpanzee genomes, where hotspots change their exact locations but the global distributions of recombination events are very similar.
Wang, Lin; Fei, Chang; Huang, Zheng-Lan; Li, Hui; Liu, Zhang-Lin; Feng, Wen-Li
2015-08-01
To investigate the effect of SH2-Caspase 8 fusion protein expressed by recombinant adenovirus AdE-SH2-Caspase8-HA-GFP (SC) on the apoptosis of K562/G01 cell line, which is a BCR/ABL positive chronic myeloid leukemia cell line and resistant to imatinib. The K562/G01 cell line was infected with AdE-SH2-Caspase 8-HA-GFP adenovirus (SC), then the cells were divided into 3 groups: AdE-SH2m-Caspase 8-HA-GFP (SmC) group, AdE-GFP (CMV) group and PBS group as control. The infection efficiency was observed under fluorescent microscopy and by flow cytometry. The expression of fusion protein SH2-Caspase 8-HA was measured by Western blot. The morphology of the cells detected by Wright's staining. The apoptosis of the cells were detected by flow cytometry and DNA ladder. The expression of Caspase 3 and PARP were detected by Western blot. The infection efficiency of SC on K562/G01 cells was high which was confirmed by fluorescent microscopy and FCM. SH2-Caspase 8-HA fusion protein were expressed correctly in K562/G01 cells. After treatment with SC the apoptosis of K562/G01 cells could be observed by microscopy. The result of FCM showed that early apoptosis of K562/G01 cells increased significantly as compared with control groups (P < 0.05). DNA ladder showed that the classic DNA ladders appeared in K562/G01 cells after treatment with SC. The wester blot detection showed that the expression level of apoptosis-related protein Caspase 3 and PARP increased. The recombinant adenovirus SC expressing SH2-Caspase 8 fusion protein can induces the apoptosis of K562/G01 cells.
Kaján, Győző L; Kajon, Adriana E; Pinto, Alexis Castillo; Bartha, Dániel; Arnberg, Niklas
2017-10-15
A novel human adenovirus was isolated from a pediatric case of acute respiratory disease in Panama City, Panama in 2011. The clinical isolate was initially identified as an intertypic recombinant based on hexon and fiber gene sequencing. Based on the analysis of its complete genome sequence, the novel complex recombinant Human mastadenovirus D (HAdV-D) strain was classified into a new HAdV type: HAdV-84, and it was designated Adenovirus D human/PAN/P309886/2011/84[P43H17F84]. HAdV-D types possess usually an ocular or gastrointestinal tropism, and respiratory association is scarcely reported. The virus has a novel fiber type, most closely related to, but still clearly distant from that of HAdV-36. The predicted fiber is hypothesised to bind sialic acid with lower affinity compared to HAdV-37. Bioinformatic analysis of the complete genomic sequence of HAdV-84 revealed multiple homologous recombination events and provided deeper insight into HAdV evolution. Copyright © 2017 Elsevier B.V. All rights reserved.
Evidence of native starch degradation with human small intestinal maltase-glucoamylase (recombinant)
USDA-ARS?s Scientific Manuscript database
Action of human small intestinal brush border carbohydrate digesting enzymes is thought to involve only final hydrolysis reactions of oligosaccharides to monosaccharides. In vitro starch digestibility assays use fungal amyloglucosidase to provide this function. In this study, recombinant N-terminal ...
Refined genetic maps reveal sexual dimorphism in human meiotic recombination at multiple scales
NASA Astrophysics Data System (ADS)
Bhérer, Claude; Campbell, Christopher L.; Auton, Adam
2017-04-01
In humans, males have lower recombination rates than females over the majority of the genome, but the opposite is usually true near the telomeres. These broad-scale differences have been known for decades, yet little is known about differences at the fine scale. By combining data sets, we have collected recombination events from over 100,000 meioses and have constructed sex-specific genetic maps at a previously unachievable resolution. Here we show that, although a substantial fraction of the genome shows some degree of sexually dimorphic recombination, the vast majority of hotspots are shared between the sexes, with only a small number of putative sex-specific hotspots. Wavelet analysis indicates that most of the differences can be attributed to the fine scale, and that variation in rate between the sexes can mostly be explained by differences in hotspot magnitude, rather than location. Nonetheless, known recombination-associated genomic features, such as THE1B repeat elements, show systematic differences between the sexes.
Qi, Wen-Wen; Yu, Hai-Yan; Guo, Hui; Lou, Jun; Wang, Zhi-Ming; Liu, Peng; Sapin-Minet, Anne; Maincent, Philippe; Hong, Xue-Chuan; Hu, Xian-Ming; Xiao, Yu-Ling
2015-03-02
Due to overexpression of glycyrrhetinic acid (GA) receptor in liver cancer cells, glycyrrhetinic acid modified recombinant human serum albumin (rHSA) nanoparticles for targeting liver tumor cells may result in increased therapeutic efficacy and decreased adverse effects of cancer therapy. In this study, doxorubicin (DOX) loaded and glycyrrhetinic acid modified recombinant human serum albumin nanoparticles (DOX/GA-rHSA NPs) were prepared for targeting therapy for liver cancer. GA was covalently coupled to recombinant human serum albumin nanoparticles, which could efficiently deliver DOX into liver cancer cells. The resultant GA-rHSA NPs exhibited uniform spherical shape and high stability in plasma with fixed negative charge (∼-25 mV) and a size about 170 nm. DOX was loaded into GA-rHSA NPs with a maximal encapsulation efficiency of 75.8%. Moreover, the targeted NPs (DOX/GA-rHSA NPs) showed increased cytotoxic activity in liver tumor cells compared to the nontargeted NPs (DOX/rHSA NPs, DOX loaded recombinant human serum albumin nanoparticles without GA conjugating). The targeted NPs exhibited higher cellular uptake in a GA receptor-positive liver cancer cell line than nontargeted NPs as measured by both flow cytometry and confocal laser scanning microscopy. Biodistribution experiments showed that DOX/GA-rHSA NPs exhibited a much higher level of tumor accumulation than nontargeted NPs at 1 h after injection in hepatoma-bearing Balb/c mice. Therefore, the DOX/GA-rHSA NPs could be considered as an efficient nanoplatform for targeting drug delivery system for liver cancer.
Wassink, Guido; Davidson, Joanne O; Dhillon, Simerdeep K; Fraser, Mhoyra; Galinsky, Robert; Bennet, Laura; Gunn, Alistair J
2017-03-01
Perinatal asphyxia in preterm infants remains a significant contributor to abnormal long-term neurodevelopmental outcomes. Recombinant human erythropoietin has potent non-haematopoietic neuroprotective properties, but there is limited evidence for protection in the preterm brain. Preterm (0.7 gestation) fetal sheep received sham asphyxia (sham occlusion) or asphyxia induced by umbilical cord occlusion for 25 min, followed by an intravenous infusion of vehicle (occlusion-vehicle) or recombinant human erythropoietin (occlusion-Epo, 5000 international units by slow push, then 832.5 IU/h), starting 30 min after asphyxia and continued until 72 h. Recombinant human erythropoietin reduced neuronal loss and numbers of caspase-3-positive cells in the striatal caudate nucleus, CA3 and dentate gyrus of the hippocampus, and thalamic medial nucleus ( P < 0.05 vs. occlusion-vehicle). In the white matter tracts, recombinant human erythropoietin increased total, but not immature/mature oligodendrocytes ( P < 0.05 vs. occlusion-vehicle), with increased cell proliferation and reduced induction of activated caspase-3, microglia and astrocytes ( P < 0.05). Finally, occlusion-Epo reduced seizure burden, with more rapid recovery of electroencephalogram power, spectral edge frequency, and carotid blood flow. In summary, prolonged infusion of recombinant human erythropoietin after severe asphyxia in preterm fetal sheep was partially neuroprotective and improved electrophysiological and cerebrovascular recovery, in association with reduced apoptosis and inflammation.
Wassink, Guido; Davidson, Joanne O; Dhillon, Simerdeep K; Fraser, Mhoyra; Galinsky, Robert; Bennet, Laura
2016-01-01
Perinatal asphyxia in preterm infants remains a significant contributor to abnormal long-term neurodevelopmental outcomes. Recombinant human erythropoietin has potent non-haematopoietic neuroprotective properties, but there is limited evidence for protection in the preterm brain. Preterm (0.7 gestation) fetal sheep received sham asphyxia (sham occlusion) or asphyxia induced by umbilical cord occlusion for 25 min, followed by an intravenous infusion of vehicle (occlusion-vehicle) or recombinant human erythropoietin (occlusion-Epo, 5000 international units by slow push, then 832.5 IU/h), starting 30 min after asphyxia and continued until 72 h. Recombinant human erythropoietin reduced neuronal loss and numbers of caspase-3-positive cells in the striatal caudate nucleus, CA3 and dentate gyrus of the hippocampus, and thalamic medial nucleus (P < 0.05 vs. occlusion-vehicle). In the white matter tracts, recombinant human erythropoietin increased total, but not immature/mature oligodendrocytes (P < 0.05 vs. occlusion-vehicle), with increased cell proliferation and reduced induction of activated caspase-3, microglia and astrocytes (P < 0.05). Finally, occlusion-Epo reduced seizure burden, with more rapid recovery of electroencephalogram power, spectral edge frequency, and carotid blood flow. In summary, prolonged infusion of recombinant human erythropoietin after severe asphyxia in preterm fetal sheep was partially neuroprotective and improved electrophysiological and cerebrovascular recovery, in association with reduced apoptosis and inflammation. PMID:27207167
Prominent mitochondrial DNA recombination intermediates in human heart muscle.
Kajander, O A; Karhunen, P J; Holt, I J; Jacobs, H T
2001-11-01
Recombination intermediates containing four-way (Holliday) junctions are generated during DNA repair and replication in many systems, including yeast mitochondrial DNA (mtDNA). In contrast, convincing evidence for recombination in mammalian mtDNA is lacking. We have used two-dimensional agarose-gel electrophoresis to analyse non-linear forms of mtDNA in human heart muscle. Replication intermediates from both the coupled and strand-asynchronous mtDNA replication pathways were detected. An additional class of non-linear molecules, with the electrophoretic properties of four-way junctions, was also prominent. These molecules were insensitive to topoisomerase I or RNase H, but were diminished by branch migration or RuvC treatment. Junctional molecules were detected in all regions of the mitochondrial genome, were found in myocardial DNA from young and old adults, but were present at lower levels in skeletal muscle and placenta. We suggest that they could represent intermediates of mtDNA repair, given their prevalence in the oxyradical-rich environment of heart muscle mitochondria.
Lesecque, Yann; Glémin, Sylvain; Lartillot, Nicolas; Mouchiroud, Dominique; Duret, Laurent
2014-01-01
Recombination is an essential process in eukaryotes, which increases diversity by disrupting genetic linkage between loci and ensures the proper segregation of chromosomes during meiosis. In the human genome, recombination events are clustered in hotspots, whose location is determined by the PRDM9 protein. There is evidence that the location of hotspots evolves rapidly, as a consequence of changes in PRDM9 DNA-binding domain. However, the reasons for these changes and the rate at which they occur are not known. In this study, we investigated the evolution of human hotspot loci and of PRDM9 target motifs, both in modern and archaic human lineages (Denisovan) to quantify the dynamic of hotspot turnover during the recent period of human evolution. We show that present-day human hotspots are young: they have been active only during the last 10% of the time since the divergence from chimpanzee, starting to be operating shortly before the split between Denisovans and modern humans. Surprisingly, however, our analyses indicate that Denisovan recombination hotspots did not overlap with modern human ones, despite sharing similar PRDM9 target motifs. We further show that high-affinity PRDM9 target motifs are subject to a strong self-destructive drive, known as biased gene conversion (BGC), which should lead to the loss of the majority of them in the next 3 MYR. This depletion of PRDM9 genomic targets is expected to decrease fitness, and thereby to favor new PRDM9 alleles binding different motifs. Our refined estimates of the age and life expectancy of human hotspots provide empirical evidence in support of the Red Queen hypothesis of recombination hotspots evolution. PMID:25393762
Lesecque, Yann; Glémin, Sylvain; Lartillot, Nicolas; Mouchiroud, Dominique; Duret, Laurent
2014-11-01
Recombination is an essential process in eukaryotes, which increases diversity by disrupting genetic linkage between loci and ensures the proper segregation of chromosomes during meiosis. In the human genome, recombination events are clustered in hotspots, whose location is determined by the PRDM9 protein. There is evidence that the location of hotspots evolves rapidly, as a consequence of changes in PRDM9 DNA-binding domain. However, the reasons for these changes and the rate at which they occur are not known. In this study, we investigated the evolution of human hotspot loci and of PRDM9 target motifs, both in modern and archaic human lineages (Denisovan) to quantify the dynamic of hotspot turnover during the recent period of human evolution. We show that present-day human hotspots are young: they have been active only during the last 10% of the time since the divergence from chimpanzee, starting to be operating shortly before the split between Denisovans and modern humans. Surprisingly, however, our analyses indicate that Denisovan recombination hotspots did not overlap with modern human ones, despite sharing similar PRDM9 target motifs. We further show that high-affinity PRDM9 target motifs are subject to a strong self-destructive drive, known as biased gene conversion (BGC), which should lead to the loss of the majority of them in the next 3 MYR. This depletion of PRDM9 genomic targets is expected to decrease fitness, and thereby to favor new PRDM9 alleles binding different motifs. Our refined estimates of the age and life expectancy of human hotspots provide empirical evidence in support of the Red Queen hypothesis of recombination hotspots evolution.
Varghese, Anju; Raina, Opinder K; Chandra, Dinesh; Mirdha, Bijay R; Kelawala, Naresh H; Solanki, Jayesh B; Kumar, Niranjan; Ravindran, Reghu; Arun, Anandanarayanan; Rialch, Ajayta; Lalrinkima, Hniang; Kelawala, Rohan N; Samanta, Subhamoy
2017-12-20
Three recombinant antigens viz. arginine kinase, cathepsin L-1 and TES-26 of Toxocara canis were expressed in Escherichia coli and evaluated for their potential in the detection of T. canis larval infection in human in immunoglobulin G-enzyme linked immunosorbent assay (IgG-ELISA). Results of the IgG-ELISA with the above recombinant antigens were confirmed with commercially available IgG detection kit for T. canis infection used as a standard test. All three recombinant antigens were 100% sensitive in the detection of positive cases (n = 6) of T. canis infection in human and were screened for their cross-reactivity in human patients with history of Toxoplasma gondii, Plasmodium vivax, Entamoeba histolytica, hydatid and hookworm infections. The recombinant TES-26 antigen showed higher specificity and cross-reacted with T. gondii infection sera only. However, arginine kinase and cathepsin L-1 recombinant antigens showed cross-reactions with sera of patients infected with T. gondii, P. vivax and E. histolytica but not with the patient sera infected with hydatid and hookworm. These results show that recombinant TES-26 is a potential diagnostic candidate antigen for human toxocarosis caused by migrating T. canis larvae.
Effects of recombinant human growth hormone on enterocutaneous fistula patients.
Gu, Guo-Sheng; Ren, Jian-An; Li, Ning; Li, Jie-Shou
2008-11-28
To explore the effects of recombinant human growth hormone (rhGH) on intestinal mucosal epithelial cell proliferation and nutritional status in patients with enterocutaneous fistula. Eight patients with enterocutaneous fistulas received recombinant human growth hormone (10 microg/d) for 7 d. Image analysis and immunohistochemical techniques were used to analyse the expression of proliferating cell nuclear antigen (PCNA) in intestinal mucosal epithelial cells in biopsy samples from the patients who had undergone an endoscopic biopsy through the fistula at day 0, 4 and 7. Body weights, nitrogen excretion, serum levels of total proteins, albumin, prealbumin, transferrin and fibronectin were measured at day 0, 4 and 7. Significant improvements occurred in the expression of PCNA in the intestinal mucosal epithelial cells at day 4 and 7 compared to day 0 (24.93 +/- 3.41%, 30.46 +/- 5.24% vs 12.92 +/- 4.20%, P < 0.01). These changes were accompanied by the significant improvement of villus height (500.54 +/- 53.79 microm, 459.03 +/- 88.98 microm vs 210.94 +/- 49.16 microm, P < 0.01), serum levels of total proteins (70.52 +/- 5.13 g/L, 74.89 +/- 5.16 g/L vs 63.51 +/- 2.47 g/L, P < 0.01), albumin (39.44 +/- 1.18 g/L, 42.39 +/- 1.68 g/L vs 35.74 +/- 1.75 g/L, P < 0.01) and fibronectin (236.3 +/- 16.5 mg/L, 275.8 +/- 16.9 mg/L vs 172.5 +/- 21.4 mg/L, P < 0.01) at day 4 and 7, and prealbumin (286.38 +/- 65.61 mg/L vs 180.88 +/- 48.28 mg/L, P < 0.05), transferrin (2.61 +/- 0.12 g/L vs 2.41 +/- 0.14 g/L, P < 0.05) at day 7. Nitrogen excretion was significantly decreased at day 7 (3.40 +/- 1.65 g/d vs 7.25 +/- 3.92 g/d, P < 0.05). No change was observed in the body weight. Recombinant human growth hormone could promote intestinal mucosal epithelial cell proliferation and protein synthesis in patients with enterocutaneous fistula.
Metabolism of ethylbenzene by human liver microsomes and recombinant human cytochrome P450s (CYP).
Sams, Craig; Loizou, George D; Cocker, John; Lennard, Martin S
2004-03-07
The enzyme kinetics of the initial hydroxylation of ethylbenzene to form 1-phenylethanol were determined in human liver microsomes. The individual cytochrome P450 (CYP) forms catalysing this reaction were identified using selective inhibitors and recombinant preparations of hepatic CYPs. Production of 1-phenylethanol in hepatic microsomes exhibited biphasic kinetics with a high affinity, low Km, component (mean Km = 8 microM; V(max) = 689 pmol/min/mg protein; n = 6 livers) and a low affinity, high Km, component (Km = 391 microM; V(max) = 3039 pmol/min/mg protein; n = 6). The high-affinity component was inhibited 79%-95% (mean 86%) by diethyldithiocarbamate, and recombinant CYP2E1 was shown to metabolise ethylbenzene with low Km (35 microM), but also low (max) (7 pmol/min/pmol P450), indicating that this isoform catalysed the high-affinity component. Recombinant CYP1A2 and CYP2B6 exhibited high V(max) (88 and 71 pmol/min/pmol P450, respectively) and high Km (502 and 219 microM, respectively), suggesting their involvement in catalysing the low-affinity component. This study has demonstrated that CYP2E1 is the major enzyme responsible for high-affinity side chain hydroxylation of ethylbenzene in human liver microsomes. Activity of this enzyme in the population is highly variable due to induction or inhibition by physiological factors, chemicals in the diet or some pharmaceuticals. This variability can be incorporated into the risk assessment process to improve the setting of occupational exposure limits and guidance values for biological monitoring.
Genome-wide analyses of HTLV-1aD strains from Cape Verde, Africa.
Zanella, Louise; Pina-Araujo I, Isabel de; Morgado, Mariza G; Vicente, Ana Carolina
2016-09-01
We characterised and reported the first full-length genomes of Human T-cell Lymphotropic Virus Type 1 subgroup HTLV-1aD (CV21 and CV79). This subgroup is one of the major determinants of HTLV-1 infections in North and West Africa, and recombinant strains involving this subgroup have been recently demonstrated. The CV21 and CV79 strains from Cape Verde/Africa were characterised as pure HTLV-1aD genomes, comparative analyses including HTLV-1 subtypes and subgroups revealed HTLV-1aD signatures in the envelope, pol, and pX regions. These genomes provide original information that will contribute to further studies on HTLV-1a epidemiology and evolution.
Wanscher, Anne Sofie Molsted; Williamson, Michael; Ebersole, Tasja Wainani; Streicher, Werner; Wikström, Mats; Cazzamali, Giuseppe
2015-04-01
Insulin-like growth factor binding proteins (IGFBPs) display many functions in humans including regulation of the insulin-like growth factor (IGF) signaling pathway. The various roles of human IGFBPs make them attractive protein candidates in drug discovery. Structural and functional knowledge on human proteins with therapeutic relevance is needed to design and process the next generation of protein therapeutics. In order to conduct structural and functional investigations large quantities of recombinant proteins are needed. However, finding a suitable recombinant production system for proteins such as full-length human IGFBPs, still remains a challenge. Here we present a mammalian HEK293 expression method suitable for over-expression of secretory full-length human IGFBP-1 to -7. Protein purification of full-length human IGFBP-1, -2, -3 and -5 was conducted using a two-step chromatography procedure and the final protein yields were between 1 and 12mg protein per liter culture media. The recombinant IGFBPs contained PTMs and exhibited high-affinity interactions with their natural ligands IGF-1 and IGF-2. Copyright © 2014 Elsevier Inc. All rights reserved.
Intragenic Mapping of Chemically Induced ad-7 Mutants of Schizosaccharomyces pombe
Loprieno, Nicola
1967-01-01
Thirty adenine-requiring ad-7 mutants of Schizosaccharomyces pombe, induced by ethylmethanesulfonate, methyl-methanesulfonate, and hydroxylamine and exhibiting low spontaneous reversion frequencies, were located by intragenic recombination analysis. Their identification as ad-7 mutants was assessed in relation to two previously mapped ad-7 mutants. Each mutant was found to occupy a distinct mutational site; the smallest recombination fraction observed between the two closest mutational sites was of the order of 0.5 × 10−6. PMID:6051345
Mackiewicz, Dorota; de Oliveira, Paulo Murilo Castro; Moss de Oliveira, Suzana; Cebrat, Stanisław
2013-01-01
Recombination is the main cause of genetic diversity. Thus, errors in this process can lead to chromosomal abnormalities. Recombination events are confined to narrow chromosome regions called hotspots in which characteristic DNA motifs are found. Genomic analyses have shown that both recombination hotspots and DNA motifs are distributed unevenly along human chromosomes and are much more frequent in the subtelomeric regions of chromosomes than in their central parts. Clusters of motifs roughly follow the distribution of recombination hotspots whereas single motifs show a negative correlation with the hotspot distribution. To model the phenomena related to recombination, we carried out computer Monte Carlo simulations of genome evolution. Computer simulations generated uneven distribution of hotspots with their domination in the subtelomeric regions of chromosomes. They also revealed that purifying selection eliminating defective alleles is strong enough to cause such hotspot distribution. After sufficiently long time of simulations, the structure of chromosomes reached a dynamic equilibrium, in which number and global distribution of both hotspots and defective alleles remained statistically unchanged, while their precise positions were shifted. This resembles the dynamic structure of human and chimpanzee genomes, where hotspots change their exact locations but the global distributions of recombination events are very similar. PMID:23776462
Preparation and characterization of human recombinant protein 1/Clara cell M(r) 10,000 protein.
Okutani, R; Itoh, Y; Yamada, T; Yamaguchi, T; Singh, G; Yagisawa, H; Kawai, T
1996-09-01
Protein 1, which is identical to human Clara cell M(r) 10(4) protein, is a homodimeric, low molecular mass protein (M(r) 14,000) and an effective inhibitor of phospholipase A2 activity. We have expressed this protein in E. coli and characterized its physiochemical and biological properties. Using a pET expression system, about 1.7 mg of purified recombinant protein 1 was obtained from 250 ml of E. coli culture. The amino-terminal sequence of recombinant protein 1 up to the 20th residue was identical to that of native protein 1 except for an extra methionine at the amino-terminus. On reversed-phase HPLC, recombinant protein 1 eluted at the same retention time as native protein 1. The dose-response curves of recombinant protein 1 and native protein 1 in an enzyme-linked immunosorbent assay for protein 1 were identical. Recombinant protein 1 inhibited both porcine pancreas and cobra venom phospholipase A2 activities. These results indicated that recombinant protein 1 is structurally and biologically identical to native protein 1. We found that recombinant protein 1 also inhibits phosphatidylinositol-specific phospholipase C activity.
Recombinant adenovirus-p21 attenuates proliferative responses associated with excessive scarring.
Gu, Danling; Atencio, Isabella; Kang, David W; Looper, L David; Ahmed, C M I; Levy, Alina; Maneval, Dan; Zepeda, Monica L
2005-01-01
Excessive cutaneous scarring is an important clinical disorder resulting in adverse tissue growth and function as well as undesirable cosmetic appearance. p21WAF-1/Cip-1 is a cyclin-dependent kinase inhibitor that blocks cell cycle progression and inhibits cell proliferation. We used a recombinant adenovirus containing the human p21WAF-1/Cip-1 cDNA (rAd-p21) to evaluate proliferative responses in skin models. In vitro dose-response studies using primary human dermal fibroblasts resulted in a dose-dependent expression of p21WAF-1/Cip-1 protein and a 3- to 80-fold reduction in cell proliferation as measured by 5-bromodeoxyuridine incorporation. Further, rAd-p21 reduced type I procollagen production when compared to control virus. A rat polyvinyl alcohol sponge model was used to determine rAd-p21 effects on granulation tissue formation in vivo. Sponges pretreated with a granulation tissue stimulator, rAd-PDGF-B and subsequently rAd-p21 on a second injection, showed a p21WAF-1/Cip-1 specific dose-dependent decrease in percent granulation fill as the rAd-p21 dose increased (p < 0.001). Immunohistochemistry identified human p21WAF-1/Cip-1 expression in sponges treated with rAd-p21 5 days postinjection. Additionally, 5-bromodeoxyuridine and Ki67 staining in sponges treated with rAd-p21 showed a significant decrease in proliferation when compared to rAd-platelet-derived growth factor-B alone or vehicle control groups (p < 0.01). These data support the utility of p21WAF-1/Cip-1 in targeting hyperproliferative disorders of the skin.
Liu, Feng; Du, JinTao; Xian, Junming; Liu, Yafeng; Liu, Shixi; Lin, Yan
2015-01-01
The tumor suppressor p14(ARF) and proto-oncogene epidermal growth factor receptor (EGFR) play important roles in the development of laryngeal squamous cell carcinoma (LSCC). This study was aimed to determine whether combining recombinant p14(ARF) with antisense complementary DNA of EGFR could improve the therapeutic effectiveness in LSCC. After human larynx cancer cells (Hep-2) were infected with recombinant adenoviruses (Ad-p14(ARF) and Ad-antisense EGFR) together or alone in vitro, the proliferation and cell cycle distribution of Hep-2 cells were detected by MTT assay and flow cytometer analysis, respectively. Furthermore, the antitumor effects of recombinant adenoviruses together or alone on Hep-2 xenografts were examined in vivo. The levels of p14(ARF) and EGFR expressed in Hep-2 cells and xenografts were determined by western blot assay. Ad-p14(ARF) combining with Ad-antisense EGFR markedly inhibited the Hep-2 proliferation compared with alone (P=0.001, P=0.002 respectively). Combination of Ad-p14(ARF) and Ad-antisense EGFR led to the proportion of Hep-2 cells in G0/G1 phases increased by up to 86.9%. The down-expression of EGFR protein and overexpression of p14(ARF) protein were observed in vitro and in vivo, and this effect was preserved when Ad-p14(ARF) was combined with Ad-antisense EGFR. Besides, Ad-p14(ARF) plus Ad-antisense EGFR significantly (P<0.05) increased the antitumor activity against Hep-2 tumor xenografts comparing with Ad-p14(ARF) or Ad-antisense EGFR alone. Combination Ad-p14(ARF) with Ad-antisense EGFR significantly increased the antitumor responses in LSCC. An effectively potential gene therapy to prevent proliferation of LSCC was provided. Copyright © 2015 Elsevier Inc. All rights reserved.
Limited infection upon human exposure to a recombinant raccoon pox vaccine vector
Rocke, T.E.; Dein, F.J.; Fuchsberger, M.; Fox, B.C.; Stinchcomb, D.T.; Osorio, J.G.
2004-01-01
A laboratory accident resulted in human exposure to a recombinant raccoon poxvirus (RCN) developed as a vaccine vector for antigens of Yersinia pestis for protection of wild rodents (and other animals) against plague. Within 9 days, the patient developed a small blister that healed within 4 weeks. Raccoon poxvirus was cultured from the lesion, and the patient developed antibody to plague antigen (F1) and RCN. This is the first documented case of human exposure to RCN.
Alves, Joao M; Chikhi, Lounès; Amorim, António; Lopes, Alexandra M
2014-04-01
For decades, chromosomal inversions have been regarded as fascinating evolutionary elements as they are expected to suppress recombination between chromosomes with opposite orientations, leading to the accumulation of genetic differences between the two configurations over time. Here, making use of publicly available population genotype data for the largest polymorphic inversion in the human genome (8p23-inv), we assessed whether this inhibitory effect of inversion rearrangements led to significant differences in the recombination landscape of two homologous DNA segments, with opposite orientation. Our analysis revealed that the accumulation of genetic differentiation is positively correlated with the variation in recombination profiles. The observed recombination dissimilarity between inversion types is consistent across all populations analyzed and surpasses the effects of geographic structure, suggesting that both structures (orientations) have been evolving independently over an extended period of time, despite being subjected to the very same demographic history. Aside this mainly independent evolution, we also identified a short segment (350 kb, <10% of the whole inversion) in the central region of the inversion where the genetic divergence between the two structural haplotypes is diminished. Although it is difficult to demonstrate it, this could be due to gene flow (possibly via double-crossing over events), which is consistent with the higher recombination rates surrounding this segment. This study demonstrates for the first time that chromosomal inversions influence the recombination landscape at a fine-scale and highlights the role of these rearrangements as drivers of genome evolution.
Shao, Renfu; Barker, Stephen C
2011-02-15
The mitochondrial (mt) genome of the human body louse, Pediculus humanus, consists of 18 minichromosomes. Each minichromosome is 3 to 4 kb long and has 1 to 3 genes. There is unequivocal evidence for recombination between different mt minichromosomes in P. humanus. It is not known, however, how these minichromosomes recombine. Here, we report the discovery of eight chimeric mt minichromosomes in P. humanus. We classify these chimeric mt minichromosomes into two groups: Group I and Group II. Group I chimeric minichromosomes contain parts of two different protein-coding genes that are from different minichromosomes. The two parts of protein-coding genes in each Group I chimeric minichromosome are joined at a microhomologous nucleotide sequence; microhomologous nucleotide sequences are hallmarks of non-homologous recombination. Group II chimeric minichromosomes contain all of the genes and the non-coding regions of two different minichromosomes. The conserved sequence blocks in the non-coding regions of Group II chimeric minichromosomes resemble the "recombination repeats" in the non-coding regions of the mt genomes of higher plants. These repeats are essential to homologous recombination in higher plants. Our analyses of the nucleotide sequences of chimeric mt minichromosomes indicate both homologous and non-homologous recombination between minichromosomes in the mitochondria of the human body louse. Copyright © 2010 Elsevier B.V. All rights reserved.
[Construction and expression of a recombinant adenovirus with LZP3].
Chen, Bang-dang; Zhang, Fu-chun; Sun, Mei-yu; Li, Yi-jie; Ma, Zheng-hai
2007-08-01
To explore a new immunocontraceptive vaccine and construct an attenuated recombinant adenoviral vaccine against Lagurus lagurus zona pellucida 3(LZP3). LZP3 gene was subcloned into the shuttle vector pShuttle-CMV, and then a two-step transformation procedure was employed to construct a recombinant adenoviral plasmid with LZP3, which was digested with Pac I and transfected into HEK293 cells to package recombinant adenovirus particles. Finally, HeLa cells were infected by the recombinant adenovirus. LZP3 gene was detected from the recombinant virus by PCR, and its transcription and expression were analyzed by RT-PCR and Western blot. Recombinant adenovirus vector pAd-LZP3 with LZP3 gene was constructed by homologous recombination in E.coli, and a recombinant adenovirus was obtained by transfecting HEK293 cells with pAd-LZP3. PCR test indicated that LZP3 gene was successfully integrated into the adenoviral genome, and the titer of the recombinant adenovirus reached 1.2x10(10) pfu/L. The transcription and expression of LZP3 gene in the infected HeLa cells were confirmed by RT-PCR and Western blot. The recombinant adenovirus RAd-LZP3 can be successfully expressed in the infected HeLa cells, which lays the foundation for further researches into immunizing animals with RAd-LZP3.
Hanlon, Steven P; Camattari, Andrea; Abad, Sandra; Glieder, Anton; Kittelmann, Matthias; Lütz, Stephan; Wirz, Beat; Winkler, Margit
2012-06-18
A panel of human flavin monooxygenases were heterologously expressed in E. coli to obtain ready-to-use biocatalysts for the in vitro preparation of human drug metabolites. Moclobemide-N-oxide (65 mg) was the first high-priced metabolite prepared with recombinant hFMO3 on the multi-milligram scale.
Pitsiladis, Yannis P; Durussel, Jérôme; Rabin, Olivier
2014-05-01
Administration of recombinant human erythropoietin (rHumanEPO) improves sporting performance and hence is frequently subject to abuse by athletes, although rHumanEPO is prohibited by the WADA. Approaches to detect rHumanEPO doping have improved significantly in recent years but remain imperfect. A new transcriptomic-based longitudinal screening approach is being developed that has the potential to improve the analytical performance of current detection methods. In particular, studies are being funded by WADA to identify a 'molecular signature' of rHumanEPO doping and preliminary results are promising. In the first systematic study to be conducted, the expression of hundreds of genes were found to be altered by rHumanEPO with numerous gene transcripts being differentially expressed after the first injection and further transcripts profoundly upregulated during and subsequently downregulated up to 4 weeks postadministration of the drug; with the same transcriptomic pattern observed in all participants. The identification of a blood 'molecular signature' of rHumanEPO administration is the strongest evidence to date that gene biomarkers have the potential to substantially improve the analytical performance of current antidoping methods such as the Athlete Biological Passport for rHumanEPO detection. Given the early promise of transcriptomics, research using an 'omics'-based approach involving genomics, transcriptomics, proteomics and metabolomics should be intensified in order to achieve improved detection of rHumanEPO and other doping substances and methods difficult to detect such a recombinant human growth hormone and blood transfusions.
The rise and fall of a human recombination hot spot.
Jeffreys, Alec J; Neumann, Rita
2009-05-01
Human meiotic crossovers mainly cluster into narrow hot spots that profoundly influence patterns of haplotype diversity and that may also affect genome instability and sequence evolution. Hot spots also seem to be ephemeral, but processes of hot-spot activation and their subsequent evolutionary dynamics remain unknown. We now analyze the life cycle of a recombination hot spot. Sperm typing revealed a polymorphic hot spot that was activated in cis by a single base change, providing evidence for a primary sequence determinant necessary, though not sufficient, to activate recombination. This activating mutation occurred roughly 70,000 y ago and has persisted to the present, most likely fortuitously through genetic drift despite its systematic elimination by biased gene conversion. Nonetheless, this self-destructive conversion will eventually lead to hot-spot extinction. These findings define a subclass of highly transient hot spots and highlight the importance of understanding hot-spot turnover and how it influences haplotype diversity.
Tanaka, H; Kaneko, T
1992-07-01
The pharmacokinetics and biological activities of recombinant human granulocyte colony-stimulating factor (hG-CSF) produced in Escherichia coli were compared with those of hG-CSF purified from human bladder carcinoma cell line 5637 culture medium (5637-hG-CSF). Recombinant hG-CSF was biologically active in a bone marrow cell proliferation assay in vitro, with a dose-response curve similar to that of 5637-hG-CSF. The effects of 5637- and recombinant hG-CSF administered via i.v. injection to rats showed similar response patterns of neutrophil counts in peripheral blood. From these results, it is concluded that the O-linked sugar chain of hG-CSF does not contribute to the in vitro and in vivo biological activities. The pharmacokinetics of both forms of hG-CSF in rats were investigated using a sandwich enzyme-linked immunosorbent assay. After i.v. administration, the serum concentration-time curves of 5637- and recombinant hG-CSF declined biexponentially. Total body clearance and steady-state volume of distribution of 5637-hG-CSF were smaller than those for the recombinant form. After s.c. administration, a lower peak serum level, smaller AUC, and lower bioavailability of 5637-hG-CSF were observed compared to recombinant hG-CSF.
Mirkalantari, Shiva; Zarnani, Amir-Hassan; Nazari, Mahboobeh; Irajian, Gholam Reza; Amirmozafari, Nour
2017-03-03
The numerous drawbacks of current serological tests for diagnosis of brucellosis which mainly results from cross reactivity with LPS from other gram-negative bacteria have generated an increasing interest to find more specific non-LPS antigens. Previous studies had indicated that Brucella VirB12 protein, a cell surface protein and component of type IV secretion system, induces antibody response during animal infection. However, this protein has not yet been tested as a serological diagnostic marker in human brucellosis. Recombinant VirB12 protein was prepared and evaluated the efficacy of it in an indirect enzyme-linked immunosorbent assay (ELISA) for brucellosis with sera collected from different region of Iran and the results were compared with a commercial ELISA kit. Sera from human brucellosis patients strongly reacted to the purified recombinant VirB12. The sensitivity, specificity, accuracy, negative predictive value and positive predictive value of recombinant VirB12-based ELISA related to the commercial-ELISA method were 87.8, 94, 90, 80 and 96.6% respectively. We concluded that antigenic VirB12 have a property value that can be considered as a candidate for using in serodiagnostic tests for human brucellosis.
Accumulation of functional recombinant human coagulation factor IX in transgenic soybean seeds.
Cunha, Nicolau B; Murad, André M; Ramos, Gustavo L; Maranhão, Andréia Q; Brígido, Marcelo M; Araújo, Ana Cláudia G; Lacorte, Cristiano; Aragão, Francisco J L; Covas, Dimas T; Fontes, Aparecida M; Souza, Gustavo H M F; Vianna, Giovanni R; Rech, Elíbio L
2011-08-01
The seed-based production of recombinant proteins is an efficient strategy to achieve the accumulation, correct folding, and increased stability of these recombinant proteins. Among potential plant molecular farming systems, soybean [Glycine max (L.) Merrill] is a viable option for the production of recombinant proteins due to its high protein content, known regulatory sequences, efficient gene transfer protocols, and a scalable production system under greenhouse conditions. We report here the expression and stable accumulation of human coagulation factor IX (hFIX) in transgenic soybean seeds. A biolistic process was utilised to co-introduce a plasmid carrying the hFIX gene under the transcriptional control of the α' subunit of a β-conglycinin seed-specific promoter and an α-Coixin signal peptide in soybean embryonic axes from mature seeds. The 56-kDa hFIX protein was expressed in the transgenic seeds at levels of up to 0.23% (0.8 g kg(-1) seed) of the total soluble seed protein as determined by an enzyme-linked immunosorbent assay (ELISA) and western blot. Ultrastructural immunocytochemistry assays indicated that the recombinant hFIX in seed cotyledonary cells was efficiently directed to protein storage vacuoles. Mass spectrometry characterisation confirmed the presence of the hFIX recombinant protein sequence. Protein extracts from transgenic seeds showed a blood-clotting activity of up to 1.4% of normal plasma. Our results demonstrate the correct processing and stable accumulation of functional hFIX in soybean seeds stored for 6 years under room temperature conditions (22 ± 2°C).
A patterned recombinant human IgM guides neurite outgrowth of CNS neurons
Xu, Xiaohua; Wittenberg, Nathan J.; Jordan, Luke R.; Kumar, Shailabh; Watzlawik, Jens O.; Warrington, Arthur E.; Oh, Sang-Hyun; Rodriguez, Moses
2013-01-01
Matrix molecules convey biochemical and physical guiding signals to neurons in the central nervous system (CNS) and shape the trajectory of neuronal fibers that constitute neural networks. We have developed recombinant human IgMs that bind to epitopes on neural cells, with the aim of treating neurological diseases. Here we test the hypothesis that recombinant human IgMs (rHIgM) can guide neurite outgrowth of CNS neurons. Microcontact printing was employed to pattern rHIgM12 and rHIgM22, antibodies that were bioengineered to have variable regions capable of binding to neurons or oligodendrocytes, respectively. rHIgM12 promoted neuronal attachment and guided outgrowth of neurites from hippocampal neurons. Processes from spinal neurons followed grid patterns of rHIgM12 and formed a physical network. Comparison between rHIgM12 and rHIgM22 suggested the biochemistry that facilitates anchoring the neuronal surfaces is a prerequisite for the function of IgM, and spatial properties cooperate in guiding the assembly of neuronal networks. PMID:23881231
Weber, James L.; Wang, Zhenyuan; Hansen, Kevin; Stephenson, Matt; Kappel, Clarisse; Salzman, Sherry; Wilkie, Patricia J.; Keats, Bronya; Dracopoli, Nicholas C.; Brandriff, Brigitte F.; Olsen, Anne S.
1993-01-01
An improved linkage map for human chromosome 19 containing 35 short tandem repeat polymorphisms (STRPs) and one VNTR (D19S20) was constructed. The map included 12 new (GATA)n tetranucleotide STRPs. Although total lengths of the male (114 cM) and female (128 cM) maps were similar, at both ends of the chromosome male recombination exceeded female recombination, while in the interior portion of the map female recombination was in excess. Cosmid clones containing the STRP sequences were identified and were positioned along the chromosome by fluorescent in situ hybridization. Four rounds of careful checking and removal of genotyping errors allowed biologically relevant conclusions to be made concerning the numbers and distributions of recombination events on chromosome 19. The average numbers of recombinations per chromosome matched closely the lengths of the genetic maps computed by using the program CRIMAP. Significant numbers of chromosomes with zero, one, two, or three recombinations were detected as products of both female and male meioses. On the basis of the total number of observed pairs of recombination events in which only a single informative marker was situated between the two recombinations, a maximal estimate for the rate of meiotic STRP “gene” conversion without recombination was calculated as 3 × 10−4/meiosis. For distances up to 30 cM between recombinations, many fewer chromosomes which had undergone exactly two recombinations were observed than were expected on the basis of the assumption of independent recombination locations. This strong new evidence for human meiotic interference will help to improve the accuracy of interpretation of clinical DNA test results involving polymorphisms flanking a genetic abnormality. PMID:8213834
NASA Astrophysics Data System (ADS)
Watanabe, Mamoru; Boyson, Jonathan E.; Lord, Carol I.; Letvin, Norman L.
1992-06-01
In view of the efficiency with which human immunodeficiency virus replication can be blocked in vitro with anti-CD4 antibodies, the elicitation of an anti-CD4 antibody response through active immunization might represent a useful therapeutic strategy for AIDS. Here we demonstrate that immunization of chimpanzees with recombinant soluble human CD4 elicited an anti-CD4 antibody response. The elicited antibody bound self CD4 on digitonin-treated but not freshly isolated lymphocytes. Nevertheless, this antibody blocked human immunodeficiency virus replication in chimpanzee and human lymphocytes. These observations suggest that immunization with recombinant soluble CD4 from human immunodeficiency virus-infected humans may be feasible and therapeutically beneficial.
Drug eruption caused by recombinant human G-CSF.
Sasaki, O; Yokoyama, A; Uemura, S; Fujino, S; Inoue, Y; Kohno, N; Hiwada, K
1994-10-01
Two types of recombinant human granulocyte colony-stimulating factor (rhG-CSF) are available, and equally used for mitigation of neutropenia. One is a glycosylated natural product from mammalian cells, and the other a non-glycosylated form from Escherichia coli. Though only minimal adverse effects have been reported for both, we treated two patients with rhG-CSF-induced systemic eruption. Based on these patients, the following should be noted: 1) drug eruption may occur in both types of rhG-CSF without detectable antibodies, 2) intradermal test is useful for determination of the causal drug, and 3) if one rhG-CSF product causes eruption, the alternative one may possibly be safe and effective.
Maxillary anterior ridge augmentation with recombinant human bone morphogenetic protein 2.
Edmunds, Ryan K; Mealey, Brian L; Mills, Michael P; Thoma, Daniel S; Schoolfield, John; Cochran, David L; Mellonig, Jim
2014-01-01
No human studies exist on the use of recombinant human bone morphogenetic protein 2 (rhBMP-2) on an absorbable collagen sponge (ACS) as a sole graft material for lateral ridge augmentation in large ridge defect sites. This series evaluates the treatment outcome of maxillary anterior lateral ridge augmentation with rhBMP-2/ACS. Twenty patients were treated with rhBMP-2/ACS and fixation screws for space maintenance. Cone beam volumetric tomography measurements were used to determine gain in ridge width, and a bone core biopsy was obtained. The mean horizontal ridge gain was 1.2 mm across sites, and every site gained width.
Rasmussen, P B; Bjørn, S; Hastrup, S; Nielsen, P F; Norris, K; Thim, L; Wiberg, F C; Flodgaard, H
1996-07-15
Neutrophil-derived heparin-binding protein (HBP) is a strong chemoattractant for monocytes. We report here for the first time the expression of recombinant HBP. A baculovirus containing the human HBP cDNA mediated in insect cells the secretion of a 7-residue N-terminally extended HBP form (pro-HBP). Deletion of the pro-peptide-encoding cDNA sequence resulted in correctly processed HBP at the N-terminus. Electrospray mass spectrum analysis of recombinant HBP yielded a molecular weight of 27.237 +/- 3 amu. Consistent with this mass is a HBP form of 225 amino acids (mature part +3 amino acid C-terminal extension). The biological activity of recombinant HBP was confirmed by its chemotactic action towards monocytes. Furthermore, we have shown that recombinant HBP stimulates in a dose-dependent manner the lipopolysaccharide (LPS)-induced cytokine release from human monocytes.
ABSTRACT
We report quantitative estimates of the parameters for metabolism of bromodichloromethane (BDCM) by recombinant preparations of hepatic cytochrome P450s (CYPs) from rat and human. BDCM is a drinking water disinfectant byproduct that has been implicated in liver, kidn...
Enzymatic properties of Staphylococcus aureus adenosine synthase (AdsA)
2011-01-01
Background Staphylococcus aureus is a human pathogen that produces extracellular adenosine to evade clearance by the host immune system, an activity attributed to the 5'-nucleotidase activity of adenosine synthase (AdsA). In mammals, conversion of adenosine triphosphate to adenosine is catalyzed in a two-step process: ecto-nucleoside triphosphate diphosphohydrolases (ecto-NTDPases) hydrolyze ATP and ADP to AMP, whereas 5'-nucleotidases hydrolyze AMP to adenosine. NTPDases harbor apyrase conserved regions (ACRs) that are critical for activity. Results NTPDase ACR motifs are absent in AdsA, yet we report here that recombinant AdsA hydrolyzes ADP and ATP in addition to AMP. Competition assays suggest that hydrolysis occurs following binding of all three substrates at a unique site. Alanine substitution of two amino acids, aspartic acid 127 and histidine 196 within the 5'-nucleotidase signature sequence, leads to reduced AMP or ADP hydrolysis but does not affect the binding of these substrates. Conclusion Collectively, these results provide insight into the unique ability of AdsA to produce adenosine through the consecutive hydrolysis of ATP, ADP and AMP, thereby endowing S. aureus with the ability to modulate host immune responses. PMID:22035583
Cowley, Lauren A; Petersen, Fernanda C; Junges, Roger; Jimson D Jimenez, Med; Morrison, Donald A; Hanage, William P
2018-06-01
Homologous recombination in the genetic transformation model organism Streptococcus pneumoniae is thought to be important in the adaptation and evolution of this pathogen. While competent pneumococci are able to scavenge DNA added to laboratory cultures, large-scale transfers of multiple kb are rare under these conditions. We used whole genome sequencing (WGS) to map transfers in recombinants arising from contact of competent cells with non-competent 'target' cells, using strains with known genomes, distinguished by a total of ~16,000 SNPs. Experiments designed to explore the effect of environment on large scale recombination events used saturating purified donor DNA, short-term cell assemblages on Millipore filters, and mature biofilm mixed cultures. WGS of 22 recombinants for each environment mapped all SNPs that were identical between the recombinant and the donor but not the recipient. The mean recombination event size was found to be significantly larger in cell-to-cell contact cultures (4051 bp in filter assemblage and 3938 bp in biofilm co-culture versus 1815 bp with saturating DNA). Up to 5.8% of the genome was transferred, through 20 recombination events, to a single recipient, with the largest single event incorporating 29,971 bp. We also found that some recombination events are clustered, that these clusters are more likely to occur in cell-to-cell contact environments, and that they cause significantly increased linkage of genes as far apart as 60,000 bp. We conclude that pneumococcal evolution through homologous recombination is more likely to occur on a larger scale in environments that permit cell-to-cell contact.
Levin, W; Daniel, R F; Stoner, C R; Stoller, T J; Wardwell-Swanson, J A; Angelillo, Y M; Familletti, P C; Crowl, R M
1992-02-01
Recombinant human secretory phospholipase A2 (Group II) was expressed in long-term culture of immobilized Chinese hamster ovary cells utilizing a continuous-perfusion airlift bioreactor. The bioreactor was continuously perfused with cell-culture medium supplemented with 5% fetal calf serum at an average flow rate of 5 liters/day for 30 days. Recombinant phospholipase A2, at concentrations ranging from 100 to 500 micrograms/liter, was purified to apparent homogeneity by an efficient two-step procedure involving a silica-based cation-exchange resin and hydrophobic interaction chromatography (greater than 65% recovery of phospholipase A2). The purified recombinant protein has an apparent molecular weight of 16 kDa, identical to that of purified human placental or synovial fluid phospholipase A2, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Application of the purified protein onto several different gel filtration columns resulted in elution of the protein at molecular weights corresponding to 3.1-4.7 kDa, suggesting an interaction of the protein with the column resins. However, analytical ultracentrifugation experiments revealed that the protein behaves as a monomer (13.8-14.2 kDa) over a protein concentration range of approximately 10 micrograms/ml to 5 mg/ml. With autoclaved Escherichia coli membranes as substrate, the recombinant protein has catalytic properties (pH optimum, effects of bovine serum albumin, sodium chloride concentration, and requirement for calcium) similar to those of the protein purified from human placenta.
Production of recombinant human lysozyme in the milk of transgenic pigs.
Tong, Jia; Wei, HengXi; Liu, XiaoFang; Hu, WenPing; Bi, MingJun; Wang, YuanYuan; Li, QiuYan; Li, Ning
2011-04-01
In the swine industry pathogenic infections have a significant negative impact on neonatal survival. Piglets fed with human lysozyme, a natural antibiotic, might be more resistant to gastrointestinal infections. Here we describe the generation of transgenic swine expressing recombinant human lysozyme by somatic cell nuclear transfer. Three cloned female pigs were born, one of which expressed rhLZ at 0.32 ± 0.01 μg/ml in milk, 50-fold higher than that of the pig native lysozyme. Both the transgenic gilts and their progeny appear healthy. Introducing human lysozyme into pigs' milk has a potential to benefit the piglets by enhancing immune function and defending against pathogenic bacteria, thereby increasing the new born survival rate. This advance could be of great value to commercial swine producers.
[Use of recombinant Human Growth Hormone (rHGH)].
Calzada-León, Raúl
2017-01-01
Recombinant human growth hormone, synthesized in E.coli or mammalian cells cultures, is since 1985, a useful therapeutic resource to increase growth velocity and final height. In this paper are discussed the four phases (aims, security and efficacy, utility and efficiency) indispensables to define the start of treatment, as well as the absolute, relative and metabolic indications and the transitory and permanent conditions that contraindicate its use. It is commented the way to optimize the results (simple but indispensables indications for the physician, the patients and their family). Finally it is analyzed the results of treatment in patients with growth hormone deficiency, Turner syndrome, chronic renal failure, Prader-Willi syndrome, Noonan syndrome, SHOX deficiency, intrauterine growth retardation and idiopathic short stature.
International Validation of Two Human Recombinant Estrogen ...
An international validation study has been successfully completed for 2 competitive binding assays using human recombinant ERa. Assays evaluated included the Freyberger-Wilson (FW) assay using a full length human ER, and the Chemical Evaluation and Research Institute (CERI) assay using a ligand-binding domain of the human ER. Twenty three compounds were tested in 6 laboratories for the FW assay and 5 for the CERJ assay, which included three controls (used with every run), 9 uncoded, and 14 coded chemicals across 3 subtasks. The overall goal of this validation study was to demonstrate the ability of each of the two assays to reliably classify the test chemicals as binders or non-binders. Laboratories had little trouble with the ER binders that produced a full binding curve when using either the CERI or FW assays. As is typical with all ER competitive binding assays, the weak binders proved to be more challenging. However, overall results from both the FW and CERI assays were consistent and in agreement with expected classifications regardless of the form of the hrER (i.e., full length ER versus an ER ligand binding domain) or the subtle differences in the protocols for conducting each assay. The reproducibility and accuracy for classification of chemicals as potential ER binders and non- binders using the FW and CERI hrER binding assays were comparable to that of the U.S.EPA’s existing ER binding test guideline OPPTS 890.1250, while providing an improved, highe
Ponnazhagan, Selvarangan; Weigel, Kirsten A.; Raikwar, Sudhanshu P.; Mukherjee, Pinku; Yoder, Mervin C.; Srivastava, Arun
1998-01-01
A novel packaging strategy combining the salient features of two human parvoviruses, namely the pathogenic parvovirus B19 and the nonpathogenic adeno-associated virus type 2 (AAV), was developed to achieve erythroid cell-specific delivery as well as expression of the transduced gene. The development of such a chimeric vector system was accomplished by packaging heterologous DNA sequences cloned within the inverted terminal repeats of AAV and subsequently packaging the DNA inside the capsid structure of B19 virus. Recombinant B19 virus particles were assembled, as evidenced by electron microscopy as well as DNA slot blot analyses. The hybrid vector failed to transduce nonerythroid human cells, such as 293 cells, as expected. However, MB-02 cells, a human megakaryocytic leukemia cell line which can be infected by B19 virus following erythroid differentiation with erythropoietin (N. C. Munshi, S. Z. Zhou, M. J. Woody, D. A. Morgan, and A. Srivastava, J. Virol. 67:562–566, 1993) but lacks the putative receptor for AAV (S. Ponnazhagan, X.-S. Wang, M. J. Woody, F. Luo, L. Y. Kang, M. L. Nallari, N. C. Munshi, S. Z. Zhou, and A. Srivastava, J. Gen. Virol. 77:1111–1122, 1996), were readily transduced by this vector. The hybrid vector was also found to specifically target the erythroid population in primary human bone marrow cells as well as more immature hematopoietic progenitor cells following erythroid differentiation, as evidenced by selective expression of the transduced gene in these target cells. Preincubation with anticapsid antibodies against B19 virus, but not anticapsid antibodies against AAV, inhibited transduction of primary human erythroid cells. The efficiency of transduction of primary human erythroid cells by the recombinant B19 virus vector was significantly higher than that by the recombinant AAV vector. Further development of the AAV-B19 virus hybrid vector system should prove beneficial in gene therapy protocols aimed at the correction of inherited
2009-01-01
Literature 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Dramatic Differences in Organophosphorus Hydrolase Activity between Human and 5a... activity , V-agents, VX, bioscavenger, medical countermeasures 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES...Organophosphorus Hydrolase Activity between Human and Chimeric Recombinant Mammalian Paraoxonase-1 Enzymes† Tamara C. Otto,‡ Christina K. Harsch,§ David T
Kim, Hak; Kim, Kisoon; Kim, Dae-Won; Jung, Hee-Dong; Min Cheong, Hyang; Kim, Ki Hwan; Soo Kim, Dong; Kim, You-Jin
2013-01-01
Human rhinoviruses (HRVs), in the Enterovirus genus within the family Picornaviridae, are a highly prevalent cause of acute respiratory infection (ARI). Enteroviruses are genetically highly variable, and recombination between serotypes is known to be a major contribution to their diversity. Recently it was reported that recombination events in HRVs cause the diversity of HRV-C. This study analyzed parts of the viral genes spanning the 5′ non- coding region (NCR) through to the viral protein (VP) encoding sequences of 105 HRV field isolates from 51 outpatient cases of Acute Respiratory Infectious Network (ARINET) and 54 inpatient cases of severe lower respiratory infection (SLRI) surveillance, in order to identify recombination in field samples. When analyzing parts of the 5′NCR and VP4/VP2 encoding sequences, we found intra- and interspecies recombinants in field strains of HRV-A and -C. Nineteen cases of recombination events (18.1%) were found among 105 field strains. For HRV-A, there were five cases (4.8%) of intraspecies recombination events and three cases (2.8%) of interspecies recombination events. For HRV-C, there were four cases (3.8%) of intraspecies recombination events and seven cases (6.7%) of interspecies recombination events. Recombination events were significantly more frequently observed in the ARINET samples (18 cases) than in the SLRI samples (1 case; P< 0.0001). The recombination breakpoints were located in nucleotides (nt) 472–554, which comprise stem-loop 5 in the internal ribosomal entry site (IRES), based on the HRV-B 35 sequence (accession no. FJ445187). Our findings regarding genomic recombination in circulating HRV-A and -C strains suggest that recombination might play a role in HRV fitness and could be a possible determinant of disease severity caused by various HRV infections in patients with ARI. PMID:23826363
Coppen, S R; Newsam, R; Bull, A T; Baines, A J
1995-04-20
The Chinese hamster ovary (CHO) cell line has great commercial importance in the production of recombinant human proteins, especially those for therapeutic use. Much attention has been paid to CHO cell population physiology in order to define factors affecting product fidelity and yield. Such studies have revealed that recombinant proteins, including human interferon-gamma (IFN-gamma), can be heterogeneous both in glycosylation and in proteolytic processing. The type of heterogeneity observed depends on the growth physiology of the cell population, although the relationship between them is complex. In this article we report results of a cytological study of the CHO320 line which expresses recombinant human IFN-gamma. When grown in suspension culture, this cell line exhibited three types of heterogeneity: (1) heterogeneity of the production of IFN-gamma within the cell population, (2) heterogeneity of the number of nuclei and mitotic spindles in dividing cells, and (3) heterogeneity of cellular environment. The last of these arises from cell aggregates which form in suspension culture: Some cells are exposed to the culture medium; others are fully enclosed within the mass with little or no direct access to the medium. Thus, live cells producing IFN-gamma are heterogeneous in their environment, with variable access to O(2) and nutrients. Within the aggregates, it appears that live cells proliferate on a dead cell mass. The layer of live cells can be several cells deep. Specific cell-cell attachments are observed between the living cells in these aggregates. Two proteins, known to be required for the formation of certain types of intercellular junctions, spectrin and vinculin, have been localized to the regions of cell-cell contact. The aggregation of the cells appears to be an active process requiring protein synthesis. (c) 1995 John Wiley & Sons, Inc.
Analysis of the N-glycans of recombinant human Factor IX purified from transgenic pig milk
Gil, Geun-Cheol; Velander, William H; Van Cott, Kevin E
2008-01-01
Glycosylation of recombinant proteins is of particular importance because it can play significant roles in the clinical properties of the glycoprotein. In this work, the N-glycan structures of recombinant human Factor IX (tg-FIX) produced in the transgenic pig mammary gland were determined. The majority of the N-glycans of transgenic pig-derived Factor IX (tg-FIX) are complex, bi-antennary with one or two terminal N-acetylneuraminic acid (Neu5Ac) moieties. We also found that the N-glycan structures of tg-FIX produced in the porcine mammary epithelial cells differed with respect to N-glycans from glycoproteins produced in other porcine tissues. tg-FIX contains no detectable Neu5Gc, the sialic acid commonly found in porcine glycoproteins produced in other tissues. Additionally, we were unable to detect glycans in tg-FIX that have a terminal Galα(1,3)Gal disaccharide sequence, which is strongly antigenic in humans. The N-glycan structures of tg-FIX are also compared to the published N-glycan structures of recombinant human glycoproteins produced in other transgenic animal species. While tg-FIX contains only complex structures, antithrombin III (goat), C1 inhibitor (rabbit), and lactoferrin (cow) have both high mannose and complex structures. Collectively, these data represent a beginning point for the future investigation of species-specific and tissue/cell-specific differences in N-glycan structures among animals used for transgenic animal bioreactors. PMID:18456721
Hunt, A P; Frier, M; Johnson, R A; Berezenko, S; Perkins, A C
2006-01-01
Human serum albumin (HSA) extracted from pooled blood taken from human donors is used in the production of (99m)Tc-labelled macroaggregated albumin (MAA) for lung perfusion imaging. However, concerns for the safety of blood-derived products due to potential contamination by infective agents (e.g. new variant CJD), make alternative production methods necessary. Recombinant DNA technology is a promising method of albumin production avoiding problems associated with human-derived HSA. This paper presents results comparing MAA prepared from recombinant human albumin (rHA, Recombumin) (rMAA) with in-house produced HSA MAA (hMAA) and commercially available MAA (cMAA). (99m)Tc-MAA was prepared using previously published production methods by heating a mixture of albumin and stannous chloride in acetate buffer (pH 5.4) at 70 degrees C for 20 min. Parameters investigated include aggregate size, radiolabelling efficiency, radiochemical and aggregate stability at 4 degrees C and in vitro (in whole human blood) at 37 degrees C and biodistribution studies. Results showed that rMAA could be produced with similar morphology, labelling efficiency and stability to hMAA and cMAA. Our findings confirm that rHA shows significant potential as a direct replacement for HSA in commercially available MAA.
Irani, Zahra Azimzadeh; Kerkhoven, Eduard J; Shojaosadati, Seyed Abbas; Nielsen, Jens
2016-05-01
Pichia pastoris is used for commercial production of human therapeutic proteins, and genome-scale models of P. pastoris metabolism have been generated in the past to study the metabolism and associated protein production by this yeast. A major challenge with clinical usage of recombinant proteins produced by P. pastoris is the difference in N-glycosylation of proteins produced by humans and this yeast. However, through metabolic engineering, a P. pastoris strain capable of producing humanized N-glycosylated proteins was constructed. The current genome-scale models of P. pastoris do not address native nor humanized N-glycosylation, and we therefore developed ihGlycopastoris, an extension to the iLC915 model with both native and humanized N-glycosylation for recombinant protein production, but also an estimation of N-glycosylation of P. pastoris native proteins. This new model gives a better prediction of protein yield, demonstrates the effect of the different types of N-glycosylation of protein yield, and can be used to predict potential targets for strain improvement. The model represents a step towards a more complete description of protein production in P. pastoris, which is required for using these models to understand and optimize protein production processes. © 2015 Wiley Periodicals, Inc.
Borowicz, Piotr; Bocian, Wojciech; Sitkowski, Jerzy; Bednarek, Elżbieta; Mikiewicz-Syguła, Diana; Błażej-Sosnowska, Sylwia; Bogiel, Monika; Rusek, Dorota; Kurzynoga, Dariusz; Kozerski, Lech
2011-11-01
A tertiary structure of recombinant A22(G)-B31(K)-B32(R)-human insulin monomer (insulin GKR) has been characterized by (1)H, (13)C NMR at natural isotopic abundance using NOESY, TOCSY, (1)H/(13)C-GHSQC, and (1)H/(13)C-GHSQC-TOCSY spectra. Translational diffusion studies indicate the monomer structure in water/acetonitrile (65/35vol.%). CSI analysis confirms existence of secondary structure motifs present in human insulin standard (HIS). Both techniques allow to establish that in this solvent recombinant insulin GKR exists as a monomer. Starting from structures calculated by the program CYANA, two different refinement protocols used molecular dynamics simulated annealing with the program AMBER; in vacuum (AMBER_VC), and including a generalized Born solvent model (AMBER_GB). From these calculations an ensemble of 20 structures of lowest energy was chosen which represents the tertiary structure of studied insulin. Here we present novel insulin with added A22(G) amino acid which interacts with β-turn environment resulting in high flexibility of B chain C-terminus. Copyright © 2011 Elsevier B.V. All rights reserved.
Alexander, Jeff; Ward, Simone; Mendy, Jason; Manayani, Darly J; Farness, Peggy; Avanzini, Jenny B; Guenther, Ben; Garduno, Fermin; Jow, Lily; Snarsky, Victoria; Ishioka, Glenn; Dong, Xin; Vang, Lo; Newman, Mark J; Mayall, Tim
2012-01-01
Influenza virus remains a significant health and social concern in part because of newly emerging strains, such as avian H5N1 virus. We have developed a prototype H5N1 vaccine using a recombinant, replication-competent Adenovirus serotype 4 (Ad4) vector, derived from the U.S. military Ad4 vaccine strain, to express the hemagglutinin (HA) gene from A/Vietnam/1194/2004 influenza virus (Ad4-H5-Vtn). Our hypothesis is that a mucosally-delivered replicating Ad4-H5-Vtn recombinant vector will be safe and induce protective immunity against H5N1 influenza virus infection and disease pathogenesis. The Ad4-H5-Vtn vaccine was designed with a partial deletion of the E3 region of Ad4 to accommodate the influenza HA gene. Replication and growth kinetics of the vaccine virus in multiple human cell lines indicated that the vaccine virus is attenuated relative to the wild type virus. Expression of the HA transgene in infected cells was documented by flow cytometry, western blot analysis and induction of HA-specific antibody and cellular immune responses in mice. Of particular note, mice immunized intranasally with the Ad4-H5-Vtn vaccine were protected against lethal H5N1 reassortant viral challenge even in the presence of pre-existing immunity to the Ad4 wild type virus. Several non-clinical attributes of this vaccine including safety, induction of HA-specific humoral and cellular immunity, and efficacy were demonstrated using an animal model to support Phase 1 clinical trial evaluation of this new vaccine.
Homologous and heterologous recombination between adenovirus vector DNA and chromosomal DNA.
Stephen, Sam Laurel; Sivanandam, Vijayshankar Ganesh; Kochanek, Stefan
2008-11-01
Adenovirus vector DNA is perceived to remain as episome following gene transfer. We quantitatively and qualitatively analysed recombination between high capacity adenoviral vector (HC-AdV) and chromosomal DNA following gene transfer in vitro. We studied homologous and heterologous recombination with a single HC-AdV carrying (i) a large genomic HPRT fragment with the HPRT CHICAGO mutation causing translational stop upon homologous recombination with the HPRT locus and (ii) a selection marker to allow for clonal selection in the event of heterologous recombination. We analysed the sequences at the junctions between vector and chromosomal DNA. In primary cells and in cell lines, the frequency of homologous recombination ranged from 2 x 10(-5) to 1.6 x 10(-6). Heterologous recombination occurred at rates between 5.5 x 10(-3) and 1.1 x 10(-4). HC-AdV DNA integrated via the termini mostly as intact molecules. Analysis of the junction sequences indicated vector integration in a relatively random manner without an obvious preference for particular chromosomal regions, but with a preference for integration into genes. Integration into protooncogenes or tumor suppressor genes was not observed. Patchy homologies between vector termini and chromosomal DNA were found at the site of integration. Although the majority of integrations had occurred without causing mutations in the chromosomal DNA, cases of nucleotide substitutions and insertions were observed. In several cases, deletions of even relative large chromosomal regions were likely. These results extend previous information on the integration patterns of adenovirus vector DNA and contribute to a risk-benefit assessment of adenovirus-mediated gene transfer.
Tao, Ying; Shi, Mang; Chommanard, Christina; Queen, Krista; Zhang, Jing; Markotter, Wanda; Kuzmin, Ivan V.; Holmes, Edward C.
2017-01-01
ABSTRACT Bats harbor a large diversity of coronaviruses (CoVs), several of which are related to zoonotic pathogens that cause severe disease in humans. Our screening of bat samples collected in Kenya from 2007 to 2010 not only detected RNA from several novel CoVs but, more significantly, identified sequences that were closely related to human CoVs NL63 and 229E, suggesting that these two human viruses originate from bats. We also demonstrated that human CoV NL63 is a recombinant between NL63-like viruses circulating in Triaenops bats and 229E-like viruses circulating in Hipposideros bats, with the breakpoint located near 5′ and 3′ ends of the spike (S) protein gene. In addition, two further interspecies recombination events involving the S gene were identified, suggesting that this region may represent a recombination “hot spot” in CoV genomes. Finally, using a combination of phylogenetic and distance-based approaches, we showed that the genetic diversity of bat CoVs is primarily structured by host species and subsequently by geographic distances. IMPORTANCE Understanding the driving forces of cross-species virus transmission is central to understanding the nature of disease emergence. Previous studies have demonstrated that bats are the ultimate reservoir hosts for a number of coronaviruses (CoVs), including ancestors of severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and human CoV 229E (HCoV-229E). However, the evolutionary pathways of bat CoVs remain elusive. We provide evidence for natural recombination between distantly related African bat coronaviruses associated with Triaenops afer and Hipposideros sp. bats that resulted in a NL63-like virus, an ancestor of the human pathogen HCoV-NL63. These results suggest that interspecies recombination may play an important role in CoV evolution and the emergence of novel CoVs with zoonotic potential. PMID:28077633
Genot, Séverine; Franck, Jacqueline; Forel, Jean-Marie; Rebaudet, Stanislas; Ajzenberg, Daniel; de Paula, Andre Maues; Dardé, Marie-Laure; Stein, Andreas; Ranque, Stéphane
2007-01-01
The reactivation of an uncommon type I/III recombinant-genotype Toxoplasma gondii strain resulted in unusually severe encephalitis and chorioretinitis associated with a cerebral salt wasting syndrome in an African human immunodeficiency virus patient. This observation suggests an influence of the parasite genotype on disease expression in immunocompromised patients. PMID:17634310
Iacono-Connors, L C; Novak, J; Rossi, C; Mangiafico, J; Ksiazek, T
1994-01-01
We developed an antigen capture enzyme-linked immunosorbent assay (ELISA) which does not require purified protective antigen (PA) for detection of human antibodies to Bacillus anthracis PA. Lysates of Spodoptera frugiperda (Sf-9) cells infected with recombinant baculovirus containing the PA gene were used as the source of PA to develop the ELISA. Recombinant PA from crude Sf-9 cell lysates or PA purified from B. anthracis Sterne strain was captured by an anti-PA monoclonal antibody coated onto microtiter plates. We demonstrated that human serum antibody titers to PA were identical in the ELISA whether we used crude Sf-9 cell lysates containing recombinant baculovirus-expressed PA or purified Sterne PA. Finally, false-positive results observed in a direct ELISA were eliminated with this antigen capture ELISA. Thus, the antigen capture ELISA with crude preparations of baculovirus-expressed PA is reliable, safe, and inexpensive for determining anti-PA antibody levels in human sera. PMID:7496927
Takeuchi, M; Inoue, N; Strickland, T W; Kubota, M; Wada, M; Shimizu, R; Hoshi, S; Kozutsumi, H; Takasaki, S; Kobata, A
1989-01-01
Two forms of erythropoietin, EPO-bi and EPO-tetra, with different biological activities were isolated from the culture medium of a recombinant Chinese hamster ovary cell line, B8-300, into which the human erythropoietin gene had been introduced. EPO-bi, an unusual form, showed only one-seventh the in vivo activity and 3 times higher in vitro activity of the previously described recombinant human EPO (standard EPO). In contrast, EPO-tetra showed both in vivo and in vitro activities comparable to those of the standard EPO. EPO-bi, EPO-tetra, and the standard EPO had the same amino acid composition and immunoreactivity. However, structural analyses of their N-linked sugar chains revealed that EPO-bi contains the biantennary complex type as the major sugar chain, while EPO-tetra and the standard EPO contain the tetraantennary complex type as the major sugar chain. From examination of various preparations of recombinant human EPO, we found a positive correlation between the in vivo activity of EPO and the ratio of tetraantennary to biantennary oligosaccharides. These results suggest that higher branching of the N-linked sugar chains is essential for effective expression of in vivo biological activity of EPO. PMID:2813359
Flavonoids of cocoa inhibit recombinant human 5-lipoxygenase.
Schewe, Tankred; Kühn, Hartmut; Sies, Helmut
2002-07-01
(-)-Epicatechin and its related oligomers, the procyanidins, are present in sizable amounts in some cocoas and chocolates. Intake of flavonoid-rich chocolate in humans has been reported to increase the plasma level of (-)-epicatechin and concomitantly to significantly decrease the plasma level of proinflammatory cysteinyl leukotrienes. Because leukotrienes are formed via the 5-lipoxygenase pathway of arachidonic acid metabolism, we examined whether 5-lipoxygenase is a possible target for the flavonoids of cocoa. Recombinant human 5-lipoxygenase was reacted with arachidonic acid and yielded a mixture of mainly 5-hydroperoxy-6E,8Z, 11Z,14Z-eicosatetraenoic acid (5-HpETE) and hydrolysis products of 5,6-leukotriene A(4) (LTA(4)). The formation of these products was significantly inhibited by (-)-epicatechin in a dose-dependent manner with 50% inhibitory concentrations (IC(50)) of 22 and 50 micromol/L, respectively. Among the procyanidin fractions isolated from the seeds of Theobroma cacao, only the dimer fraction and, to a lesser extent, the trimer through pentamer fractions exhibited comparable effects, whereas the larger procyanidins (hexamer through nonamer) were almost inactive. We conclude that (-)-epicatechin and its low-molecular procyanidins inhibit both dioxygenase and LTA(4) synthase activities of human 5-lipoxygenase and that this action may contribute to a putative anti-inflammatory effect of cocoa products.
Characteristics of recombinantly expressed rat and human histamine H3 receptors.
Wulff, Birgitte S; Hastrup, Sven; Rimvall, Karin
2002-10-18
Human and rat histamine H(3) receptors were recombinantly expressed and characterized using receptor binding and a functional cAMP assay. Seven of nine agonists had similar affinities and potencies at the rat and human histamine H(3) receptor. S-alpha-methylhistamine had a significantly higher affinity and potency at the human than rat receptor, and for 4-[(1R*,2R*)-2-(5,5-dimethyl-1-hexynyl)cyclopropyl]-1H-imidazole (Perceptin) the preference was the reverse. Only two of six antagonists had similar affinities and potencies at the human and the rat histamine H(3) receptor. Ciproxifan, thioperamide and (1R*,2R*)-trans-2-imidazol-4 ylcyclopropyl) (cyclohexylmethoxy) carboxamide (GT2394) had significantly higher affinities and potencies at the rat than at the human histamine H(3) receptor, while for N-(4-chlorobenzyl)-N-(7-pyrrolodin-1-ylheptyl)guanidine (JB98064) the preference was the reverse. All antagonists also showed potent inverse agonism properties. Iodoproxyfan, Perceptin, proxyfan and GR175737, compounds previously described as histamine H(3) receptor antagonists, acted as full or partial agonists at both the rat and the human histamine H(3) receptor. Copyright 2002 Elsevier Science B.V.
A yeast-based genetic screening to identify human proteins that increase homologous recombination.
Collavoli, Anita; Comelli, Laura; Rainaldi, Giuseppe; Galli, Alvaro
2008-05-01
To identify new human proteins implicated in homologous recombination (HR), we set up 'a papillae assay' to screen a human cDNA library using the RS112 strain of Saccharomyces cerevisiae containing an intrachromosomal recombination substrate. We isolated 23 cDNAs, 11 coding for complete proteins and 12 for partially deleted proteins that increased HR when overexpressed in yeast. We characterized the effect induced by the overexpression of the complete human proteasome subunit beta 2, the partially deleted proteasome subunits alpha 3 and beta 8, the ribosomal protein L12, the brain abundant membrane signal protein (BASP1) and the human homologue to v-Ha-RAS (HRAS), which elevated HR by 2-6.5-fold over the control. We found that deletion of the RAD52 gene, which has a key role in most HR events, abolished the increase of HR induced by the proteasome subunits and HRAS; by contrast, the RAD52 deletion did not affect the high level of HR due to BASP1 and RPL12. This suggests that the proteins stimulated yeast HR via different mechanisms. Overexpression of the complete beta 2 human proteasome subunit or the partially deleted alpha 3 and beta 8 subunits increased methyl methanesulphonate (MMS) resistance much more in the rad52 Delta mutant than in the wild-type. Overexpression of RPL12 and BASP1 did not affect MMS resistance in both the wild-type and the rad52 Delta mutant, whereas HRAS decreased MMS resistance in the rad52 Delta mutant. The results indicate that these proteins may interfere with the pathway(s) involved in the repair of MMS-induced DNA damage. Finally, we provide further evidence that yeast is a helpful tool to identify human proteins that may have a regulatory role in HR.
Geylis, Valeria; Steinitz, Michael
2006-01-01
The deposition of amyloid beta (Abeta) protein is a key pathological feature in Alzheimer's disease (AD). In murine models of AD, both active and passive immunization against Abeta induce a marked reduction in amyloid brain burden and an improvement in cognitive functions. Preliminary results of a prematurely terminated clinical trial where AD patients were actively vaccinated with aggregated Abeta bear resemblance to those documented in murine models. Passive immunization of AD patients with anti-Abeta antibodies, in particular human antibodies, is a strategy that provides a more cautious management and control of any undesired side effects. Sera of all healthy adults contain anti-Abeta IgG autoimmune antibodies. Hence antigen-committed human B-cells are easily immortalized by Epstein-Barr virus (EBV) into anti-Abeta secreting cell lines. Two anti-Abeta human monoclonal antibodies which we recently prepared bind to the N-terminus of Abeta peptide and were shown to stain amyloid plaques in non-fixed brain sections from an AD patient. It is anticipated that specifically selected anti-Abeta human monoclonal antibodies could reduce and inhibit deposits of amyloid in brain while avoiding the cognitive decline that characterizes AD. In the future, this type of antibody may prove to be a promising immune therapy for the disease.
Juozapaitis, Mindaugas; Zvirbliene, Aurelija; Kucinskaite, Indre; Sezaite, Indre; Slibinskas, Rimantas; Coiras, Mayte; de Ory Manchon, Fernando; López-Huertas, María Rosa; Pérez-Breña, Pilar; Staniulis, Juozas; Narkeviciute, Irena; Sasnauskas, Kestutis
2008-05-01
Human parainfluenza virus types 1 and 3 (HPIV1 and HPIV3, respectively), members of the virus family Paramyxoviridae, are common causes of lower respiratory tract infections in infants, young children, the immunocompromised, the chronically ill, and the elderly. In order to synthesize recombinant HPIV1 and HPIV3 nucleocapsid proteins, the coding sequences were cloned into the yeast Saccharomyces cerevisiae expression vector pFGG3 under control of GAL7 promoter. A high level of recombinant virus nucleocapsid proteins expression (20-24 mg l(-1) of yeast culture) was obtained. Electron microscopy demonstrated the assembly of typical herring-bone structures of purified recombinant nucleocapsid proteins, characteristic for other paramyxoviruses. These structures contained host RNA, which was resistant to RNase treatment. The nucleocapsid proteins were stable in yeast and were easily purified by caesium chloride gradient ultracentrifugation. Therefore, this system proved to be simple, efficient and cost-effective, suitable for high-level production of parainfluenza virus nucleocapsids as nucleocapsid-like particles. When used as coating antigens in an indirect ELISA, the recombinant N proteins reacted with sera of patients infected with HPIV1 or 3. Serological assays to detect HPIV-specific antibodies could be designed on this basis.
Treatment of dwarfism with recombinant human insulin-like growth factor-1.
Ranke, Michael B; Wölfle, Joachim; Schnabel, Dirk; Bettendorf, Markus
2009-10-01
The growth hormone-IGF (insulin-like growth factor) system plays a central role in hormonal growth regulation. Recombinant human (rh) growth hormone (GH) has been available since the late 1980s for replacement therapy in GH-deficient patients and for the stimulation of growth in patients with short stature of various causes. Growth promotion by GH occurs in part indirectly through the induction of IGF-1 synthesis. In primary disturbances of IGF-1 production, short stature can only be treated with recombinant human IGF-1 (rhIGF-1). rhIGF-1 was recently approved for this indication but can also be used to treat other conditions. Selective review of the literature on IGF-1 therapy, based on a PubMed search. In children with severe primary IGF-1 deficiency (a rare condition whose prevalence is less than 1:10,000), the prognosis for final height is very poor (ca. 130 cm), and IGF-1 therapy is the appropriate form of pathophysiologically based treatment. There is no alternative treatment at present. The subcutaneous administration of IGF-1 twice daily in doses of 80 to 120 microg/kg accelerates growth and increases final height by 12 to 15 cm, according to current data. There is, however, a risk of hypoglycemia, as IGF-1 has an insulin-like effect. As treatment with IGF-1 is complex, this new medication should only be prescribed, for the time being, by experienced pediatric endocrinologists and diabetologists.
Positron cooling of antiprotons: precursor of recombination
NASA Astrophysics Data System (ADS)
Tan, J. N.; Estrada, J.; Yesley, P.; Bowden, N.; Oxley, P.; Storry, C.; Wessels, M.; Tan, J.; Gabrielse, G.; Oelert, W.; Scheppers, G.; Gronzonka, D.; Sefsick, T.; Fermann, H.; Zmeskal, H.; Breunlich, W.; Kalinowsky, H.; Wesdorp, C.
2001-05-01
The quest for cold antihydrogen, interrupted with the shut-down of LEAR, resumed with the operation of the newest antiproton decelerator (AD) at CERN.[See G.Gabrielse,Adv. in AMO Physics,vol.45,pp.1-38(2001).] Antiprotons injected into the AD with 2.75 GeV of kinetic energy slow to 5.31 MeV before extraction into the ATRAP apparatus, built for antihydrogen recombination experiments. Antiprotons extracted from the AD and positrons emitted from a 112 mCi ^22Na source are simultaneously accumulated in the ultra-high vacuum and 6 T field of a prototype Penning trap incorporating a miniature rotatable electrode. Preloaded electrons are used to thermalize ~ 10^5 antiprotons with the LHe-cooled trap (4.2K). Over 10^6 positrons/hr can be loaded with a new mechanism involving Rydberg positronium. After accumulation, the positrons are moved through the rotatable electrode into close proximity with the antiprotons to study their interactions. We report the first observation of positron cooling of antiprotons in a nested trap configuration suited for three-body recombination and other mechanisms.
Yin, Ling-Ling; Ruan, Su-Hong; Tian, Yu; Zhao, Kai; Xu, Kai Lin
2015-10-01
To clone the variable region genes of human anti-IL1RAP (IL-1 receptor accessory protein) monoclonal antibodies (McAb) and to construct IL1RAP chimeric antigen receptors (CARs). The VH and VL DNA of IL1RAP single chain antibodies were amplified by RACE and overlap extension PCR from total RNA extracted from 3H6E10 and 10D8A7 hybridoma and ligated into specific IL1RAP single-chain variable fragments (scFv). CD8α transmembrane domain, CD137 intracellular domain, TCR ζ chain, human CD8α signal peptide and scFv-anti-IL1RAP were cloned into plasmid LV-lac. Recombinant lentiviruses were generated by co-transfection of recombinant plasmid LV-lac, pMD2. G, and psPAX2 helper vectors into 293FT packing cells. The VH and VL genes of 2 human anti-IL1RAP McAb were acquired. The 3H6E10 VH and VL genes consisted of 402 bp and 393 bp encoding 134 and 131 aminoacid residues, respectively; 10D8A7 VH and VL genes consisted of 423 bp and 381 bp encoding 141 and 127 amine acid residues, respectively. Recombinant expression vertors LV-3H6E10 scFv-ICD and LV-10D8A7 scFv-ICD (ICD: CD8α transmembrane domain-CD137 intracellular domain-TCR ζ chain) were constructed. The target fragments were demonstrated by sequencing analysis. Recombinant plasmids were transfected into 293FT cells and lentiviral particles were acquired. Human anti-IL1RAP recombinant receptors are constructed successfully and lay a good foundation for the construction of IL1RAP-CAR killer T cell vaccine.
Site-specific genetic recombination: hops, flips, and flops.
Sadowski, P D
1993-06-01
Genetic recombination plays a key role in the life of organisms as diverse as bacteriophages and humans. Contrary to our idea that chromosomes are stable structures, studies of recombination over the past few decades have shown that in fact DNA replicons are remarkably plastic, undergoing frequent recombination-induced rearrangements. This review summarizes our recent knowledge of the biochemistry of the two major classes of site-specific recombination: 1) transpositional recombination, and 2) conservative site-specific recombination.
2013-01-01
Toxoplasma gondii is a parasitic protozoan which is the cause of toxoplasmosis. Although human toxoplasmosis in healthy adults is usually asymptomatic, serious disease can occur in the case of congenital infections and immunocompromised individuals. Furthermore, despite the exact recognition of its etiology, it still presents a diagnostic problem. Diagnosis of toxoplasmosis is mainly based on the results of serological tests detecting anti-T. gondii-specific antibodies in the patient's serum sample. The specificities and sensitivities of serology tests depend mostly on the diagnostic antigen(s) used. Most of the commercial serological kits currently available are based on Toxoplasma lysate antigens (TLAs). In recent years, many studies showed that recombinant antigenic proteins of T. gondii may be an alternative source of antigens which are very useful for the serodiagnosis of toxoplasmosis. This article presents a review of current studies on the application and usefulness of different T. gondii recombinant antigens in serological tests for the diagnosis of human toxoplasmosis. PMID:23784855
Sreenivasa, B P; Mohapatra, J K; Pauszek, S J; Koster, M; Dhanya, V C; Tamil Selvan, R P; Hosamani, M; Saravanan, P; Basagoudanavar, Suresh H; de Los Santos, T; Venkataramanan, R; Rodriguez, L L; Grubman, M J
2017-05-01
Recombinant adenovirus-5 vectored foot-and-mouth disease constructs (Ad5- FMD) were made for three Indian vaccine virus serotypes O, A and Asia 1. Constructs co-expressing foot-and- mouth disease virus (FMDV) capsid and viral 3C protease sequences, were evaluated for their ability to induce a neutralizing antibody response in indigenous cattle (Bos indicus). Purified Ad5-FMD viruses were inoculated in cattle as monovalent (5×10 9 pfu/animal) or trivalent (5×10 9 pfu/animal per serotype) vaccines. Animals vaccinated with monovalent Ad5-FMD vaccines were boosted 63days later with the same dose. After primary immunization, virus neutralization tests (VNT) showed seroconversion in 83, 67 and 33% of animals vaccinated with Ad5-FMD O, A and Asia 1, respectively. Booster immunization elicited seroconversion in all of the animals (100%) in the monovalent groups. When used in a trivalent form, the Ad5-FMD vaccine induced neutralizing antibodies in only 33, 50 and 16% of animals against serotypes O, A and Asia 1, respectively on primo-vaccination, and titers were significantly lower than when the same vectors were used in monovalent form. Neutralizing antibody titers differed by serotype for both Ad5-FMD monovalent and trivalent vaccines, with Asia 1 serotype inducing the lowest titers. Antibody response to Ad5 vector in immunized cattle was also assessed by VNT. It appeared that the vector immunity did not impact the recall responses to expressed FMDV antigens on booster immunization. In summary, the study suggested that the recombinant Ad5-FMD vaccine has a potential use in monovalent form, while its application in multivalent form is not currently encouraging. Copyright © 2017 Elsevier B.V. All rights reserved.
A novel platform for biologically active recombinant human interleukin-13 production.
Wang, David J; Brandsma, Martin; Yin, Ziqin; Wang, Aiming; Jevnikar, Anthony M; Ma, Shengwu
2008-06-01
Interleukin-13 (IL-13) is a pleiotropic regulatory cytokine with the potential for treating several human diseases, including type-1 diabetes. Thus far, conventional expression systems for recombinant IL-13 production have proven difficult and are limited by efficiency. In this study, transgenic plants were used as a novel expression platform for the production of human IL-13 (hIL-13). DNA constructs containing hIL-13 cDNA were introduced into tobacco plants. Transcriptional expression of the hIL-13 gene in transgenic plants was confirmed by reverse transcriptase-polymerase chain reaction and Northern blotting. Western blot analysis showed that the hIL-13 protein was efficiently accumulated in transgenic plants and present in multiple molecular forms, with an expression level as high as 0.15% of total soluble protein in leaves. The multiple forms of plant-derived recombinant hIL-13 (rhIL-13) are a result of differential N-linked glycosylation, as revealed by enzymatic and chemical deglycosylation, but not of disulphide-linked oligomerization. In vitro trypsin digestion indicated that plant rhIL-13 was more resistant than unglycosylated control rhIL-13 to proteolysis. The stability of plant rhIL-13 to digestion was further supported with simulated gastric and intestinal fluid digestion. In vitro bioassays using a factor-dependent human erythroleukaemic cell line (TF-1 cells) showed that plant rhIL-13 retained the biological functions of the authentic hIL-13 protein. These results demonstrate that transgenic plants are superior to conventional cell-based expression systems for the production of rhIL-13. Moreover, transgenic plants synthesizing high levels of rhIL-13 may prove to be an attractive delivery system for direct oral administration of IL-13 in the treatment of clinical diseases such as type-1 diabetes.
Biedermann, J S; van den Besselaar, A M H P; de Maat, M P M; Leebeek, F W G; Kruip, M J H A
2017-03-01
Essentials Differences in sensitivity to factor VII (FVII) have been suggested between thromboplastins. FVII-induced International Normalized Ratio (INR) changes differ between commercial reagents. Recombinant human thromboplastins are more sensitive to FVII than tissue-extract thromboplastins. Thromboplastin choice may affect FVII-mediated INR stability. Background Differences regarding sensitivity to factor VII have been suggested for recombinant human and tissue-extract thromboplastins used for International Normalized Ratio (INR) measurement, but the evidence is scarce. Differences in FVII sensitivity are clinically relevant, as they can affect INR stability during treatment with vitamin K antagonists (VKAs). Objectives To determine whether commercial thromboplastins react differently to changes in FVII. Methods We studied the effect of addition of FVII on the INR in plasma by using three tissue-extract (Neoplastin C1+, Hepato Quick, and Thromborel S) and three recombinant human (Recombiplastin 2G, Innovin, and CoaguChek XS) thromboplastins. Three different concentrations of purified human FVII (0.006, 0.012 and 0.062 μg mL -1 plasma), or buffer, were added to five certified pooled plasmas of patients using VKAs (INR of 1.5-3.5). Changes in FVII activity were measured with two bioassays (Neoplastin and Recombiplastin), and relative INR changes were compared between reagents. Results After addition of 0.062 μg mL -1 FVII, FVII activity in the pooled plasmas increased by approximately 20% (Neoplastin) or 32% (Recombiplastin) relative to the activity in pooled normal plasma. All thromboplastins showed dose-dependent INR decreases. The relative INR change in the pooled plasmas significantly differed between the six thromboplastins. No differences were observed among recombinant or tissue-extract thromboplastins. Pooled results indicated that the FVII-induced INR change was greater for recombinant than for tissue-extract thromboplastins. Conclusions Differences
This Integrated Summary Report (ISR) summarizes, in a single document, the results from an international multi-laboratory validation study conducted for two in vitro estrogen receptor (ER) binding assays. These assays both use human recombinant estrogen receptor, alpha subtype (h...
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2013-12-27
... Hormone AGENCY: United States Patent and Trademark Office, Commerce. ACTION: Notice of interim patent term... No. 5,496,801. The patent claims the human biological product recombinant human parathyroid hormone... human parathyroid hormone, was filed on October 24, 2013, and is currently undergoing regulatory review...
Purification and Characterization of Recombinant Human Lysozyme from Eggs of Transgenic Chickens.
Wu, Hanyu; Cao, Dainan; Liu, Tongxin; Zhao, Jianmin; Hu, Xiaoxiang; Li, Ning
2015-01-01
Transgenic chickens as bioreactors have several advantages, such as the simple establishment procedure, correct glycosylation profile of expressed proteins, etc. Lysozyme is widely used in food industry, livestock farming, and medical field as a replacement of antibiotics because of its antibacterial and complement system-modulating activity. In this study, we used RT-PCR, Western blot, and immunofluorescence to detect the expression of recombinant human lysozyme (rhLY) in the transgenic chicken. We demonstrated that the transgene of rhLY was genetically stable across different generations. We next optimized the purification procedure of rhLY from the transgenic eggs by utilizing two steps of cation-exchange chromatography and one gel-filtration chromatography. About 6 mg rhLY with the purity exceeding 90% was obtained from ten eggs, and the purification efficiency was about 75%. The purified rhLY had similar physicochemical and biological properties in molecular mass and antibacterial activity compared to the commercial human lysozyme. Additionally, both of them exhibited thermal stability at 60°C and tolerated an extensive pH range of 2 to 11. In conclusion, our study proved that the transgenic chickens we have previously generated were genetically stable and suitable for the production of active rhLY. We also provided a pipeline for purifying the recombinant proteins from transgenic eggs, which could be useful for other studies.
Purification and Characterization of Recombinant Human Lysozyme from Eggs of Transgenic Chickens
Wu, Hanyu; Cao, Dainan; Liu, Tongxin; Zhao, Jianmin; Hu, Xiaoxiang; Li, Ning
2015-01-01
Transgenic chickens as bioreactors have several advantages, such as the simple establishment procedure, correct glycosylation profile of expressed proteins, etc. Lysozyme is widely used in food industry, livestock farming, and medical field as a replacement of antibiotics because of its antibacterial and complement system-modulating activity. In this study, we used RT-PCR, Western blot, and immunofluorescence to detect the expression of recombinant human lysozyme (rhLY) in the transgenic chicken. We demonstrated that the transgene of rhLY was genetically stable across different generations. We next optimized the purification procedure of rhLY from the transgenic eggs by utilizing two steps of cation-exchange chromatography and one gel-filtration chromatography. About 6 mg rhLY with the purity exceeding 90% was obtained from ten eggs, and the purification efficiency was about 75%. The purified rhLY had similar physicochemical and biological properties in molecular mass and antibacterial activity compared to the commercial human lysozyme. Additionally, both of them exhibited thermal stability at 60°C and tolerated an extensive pH range of 2 to 11. In conclusion, our study proved that the transgenic chickens we have previously generated were genetically stable and suitable for the production of active rhLY. We also provided a pipeline for purifying the recombinant proteins from transgenic eggs, which could be useful for other studies. PMID:26713728
Pathak, Prachi; Kumar, Ashu; Thavaselvam, Duraipandian
2017-07-11
Brucellosis is an important zoonotic disease caused by different Brucella species and human brucellosis is commonly prevalent in different states of India. Among various Brucella species, B. melitensis is most pathogenic to human and included as category B biothreat which can cause infection through aerosol, cut, wounds in skin and contact with infected animals. The diagnosis of human brucellosis is very important for proper treatment and management of disease as there is no vaccine available for human use. The present study was designed to clone, express and purify immunodominant recombinant omp2a (rOmp2a) porin protein of B. melitensis and to evaluate this new antigen candidate for specific serodiagnosis of human brucellosis by highly sensitive iELISA (indirect enzyme linked immunosorbent assay). Omp2a gene of B. melitensis 16 M strain was cloned and expressed in pET-SUMO expression system. The recombinant protein was purified under denaturing conditions using 8 M urea. The purified recombinant protein was confirmed by western blotting by reacting with anti-HIS antibody. The sero-reactivity of the recombinant protein was also checked by reacting with antisera of experimentally infected mice with B. melitensis 16 M at different time points. Serodiagnostic potential of recombinant porin antigen was tested against 185 clinical serum samples collected from regions endemic to brucellosis in southern part of India by iELISA. The samples were grouped into five groups. Group 1 contained cultured confirmed positive serum samples of brucellosis (n = 15), group 2 contained sera samples from positive cases of brucellosis previously tested by conventional methods of RBPT (n = 28) and STAT (n = 26), group 3 contained sera samples negative by RBPT(n = 36) and STAT (n = 32), group 4 contained sera samples of other febrile illness and PUO case (n = 35) and group 5 contained confirmed negative sera samples from healthy donors (n = 23). The rOmp2a was found to be
Melé, Marta; Javed, Asif; Pybus, Marc; Zalloua, Pierre; Haber, Marc; Comas, David; Netea, Mihai G; Balanovsky, Oleg; Balanovska, Elena; Jin, Li; Yang, Yajun; Pitchappan, R M; Arunkumar, G; Parida, Laxmi; Calafell, Francesc; Bertranpetit, Jaume
2012-01-01
The information left by recombination in our genomes can be used to make inferences on our recent evolutionary history. Specifically, the number of past recombination events in a population sample is a function of its effective population size (Ne). We have applied a method, Identifying Recombination in Sequences (IRiS), to detect specific past recombination events in 30 Old World populations to infer their Ne. We have found that sub-Saharan African populations have an Ne that is approximately four times greater than those of non-African populations and that outside of Africa, South Asian populations had the largest Ne. We also observe that the patterns of recombinational diversity of these populations correlate with distance out of Africa if that distance is measured along a path crossing South Arabia. No such correlation is found through a Sinai route, suggesting that anatomically modern humans first left Africa through the Bab-el-Mandeb strait rather than through present Egypt.
Bozzini, Sabrina; Giuliano, Liliana; Altomare, Lina; Petrini, Paola; Bandiera, Antonella; Conconi, Maria Teresa; Farè, Silvia; Tanzi, Maria Cristina
2011-12-01
The use of polymers naturally occurring in the extracellular matrix (ECM) is a promising strategy in regenerative medicine. If compared to natural ECM proteins, proteins obtained by recombinant DNA technology have intrinsic advantages including reproducible macromolecular composition, sequence and molecular mass, and overcoming the potential pathogens transmission related to polymers of animal origin. Among ECM-mimicking materials, the family of recombinant elastin-like polymers is proposed for drug delivery applications and for the repair of damaged elastic tissues. This work aims to evaluate the potentiality of a recombinant human elastin-like polypeptide (HELP) as a base material of cross-linked matrices for regenerative medicine. The cross-linking of HELP was accomplished by the insertion of cross-linking sites, glutamine and lysine, in the recombinant polymer and generating ε-(γ-glutamyl) lysine links through the enzyme transglutaminase. The cross-linking efficacy was estimated by infrared spectroscopy. Freeze-dried cross-linked matrices showed swelling ratios in deionized water (≈2500%) with good structural stability up to 24 h. Mechanical compression tests, performed at 37°C in wet conditions, in a frequency sweep mode, indicated a storage modulus of 2/3 kPa, with no significant changes when increasing number of cycles or frequency. These results demonstrate the possibility to obtain mechanically resistant hydrogels via enzymatic crosslinking of HELP. Cytotoxicity tests of cross-linked HELP were performed with human umbilical vein endothelial cells, by use of transwell filter chambers for 1-7 days, or with its extracts in the opportune culture medium for 24 h. In both cases no cytotoxic effects were observed in comparison with the control cultures. On the whole, the results suggest the potentiality of this genetically engineered HELP for regenerative medicine applications, particularly for vascular tissue regeneration.
Zhou, Min; Kitagawa, Yoshinori; Yamaguchi, Mayu; Uchiyama, Chika; Itoh, Masae; Gotoh, Bin
2013-01-01
Human metapneumovirus (HMPV) is a common cause of respiratory diseases in persons of all ages. Because of its slow replication and weak cytopathic effect in cultured cells, conventional neutralization assays for HMPV require around one week for completion. The purpose of this study is to establish a rapid neutralization assay based on a recombinant virus expressing Renilla luciferase (Rluc). A recombinant HMPV expressing both Rluc and green fluorescent protein (GFP) was created by reverse genetics method. Two-fold serial dilutions of human 23 sera were made in a 96-well plate and incubated with 50 pfu/well of the recombinant virus at 4°C for 1 h. The mixtures were then transferred to LLC-MK2 cells in a 96-well plate, incubated for 2 h, and replaced with trypsin-free fresh media. After incubation at 32°C for 24 h, the cells were lysed and measured for Rluc activity. The neutralization titer was defined as the reciprocal of the highest serum dilution that resulted in 50% reduction of Rluc activity. The novel assay could be completed within 24 h and eliminated the requirement of trypsin supporting multistep replication in cultured cells, as well as laborious processes including the plaque assay with immunostaining. Neutralization titers correlated well with those determined by a GFP-based assay previously developed. The neutralization assay based on Rluc activity is the fastest and the most straightforward of all previous assays, and may be available for high throughput screening of neutralizing antibodies. Copyright © 2012 Elsevier B.V. All rights reserved.
Gabitzsch, Elizabeth S.; Tsang, Kwong Yok; Palena, Claudia; David, Justin M.; Fantini, Massimo; Kwilas, Anna; Rice, Adrian E.; Latchman, Yvette; Hodge, James W.; Gulley, James L.; Madan, Ravi A.; Heery, Christopher R.; Balint, Joseph P.
2015-01-01
Phenotypic heterogeneity of human carcinoma lesions, including heterogeneity in expression of tumor-associated antigens (TAAs), is a well-established phenomenon. Carcinoembryonic antigen (CEA), MUC1, and brachyury are diverse TAAs, each of which is expressed on a wide range of human tumors. We have previously reported on a novel adenovirus serotype 5 (Ad5) vector gene delivery platform (Ad5 [E1-, E2b-]) in which regions of the early 1 (E1), early 2 (E2b), and early 3 (E3) genes have been deleted. The unique deletions in this platform result in a dramatic decrease in late gene expression, leading to a marked reduction in host immune response to the vector. Ad5 [E1-, E2b-]-CEA vaccine (ETBX-011) has been employed in clinical studies as an active vaccine to induce immune responses to CEA in metastatic colorectal cancer patients. We report here the development of novel recombinant Ad5 [E1-, E2b-]-brachyury and-MUC1 vaccine constructs, each capable of activating antigen-specific human T cells in vitro and inducing antigen-specific CD4+ and CD8+ T cells in vaccinated mice. We also describe the use of a combination of the three vaccines (designated Tri-Ad5) of Ad5 [E1-, E2b-]-CEA, Ad5 [E1-, E2b-]-brachyury and Ad5 [E1-, E2b-]-MUC1, and demonstrate that there is minimal to no “antigenic competition” in in vitro studies of human dendritic cells, or in murine vaccination studies. The studies reported herein support the rationale for the application of Tri-Ad5 as a therapeutic modality to induce immune responses to a diverse range of human TAAs for potential clinical studies. PMID:26374823
Oh, Hye Ji; Moon, Hye Yun; Cheon, Seon Ah; Hahn, Yoonsoo; Kang, Hyun Ah
2016-10-01
O-linked β-N-acetylglucosamine (O-GlcNAc) glycosylation is an important post-translational modification in many cellular processes. It is mediated by O-GlcNAc transferases (OGTs), which catalyze the addition of O-GlcNAc to serine or threonine residues of the target proteins. In this study, we expressed a putative Yarrowia lipolytica OGT (YlOGT), the only homolog identified in the subphylum Saccharomycotina through bioinformatics analysis, and the human OGT (hOGT) as recombinant proteins in Saccharomyces cerevisiae, and performed their functional characterization. Immunoblotting assays using antibody against O-GlcNAc revealed that recombinant hOGT (rhOGT), but not the recombinant YlOGT (rYlOGT), undergoes auto-O-GlcNAcylation in the heterologous host S. cerevisiae. Moreover, the rhOGT expressed in S. cerevisiae showed a catalytic activity during in vitro assays using casein kinase II substrates, whereas no such activity was obtained in rYlOGT. However, the chimeric human-Y. lipolytica OGT, carrying the human tetratricopeptide repeat (TPR) domain along with the Y. lipolytica catalytic domain (CTD), mediated the transfer of O-GlcNAc moiety during the in vitro assays. Although the overexpression of full-length OGTs inhibited the growth of S. cerevisiae, no such inhibition was obtained upon overexpression of only the CTD fragment, indicating the role of TPR domain in growth inhibition. This is the first report on the functional analysis of the fungal OGT, indicating that the Y. lipolytica OGT retains its catalytic activity, although the physiological role and substrates of YlOGT remain to be elucidated.
Nandi, Somen; Yalda, Dorice; Lu, Stephen; Nikolov, Zivko; Misaki, Ryo; Fujiyama, Kazuhito; Huang, Ning
2005-06-01
In this paper, we show that recombinant human lactoferrin (rhLF) has been stably expressed at 0.5% brown rice flour weight for nine generations. Process development indicates that rhLF can be efficiently extracted from rice flour in 20 mM phosphate buffer (pH 7.0) containing up to 0.5 M NaCl and at a ratio of 1 kg flour to 10 L buffer. After solid/liquid separation, the extract can then be loaded directly onto an ion-exchange column and rhLF can be eluted using 0.8 M NaCl. The resulting rhLF is about 95% pure. A range of biochemical and biophysical analyses were carried out and results indicated that the purified rhLF was identical to its native human counterpart other than its glycosylation. Economic analysis shows that at 600 kg/year scale, the cash cost to produce 1 g of rhLF of pharmaceutical grade is US$ 5.90. Analysis also indicates that the expression level has profound impact on costs related to planting, milling, extraction and purification, thus high level expression of recombinant protein in plants is one of the key parameters for the success of plant made pharmaceuticals.
[Genetic evidence for recombination and mutation in the emergence of human enterovirus 71].
Liu, Ai-Ping; Tan, Hui; Xie, Qun; Chen, Bai-Tang; Liu, Xiao-Feng; Zhang, Yong
2014-09-01
We wished to understand the genetic recombination and phylogenetic characteristics of human en- terovirus A71 (EV-A71) and to explore its potential virulence-related sites. Full-length genomes of three EV-A71 strains isolated from patients in Chenzhou City (China) were sequenced and analyzed. Possible re- combination events and crossover sites were analyzed with Recombination Detection Program v4. 1. 6 by comparison with the complete genome sequences of 231 strains of EV-A71. Similarly, plot and bootscanning analyses were undertaken with SimPlot v3. 5. 1. Phylogenetic trees based on the sequences of VP1 regions were constructed with MEGA v5. 2 using the Kimura two-parameter model and neighbor-joining method. Results suggested that recombination events were detected among the three EV-A71 isolates from Chenzhou City. The common main parent sequence was from JF799986 isolated from samples in Guang- zhou City (China) in 2009, and the minor parent sequence was TW/70516/08. Intertypic recombination e- vents were found in the C4b strain (strain SHZH98 isolated in 1998) and C4a strain (Fuyang strain isola- ted in 2008) with the prototype strains of CVA4 and CVA14 in the 3D region. The chi-square test was used to screen-out potential virulence-related sites with nucleotide substitutions of different types of hand, foot, and mouth disease (HFMD) cases using SPSS v19.0. Results suggested that there were no significant nucleotide substitutions between death cases and severe-HFMD cases. Eighteen significant nucleotide substitutions were found between death/severe-HFMD cases and mild-HFMD cases, and all these 18 substitutions were distributed only in P2 and P3 regions. Intertypic recombination among the predominant circulating EV-A71 strains in the Chinese mainland and other EV-A strains probably dates before 1998, and intratypic recombination might have occurred frequently in the HFMD outbreak from 2008 to 2012. Substitutions in the non-capsid region may be correlated with the
Brar, Kanwaljit; Leung, Donald Y M
2016-01-01
Atopic dermatitis (AD) is the most common inflammatory skin disease in the general population. There are different endophenotypes of AD that likely have a unique immune and molecular basis, such as those who are predisposed to eczema herpeticum, or Staphylococcus aureus infections. In this review, we highlight the endophenotypes of AD where reduced interferon gamma expression may be playing a role. Additionally, we review the potential role of recombinant interferon gamma therapy in the treatment of atopic dermatitis and the particular phenotypes that may benefit from this treatment. Recombinant interferon gamma treatment will likely benefit the pediatric population with AD, as well as those with susceptibilities for skin infections. Future studies are needed to elucidate whether IFN-γ may reduce the prevalence of skin infection in AD.
Arif, Bahar; Ferhan, Karademir
2005-02-01
This study aimed to detect the effectiveness of recombinant human erythropoietin therapy in preventing premature anemia in low-birthweight preterm infants. A total of 292 premature infants who were born earlier than 33 gestational weeks and smaller than 1500 g birthweight were enrolled into the study. In addition to their conventional supportive therapy (medications), recombinant human erythropoietin 200 U/kg twice a week, subcutaneously, was given to randomly selected 142 premature infants for 6 weeks. The blood count variables and need for transfusions were compared with the remaining 150 premature infants during 6 months follow up. Serum erythropoietin levels were 11.3 +/- 6.1 mU/mL and 38.3 +/- 19.1 mU/mL in the erythropoietin group before and at the fourth week of the study, respectively (P < 0.001). Reticulocyte counts of the group treated with erythropoietin were 146 x 10(6) +/- 28 x 10(6)/mL and 122 x 10(6) +/- 27 x 10(6)/mL at the fourth and seventh week of the study, respectively, and these values were significantly higher when compared with the control group (P < 0.001 and P < 0.001). At the same period, hematocrit values were also found to be higher in the treatment group than the control group (P < 0.001). Serum ferritin levels were lower in the treatment group compared with the control group at the fourth week of the study. No side-effects related to erythropoietin usage were encountered. The need for packed cell transfusions were 47% in the group treated with erythropoietin and 62.6% in the control group. A statistically significant difference was found for transfusion needs between the control and treatment groups (P < 0.001). Recombinant erythropoietin is effective therapy for maintaining stable hematocrit levels in low-birthweight preterm infants and prevents the need for blood transfusions.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Atsmon, Jacob; Sackler Faculty of Medicine, Tel Aviv University; Brill-Almon, Einat
PRX-105 is a plant-derived recombinant version of the human ‘read-through’ acetylcholinesterase splice variant (AChE-R). Its active site structure is similar to that of the synaptic variant, and it displays the same affinity towards organophosphorus (OP) compounds. As such, PRX-105 may serve as a bio-scavenger for OP pesticides and chemical warfare agents. To assess its potential use in prophylaxis and treatment of OP poisoning we conducted several preliminary tests, reported in this paper. Intravenous (IV) PRX-105 was administered to mice either before or after exposure to an OP toxin. All mice who received an IV dose of 50 nmol/kg PRX-105, 2more » min before being exposed to 1.33 × LD{sub 50} and 1.5 × LD{sub 50} of toxin and 10 min after exposure to 1.5 × LD{sub 50} survived. The pharmacokinetic and toxicity profiles of PRX-105 were evaluated in mice and mini-pigs. Following single and multiple IV doses (50 to 200 mg/kg) no deaths occurred and no significant laboratory and histopathological changes were observed. The overall elimination half-life (t{sub ½}) in mice was 994 (± 173) min. Additionally, a first-in-human study, to assess the safety, tolerability and pharmacokinetics of the compound, was conducted in healthy volunteers. The t{sub ½} in humans was substantially longer than in mice (average 26.7 h). Despite the small number of animals and human subjects who were assessed, the fact that PRX-105 exerts a protective and therapeutic effect following exposure to lethal doses of OP, its favorable safety profile and its relatively long half-life, renders it a promising candidate for treatment and prophylaxis against OP poisoning and warrants further investigation. - Highlights: • PRX-105 is a PEGylated plant-derived recombinant human acetylcholinesterase-R. • PRX-105 is a promising bio-scavenger for organophosphorous toxins at lethal doses. • PRX-105 was shown to protect animals both prophylactically and post-poisoning. • First-in-human
Xu, Bingfang; Copolla, Michael; Herr, John C; Timko, Michael P
2007-01-01
The murine monoclonal antibody (mAB) S19 recognizes an N-linked carbohydrate antigen designated sperm agglutination antigen-1 (SAGA1) located on the membrane protein CD52. This antigen is added to the sperm surface during epididymal maturation. Binding of the S19 mAB to SAGA-1 causes the rapid agglutination of sperm and blocks pre-fertilization events. Previous studies indicated that the S19 mAB may be a potential specific spermicidal agent (termed a spermistatic) capable of replacing current spermicidal products that contain harsh detergents with harmful side effects. The nucleotide sequences encoding the heavy (H) and light (L) chains of the S19 antibody were cloned. A chimeric gene was constructed using the nucleotide sequences encoding the variable regions of both the H and L chains, and this gene (scFv1 9) was expressed in transgenic tobacco (Nicotiana tabacum L.) to produce a recombinant anti-sperm antibody (RASA). Highest levels of RASA expression were observed in BY-2 plant cell suspension cultures and regenerated N. tabacum cv. Xanthi plants transformant in which the RASA coding sequences were expressed under the control of the Cauliflower Mosaic Virus 35S promoter containing a double-enhancer sequence (2X CaMV 35S). Subsequent modifications of the transgene including the addition of a 5'-untranslated sequence from the tobacco etch virus (TEV leader sequence), N-terminal fusion of the coding region with an endoplasmic reticulum targeting signal of patatin (pat) and C-terminal fusion with the endoplasmic reticulum retention signal peptide KDEL showed further enhancement of RASA expression. The plant-expressed RASA formed intrachain disulfide bonds and was primarily soluble in the cytoplasmic fraction of the cells. Introduction of a poly-histidine (6xHIS) tag in the recombinant RASA protein allowed for rapid purification of the recombinant protein using Ni-NTA chromatography. Optimization of scale-up production and purification of this plant
Bian, Liujiao; Ji, Xu; Hu, Wei
2014-07-01
In this work, a novel method was established to isolate and purify Human plasminogen Kringle 5 (HPK5) as a histidine-tagged fusion protein expressed in Escherichia coli BL21 (DE3). This method consisted of sample extraction using a Ni-chelated Sepharose Fast-Flow affinity column, ammonium sulfate salting-out and Sephadex G-75 size-exclusion column in turn. The purity analysis by SDS-PAGE, high-performance size-exclusion and reversed-phase chromatographies showed that the obtained recombinant fusion HPK5 was homogeneous and its purity was higher than 96%; the activity analysis by chorioallantoic membrane model of chicken embryos revealed that the purified recombinant HPK5 exhibited an obvious anti-angiogenic activity under the effective range of 5.0-25.0 µg/mL. Through this procedure, about 19 mg purified recombinant fusion HPK5 can be obtained from 1 L of original fermentation solution. Approximate 32% of the total recombinant fusion HPK5 can be captured and the total yield was approximately 11%. Copyright © 2013 John Wiley & Sons, Ltd.
Bolton, Diane L; Santra, Sampa; Swett-Tapia, Cindy; Custers, Jerome; Song, Kaimei; Balachandran, Harikrishnan; Mach, Linh; Naim, Hussein; Kozlowski, Pamela A; Lifton, Michelle; Goudsmit, Jaap; Letvin, Norman; Roederer, Mario; Radošević, Katarina
2012-09-07
Licensed live attenuated virus vaccines capable of expressing transgenes from other pathogens have the potential to reduce the number of childhood immunizations by eliciting robust immunity to multiple pathogens simultaneously. Recombinant attenuated measles virus (rMV) derived from the Edmonston Zagreb vaccine strain was engineered to express simian immunodeficiency virus (SIV) Gag protein for the purpose of evaluating the immunogenicity of rMV as a vaccine vector in rhesus macaques. rMV-Gag immunization alone elicited robust measles-specific humoral and cellular responses, but failed to elicit transgene (Gag)-specific immune responses, following aerosol or intratracheal/intramuscular delivery. However, when administered as a priming vaccine to a heterologous boost with recombinant adenovirus serotype 5 expressing the same transgene, rMV-Gag significantly enhanced Gag-specific T lymphocyte responses following rAd5 immunization. Gag-specific humoral responses were not enhanced, however, which may be due to either the transgene or the vector. Cellular response priming by rMV against the transgene was highly effective even when using a suboptimal dose of rAd5 for the boost. These data demonstrate feasibility of using rMV as a priming component of heterologous prime-boost vaccine regimens for pathogens requiring strong cellular responses. Copyright © 2012 Elsevier Ltd. All rights reserved.
Miller, A M; Savinelli, E A; Couture, S M; Hannigan, G M; Han, Z; Selden, R F; Treco, D A
1993-01-01
Recombination walking is based on the genetic selection of specific human clones from a yeast artificial chromosome (YAC) library by homologous recombination. The desired clone is selected from a pooled (unordered) YAC library, eliminating labor-intensive steps typically used in organizing and maintaining ordered YAC libraries. Recombination walking represents an efficient approach to library screening and is well suited for chromosome-walking approaches to the isolation of genes associated with common diseases. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8367472
Xu, Jianping; Yan, Zhun; Guo, Hong
2009-06-01
The inheritance of mitochondrial genes and genomes are uniparental in most sexual eukaryotes. This pattern of inheritance makes mitochondrial genomes in natural populations effectively clonal. Here, we examined the mitochondrial population genetics of the emerging human pathogenic fungus Cryptococcus gattii. The DNA sequences for five mitochondrial DNA fragments were obtained from each of 50 isolates belonging to two evolutionary divergent lineages, VGI and VGII. Our analyses revealed a greater sequence diversity within VGI than that within VGII, consistent with observations of the nuclear genes. The combined analyses of all five gene fragments indicated significant divergence between VGI and VGII. However, the five individual genealogies showed different relationships among the isolates, consistent with recent hybridization and mitochondrial gene transfer between the two lineages. Population genetic analyses of the multilocus data identified evidence for predominantly clonal mitochondrial population structures within both lineages. Interestingly, there were clear signatures of recombination among mitochondrial genes within the VGII lineage. Our analyses suggest historical mitochondrial genome divergence within C. gattii, but there is evidence for recent hybridization and recombination in the mitochondrial genome of this important human yeast pathogen.
Daniloski, Zharko; Smith, Susan
2017-10-15
Sister chromatids are held together by cohesin, a tripartite ring with a peripheral SA1/2 subunit, where SA1 is required for telomere cohesion and SA2 for centromere cohesion. The STAG2 gene encoding SA2 is often inactivated in human cancer, but not in in a manner associated with aneuploidy. Thus, how these tumors maintain chromosomal cohesion and how STAG2 loss contributes to tumorigenesis remain open questions. Here we show that, despite a loss in centromere cohesion, sister chromatids in STAG2 mutant tumor cells maintain cohesion in mitosis at chromosome arms and telomeres. Telomere maintenance in STAG2 mutant tumor cells occurred by either telomere recombination or telomerase activation mechanisms. Notably, these cells were refractory to telomerase inhibitors, indicating recombination can provide an alternative means of telomere maintenance. STAG2 silencing in normal human cells that lack telomerase led to increased recombination at telomeres, delayed telomere shortening, and postponed senescence onset. Insofar as telomere shortening and replicative senescence prevent genomic instability and cancer by limiting the number of cell divisions, our findings suggest that extending the lifespan of normal human cells due to inactivation of STAG2 could promote tumorigenesis by extending the period during which tumor-driving mutations occur. Cancer Res; 77(20); 5530-42. ©2017 AACR . ©2017 American Association for Cancer Research.
Crow, J. Allen; Herring, Katye L.; Xie, Shuqi; Borazjani, Abdolsamad; Potter, Philip M.; Ross, Matthew K.
2009-01-01
Summary Two major isoforms of human carboxylesterases (CEs) are found in metabolically active tissues, CES1 and CES2. These hydrolytic enzymes are involved in xenobiotic and endobiotic metabolism. CES1 is abundantly expressed in human liver and monocytes/macrophages, including the THP1 cell line; CES2 is expressed in liver but not in monocytes/macrophages. The cholesteryl ester hydrolysis activity in human macrophages has been attributed to CES1. Here, we report the direct inhibitory effects of several endogenous oxysterols and fatty acids on the CE activity of THP1 monocytes/macrophages and recombinant human CES1 and CES2. Using THP1 whole-cell lysates we found: (1) 27-hydroxycholesterol (27-HC) is a potent inhibitor of carboxylesterase activity (IC50=33 nM); (2) 24(S),25-epoxycholesterol had moderate inhibitory activity (IC50=8.1 μM); and (3) cholesterol, 7-ketocholesterol, 22(R)-hydroxycholesterol, 24(S)-hydroxycholesterol, and 25-hydroxycholesterol each had little inhibitory activity. 27-HC was a partially noncompetitive inhibitor of recombinant CES1 (Kiapp=10 nM) and impaired intracellular CES1 activity following treatment of intact THP1 cells. In contrast, recombinant CES2 activity was not inhibited by 27-HC, suggesting isoform-selective inhibition by 27-HC. Furthermore, unsaturated fatty acids were better inhibitors of CES1 activity than saturated fatty acids, while CES2 activity was unaffected by any fatty acid. Arachidonic acid (AA) was the most potent fatty acid inhibitor of recombinant CES1 and acted by a noncompetitive mechanism (Kiapp=1.7 μM); when not complexed to albumin, exogenous AA penetrated intact THP1 cells and inhibited CES1. Inhibition results are discussed in light of recent structural models for CES1 that describe ligand binding sites separate from the active site. In addition, oxysterol-mediated inhibition of CES1 activity was demonstrated by pretreatment of human liver homogenates or intact THP1 cells with exogenous 27-HC, which
USDA-ARS?s Scientific Manuscript database
Recombinant adenovirus-5 vectored foot-and-mouth disease constructs (Ad5- FMD) were made for three Indian vaccine virus serotypes O,A and Asia 1. Constructs co-expressing foot-and- mouth disease virus (FMDV) capsid and viral 3C protease sequences, were evaluated for their ability to induce a neutral...
Recombinant Allergens in Structural Biology, Diagnosis, and Immunotherapy
Tscheppe, Angelika; Breiteneder, Heimo
2017-01-01
The years 1988–1995 witnessed the beginning of allergen cloning and the generation of recombinant allergens, which opened up new avenues for the diagnosis and research of human allergic diseases. Most crystal and solution structures of allergens have been obtained using recombinant allergens. Structural information on allergens allows insights into their evolutionary biology, illustrates clinically observed cross-reactivities, and makes the design of hypoallergenic derivatives for allergy vaccines possible. Recombinant allergens are widely used in molecule-based allergy diagnosis such as protein microarrays or suspension arrays. Recombinant technologies have been used to produce well-characterized, noncontaminated vaccine components with known biological activities including a variety of allergen derivatives with reduced IgE reactivity. Such recombinant hypoallergens as well as wild-type recombinant allergens have been used successfully in several immunotherapy trials for more than a decade to treat birch and grass pollen allergy. As a more recent application, the development of antibody repertoires directed against conformational epitopes during immunotherapy has been monitored by recombinant allergen chimeras. Although much progress has been made, the number and quality of recombinant allergens will undoubtedly increase and keep improving our knowledge in basic scientific investigations, diagnosis, and therapy of human allergic diseases. PMID:28467993
Population Demographic History Can Cause the Appearance of Recombination Hotspots
Johnston, Henry R.; Cutler, David J.
2012-01-01
Although the prevailing view among geneticists suggests that recombination hotspots exist ubiquitously across the human genome, there is only limited experimental evidence from a few genomic regions to support the generality of this claim. A small number of true recombination hotspots are well supported experimentally, but the vast majority of hotspots have been identified on the basis of population genetic inferences from the patterns of linkage disequilibrium (LD) seen in the human population. These inferences are made assuming a particular model of human history, and one of the assumptions of that model is that the effective population size of humans has remained constant throughout our history. Our results show that relaxation of the constant population size assumption can create LD and variation patterns that are qualitatively and quantitatively similar to human populations without any need to invoke localized hotspots of recombination. In other words, apparent recombination hotspots could be an artifact of variable population size over time. Several lines of evidence suggest that the vast majority of hotspots identified on the basis of LD information are unlikely to have elevated recombination rates. PMID:22560089
Recombination of Globally Circulating Varicella-Zoster Virus
Depledge, Daniel P.; Kundu, Samit; Atkinson, Claire; Brown, Julianne; Haque, Tanzina; Hussaini, Yusuf; MacMahon, Eithne; Molyneaux, Pamela; Papaevangelou, Vassiliki; Sengupta, Nitu; Koay, Evelyn S. C.; Tang, Julian W.; Underhill, Gillian S.; Grahn, Anna; Studahl, Marie; Breuer, Judith; Bergström, Tomas
2015-01-01
ABSTRACT Varicella-zoster virus (VZV) is a human herpesvirus, which during primary infection typically causes varicella (chicken pox) and establishes lifelong latency in sensory and autonomic ganglia. Later in life, the virus may reactivate to cause herpes zoster (HZ; also known as shingles). To prevent these diseases, a live-attenuated heterogeneous vaccine preparation, vOka, is used routinely in many countries worldwide. Recent studies of another alphaherpesvirus, infectious laryngotracheitis virus, demonstrate that live-attenuated vaccine strains can recombine in vivo, creating virulent progeny. These findings raised concerns about using attenuated herpesvirus vaccines under conditions that favor recombination. To investigate whether VZV may undergo recombination, which is a prerequisite for VZV vaccination to create such conditions, we here analyzed 115 complete VZV genomes. Our results demonstrate that recombination occurs frequently for VZV. It thus seems that VZV is fully capable of recombination if given the opportunity, which may have important implications for continued VZV vaccination. Although no interclade vaccine-wild-type recombinant strains were found, intraclade recombinants were frequently detected in clade 2, which harbors the vaccine strains, suggesting that the vaccine strains have already been involved in recombination events, either in vivo or in vitro during passages in cell culture. Finally, previous partial and complete genomic studies have described strains that do not cluster phylogenetically to any of the five established clades. The additional VZV strains sequenced here, in combination with those previously published, have enabled us to formally define a novel sixth VZV clade. IMPORTANCE Although genetic recombination has been demonstrated to frequently occur for other human alphaherpesviruses, herpes simplex viruses 1 and 2, only a few ancient and isolated recent recombination events have hitherto been demonstrated for VZV. In the
Beyond erythropoiesis: novel applications for recombinant human erythropoietin.
Cerami, A
2001-07-01
Erythropoietin (EPO) primarily is produced in the kidney and acts as a principal mediator of the physiologic response to hypoxia by increasing red blood cell production. Astrocytes and neurons in the central nervous system (CNS) also are known to produce EPO in response to hypoxia/ischemia. EPO appears to play a neuroprotective role based on preclinical data demonstrating the ability of recombinant human erythropoietin (r-HuEPO) to shield neurons from hypoxic/ischemic stress when administered intracerebraventricularly. In CNS models, systemically administered r-HuEPO has not been intensely investigated because large glycosylated molecules generally were deemed incapable of crossing the blood-brain barrier (BBB). A collaborative research effort identified expression of EPO receptors on human brain capillaries and a specific receptor-mediated transport of r-HuEPO across the BBB after a single intraperitoneal (IP) injection in rodents, with subsequent protection against various types of neuronal damage. For example, administration of r-HuEPO 24 hours before or up to 6 hours after focal ischemic stroke significantly reduced the extent of infarction. r-HuEPO also attenuated concussive brain injury, kainate-induced seizure activity, and autoimmune encephalomyelitis. These preclinical findings suggest that r-HuEPO may have therapeutic potential for stroke, head trauma, and epilepsy; additional studies are needed to confirm and extend these encouraging observations in animal models. Copyright 2001 by W.B. Saunders Company.
One single method to produce native and Tat-fused recombinant human α-synuclein in Escherichia coli.
Caldinelli, Laura; Albani, Diego; Pollegioni, Loredano
2013-04-04
Human α-synuclein is a small-sized, natively unfolded protein that in fibrillar form is the primary component of Lewy bodies, the pathological hallmark of Parkinson's disease. Experimental evidence suggests that α-synuclein aggregation is the key event that triggers neurotoxicity although additional findings have proposed a protective role of α-synuclein against oxidative stress. One way to address the mechanism of this protective action is to evaluate α-synuclein-mediated protection by delivering this protein inside cells using a chimeric protein fused with the Tat-transduction domain of HIV Tat, named TAT-α-synuclein. A reliable protocol was designed to efficiently express and purify two different forms of human α-synuclein. The synthetic cDNAs encoding for the native α-synuclein and the fusion protein with the transduction domain of Tat protein from HIV were overexpressed in a BL21(DE3) E. coli strain as His-tagged proteins. The recombinant proteins largely localized (≥ 85%) to the periplasmic space. By using a quick purification protocol, based on recovery of periplasmic space content and metal-chelating chromatography, the recombinant α-synuclein protein forms could be purified in a single step to ≥ 95% purity. Both α-synuclein recombinant proteins form fibrils and the TAT-α-synuclein is also cytotoxic in the micromolar concentration range. To further characterize the molecular mechanisms of α-synuclein neurotoxicity both in vitro and in vivo and to evaluate the relevance of extracellular α-synuclein for the pathogenesis and progression of Parkinson's disease, a suitable method to produce different high-quality forms of this pathological protein is required. Our optimized expression and purification procedure offers an easier and faster means of producing different forms (i.e., both the native and the TAT-fusion form) of soluble recombinant α-synuclein than previously described procedures.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vita, N.; Magazin, M.; Marchese, E.
We report here the study of the glycosylation pattern of human recombinant (r) IL2 expressed in a Chinese hamster ovary (CHO) cell line. The human rIL2 secreted by this high-producing recombinant CHO cell line was metabolically radiolabelled with (35S)-methionine, or with (3H)-glucosamine and (3H)-galactose, purified to homogeneity, and then characterized. The electrophoretic analysis of the (35S)-methionine-labelled proteins present in the culture medium of the CHO cell line showed that the rIL2 represents approximately 12% of the total secreted proteins. Furthermore, pulse-chase experiments showed that the glycosylated rIL2 is synthesized and secreted within 30 min. The point of attachment and themore » structure of the carbohydrate moiety of the rIL2 was determined by: amino-terminal sequencing and fingerprint analysis of the 3H-labelled rIL2, mass spectroscopy of the amino-terminal tryptic octapeptide, and carbohydrate analysis after enzymatic (Vibrio cholerae neuraminidase and Aspergillus oryzae beta-galactosidase) or sulfuric acid hydrolysis. The results indicate that the recombinant protein possesses a sugar moiety O-linked to the threonine residue at position 3 of the polypeptide chain, and that sialic acid, galactose and N-acetyl galactosamine are components of this carbohydrate moiety. Taken together these results suggest that the recombinant molecule is identical to natural IL2.« less
Abramczyk, Olga; Tavares, Clint D. J.; Devkota, Ashwini K.; Ryazanov, Alexey G.; Turk, Benjamin E.; Riggs, Austen F.; Ozpolat, Bulent; Dalby, Kevin N.
2012-01-01
The eukaryotic elongation factor 2 kinase (eEF-2K) modulates the rate of protein synthesis by impeding the elongation phase of translation by inactivating the eukaryotic elongation factor 2 (eEF-2) via phosphorylation. eEF-2K is known to be activated by calcium and calmodulin, whereas the mTOR and MAPK pathways are suggested to negatively regulate kinase activity. Despite its pivotal role in translation regulation and potential role in tumor survival, the structure, function and regulation of eEF-2K have not been described in detail. This deficiency may result from the difficulty of obtaining the recombinant kinase in a form suitable for biochemical analysis. Here we report the purification and characterization of recombinant human eEF-2K expressed in the Escherichia coli strain Rosetta-gami 2(DE3). Successive chromatography steps utilizing Ni-NTA affinity, anion-exchange and gel filtration columns accomplished purification. Cleavage of the thioredoxin-His6-tag from the N-terminus of the expressed kinase with TEV protease yielded 9 mg of recombinant (G-D-I)-eEF-2K per liter of culture. Light scattering shows that eEF-2K is a monomer of ~ 85 kDa. In vitro kinetic analysis confirmed that recombinant human eEF-2K is able to phosphorylate wheat germ eEF-2 with kinetic parameters comparable to the mammalian enzyme. PMID:21605678
Esipov, Roman S; Stepanenko, Vasily N; Gurevich, Alexandr I; Chupova, Larisa A; Miroshnikov, Anatoly I
2006-01-01
Chemico-enzymatic synthesis and cloning in Esherichia coli of an artificial gene coding human glucagon was performed. Recombinant plasmid containing hybrid glucagons gene and intein Ssp dnaB from Synechocestis sp. was designed. Expression of the obtained hybrid gene in E. coli, properties of the formed hybrid protein, and conditions of its autocatalytic cleavage leading to glucagon formation were studied.
Khamrin, Pattara; Okitsu, Shoko; Ushijima, Hiroshi; Maneekarn, Niwat
2013-07-01
Epidemiological surveillance of human bocavirus (HBoV) was conducted on fecal specimens collected from hospitalized children with diarrhea in Chiang Mai, Thailand in 2011. By partial sequence analysis of VP1 gene, an unusual strain of HBoV (CMH-S011-11), was initially identified as HBoV4. The complete genome sequence of CMH-S011-11 was performed and analyzed further to clarify whether it was a recombinant strain or a new HBoV variant. Analysis of complete genome sequence revealed that the coding sequence starting from NS1, NP1 to VP1/VP2 was 4795 nucleotides long. Interestingly, the nucleotide sequence of NS1 gene of CMH-S011-11 was most closely related to the HBoV2 reference strains detected in Pakistan, which contradicted to the initial genotyping result of the partial VP1 region in the previous study. In addition, comparison of NP1 nucleotide sequence of CMH-S011-11 with those of other HBoV1-4 reference strains also revealed a high level of sequence identity with HBoV2. On the other hand, nucleotide sequence of VP1/VP2 gene of CMH-S011-11 was most closely related to those of HBoV4 reference strains detected in Nigeria. The overall full-length sequence analysis revealed that this CMH-S011-11 was grouped within HBoV4 species, but located in a separate branch from other HBoV4 prototype strains. Recombination analysis revealed that CMH-S011-11 was the result of recombination between HBoV2 and HBoV4 strains with the break point located near the start codon of VP2. Copyright © 2013 Elsevier B.V. All rights reserved.
Gao, Rong-Bao; Li, Yan-Qiu; Wang, Ming-Li
2006-06-01
To construct eucaryotic expression recombinant vector containing vivo truncated region of UL83 gene of human cytomegalovirus, realize its steady expression in Hep-2 cell, and study sheltered effect of the eucaryotic expression recombinant vector as DNA vaccine. A vivo truncated UL83 gene fragment encoding for truncated HCMV pp65 was obtained by PCR from human cytomegalovirus AD169 stock genome. By gene recombinant ways, the truncated UL83 gene fragment was cloned into eucaryotic expression vector pEGFP-C1 with reported gene coding GFP to construct recombinant vector pEGFP-C1-UL83. The recombinant vector pEGFP-C1-UL83 was tested by different methods including PCR, restriction digestion and gene sequencing. Test results showed the recombinant vector was constructed successfully. After pEGFP-C1-UL83 was transfected into Hep-2 cell by lipofectin mediation, expression of GFP and truncated pp65 fusion protein in Hep-2 cell was observed at different time points by fluorescence microscope. Results showed that quantity of fusion protein expression was the highest at 36h point. Then, Hep-2 cell was cultured selectively by RPMI-1640 containing G418 (200 microg/mL) to obtain a new cell stock of expressing truncated UL83 Gene fragment steadily. RT-PCR and Western blot results showed the truncated fragment of UL83 gene could be expressed steadily in Hep-2 cell. The result showed a new cell stock of expressing Tpp65 was established. This cell stock could be useful in some HCMV research fields, for example, it could be a tool in study of pp65 and HCMV infection, and it could provide a platform for the research into the therapy of HCMV infection. Immune sheltered effect of pEGFP-C1-UL83 as DNA vaccine was studied in vivo of HCMV congenital infection mouse model. The mouse model was immunized solely by pEGFP-C1-UL83, and was immunized jointly by pEGFP-C1-UL83 and its expression product. When the mouse was pregnant and brought to bed, differential antibody of anti-HCMV pp65 was
Lu, Dan; Liu, Shen; Shang, Shengzhe; Wu, Fangfang; Wen, Xiao; Li, Zhiyuan; Li, Yan; Hu, Xiaoxiang; Zhao, Yaofeng; Li, Qiuyan; Li, Ning
2015-01-01
Human lysozyme is a natural non-specific immune factor in human milk that plays an important role in the defense of breastfed infants against pathogen infection. Although lysozyme is abundant in human milk, there is only trace quantities in pig milk. Here, we successfully generated transgenic cloned pigs with the expression vector pBAC-hLF-hLZ-Neo and their first generation hybrids (F1). The highest concentration of recombinant human lysozyme (rhLZ) with in vitro bioactivity was 2759.6 ± 265.0 mg/L in the milk of F0 sows. Compared with wild-type milk, rhLZ milk inhibited growth of Escherichia coli K88 during the exponential growth phase. Moreover, rhLZ in milk from transgenic sows was directly absorbed by the intestine of piglets with no observable anaphylactic reaction. Our strategy may provide a powerful tool for large-scale production of this important human protein in pigs to improve resistance to pathogen infection.
Smukowski Heil, Caiti S; Ellison, Chris; Dubin, Matthew; Noor, Mohamed A F
2015-10-01
Meiotic recombination rate varies across the genome within and between individuals, populations, and species in virtually all taxa studied. In almost every species, this variation takes the form of discrete recombination hotspots, determined in some mammals by a protein called PRDM9. Hotspots and their determinants have a profound effect on the genomic landscape, and share certain features that extend across the tree of life. Drosophila, in contrast, are anomalous in their absence of hotspots, PRDM9, and other species-specific differences in the determination of recombination. To better understand the evolution of meiosis and general patterns of recombination across diverse taxa, we present a truly comprehensive portrait of recombination across time, combining recently published cross-based contemporary recombination estimates from each of two sister species with newly obtained linkage-disequilibrium-based historic estimates of recombination from both of these species. Using Drosophila pseudoobscura and Drosophila miranda as a model system, we compare recombination rate between species at multiple scales, and we suggest that Drosophila replicate the pattern seen in human-chimpanzee in which recombination rate is conserved at broad scales. We also find evidence of a species-wide recombination modifier(s), resulting in both a present and historic genome-wide elevation of recombination rates in D. miranda, and identify broad scale effects on recombination from the presence of an inversion. Finally, we reveal an unprecedented view of the distribution of recombination in D. pseudoobscura, illustrating patterns of linked selection and where recombination is taking place. Overall, by combining these estimation approaches, we highlight key similarities and differences in recombination between Drosophila and other organisms. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Jing, Pei; Cao, Shousong; Xiao, Shuangli; Zhang, Xiaoqin; Ke, Siyun; Ke, Famin; Yu, Xin; Wang, Li; Wang, Shurong; Luo, Yuling; Zhong, Zhirong
2016-12-28
The peptide aptamer DUP-1 targets prostate-specific membrane antigen (PSMA)-negative cells, while the RNA aptamer A10-3.2 targets PSMA-positive prostate cancer cells. Moreover, the tumor-suppressor gene phosphatase and tensin homolog (PTEN) and the chemotherapeutic agent doxorubicin (DOX) effectively inhibit prostate cancer, and a recombinant adenovirus (Ad5) mediates high gene transfer efficiency. Here, we design a dual-aptamer modified tumor targeting gene and DOX delivery system mediated by recombinant adenovirus (A10-3.2(DOX)/DUP-1-PEG-Ad5, ADDP-Ad5). DUP-1 and A10-3.2 are connected to the adenovirus through polyethylene glycol (PEG), PTEN is integrated into Ad5, and DOX is embedded into the double chain of aptamer A10-3.2. The PEG-modification rate of Ad5 is 98.70 ± 2.43%. The DUP-1 and A10-3.2 modified products yield 80.40 ± 1.36% and 82.20 ± 2.14%, respectively. The uptake of ADDP-Ad5 and the expression of the reporter gene are enhanced by the system in PSMA-positive LNCaP and PSMA-negative PC3 human prostate cancer cells. ADDP-Ad5 significantly inhibits the cell growth of both LNCaP and PC3 cells. More importantly, ADDP-Ad5 is active in vivo against LNCaP and PC3 tumor xenografts and exhibits no significant toxicity to the mice. Therefore, ADDP-Ad5 may have clinical potential in prostate cancer therapy. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Li, Xiaofeng; Suhar, Tom; Glass, Lateca; Rajaraman, Ganesh
2014-03-03
Enzyme reaction phenotyping is employed extensively during the early stages of drug discovery to identify the enzymes responsible for the metabolism of new chemical entities (NCEs). Early identification of metabolic pathways facilitates prediction of potential drug-drug interactions associated with enzyme polymorphism, induction, or inhibition, and aids in the design of clinical trials. Incubation of NCEs with human recombinant enzymes is a popular method for such work because of the specificity, simplicity, and high-throughput nature of this approach for phenotyping studies. The availability of a relative abundance factor and calculated intersystem extrapolation factor for the expressed recombinant enzymes facilitates easy scaling of in vitro data, enabling in vitro-in vivo extrapolation. Described in this unit is a high-throughput screen for identifying enzymes involved in the metabolism of NCEs. Emphasis is placed on the analysis of the human recombinant enzymes CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2B6, and CYP3A4, including the calculation of the intrinsic clearance for each. Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.
Carulli, G; Lazzeri, E; Lagomarsini, G; Zucca, A; Cannizzo, E; Riccioni, R; Petrini, M
2007-01-01
A 55-year-old female was admitted with fever which followed an episode of pseudomembranous colitis. Despite an accurate clinical investigation, there was no evidence for specific sites of infection. Remission of fever was not obtained with antibiotic therapy (gentamycin plus carbepenem) and progressive neutropenia was observed. Neutrophils fell to 0.3 x 10(9)/1. The diagnostic approach, including a bone marrow aspirate, excluded mechanisms leading to impaired neutrophil production, and in the suspect of increased neutrophil sequestration/destruction, whole-body scintigraphy with (99m)technetium-hexamethylpropyleneamineoxime ((99m)Tc-HMPAO)-labeled autologous leukocytes was performed. As a result, a site of leukocyte sequestration localized at the medium lobe of the right lung was detected. In an attempt to enhance neutrophil functions and achieve remission of infection, recombinant human granulocyte colony-stimulating factor (Filgrastim, Granulokine 30, Roche) at the dosage of 300 microg/day, subcutaneously, was added. As a results, fever disappeared in three days, but neutrophil recovery was slower, and normalization of the absolute neutrophil count (ANC) was obtained on day +7. The results obtained in this peculiar case of neutropenia, and the kinetics of both fever and ANC, suggest the possible combination of neutrophil function enhancement and an anti-inflammatory effect of rhG-CSF.
Yamasaki, Hiroshi; Araki, Kunioki; Lim, Patricia Kim Chooi; Zasmy, Ngah; Mak, Joon Wah; Taib, Radzan; Aoki, Takashi
2000-01-01
The specificity of the recombinant Toxocara canis antigen developed for the immunodiagnosis of human toxocariasis was compared with that of the excretory-secretory antigen from T. canis second-stage larvae (TES) by enzyme-linked immunosorbent assay. A total of 153 human serum samples from patients infected with 20 different helminths, including 11 cases of toxocariasis, were examined. No false-negative reactions were observed for the toxocariasis cases. When the TES was used at concentrations of 0.5 and 0.125 μg/ml, cross-reactions were observed in 79 (55.6%) and 61 (43.0%) of 142 cases, respectively. In contrast, when the recombinant antigen was tested at a concentration of 0.5 μg/ml, cross-reactions were observed in 19 (13.4%) of 142 cases. At a concentration of 0.125 μg/ml, however, the cross-reaction rate decreased sharply to only 2.1%, corresponding to 3 of 142 cases. The cross-reactions occurred with one case each of gnathostomiasis, paragonimiasis with Paragonimus miyazakii, and spirometriasis, in which high antibody titers were detected. In addition, the recombinant antigen showed negative reactions with serum samples from patients infected with Ascaris and hookworms, which are the most common parasites in the world. These findings are also supported by experiments with animals infected with Ascaris and hookworm. From these results, the recombinant antigen is highly specific for toxocariasis and may provide more reliable diagnostic results than other methods. PMID:10747116
Cherubini, Gioia; Naim, Valeria; Caruso, Paola; Burla, Romina; Bogliolo, Massimo; Cundari, Enrico; Benihoud, Karim; Saggio, Isabella; Rosselli, Filippo
2011-01-01
Deciphering the crosstalk between a host cell and a virus during infection is important not only to better define viral biology but also to improve our understanding of cellular processes. We identified the FANC pathway as a helper of viral replication and recombination by searching for cellular targets that are modified by adenovirus (Ad) infection and are involved in its outcome. This pathway, which is involved in the DNA damage response and checkpoint control, is altered in Fanconi anaemia, a rare cancer predisposition syndrome. We show here that Ad5 infection activates the FANC pathway independent of the classical DNA damage response. Infection with a non-replicating Ad shows that the presence of viral DNA is not sufficient to induce the monoubiquitination of FANCD2 but still activates the DNA damage response coordinated by phospho-NBS1 and phospho-CHK1. E1A expression alone fails to induce FANCD2 monoubiquitination, indicating that a productive viral infection and/or replication is required for FANC pathway activation. Our data indicate that Ad5 infection induces FANCD2 activation to promote its own replication. Specifically, we show that FANCD2 is involved in the recombination process that accompanies viral DNA replication. This study provides evidence of a DNA damage-independent function of the FANC pathway and identifies a cellular system involved in Ad5 recombination. PMID:21421559
Bacteriophage recombination systems and biotechnical applications.
Nafissi, Nafiseh; Slavcev, Roderick
2014-04-01
Bacteriophage recombination systems have been widely used in biotechnology for modifying prokaryotic species, for creating transgenic animals and plants, and more recently, for human cell gene manipulation. In contrast to homologous recombination, which benefits from the endogenous recombination machinery of the cell, site-specific recombination requires an exogenous source of recombinase in mammalian cells. The mechanism of bacteriophage evolution and their coexistence with bacterial cells has become a point of interest ever since bacterial viruses' life cycles were first explored. Phage recombinases have already been exploited as valuable genetic tools and new phage enzymes, and their potential application to genetic engineering and genome manipulation, vectorology, and generation of new transgene delivery vectors, and cell therapy are attractive areas of research that continue to be investigated. The significance and role of phage recombination systems in biotechnology is reviewed in this paper, with specific focus on homologous and site-specific recombination conferred by the coli phages, λ, and N15, the integrase from the Streptomyces phage, ΦC31, the recombination system of phage P1, and the recently characterized recombination functions of Yersinia phage, PY54. Key steps of the molecular mechanisms involving phage recombination functions and their application to molecular engineering, our novel exploitations of the PY54-derived recombination system, and its application to the development of new DNA vectors are discussed.
Tu, Ming-li; Wang, Han-qin; Lei, Huai-ding; Luo, Guo-shi; Liu, Xian-jun; Liu, Wei-shun; Xiong, Chang; Liu, Yu-quan; Ren, Si-qun
2005-04-01
To investigate the effect of human angiotensin II (AngII) type 1 receptor (AT(1)R) antisense cDNA (ahAT(1)) on migration, proliferation, and apoptosis of cultured human pulmonary artery smooth muscle cells (PASMC). Two recombinant adenoviral vectors, AdCMVahAT(1) containing full length antisense cDNA targeting to human AT(1)R mRNA, and AdCMVLacZ containing LacZ, were constructed by orientation clone technology and homologous recombination. The PASMC was divided into 3 groups (DMEM, AdCMVLacZ, AdCMVahAT(1)) and different interventions were given to different groups. AT(1)R expression was detected by RT-PCR and immunohistochemistry method; migration of PASMC was measured by Boyden's Chamer method. Other PASMC was divided into 4 groups (DMEM, AngII, AdCMVLacZ + AngII and AdCMVahAT(1) + AngII), and only the last 2 groups were respectively transfected with AdCMVLacZ and AdCMVahAT(1) before administration of AngII. From 6 h to 96 h after stimulation by AngII (10(-7) mol/L), proliferation index (PI) and apoptosis of PASMC were determined by flow cytometry. At the 48 h the level of AT(1)R mRNA was significantly less in PASMC transfected AdCMVahAT(1) than that in group DMEM and in group AdCMVLacZ. The protein level showed a same difference (P < 0.01). At 24 h the migration distance of PASMC also was significantly less in group AdCMVahAT(1) than that in group DMEM and Group AdCMVLacZ (P < 0.01). Stimulated by AngII for 48 h, in group AngII the PI of PASMC markedly increased (P < 0.01 vs group DMEM). But in Group AdCMVahAT(1) + AngII PI of PASMC clearly decreased (P < 0.01 vs group AngII and group DMEM respectively). There was no statistic difference of PI between group AdCMVLacZ + AngII and group AngII. Moreover, apoptosis peak emerged only in group AdCMVahAT(1) + AngII. The rate of apoptosis in those PASMC used AdCMVahAT(1) and AngII was 24.70 +/- 4.04 (P < 0.01 vs the other 3 groups respectively). These results indicate that AngII stimulates proliferation via AT(1
Kim, Ha-Hyun; Yang, Dong-Kun; Nah, Jin-Ju; Song, Jae-Young; Cho, In-Soo
2017-06-24
Rabies is an important viral zoonosis that causes acute encephalitis and death in mammals. To date, several recombinant vaccines have been developed based on G protein, which is considered to be the main antigen, and these vaccines are used for rabies control in many countries. Most recombinant viruses expressing RABV G protein retain the G gene from attenuated RABV. Not enough is currently known about the protective effect against RABV of a combination of recombinant adenoviruses expressing the G and N proteins of pathogenic street RABV. We constructed a recombinant adenovirus (Ad-0910Gsped) expressing the signal peptide and ectodomain (sped) of G protein of the Korean street strain, and evaluated the immunological protection conferred by a single and combination of three kinds of recombinant adenoviruses (Ad-0910Gsped and Ad-0910G with or without Ad-0910 N) in mice. A combination of Ad-0910G and Ad-0910 N conferred improved immunity against intracranial challenge compared to single administration of Ad-0910G. The Ad-0910G virus, expressing the complete G protein, was more immunogenic than Ad-0910Gsped, which expressed a truncated G protein with the transmembrane and cytoplasmic domains removed. Additionally, oral vaccination using a combination of viruses led to complete protection. Our results suggest that this combination of viruses is a viable new intramuscular and oral vaccine candidate.
Targeting vector construction through recombineering.
Malureanu, Liviu A
2011-01-01
Gene targeting in mouse embryonic stem cells is an essential, yet still very expensive and highly time-consuming, tool and method to study gene function at the organismal level or to create mouse models of human diseases. Conventional cloning-based methods have been largely used for generating targeting vectors, but are hampered by a number of limiting factors, including the variety and location of restriction enzymes in the gene locus of interest, the specific PCR amplification of repetitive DNA sequences, and cloning of large DNA fragments. Recombineering is a technique that exploits the highly efficient homologous recombination function encoded by λ phage in Escherichia coli. Bacteriophage-based recombination can recombine homologous sequences as short as 30-50 bases, allowing manipulations such as insertion, deletion, or mutation of virtually any genomic region. The large availability of mouse genomic bacterial artificial chromosome (BAC) libraries covering most of the genome facilitates the retrieval of genomic DNA sequences from the bacterial chromosomes through recombineering. This chapter describes a successfully applied protocol and aims to be a detailed guide through the steps of generation of targeting vectors through recombineering.
Dinarello, C A; O'Connor, J V; LoPreste, G; Swift, R L
1984-01-01
Human growth hormone is biosynthetically produced in recombinant strains of Escherichia coli as methionyl human growth hormone (met-hGH). When purified from the bacterial culture, met-hGH is biologically active in established assays for growth hormone. Therefore, a phase I trial of met-hGH was carried out in healthy human adults; during the first trial, however, signs, symptoms, and clinical laboratory tests characteristic of an acute-phase response to pyrogenic agents was observed. Prior testing of the met-hGH preparation used in the phase I trial did not reveal evidence of toxicity, and the U.S. Pharmacopeial Convention rabbit pyrogen test, as well as the Limulus amoebocyte lysate (LAL) test, had not detected significant levels of exogenous pyrogens or endotoxin. In addition, standard inhibition studies with added endotoxin showed no inhibition by the LAL test. When this preparation of met-hGH was incubated with human blood mononuclear cells, leukocytic pyrogen (LP) was released into the supernatant medium, suggesting that the preparation contained pyrogenic material. Various lots of met-hGH based on different purification and formulating methods were tested by the human LP assay for contaminating pyrogens. The results of these tests aided in the identification of procedures for met-hGH preparations which did not induce LP in vitro. Thus, subsequent lots of met-hGH which had passed the LP test were used in repeat clinical studies, and no inflammatory or pyrogenic reactions were observed. When the LP test was used, experiments revealed that the original lot of met-hGH was contaminated with endotoxin which had not been detected in the LAL or rabbit pyrogen tests. Lyophilization in glycine-phosphate buffer had resulted in a 10- to 20-fold reduction of endotoxin reactivity in the LAL test and the U.S. Pharmacopeial Convention rabbit pyrogen test. These data provide a probable explanation for the negative result from the LAL and rabbit pyrogen test in the initial lot
USDA-ARS?s Scientific Manuscript database
Recombinant human Growth Hormone (rhGH) has been in use for 30 years, and over that time its safety and efficacy in children and adults has been subject to considerable scrutiny. In 2001, a statement from the GH Research Society (GRS) concluded that 'for approved indications, GH is safe'; however, t...
Tan, Yongjun; Adami, Guy; Costa, Robert H
2002-04-01
The hepatocyte nuclear factor 3 (HNF-3) proteins are members of the Forkhead Box (Fox) family of transcription factors that play important roles in regulating expression of genes involved in cellular proliferation, differentiation, and metabolic homeostasis. In previous studies we increased liver expression of HNF-3beta by using either transgenic mice (transthyretin HNF-3beta) or recombinant adenovirus infection (AdHNF3beta), and observed diminished hepatic levels of glycogen, and glucose transporter 2 (Glut-2), as well as the HNF-6, HNF-3, HNF-1alpha, HNF-4alpha, and C/EBPalpha transcription factors. We conducted the present study to determine whether maintaining HNF-6 protein expression during AdHNF3beta infection prevents reduction of hepatic levels of glycogen and the earlier-mentioned genes. Here, we show that AdHNF3beta- and AdHNF6-infected mouse liver displayed increased hepatic levels of glycogen, Glut-2, HNF-3gamma, HNF-1alpha, and HNF-4alpha at 2 and 3 days postinfection (PI). Furthermore, restoration of hepatic glycogen levels after AdHNF3beta and AdHNF6 coinfection was associated with increased Glut-2 expression. AdHNF6 infection alone caused a 2-fold increase in hepatic Glut-2 levels, suggesting that HNF 6 stimulates in vivo transcription of the Glut-2 gene. DNA binding assays showed that only recombinant HNF-6 protein, but not the HNF-3 proteins, binds to the mouse -185 to -144 bp Glut-2 promoter sequences. Cotransfection assays in human hepatoma (HepG2) cells with either HNF-3 or HNF-6 expression vectors show that only HNF-6 provided significant transcriptional activation of the Glut-2 promoter. In conclusion, these studies show that the hepatic Glut-2 promoter is a direct target for HNF-6 transcriptional activation.
Li, Ming; Fan, Hua; Liu, Jiahua; Wang, Minhong; Wang, Lili; Wang, Chaozhan
2012-03-01
Recombinant human granulocyte colony-stimulating factor (rhG-CSF) is a very efficient therapeutic protein drug which has been widely used in human clinics to treat cancer patients suffering from chemotherapy-induced neutropenia. In this study, rhG-CSF was solubilized from inclusion bodies by using a high-pH solution containing low concentration of urea. It was found that solubilization of the rhG-CSF inclusion bodies greatly depended on the buffer pH employed; alkalic pH significantly favored the solubilization. In addition, when small amount of urea was added to the solution at high pH, the solubilization was further enhanced. After solubilization, the rhG-CSF was renatured with simultaneous purification by using weak anion exchange, strong anion exchange, and hydrophobic interaction chromatography, separately. The results indicated that the rhG-CSF solubilized by the high-pH solution containing low concentration of urea had much higher mass recovery than the one solubilized by 8 M urea when using anyone of the three refolding methods employed in this work. In the case of weak anion exchange chromatography, the high pH solubilized rhG-CSF could get a mass recovery of 73%. The strategy of combining solubilization of inclusion bodies at high pH with refolding of protein using liquid chromatography may become a routine method for protein production from inclusion bodies.
The use of recombinant human erythropoietin in lung transplantation.
End, A; Stift, A; Ringl, H; Inhauser, T; Grimm, M; Geissler, K; Stockenhuber, F; Klepetko, W
1995-01-01
Recombinant human erythropoietin (r-HuEPO) was administered in 4 lung transplant recipients to treat chronic anemia beyond the immediate postoperative period. There were 2 males and 2 females with a mean age of 38 years (range 22-49). None of the patients had major infection or rejection problems, and no blood products were used. Because of different individual responses duration of therapy was 1 to 17 weeks (median 5) with a total dosage ranging from 8 to 36 x 10(3) IU (mean 21 x 10(3)). The median single dose was 58 IU/kg (range 36-100). Hemoglobin levels increased significantly from 9.1 +/- 0.2 to 12.7 +/- 0.3 g/dl (mean +/- SE; p < 0.01). There were no side effects. r-HuEPO is recommended in treatment of chronic anemia in lung transplant patients to save blood products and to exclude the potential risk of transfusion-transmitted viral infections.
NASA Astrophysics Data System (ADS)
Sanna, Pietro Paolo; Williamson, R. Anthony; de Logu, Alessandro; Bloom, Floyd E.; Burton, Dennis R.
1995-07-01
Human monoclonal antibodies have considerable potential in the prophylaxis and treatment of viral disease. However, only a few such antibodies suitable for clinical use have been produced to date. We have previously shown that large panels of human recombinant monoclonal antibodies against a plethora of infectious agents, including herpes simplex virus types 1 and 2, can be established from phage display libraries. Here we demonstrate that facile cloning of recombinant Fab fragments against specific viral proteins in their native conformation can be accomplished by panning phage display libraries against viral glycoproteins "captured" from infected cell extracts by specific monoclonal antibodies immobilized on ELISA plates. We have tested this strategy by isolating six neutralizing recombinant antibodies specific for herpes simplex glycoprotein gD or gB, some of which are against conformationally sensitive epitopes. By using defined monoclonal antibodies for the antigen-capture step, this method can be used for the isolation of antibodies to specific regions and epitopes within the target viral protein. For instance, monoclonal antibodies to a nonneutralizing epitope can be used in the capture step to clone antibodies to neutralizing epitopes, or antibodies to a neutralizing epitope can be used to clone antibodies to a different neutralizing epitope. Furthermore, by using capturing antibodies to more immunodominant epitopes, one can direct the cloning to less immunogenic ones. This method should be of value in generating antibodies to be used both in the prophylaxis and treatment of viral infections and in the characterization of the mechanisms of antibody protective actions at the molecular level.
Effect of Hemodilution on Coagulation and Recombinant Factor VIIa Efficacy in Human Blood In Vitro
2011-11-01
thrombasthenia.12 In trauma, when a blood vessel is injured, tissue factor on subendothelial pericytes is exposed and binds to endogenous FVII ...a more complex effect on coagulation than simply dilution of any single coagulation factor like FVII or fibrinogen (Fig. 1). It is interesting to note...ORIGINAL ARTICLE Effect of Hemodilution on Coagulation and Recombinant Factor VIIa Efficacy in Human Blood In Vitro Daniel N. Darlington, PhD, Angel
A facile method for isolation of recombinant human apolipoprotein A-I from E. coli
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ikon, Nikita; Shearer, Jennifer; Liu, Jianfang
Apolipoprotein (apo) A-I is the major protein component of high-density lipoprotein (HDL) and plays key roles in the Reverse Cholesterol Transport pathway. In the past decade, reconstituted HDL (rHDL) has been employed as a therapeutic agent for treatment of atherosclerosis. The ability of rHDL to promote cholesterol efflux from peripheral cells has been documented to reduce the size of atherosclerotic plaque lesions. However, development of apoA-I rHDL-based therapeutics for human use requires a cost effective process to generate an apoA-I product that meets “Good Manufacturing Practice” standards. Methods available for production and isolation of unmodified recombinant human apoA-I at scalemore » are cumbersome, laborious and complex. To overcome this obstacle, a streamlined two-step procedure has been devised for isolation of recombinant untagged human apoA-I from E. coli that takes advantage of its ability to re-fold to a native conformation following denaturation. Heat treatment of a sonicated E. coli supernatant fraction induced precipitation of a large proportion of host cell proteins (HCP), yielding apoA-I as the major soluble protein. Reversed-phase HPLC of this material permitted recovery of apoA-I largely free of HCP and endotoxin. In conclusion, purified apoA-I possessed α-helix secondary structure, formed rHDL upon incubation with phospholipid and efficiently promoted cholesterol efflux from cholesterol loaded J774 macrophages.« less
A facile method for isolation of recombinant human apolipoprotein A-I from E. coli
Ikon, Nikita; Shearer, Jennifer; Liu, Jianfang; ...
2017-03-20
Apolipoprotein (apo) A-I is the major protein component of high-density lipoprotein (HDL) and plays key roles in the Reverse Cholesterol Transport pathway. In the past decade, reconstituted HDL (rHDL) has been employed as a therapeutic agent for treatment of atherosclerosis. The ability of rHDL to promote cholesterol efflux from peripheral cells has been documented to reduce the size of atherosclerotic plaque lesions. However, development of apoA-I rHDL-based therapeutics for human use requires a cost effective process to generate an apoA-I product that meets “Good Manufacturing Practice” standards. Methods available for production and isolation of unmodified recombinant human apoA-I at scalemore » are cumbersome, laborious and complex. To overcome this obstacle, a streamlined two-step procedure has been devised for isolation of recombinant untagged human apoA-I from E. coli that takes advantage of its ability to re-fold to a native conformation following denaturation. Heat treatment of a sonicated E. coli supernatant fraction induced precipitation of a large proportion of host cell proteins (HCP), yielding apoA-I as the major soluble protein. Reversed-phase HPLC of this material permitted recovery of apoA-I largely free of HCP and endotoxin. In conclusion, purified apoA-I possessed α-helix secondary structure, formed rHDL upon incubation with phospholipid and efficiently promoted cholesterol efflux from cholesterol loaded J774 macrophages.« less
Analysis of European mtDNAs for recombination.
Elson, J L; Andrews, R M; Chinnery, P F; Lightowlers, R N; Turnbull, D M; Howell, N
2001-01-01
The standard paradigm postulates that the human mitochondrial genome (mtDNA) is strictly maternally inherited and that, consequently, mtDNA lineages are clonal. As a result of mtDNA clonality, phylogenetic and population genetic analyses should therefore be free of the complexities imposed by biparental recombination. The use of mtDNA in analyses of human molecular evolution is contingent, in fact, on clonality, which is also a condition that is critical both for forensic studies and for understanding the transmission of pathogenic mtDNA mutations within families. This paradigm, however, has been challenged recently by Eyre-Walker and colleagues. Using two different tests, they have concluded that recombination has contributed to the distribution of mtDNA polymorphisms within the human population. We have assembled a database that comprises the complete sequences of 64 European and 2 African mtDNAs. When this set of sequences was analyzed using any of three measures of linkage disequilibrium, one of the tests of Eyre-Walker and colleagues, there was no evidence for mtDNA recombination. When their test for excess homoplasies was applied to our set of sequences, only a slight excess of homoplasies was observed. We discuss possible reasons that our results differ from those of Eyre-Walker and colleagues. When we take the various results together, our conclusion is that mtDNA recombination has not been sufficiently frequent during human evolution to overturn the standard paradigm.
Berg, Ingrid L; Neumann, Rita; Lam, Kwan-Wood G; Sarbajna, Shriparna; Odenthal-Hesse, Linda; May, Celia A; Jeffreys, Alec J
2010-10-01
PRDM9 has recently been identified as a likely trans regulator of meiotic recombination hot spots in humans and mice. PRDM9 contains a zinc finger array that, in humans, can recognize a short sequence motif associated with hot spots, with binding to this motif possibly triggering hot-spot activity via chromatin remodeling. We now report that human genetic variation at the PRDM9 locus has a strong effect on sperm hot-spot activity, even at hot spots lacking the sequence motif. Subtle changes within the zinc finger array can create hot-spot nonactivating or enhancing variants and can even trigger the appearance of a new hot spot, suggesting that PRDM9 is a major global regulator of hot spots in humans. Variation at the PRDM9 locus also influences aspects of genome instability-specifically, a megabase-scale rearrangement underlying two genomic disorders as well as minisatellite instability-implicating PRDM9 as a risk factor for some pathological genome rearrangements.
Berg, Ingrid L.; Neumann, Rita; Lam, Kwan-Wood G.; Sarbajna, Shriparna; Odenthal-Hesse, Linda; May, Celia A.; Jeffreys, Alec J.
2011-01-01
PRDM9 has recently been identified as a likely trans-regulator of meiotic recombination hot spots in humans and mice1-3. The protein contains a zinc finger array that in humans can recognise a short sequence motif associated with hot spots4, with binding to this motif possibly triggering hot-spot activity via chromatin remodelling5. We now show that variation in the zinc finger array in humans has a profound effect on sperm hot-spot activity, even at hot spots lacking the sequence motif. Very subtle changes within the array can create hot-spot non-activating and enhancing alleles, and even trigger the appearance of a new hot spot. PRDM9 thus appears to be the preeminent global regulator of hot spots in humans. Variation at this locus also influences aspects of genome instability, specifically a megabase-scale rearrangement underlying two genomic disorders6 as well as minisatellite instability7, implicating PRDM9 as a risk factor for some pathological genome rearrangements. PMID:20818382
Human anti-CD30 recombinant antibodies by guided phage antibody selection using cell panning
Klimka, A; Matthey, B; Roovers, R C; Barth, S; Arends, J-W; Engert, A; Hoogenboom, H R
2000-01-01
In various clinical studies, Hodgkin’s patients have been treated with anti-CD30 immunotherapeutic agents and have shown promising responses. One of the problems that appeared from these studies is the development of an immune response against the non-human therapeutics, which limits repeated administration and reduces efficacy. We have set out to make a recombinant, human anti-CD30 single-chain variable fragment (scFv) antibody, which may serve as a targeting moiety with reduced immunogenicity and more rapid tumour penetration in similar clinical applications. Rather than selecting a naive phage antibody library on recombinant CD30 antigen, we used guided selection of a murine antibody in combination with panning on the CD30-positive cell line L540. The murine monoclonal antibody Ki-4 was chosen as starting antibody, because it inhibits the shedding of the extracellular part of the CD30 antigen. This makes the antibody better suited for CD30-targeting than most other anti-CD30 antibodies. We have previously isolated the murine Ki-4 scFv by selecting a mini-library of hybridoma-derived phage scFv-antibodies via panning on L540 cells. Here, we report that phage display technology was successfully used to obtain a human Ki-4 scFv version by guided selection. The murine variable heavy (VH) and light (VL) chain genes of the Ki-4 scFv were sequentially replaced by human V gene repertoires, while retaining only the major determinant for epitope-specificity: the heavy-chain complementarity determining region 3 (CDR3) of murine Ki-4. After two rounds of chain shuffling and selection by panning on L540 cells, a fully human anti-CD30 scFv was selected. It competes with the parental monoclonal antibody Ki-4 for binding to CD30, inhibits the shedding of the extracellular part of the CD30 receptor from L540 cells and is thus a promising candidate for the generation of anti-CD30 immunotherapeutics. © 2000 Cancer Research Campaign PMID:10901379
Sirena, Dominique; Ruzsics, Zsolt; Schaffner, Walter; Greber, Urs F; Hemmi, Silvio
2005-12-20
Human adenovirus (Ad) serotype 3 causes respiratory infections. It is considered highly virulent, accounting for about 13% of all Ad isolates. We report here the complete Ad3 DNA sequence of 35,343 base pairs (GenBank accession DQ086466). Ad3 shares 96.43% nucleotide identity with Ad7, another virulent subspecies B1 serotype, and 82.56 and 62.75% identity with the less virulent species B2 Ad11 and species C Ad5, respectively. The genomic organization of Ad3 is similar to the other human Ads comprising five early transcription units, E1A, E1B, E2, E3, and E4, two delayed early units IX and IVa2, and the major late unit, in total 39 putative and 7 hypothetical open reading frames. A recombinant E1-deleted Ad3 was generated on a bacterial artificial chromosome. This prototypic virus efficiently transduced CD46-positive rodent and human cells. Our results will help in clarifying the biology and pathology of adenoviruses and enhance therapeutic applications of viral vectors in clinical settings.
Szpakowski, Piotr; Biet, Franck; Locht, Camille; Paszkiewicz, Małgorzata; Rudnicka, Wiesława; Druszczyńska, Magdalena; Allain, Fabrice; Fol, Marek; Pestel, Joël; Kowalewicz-Kulbat, Magdalena
2015-01-01
Tuberculosis remains an enormous global burden, despite wide vaccination coverage with the Bacillus Calmette-Guérin (BCG), the only vaccine available against this disease, indicating that BCG-driven immunity is insufficient to protect the human population against tuberculosis. In this study we constructed recombinant BCG producing human IL-18 (rBCGhIL-18) and investigated whether human IL-18 produced by rBCGhIL-18 modulates DC functions and enhances Th1 responses to mycobacterial antigens in humans. We found that the costimulatory CD86 and CD80 molecules were significantly upregulated on rBCGhIL-18-infected DCs, whereas the stimulation of DCs with nonrecombinant BCG was less effective. In contrast, both BCG strains decreased the DC-SIGN expression on human DCs. The rBCGhIL-18 increased IL-23, IL-10, and IP-10 production by DCs to a greater extent than nonrecombinant BCG. In a coculture system of CD4(+) T cells and loaded DCs, rBCGhIL-18 favoured strong IFN-γ but also IL-10 production by naive T cells but not by memory T cells. This was much less the case for nonrecombinant BCG. Thus the expression of IL-18 by recombinant BCG increases IL-23, IP-10, and IL-10 expression by human DCs and enhances their ability to induce IFN-γ and IL-10 expression by naive T cells, without affecting the maturation phenotype of the DCs.
Biet, Franck; Rudnicka, Wiesława; Druszczyńska, Magdalena; Fol, Marek; Pestel, Joël
2015-01-01
Tuberculosis remains an enormous global burden, despite wide vaccination coverage with the Bacillus Calmette-Guérin (BCG), the only vaccine available against this disease, indicating that BCG-driven immunity is insufficient to protect the human population against tuberculosis. In this study we constructed recombinant BCG producing human IL-18 (rBCGhIL-18) and investigated whether human IL-18 produced by rBCGhIL-18 modulates DC functions and enhances Th1 responses to mycobacterial antigens in humans. We found that the costimulatory CD86 and CD80 molecules were significantly upregulated on rBCGhIL-18-infected DCs, whereas the stimulation of DCs with nonrecombinant BCG was less effective. In contrast, both BCG strains decreased the DC-SIGN expression on human DCs. The rBCGhIL-18 increased IL-23, IL-10, and IP-10 production by DCs to a greater extent than nonrecombinant BCG. In a coculture system of CD4+ T cells and loaded DCs, rBCGhIL-18 favoured strong IFN-γ but also IL-10 production by naive T cells but not by memory T cells. This was much less the case for nonrecombinant BCG. Thus the expression of IL-18 by recombinant BCG increases IL-23, IP-10, and IL-10 expression by human DCs and enhances their ability to induce IFN-γ and IL-10 expression by naive T cells, without affecting the maturation phenotype of the DCs. PMID:26339658
Protection from cigarette smoke-induced vascular injury by recombinant human relaxin-2 (serelaxin).
Pini, Alessandro; Boccalini, Giulia; Baccari, Maria Caterina; Becatti, Matteo; Garella, Rachele; Fiorillo, Claudia; Calosi, Laura; Bani, Daniele; Nistri, Silvia
2016-05-01
Smoking is regarded as a major risk factor for the development of cardiovascular diseases (CVD). This study investigates whether serelaxin (RLX, recombinant human relaxin-2) endowed with promising therapeutic properties in CVD, can be credited of a protective effect against cigarette smoke (CS)-induced vascular damage and dysfunction. Guinea pigs exposed daily to CS for 8 weeks were treated with vehicle or RLX, delivered by osmotic pumps at daily doses of 1 or 10 μg. Controls were non-smoking animals. Other studies were performed on primary guinea pig aortic endothelial (GPAE) cells, challenged with CS extracts (CSE) in the absence and presence of 100 ng/ml (17 nmol/l) RLX. In aortic specimens from CS-exposed guinea pigs, both the contractile and the relaxant responses to phenylephrine and acetylcholine, respectively, were significantly reduced in amplitude and delayed, in keeping with the observed adverse remodelling of the aortic wall, endothelial injury and endothelial nitric oxide synthase (eNOS) down-regulation. RLX at both doses maintained the aortic contractile and relaxant responses to a control-like pattern and counteracted aortic wall remodelling and endothelial derangement. The experiments with GPAE cells showed that CSE significantly decreased cell viability and eNOS expression and promoted apoptosis by sparkling oxygen free radical-related cytotoxicity, while RLX counterbalanced the adverse effects of CSE. These findings demonstrate that RLX is capable of counteracting CS-mediated vascular damage and dysfunction by reducing oxidative stress, thus adding a tile to the growing mosaic of the beneficial effects of RLX in CVD. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.
Zsurka, Gábor; Kraytsberg, Yevgenia; Kudina, Tatiana; Kornblum, Cornelia; Elger, Christian E; Khrapko, Konstantin; Kunz, Wolfram S
2005-08-01
Experimental evidence for human mitochondrial DNA (mtDNA) recombination was recently obtained in an individual with paternal inheritance of mtDNA and in an in vitro cell culture system. Whether mtDNA recombination is a common event in humans remained to be determined. To detect mtDNA recombination in human skeletal muscle, we analyzed the distribution of alleles in individuals with multiple mtDNA heteroplasmy using single-cell PCR and allele-specific PCR. In all ten individuals who carried a heteroplasmic D-loop mutation and a distantly located tRNA point mutation or a large deletion, we observed a mixture of four allelic combinations (tetraplasmy), a hallmark of recombination. Twelve of 14 individuals with closely located heteroplasmic D-loop mutation pairs contained a mixture of only three types of mitochondrial genomes (triplasmy), consistent with the absence of recombination between adjacent markers. These findings indicate that mtDNA recombination is common in human skeletal muscle.
Lorin, Clarisse; Vanloubbeeck, Yannick; Baudart, Sébastien; Ska, Michaël; Bayat, Babak; Brauers, Geoffroy; Clarinval, Géraldine; Donner, Marie-Noëlle; Marchand, Martine; Koutsoukos, Marguerite; Mettens, Pascal; Cohen, Joe; Voss, Gerald
2015-01-01
HIV-1-specific CD4+ and CD8+ T lymphocytes are important for HIV-1 replication control. F4/AS01 consists of F4 recombinant fusion protein (containing clade B Gag/p24, Pol/RT, Nef and Gag/p17) formulated in AS01 Adjuvant System, and was shown to induce F4-specific polyfunctional CD4+ T-cell responses in humans. While replication-incompetent recombinant HIV-1/SIV antigen-expressing human adenoviral vectors can elicit high-frequency antigen-specific CD8+ T-cell responses, their use is hampered by widespread pre-existing immunity to human serotypes. Non-human adenovirus serotypes associated with lower prevalence may offer an alternative strategy. We evaluated the immunogenicity of AdC7-GRN ('A'), a recombinant chimpanzee adenovirus type 7 vector expressing clade B Gag, RT and Nef, and F4/AS01 ('P'), when delivered intramuscularly in homologous (PP or AA) and heterologous (AAPP or PPAA) prime-boost regimens, in macaques and mice. Vaccine-induced HIV-1-antigen-specific T cells in peripheral blood (macaques), liver, spleen, and intestinal and genital mucosa (mice) were characterized by intracellular cytokine staining. Vaccine-specific IgG antibodies (macaques) were detected using ELISA. In macaques, only the heterologous prime-boost regimens induced polyfunctional, persistent and balanced CD4+ and CD8+ T-cell responses specific to each HIV-1 vaccine antigen. AdC7-GRN priming increased the polyfunctionality of F4/AS01-induced CD4+ T cells. Approximately 50% of AdC7-GRN-induced memory CD8+ T cells exhibited an effector-memory phenotype. HIV-1-specific antibodies were detected with each regimen. In mice, antigen-specific CD4+ and CD8+ T-cell responses were detected in the mucosal and systemic anatomical compartments assessed. When administered in heterologous prime-boost regimens, AdC7-GRN and F4/AS01 candidate vaccines acted complementarily in inducing potent and persistent peripheral blood HIV-1-specific CD4+ and CD8+ T-cell responses and antibodies in macaques. Besides
Lorin, Clarisse; Vanloubbeeck, Yannick; Baudart, Sébastien; Ska, Michaël; Bayat, Babak; Brauers, Geoffroy; Clarinval, Géraldine; Donner, Marie-Noëlle; Marchand, Martine; Koutsoukos, Marguerite; Mettens, Pascal; Cohen, Joe; Voss, Gerald
2015-01-01
HIV-1-specific CD4+ and CD8+ T lymphocytes are important for HIV-1 replication control. F4/AS01 consists of F4 recombinant fusion protein (containing clade B Gag/p24, Pol/RT, Nef and Gag/p17) formulated in AS01 Adjuvant System, and was shown to induce F4-specific polyfunctional CD4+ T-cell responses in humans. While replication-incompetent recombinant HIV-1/SIV antigen-expressing human adenoviral vectors can elicit high-frequency antigen-specific CD8+ T-cell responses, their use is hampered by widespread pre-existing immunity to human serotypes. Non-human adenovirus serotypes associated with lower prevalence may offer an alternative strategy. We evaluated the immunogenicity of AdC7-GRN (‘A’), a recombinant chimpanzee adenovirus type 7 vector expressing clade B Gag, RT and Nef, and F4/AS01 (‘P’), when delivered intramuscularly in homologous (PP or AA) and heterologous (AAPP or PPAA) prime-boost regimens, in macaques and mice. Vaccine-induced HIV-1-antigen-specific T cells in peripheral blood (macaques), liver, spleen, and intestinal and genital mucosa (mice) were characterized by intracellular cytokine staining. Vaccine-specific IgG antibodies (macaques) were detected using ELISA. In macaques, only the heterologous prime-boost regimens induced polyfunctional, persistent and balanced CD4+ and CD8+ T-cell responses specific to each HIV-1 vaccine antigen. AdC7-GRN priming increased the polyfunctionality of F4/AS01-induced CD4+ T cells. Approximately 50% of AdC7-GRN-induced memory CD8+ T cells exhibited an effector-memory phenotype. HIV-1-specific antibodies were detected with each regimen. In mice, antigen-specific CD4+ and CD8+ T-cell responses were detected in the mucosal and systemic anatomical compartments assessed. When administered in heterologous prime-boost regimens, AdC7-GRN and F4/AS01 candidate vaccines acted complementarily in inducing potent and persistent peripheral blood HIV-1-specific CD4+ and CD8+ T-cell responses and antibodies in macaques
Recombinant human bone morphogenetic protein 2 in augmentation procedures: case reports.
Luiz, Jaques; Padovan, Luis Eduardo Marques; Claudino, Marcela
2014-01-01
To successfully rehabilitate edentulous patients using endosseous implants, there must be enough available bone. Several techniques have been proposed for augmentation of sites with insufficient bone volume. Although autogenous bone has long been considered the gold standard for such procedures, the limited availability of graft material and a high morbidity rate are potential disadvantages of this type of graft. An alternative is to use recombinant human bone morphogenetic protein 2 (rhBMP-2), which is able to support bone regeneration in the oral environment. These cases demonstrate the applicability of rhBMP-2 in maxillary sinus elevation and augmentation procedures in the maxilla to enable dental implant placement. The use of rhBMP-2 in alveolar augmentation procedures had several clinical benefits for these patients.
Generation of a Chinese Hamster Ovary Cell Line Producing Recombinant Human Glucocerebrosidase
Novo, Juliana Branco; Morganti, Ligia; Moro, Ana Maria; Paes Leme, Adriana Franco; Serrano, Solange Maria de Toledo; Raw, Isaias; Ho, Paulo Lee
2012-01-01
Impaired activity of the lysosomal enzyme glucocerebrosidase (GCR) results in the inherited metabolic disorder known as Gaucher disease. Current treatment consists of enzyme replacement therapy by administration of exogenous GCR. Although effective, it is exceptionally expensive, and patients worldwide have a limited access to this medicine. In Brazil, the public healthcare system provides the drug free of charge for all Gaucher's patients, which reaches the order of $ 84 million per year. However, the production of GCR by public institutions in Brazil would reduce significantly the therapy costs. Here, we describe a robust protocol for the generation of a cell line producing recombinant human GCR. The protein was expressed in CHO-DXB11 (dhfr−) cells after stable transfection and gene amplification with methotrexate. As expected, glycosylated GCR was detected by immunoblotting assay both as cell-associated (~64 and 59 kDa) and secreted (63–69 kDa) form. Analysis of subclones allowed the selection of stable CHO cells producing a secreted functional enzyme, with a calculated productivity of 5.14 pg/cell/day for the highest producer. Although being laborious, traditional methods of screening high-producing recombinant cells may represent a valuable alternative to generate expensive biopharmaceuticals in countries with limited resources. PMID:23091360
Lehert, Philippe; Kolibianakis, Efstratios M; Venetis, Christos A; Schertz, Joan; Saunders, Helen; Arriagada, Pablo; Copt, Samuel; Tarlatzis, Basil
2014-02-20
The potential benefit of adding recombinant human luteinizing hormone (r-hLH) to recombinant human follicle-stimulating hormone (r-hFSH) during ovarian stimulation is a subject of debate, although there is evidence that it may benefit certain subpopulations, e.g. poor responders. A systematic review and a meta-analysis were performed. Three databases (MEDLINE, Embase and CENTRAL) were searched (from 1990 to 2011). Prospective, parallel-, comparative-group randomized controlled trials (RCTs) in women aged 18-45 years undergoing in vitro fertilization, intracytoplasmic sperm injection or both, treated with gonadotrophin-releasing hormone analogues and r-hFSH plus r-hLH or r-hFSH alone were included. The co-primary endpoints were number of oocytes retrieved and clinical pregnancy rate. Analyses were conducted for the overall population and for prospectively identified patient subgroups, including patients with poor ovarian response (POR). In total, 40 RCTs (6443 patients) were included in the analysis. Data on the number of oocytes retrieved were reported in 41 studies and imputed in two studies. Therefore, data were available from 43 studies (r-hFSH plus r-hLH, n=3113; r-hFSH, n=3228) in the intention-to-treat (ITT) population (all randomly allocated patients, including imputed data). Overall, no significant difference in the number of oocytes retrieved was found between the r-hFSH plus r-hLH and r-hFSH groups (weighted mean difference -0.03; 95% confidence interval [CI] -0.41 to 0.34). However, in poor responders, significantly more oocytes were retrieved with r-hFSH plus r-hLH versus r-hFSH alone (n=1077; weighted mean difference +0.75 oocytes; 95% CI 0.14-1.36). Significantly higher clinical pregnancy rates were observed with r-hFSH plus r-hLH versus r-hFSH alone in the overall population analysed in this review (risk ratio [RR] 1.09; 95% CI 1.01-1.18) and in poor responders (n=1179; RR 1.30; 95% CI 1.01-1.67; ITT population); the observed difference was more
Rozov, S M; Permyakova, N V; Deineko, E V
2018-03-01
Most the pharmaceutical proteins are derived not from their natural sources, rather their recombinant analogs are synthesized in various expression systems. Plant expression systems, unlike mammalian cell cultures, combine simplicity and low cost of procaryotic systems and the ability for posttranslational modifications inherent in eucaryotes. More than 50% of all human proteins and more than 40% of the currently used pharmaceutical proteins are glycosylated, that is, they are glycoproteins, and their biological activity, pharmacodynamics, and immunogenicity depend on the correct glycosylation pattern. This review examines in detail the similarities and differences between N- and O-glycosylation in plant and mammalian cells, as well as the effect of plant glycans on the activity, pharmacokinetics, immunity, and intensity of biosynthesis of pharmaceutical proteins. The main current strategies of glycoengineering of plant expression systems aimed at obtaining fully humanized proteins for pharmaceutical application are summarized.
Chen, Liang-Hua; Cai, Feng; Zhang, Dan-Ju; Zhang, Li; Zhu, Peng; Gao, Shun
2017-07-01
The pharmacological importance of recombinant human stem cell factor (rhSCF) has increased the demand to establish effective and large-scale production and purification processes. A good source of bioactive recombinant protein with capability of being scaled-up without losing activity has always been a challenge. The objectives of the study were the rapid and efficient pilot-scale expression and purification of rhSCF. The gene encoding stem cell factor (SCF) was cloned into pBV220 and transformed into Escherichia coli. The recombinant SCF was expressed and isolated using a procedure consisting of isolation of inclusion bodies (IBs), denaturation, and refolding followed by chromatographic steps toward purification. The yield of rhSCF reached 835.6 g/20 L, and the expression levels of rhSCF were about 33.9% of the total E. coli protein content. rhSCF was purified by isolation of IBs, denaturation, and refolding, followed by SP-Sepharose chromatography, Source 30 reversed-phase chromatography, and Q-Sepharose chromatography. This procedure was developed to isolate 5.5 g of rhSCF (99.5% purity) with specific activity at 0.96 × 10 6 IU/mg, endotoxin levels of pyrogen at 1.0 EU/mg, and bacterial DNA at 10 ng/mg. Pilot-scale fermentations and purifications were set up for the production of rhSCF that can be upscaled for industry. © 2016 International Union of Biochemistry and Molecular Biology, Inc.
Attardi, Barbara J.; Pham, Trung C.; Radler, Lisa M.; Burgenson, Janet; Hild, Sheri A.; Reel, Jerry R.
2008-01-01
Dimethandrolone undecanoate (DMAU: 7α,11β-dimethyl-19-nortestosterone 17β-undecanoate) is a potent orally active androgen in development for hormonal therapy in men. Cleavage of the 17β-ester bond by esterases in vivo leads to liberation of the biologically active androgen, dimethandrolone (DMA), a 19-norandrogen. For hormone replacement in men, administration of C19 androgens such as testosterone (T) may lead to elevations in circulating levels of estrogens due to aromatization. As several reports have suggested that certain 19-norandrogens may serve as substrates for the aromatase enzyme and are converted to the corresponding aromatic A-ring products, it was important to investigate whether DMA, the related compound, 11β-methyl-19-nortestosterone (11β-MNT), also being tested for hormonal therapy in men, and other 19-norandrogens can be converted to aromatic A-ring products by human aromatase. The hypothetical aromatic A-ring product corresponding to each substrate was obtained by chemical synthesis. These estrogens bound with high affinity to purified recombinant human estrogen receptors (ER) α and β in competitive binding assays (IC50's: 5−12 × 10−9 M) and stimulated transcription of 3XERE-luciferase in T47Dco human breast cancer cells with a potency equal to or greater than that of estradiol (E2) (EC50's: 10−12 to 10−11 M). C19 androgens (T, 17α-methyltestosterone (17α-MT), androstenedione (AD), and 16α-hydroxyandrostenedione (16α-OHAD)), 19-norandrogens (DMA, 11β-MNT, 19-nortestosterone (19-NT), and 7α-methyl-19-nortestosterone (MENT)) or the structurally similar 19-norprogestin, norethindrone (NET) were incubated at 50 μM with recombinant human aromatase for 10−180 min at 37 °C. The reactions were terminated by extraction with acetonitrile and centrifugation, and substrate and potential product were separated by HPLC. Retention times were monitored by UV absorption, and UV peaks were quantified using standard curves. Aromatization
Cosmic microwave background bispectrum from recombination.
Huang, Zhiqi; Vernizzi, Filippo
2013-03-08
We compute the cosmic microwave background temperature bispectrum generated by nonlinearities at recombination on all scales. We use CosmoLib2nd, a numerical Boltzmann code at second order to compute cosmic microwave background bispectra on the full sky. We consistently include all effects except gravitational lensing, which can be added to our result using standard methods. The bispectrum is peaked on squeezed triangles and agrees with the analytic approximation in the squeezed limit at the few percent level for all the scales where this is applicable. On smaller scales, we recover previous results on perturbed recombination. For cosmic-variance limited data to l(max)=2000, its signal-to-noise ratio is S/N=0.47, corresponding to f(NL)(eff)=-2.79, and will bias a local signal by f(NL)(loc) ~/= 0.82.
Extracellular accumulation of recombinant protein by Escherichia coli in a defined medium.
Fu, Xiang-Yang
2010-09-01
Extracellular accumulation of recombinant proteins in the culture medium of Escherichia coli is desirable but difficult to obtain. The inner or cytoplasmic membrane and the outer membrane of E. coli are two barriers for releasing recombinant proteins expressed in the cytoplasm into the culture medium. Even if recombinant proteins have been exported into the periplasm, a space between the outer membrane and the inner membrane, the outer membrane remains the last barrier for their extracellular release. However, when E. coli was cultured in a particular defined medium, recombinant proteins exported into the periplasm could diffuse into the culture medium automatically. If a nonionic detergent, Triton X-100, was added in the medium, recombinant proteins expressed in the cytoplasm could also be released into the culture medium. It was then that extracellular accumulation of recombinant proteins could be obtained by exporting them into the periplasm or releasing them from the cytoplasm with Triton X-100 addition. The tactics described herein provided simple and valuable methods for achieving extracellular production of recombinant proteins in E. coli.
Kenley, R; Marden, L; Turek, T; Jin, L; Ron, E; Hollinger, J O
1994-10-01
In the current investigation, we report osseous regeneration in critical-size rat calvarial defects using recombinant human bone morphogenetic protein-2 (rhBMP-2) and novel delivery systems based on biomaterials. The novel systems combine rhBMP-2 with dry powder microparticles of poly(D,L-lactide-co-glycolide) (PLGA). The mixture of rhBMP-2 with PLGA microparticles is added to an aqueous solution of biopolymer to yield a semisolid paste. The biopolymers tested include autologous blood clot, hydroxypropyl methylcellulose, and sodium alginate cross-linked with calcium ion. Insoluble collageneous bone matrix was also studied as a control. Test articles were made at 0-, 10-, and 30-micrograms doses of rhBMP-2 and imiplanted in 8-mm-diameter rat calvarial defects (which will not heal if left untreated). The animals were examined 21 days after implantation by radiography, radiomorphometry, histology, and histomorphometry. All tested materials containing rhBMP-2 restored radiopacity and normal contouring to the calvarial defects. Samples without added rhBMP-2 yielded only soft tissue within the defects. Histology showed restoration of inner and outer bone tables plus marrow constituents. The PLGA microparticles were significantly resorbed at the 21-day time point. Although small differences between delivery systems were evident at 0- and 10-micrograms rhBMP-2 doses, all test articles performed essentially equivalently at the 30-micrograms dose. Thus, novel delivery systems for rhBMP-2 offer the promise of combining the intrinsic bioactivity of the osteoinductive protein with pharmaceutically acceptable biomaterials.
SequenceLDhot: detecting recombination hotspots.
Fearnhead, Paul
2006-12-15
There is much local variation in recombination rates across the human genome--with the majority of recombination occurring in recombination hotspots--short regions of around approximately 2 kb in length that have much higher recombination rates than neighbouring regions. Knowledge of this local variation is important, e.g. in the design and analysis of association studies for disease genes. Population genetic data, such as that generated by the HapMap project, can be used to infer the location of these hotspots. We present a new, efficient and powerful method for detecting recombination hotspots from population data. We compare our method with four current methods for detecting hotspots. It is orders of magnitude quicker, and has greater power, than two related approaches. It appears to be more powerful than HotspotFisher, though less accurate at inferring the precise positions of the hotspot. It was also more powerful than LDhot in some situations: particularly for weaker hotspots (10-40 times the background rate) when SNP density is lower (< 1/kb). Program, data sets, and full details of results are available at: http://www.maths.lancs.ac.uk/~fearnhea/Hotspot.
Recombination and phenotype evolution dynamics of Helicobacter pylori in colonized hosts.
Shafiee, Ahmad; Amini, Massoud; Emamirad, Hassan; Abadi, Amin Talebi Bezmin
2016-07-01
The ample genetic diversity and variability of Helicobater pylori, and therefore its phenotypic evolution, relate not only to frequent mutation and selection but also to intra-specific recombination. Webb and Blaser applied a mathematical model to distinguish the role of selection and mutation for Lewis antigen phenotype evolution during long-term gastric colonization in infected animal hosts (mice and gerbils). To investigate the role of recombination in Lewis antigen phenotype evolution, we have developed a prior population dynamic by adding recombination term to the model. We simulate and interpret the new model simulation's results with a comparative analysis of biological aspects. The main conclusions are as follows: (i) the models and consequently the hosts with higher recombination rate require a longer time for stabilization; and (ii) recombination and mutation have opposite effects on the size of H. pylori populations with phenotypes in the range of the most-fit ones (i.e. those that have a selective advantage) due to natural selection, although both can increase phenotypic diversity.
Pichia pastoris: a recombinant microfactory for antibodies and human membrane proteins.
Gonçalves, A M; Pedro, A Q; Maia, C; Sousa, F; Queiroz, J A; Passarinha, L A
2013-05-01
During the last few decades, it has become evident that the compatibility of the yeast biochemical environment with the ability to process and translate the RNA transcript, along with its capacity to modify a translated protein, are relevant requirements for selecting this host cell for protein expression in several pharmaceutical and clinical applications. In particular, Pichia pastoris is used as an industrial host for recombinant protein and metabolite production, showing a powerful capacity to meet required biomolecular target production levels in high-throughput assays for functional genomics and drug screening. In addition, there is a great advantage to using P. pastoris for protein secretion, even at high molecular weights, since the recovery and purification steps are simplified owing to relatively low levels of endogenous proteins in the extracellular medium. Clearly, no single microexpression system can provide all of the desired properties for human protein production. Moreover, chemical and physical bioprocess parameters, including culture medium formulation, temperature, pH, agitation, aeration rates, induction, and feeding strategies, can highly influence product yield and quality. In order to benefit from the currently available wide range of biosynthesis strategies using P. pastoris, this mini review focuses on the developments and technological fermentation achievements, providing both a comparative and an overall integration analysis. The main aim is to highlight the relevance and versatility of the P. pastoris biosystem to the design of more cost-effective microfactories to meet the increasing demands for recombinant membrane proteins and clinical antibodies for several therapeutic applications.
Katz, Samantha S.; Gimble, Frederick S.; Storici, Francesca
2014-01-01
Genetic modification of a chromosomal locus to replace an existing dysfunctional allele with a corrected sequence can be accomplished through targeted gene correction using the cell's homologous recombination (HR) machinery. Gene targeting is stimulated by generation of a DNA double-strand break (DSB) at or near the site of correction, but repair of the break via non-homologous end-joining without using the homologous template can lead to deleterious genomic changes such as in/del mutations, or chromosomal rearrangements. By contrast, generation of a DNA single-strand break (SSB), or nick, can stimulate gene correction without the problems of DSB repair because the uncut DNA strand acts as a template to permit healing without alteration of genetic material. Here, we examine the ability of a nicking variant of the I-SceI endonuclease (K223I I-SceI) to stimulate gene targeting in yeast Saccharomyces cerevisiae and in human embryonic kidney (HEK-293) cells. K223I I-SceI is proficient in both yeast and human cells and promotes gene correction up to 12-fold. We show that K223I I-SceI-driven recombination follows a different mechanism than wild-type I-SceI-driven recombination, thus indicating that the initial DNA break that stimulates recombination is not a low-level DSB but a nick. We also demonstrate that K223I I-SceI efficiently elevates gene targeting at loci distant from the break site in yeast cells. These findings establish the capability of the I-SceI nickase to enhance recombination in yeast and human cells, strengthening the notion that nicking enzymes could be effective tools in gene correction strategies for applications in molecular biology, biotechnology, and gene therapy. PMID:24558436
Hein, David W; Doll, Mark A
2017-08-01
Human N-acetyltransferase 2 (NAT2) catalyzes the N-acetylation of numerous aromatic amine drugs such as sulfamethazine (SMZ) and hydrazine drugs such as isoniazid (INH). NAT2 also catalyzes the N-acetylation of aromatic amine carcinogens such as 2-aminofluorene and the O- and N,O-acetylation of aromatic amine and heterocyclic amine metabolites. Genetic polymorphism in NAT2 modifies drug efficacy and toxicity as well as cancer risk. Acetyltransferase catalytic activities and heat stability associated with six novel NAT2 haplotypes (NAT2*6C, NAT2*14C, NAT2*14D, NAT2*14E, NAT2*17, and NAT2*18) were compared with that of the reference NAT2*4 haplotype following recombinant expression in Escherichia coli. N-acetyltransferase activities towards SMZ and INH were significantly (p < 0.0001) lower when catalyzed by the novel recombinant human NAT2 allozymes compared to NAT2 4. SMZ and INH N-acetyltransferase activities catalyzed by NAT2 14C and NAT2 14D were significantly lower (p < 0.001) than catalyzed by NAT2 6C and NAT2 14E. N-Acetylation catalyzed by recombinant human NAT2 17 was over several hundred-fold lower than by recombinant NAT2 4 precluding measurement of its kinetic or heat inactivation constants. Similar results were observed for the O-acetylation of N-hydroxy-2-aminofluorene and N-hydroxy-2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine and the intramolecular N,O-acetylation of N-hydroxy-N-acetyl-2-aminofluorene. The apparent V max of the novel recombinant NAT2 allozymes NAT2 6C, NAT2 14C, NAT2 14D, and NAT2 14E towards AF, 4-aminobiphenyl (ABP), and 3,2'-dimethyl-4-aminobiphenyl (DMABP) were each significantly (p < 0.001) lower while their apparent K m values did not differ significantly (p > 0.05) from recombinant NAT2 4. The apparent V max catalyzed by NAT2 14C and NAT2 14D were significantly lower (p < 0.05) than the apparent V max catalyzed by NAT2 6C and NAT2 14E towards AF, ABP, and DMABP. Heat inactivation rate constants for recombinant
Human recombinant alkaline phosphatase inhibits ex vivo platelet activation in humans.
Tunjungputri, Rahajeng N; Peters, Esther; van der Ven, André; de Groot, Philip G; de Mast, Quirijn; Pickkers, Peter
2016-11-30
Sepsis-associated acute kidney injury (AKI) is associated with high morbidity and mortality. Excessive platelet activation contributes to AKI through the formation of microthrombi and amplification of systemic inflammation. Two phase II trials demonstrated that bovine-intestinal alkaline phosphatase (AP) improved renal function in critically ill patients with sepsis-associated AKI. In this study, we characterised the platelet-inhibiting effects of a human recombinant AP. Whole blood and platelet-rich plasma (PRP) of healthy volunteers (n=6) was pre-treated ex vivo with recAP, whereafter platelet reactivity to ADP, collagen-related peptide (CRP-XL) and Pam3CSK4 was determined by flow cytometry. RecAP (40 U/ml) reduced the platelet reactivity to ADP (inhibition with a median of 47 %, interquartile range 43-49 %; p<0.001) and tended to reduce platelet reactivity to CRP-XL (9 %, 2-25 %; p=0.08) in whole blood. The platelet-inhibiting effects of recAP were more pronounced in PRP both for ADP- (64 %, 54-68 %; p=0.002) and CRP-XL-stimulated samples (60 %, 46-71 %; p=0.002). RecAP rapidly converted ADP into adenosine, whereas antagonism of the A2A adenosine receptor partially reversed the platelet inhibitory effects of recAP. Platelets of septic shock patients (n=5) showed a 31% (22-34%; p=0.03) more pronounced reactivity compared to healthy volunteers, and this was completely reversed by recAP treatment. In conclusion, we demonstrate that recAP inhibits ex vivo human platelet activation through dephosphorylation of ADP and formation of adenosine as its turnover product. RecAP is able to reverse the platelet hyperreactivity present in septic shock patients. These effects may contribute to the beneficial effects of recAP as a new therapeutic candidate for sepsis-associated AKI.
Eubanks, Lisa M.; Ellis, Beverly A.; Cai, Xiaoqing; Schlosburg, Joel E.; Janda, Kim D.
2014-01-01
Cocaine abuse remains prevalent worldwide and continues to be a major health concern; nonetheless, there is no effective therapy. Immunopharmacothery has emerged as a promising treatment strategy by which anti-cocaine antibodies bind to the drug blunting its effects. Previous passive immunization studies using our human monoclonal antibody, GNCgzk, resulted in protection against cocaine overdose and acute toxicity. To further realize the clinical potential of this antibody, a recombinant IgG form of the antibody has been produced in mammalian cells. This antibody displayed a high binding affinity for cocaine (low nanomolar) in line with the superior attributes of the GNCgzk antibody and reduced cocaine-induced ataxia in a cocaine overdose model. PMID:25205191
Preparation and characterization of human interleukin-5 expressed in recombinant Escherichia coli.
Proudfoot, A E; Fattah, D; Kawashima, E H; Bernard, A; Wingfield, P T
1990-01-01
The gene coding for human interleukin-5 was synthesized and expressed in Escherichia coli under control of a heat-inducible promoter. High-level expression, 10-15% of total cellular protein, was achieved in E. coli. The protein was produced in an insoluble state. A simple extraction, renaturation and purification scheme is described. The recombinant protein was found to be a homodimer, similar to the natural murine-derived protein. Despite the lack of glycosylation, high specific activities were obtained in three 'in vitro' biological assays. Physical characterization of the protein showed it to be mostly alpha-helical, supporting the hypothesis that a conformational similarity exists among certain cytokines. Images Fig. 1. Fig. 3. PMID:2205201
Schwarz, Harald; Schmittner, Maria; Duschl, Albert; Horejs-Hoeck, Jutta
2014-01-01
Many commercially available recombinant proteins are produced in Escherichia coli, and most suppliers guarantee contamination levels of less than 1 endotoxin unit (EU). When we analysed commercially available proteins for their endotoxin content, we found contamination levels in the same range as generally stated in the data sheets, but also some that were higher. To analyse whether these low levels of contamination have an effect on immune cells, we stimulated the monocytic cell line THP-1, primary human monocytes, in vitro differentiated human monocyte-derived dendritic cells, and primary human CD1c+ dendritic cells (DCs) with very low concentrations of lipopolysaccharide (LPS; ranging from 0.002–2 ng/ml). We show that CD1c+ DCs especially can be activated by minimal amounts of LPS, equivalent to the levels of endotoxin contamination we detected in some commercially available proteins. Notably, the enhanced endotoxin sensitivity of CD1c+ DCs was closely correlated with high CD14 expression levels observed in CD1c+ DCs that had been maintained in cell culture medium for 24 hours. When working with cells that are particularly sensitive to LPS, even low endotoxin contamination may generate erroneous data. We therefore recommend that recombinant proteins be thoroughly screened for endotoxin contamination using the limulus amebocyte lysate test, fluorescence-based assays, or a luciferase based NF-κB reporter assay involving highly LPS-sensitive cells overexpressing TLR4, MD-2 and CD14. PMID:25478795
Souza, Ana Paula; Andrade, Bruno Bezerril; Aquino, Dorlene; Entringer, Petter; Miranda, José Carlos; Alcantara, Ruan; Ruiz, Daniel; Soto, Manuel; Teixeira, Clarissa R.; Valenzuela, Jesus G.; de Oliveira, Camila Indiani; Brodskyn, Cláudia Ida; Barral-Netto, Manoel; Barral, Aldina
2010-01-01
Background Leishmania is transmitted by female sand flies and deposited together with saliva, which contains a vast repertoire of pharmacologically active molecules that contribute to the establishment of the infection. The exposure to vector saliva induces an immune response against its components that can be used as a marker of exposure to the vector. Performing large-scale serological studies to detect vector exposure has been limited by the difficulty in obtaining sand fly saliva. Here, we validate the use of two sand fly salivary recombinant proteins as markers for vector exposure. Methodology/principal findings ELISA was used to screen human sera, collected in an area endemic for visceral leishmaniasis, against the salivary gland sonicate (SGS) or two recombinant proteins (rLJM11 and rLJM17) from Lutzomyia longipalpis saliva. Antibody levels before and after SGS seroconversion (n = 26) were compared using the Wilcoxon signed rank paired test. Human sera from an area endemic for VL which recognize Lu. longipalpis saliva in ELISA also recognize a combination of rLJM17 and rLJM11. We then extended the analysis to include 40 sera from individuals who were seropositive and 40 seronegative to Lu. longipalpis SGS. Each recombinant protein was able to detect anti-saliva seroconversion, whereas the two proteins combined increased the detection significantly. Additionally, we evaluated the specificity of the anti-Lu. longipalpis response by testing 40 sera positive to Lutzomyia intermedia SGS, and very limited (2/40) cross-reactivity was observed. Receiver-operator characteristics (ROC) curve analysis was used to identify the effectiveness of these proteins for the prediction of anti-SGS positivity. These ROC curves evidenced the superior performance of rLJM17+rLJM11. Predicted threshold levels were confirmed for rLJM17+rLJM11 using a large panel of 1,077 serum samples. Conclusion Our results show the possibility of substituting Lu. longipalpis SGS for two
Herbert, Rebecca; Baron, Jana; Batten, Carrie; Baron, Michael; Taylor, Geraldine
2014-02-26
Peste des petits ruminants virus (PPRV) is a morbillivirus that can cause severe disease in sheep and goats, characterised by pyrexia, pneumo-enteritis, and gastritis. The socio-economic burden of the disease is increasing in underdeveloped countries, with poor livestock keepers being affected the most. Current vaccines consist of cell-culture attenuated strains of PPRV, which induce a similar antibody profile to that induced by natural infection. Generation of a vaccine that enables differentiation of infected from vaccinated animals (DIVA) would benefit PPR control and eradication programmes, particularly in the later stages of an eradication campaign and for countries where the disease is not endemic. In order to create a vaccine that would enable infected animals to be distinguished from vaccinated ones (DIVA vaccine), we have evaluated the immunogenicity of recombinant fowlpox (FP) and replication-defective recombinant human adenovirus 5 (Ad), expressing PPRV F and H proteins, in goats. The Ad constructs induced higher levels of virus-specific and neutralising antibodies, and primed greater numbers of CD8+ T cells than the FP-vectored vaccines. Importantly, a single dose of Ad-H, with or without the addition of Ad expressing ovine granulocyte macrophage colony-stimulating factor and/or ovine interleukin-2, not only induced strong antibody and cell-mediated immunity but also completely protected goats against challenge with virulent PPRV, 4 months after vaccination. Replication-defective Ad-H therefore offers the possibility of an effective DIVA vaccine.
Chun, B H; Bang, W G; Park, Y K; Woo, S K
2001-11-01
The recombinant a and bsubunits for human coagulation factor XIII were transfected into Chinese hamster ovary (CHO) cells. CHO cells were amplified and selected with methotrexate in adherent cultures containing serum, and CHO 1-62 cells were later selected in protein-free medium. To develop a recombinant factor XIII production process in a suspension culture, we have investigated the growth characteristics of CHO cells and the maintenance of factor XIII expression in the culture medium. Suspension adaptation of CHO cells was performed in protein-free medium, GC-CHO-PI, by two methods, such as serum weaning and direct switching from serum containing media to protein-free media. Although the growth of CHO cells in suspension culture was affected initially by serum depletion, cell specific productivity of factor XIII showed only minor changes by the direct switching to protein-free medium during a suspension culture. As for the long-term stability of factor XIII, CHO 1-62 cells showed a stable expression of factor XIII in protein-free condition for 1000 h. These results indicate that the CHO 1-62cells can be adapted to express recombinant human factor XIII in a stable maimer in suspension culture using a protein-free medium. Our results demonstrate that enhanced cell growth in a continuous manner is achievable for factor XIII production in a protein-free medium when a perfusion bioreactor culture system with a spin filter is employed.
Wang, Yanqun; Li, Yamin; Lu, Roujian; Zhao, Yanjie; Xie, Zhengde; Shen, Jun; Tan, Wenjie
2016-03-10
Human adenoviruses (HAdVs) are prevalent in hospitalized children with severe acute respiratory infection (SARI). Here, we report a unique recombinant HAdV strain (CBJ113) isolated from a HAdV-positive child with SARI. The whole-genome sequence was determined using Sanger sequencing and high-throughput sequencing. A phylogenetic analysis of the complete genome indicated that the CBJ113 strain shares a common origin with HAdV-C2, HAdV-C6, HAdV-C1, HAdV-C5, and HAdV-C57 and formed a novel subclade on the same branch as other HAdV-C subtypes. BootScan and single nucleotide polymorphism analyses showed that the CBJ113 genome has an intra-subtype recombinant structure and comprises gene regions mainly originating from two circulating viral strains: HAdV-1 and HAdV-2. The parental penton base, pVI, and DBP genes of the recombinant strain clustered with the HAdV-1 prototype strain, and the E1B, hexon, fiber, and 100 K genes of the recombinant clustered within the HAdV-2 subtype, meanwhile the E4orf1 and DNA polymerase genes of the recombinant shared the greatest similarity with those of HAdV-5 and HAdV-6, respectively. All of these findings provide insight into our understanding of the dynamics of the complexity of the HAdV-C epidemic. More extensive studies should address the pathogenicity and clinical characteristics of the novel recombinant.
Wang, Yanqun; Li, Yamin; Lu, Roujian; Zhao, Yanjie; Xie, Zhengde; Shen, Jun; Tan, Wenjie
2016-01-01
Human adenoviruses (HAdVs) are prevalent in hospitalized children with severe acute respiratory infection (SARI). Here, we report a unique recombinant HAdV strain (CBJ113) isolated from a HAdV-positive child with SARI. The whole-genome sequence was determined using Sanger sequencing and high-throughput sequencing. A phylogenetic analysis of the complete genome indicated that the CBJ113 strain shares a common origin with HAdV-C2, HAdV-C6, HAdV-C1, HAdV-C5, and HAdV-C57 and formed a novel subclade on the same branch as other HAdV-C subtypes. BootScan and single nucleotide polymorphism analyses showed that the CBJ113 genome has an intra-subtype recombinant structure and comprises gene regions mainly originating from two circulating viral strains: HAdV-1 and HAdV-2. The parental penton base, pVI, and DBP genes of the recombinant strain clustered with the HAdV-1 prototype strain, and the E1B, hexon, fiber, and 100 K genes of the recombinant clustered within the HAdV-2 subtype, meanwhile the E4orf1 and DNA polymerase genes of the recombinant shared the greatest similarity with those of HAdV-5 and HAdV-6, respectively. All of these findings provide insight into our understanding of the dynamics of the complexity of the HAdV-C epidemic. More extensive studies should address the pathogenicity and clinical characteristics of the novel recombinant. PMID:26960434
Suppression of colorectal tumorigenesis by recombinant Bacteroides fragilis enterotoxin-2 in vivo.
Lv, You; Ye, Tao; Wang, Hui-Peng; Zhao, Jia-Ying; Chen, Wen-Jie; Wang, Xin; Shen, Chen-Xia; Wu, Yi-Bin; Cai, Yuan-Kun
2017-01-28
To evaluate the impact of recombinant Bacteroides fragilis enterotoxin-2 (BFT-2, or Fragilysin) on colorectal tumorigenesis in mice induced by azoxymethane/dextran sulfate sodium (AOM/DSS). Recombinant proBFT-2 was expressed in Escherichia coli strain Rosetta (DE3) and BFT-2 was obtained and tested for its biological activity via colorectal adenocarcinoma cell strains SW-480. Seventy C57BL/6J mice were randomly divided into a blank (BC; n = 10), model (AD; n = 20), model + low-dose toxin (ADLT; n = 20, 10 μg), and a model + high-dose toxin (ADHT; n = 20, 20 μg) group. Mice weight, tumor formation and pathology were analyzed. Immunohistochemistry determined Ki-67 and Caspase-3 expression in normal and tumor tissues of colorectal mucosa. Recombinant BFT-2 was successfully obtained, along with its biological activity. The most obvious weight loss occurred in the AD group compared with the ADLT group (21.82 ± 0.68 vs 23.23 ± 0.91, P < 0.05) and the ADHT group (21.82 ± 0.68 vs 23.57 ± 1.06, P < 0.05). More tumors were found in the AD group than in the ADLT and ADHT groups (19.75 ± 3.30 vs 6.50 ± 1.73, P < 0.05; 19.75 ± 3.30 vs 6.00 ± 2.16, P < 0.05). Pathology showed that 12 mice had adenocarcinoma and 6 cases had adenoma in the AD group. Five mice had adenocarcinoma and 15 had adenoma in the ADLT group. Four mice had adenocarcinoma and 16 had adenoma in the ADHT group. The incidence of colorectal adenocarcinoma in both the ADHT group and the ADHT group was reduced compared to that in the AD group ( P < 0.05, P < 0.05). The positive rate of Ki-67 in the ADLT group and the ADHT group was 50% and 40%, respectively, both of which were lower than that found in the AD group (94.44%, P < 0.05, P < 0.05). Caspase-3 expression in the ADLT group and the ADHT group was 45% and 55%, both of which were higher than that found in the BC group (16.67%, P < 0.05, P < 0.05). Oral administration with lower-dose biologically active recombinant BFT-2 inhibited colorectal
Suppression of colorectal tumorigenesis by recombinant Bacteroides fragilis enterotoxin-2 in vivo
Lv, You; Ye, Tao; Wang, Hui-Peng; Zhao, Jia-Ying; Chen, Wen-Jie; Wang, Xin; Shen, Chen-Xia; Wu, Yi-Bin; Cai, Yuan-Kun
2017-01-01
AIM To evaluate the impact of recombinant Bacteroides fragilis enterotoxin-2 (BFT-2, or Fragilysin) on colorectal tumorigenesis in mice induced by azoxymethane/dextran sulfate sodium (AOM/DSS). METHODS Recombinant proBFT-2 was expressed in Escherichia coli strain Rosetta (DE3) and BFT-2 was obtained and tested for its biological activity via colorectal adenocarcinoma cell strains SW-480. Seventy C57BL/6J mice were randomly divided into a blank (BC; n = 10), model (AD; n = 20), model + low-dose toxin (ADLT; n = 20, 10 μg), and a model + high-dose toxin (ADHT; n = 20, 20 μg) group. Mice weight, tumor formation and pathology were analyzed. Immunohistochemistry determined Ki-67 and Caspase-3 expression in normal and tumor tissues of colorectal mucosa. RESULTS Recombinant BFT-2 was successfully obtained, along with its biological activity. The most obvious weight loss occurred in the AD group compared with the ADLT group (21.82 ± 0.68 vs 23.23 ± 0.91, P < 0.05) and the ADHT group (21.82 ± 0.68 vs 23.57 ± 1.06, P < 0.05). More tumors were found in the AD group than in the ADLT and ADHT groups (19.75 ± 3.30 vs 6.50 ± 1.73, P < 0.05; 19.75 ± 3.30 vs 6.00 ± 2.16, P < 0.05). Pathology showed that 12 mice had adenocarcinoma and 6 cases had adenoma in the AD group. Five mice had adenocarcinoma and 15 had adenoma in the ADLT group. Four mice had adenocarcinoma and 16 had adenoma in the ADHT group. The incidence of colorectal adenocarcinoma in both the ADHT group and the ADHT group was reduced compared to that in the AD group (P < 0.05, P < 0.05). The positive rate of Ki-67 in the ADLT group and the ADHT group was 50% and 40%, respectively, both of which were lower than that found in the AD group (94.44%, P < 0.05, P < 0.05). Caspase-3 expression in the ADLT group and the ADHT group was 45% and 55%, both of which were higher than that found in the BC group (16.67%, P < 0.05, P < 0.05). CONCLUSION Oral administration with lower-dose biologically active recombinant BFT-2
Metal binding proteins, recombinant host cells and methods
Summers, Anne O.; Caguiat, Jonathan J.
2004-06-15
The present disclosure provides artificial heavy metal binding proteins termed chelons by the inventors. These chelons bind cadmium and/or mercuric ions with relatively high affinity. Also disclosed are coding sequences, recombinant DNA molecules and recombinant host cells comprising those recombinant DNA molecules for expression of the chelon proteins. In the recombinant host cells or transgenic plants, the chelons can be used to bind heavy metals taken up from contaminated soil, groundwater or irrigation water and to concentrate and sequester those ions. Recombinant enteric bacteria can be used within the gastrointestinal tracts of animals or humans exposed to toxic metal ions such as mercury and/or cadmium, where the chelon recombinantly expressed in chosen in accordance with the ion to be rededicated. Alternatively, the chelons can be immobilized to solid supports to bind and concentrate heavy metals from a contaminated aqueous medium including biological fluids.
Singh, Rajbir; Ramakrishna, Rachumallu; Bhateria, Manisha; Bhatta, Rabi Sankar
2014-09-01
Bacopa monniera is a traditional Ayurvedic medicinal plant that has been used worldwide for its nootropic action. Chemically standardized extract of B. monniera is now available as over the counter herbal remedy to enhance memory in children and adults. Considering the nootropic action of B. monniera, we evaluated the effect of clinically available B. monniera extract and six of B. monniera constituents (bacoside A3, bacopaside I, bacopaside II, bacosaponin C, bacosine, and bacoside A mixture) on recombinant human monoamine oxidase (MAO) enzymes. The effect of B. monniera extract and individual constituents on human recombinant MAO-A and MAO-B enzymes was evaluated using MAO-Glo(TM) assay kit (Promega Corporation, USA), following the instruction manual. IC50 and mode of inhibition were measured for MAO enzymes. Bacopaside I and bacoside A mixture inhibited the MAO-A and MAO-B enzymes. Bacopaside I exhibited mixed mode of inhibition with IC50 and Ki values of 17.08 ± 1.64 and 42.5 ± 3.53 µg/mL, respectively, for MAO-A enzyme. Bacopaside I is the major constituent of B. monniera, which inhibited the MAO-A enzyme selectively. Copyright © 2014 John Wiley & Sons, Ltd.
Characterization of recombinant human C1 inhibitor secreted in milk of transgenic rabbits.
van Veen, Harrie A; Koiter, Jaco; Vogelezang, Carla J M; van Wessel, Noucha; van Dam, Tijtje; Velterop, Ingeborg; van Houdt, Kristina; Kupers, Luc; Horbach, Danielle; Salaheddine, Mourad; Nuijens, Jan H; Mannesse, Maurice L M
2012-12-31
C1 inhibitor (C1INH) is a single-chain glycoprotein that inhibits activation of the contact system of coagulation and the complement system. C1INH isolated from human blood plasma (pd-hC1INH) is used for the management of hereditary angioedema (HAE), a disease caused by heterozygous deficiency of C1INH, and is a promise for treatment of ischemia-reperfusion injuries like acute myocardial or cerebral infarction. To obtain large quantities of C1INH, recombinant human C1INH (rhC1INH) was expressed in the milk of transgenic rabbits (12 g/l) harboring genomic human C1INH sequences fused to 5' bovine αS(1) casein promoter sequences. Recombinant hC1INH was isolated from milk to a specific activity of 6.1 U/mg and a purity of 99%; by size-exclusion chromatography the 1% impurities consisted of multimers and N-terminal cleaved C1INH species. Mass spectrometric analysis of purified rhC1INH revealed a relative molecular mass (M(r)) of 67,200. Differences in M(r) on SDS PAGE and mass spectrometric analysis between rhC1INH and pd-hC1INH are explained by differential glycosylation (calculated carbohydrate contents of 21% and 28%, respectively), since protein sequencing analysis of rhC1INH revealed intact N- and C-termini. Host-related impurity analysis by ELISA revealed trace amounts of rabbit protein (approximately 10 ppm) in purified batches, but not endogenous rabbit C1INH. The kinetics of inhibition of the target proteases C1s, Factor XIIa, kallikrein and Factor XIa by rhC1INH and pd-hC1INH, indicated comparable inhibitory potency and specificity. Recently, rhC1INH (Ruconest(®)) has been approved by the European Medicines Agency for the treatment of acute attacks of HAE. Copyright © 2012 Elsevier B.V. All rights reserved.
Adding Stiffness to the Foot Modulates Soleus Force-Velocity Behaviour during Human Walking
Takahashi, Kota Z.; Gross, Michael T.; van Werkhoven, Herman; Piazza, Stephen J.; Sawicki, Gregory S.
2016-01-01
Previous studies of human locomotion indicate that foot and ankle structures can interact in complex ways. The structure of the foot defines the input and output lever arms that influences the force-generating capacity of the ankle plantar flexors during push-off. At the same time, deformation of the foot may dissipate some of the mechanical energy generated by the plantar flexors during push-off. We investigated this foot-ankle interplay during walking by adding stiffness to the foot through shoes and insoles, and characterized the resulting changes in in vivo soleus muscle-tendon mechanics using ultrasonography. Added stiffness decreased energy dissipation at the foot (p < 0.001) and increased the gear ratio (i.e., ratio of ground reaction force and plantar flexor muscle lever arms) (p < 0.001). Added foot stiffness also altered soleus muscle behaviour, leading to greater peak force (p < 0.001) and reduced fascicle shortening speed (p < 0.001). Despite this shift in force-velocity behaviour, the whole-body metabolic cost during walking increased with added foot stiffness (p < 0.001). This increased metabolic cost is likely due to the added force demand on the plantar flexors, as walking on a more rigid foot/shoe surface compromises the plantar flexors’ mechanical advantage. PMID:27417976
Adding Stiffness to the Foot Modulates Soleus Force-Velocity Behaviour during Human Walking
NASA Astrophysics Data System (ADS)
Takahashi, Kota Z.; Gross, Michael T.; van Werkhoven, Herman; Piazza, Stephen J.; Sawicki, Gregory S.
2016-07-01
Previous studies of human locomotion indicate that foot and ankle structures can interact in complex ways. The structure of the foot defines the input and output lever arms that influences the force-generating capacity of the ankle plantar flexors during push-off. At the same time, deformation of the foot may dissipate some of the mechanical energy generated by the plantar flexors during push-off. We investigated this foot-ankle interplay during walking by adding stiffness to the foot through shoes and insoles, and characterized the resulting changes in in vivo soleus muscle-tendon mechanics using ultrasonography. Added stiffness decreased energy dissipation at the foot (p < 0.001) and increased the gear ratio (i.e., ratio of ground reaction force and plantar flexor muscle lever arms) (p < 0.001). Added foot stiffness also altered soleus muscle behaviour, leading to greater peak force (p < 0.001) and reduced fascicle shortening speed (p < 0.001). Despite this shift in force-velocity behaviour, the whole-body metabolic cost during walking increased with added foot stiffness (p < 0.001). This increased metabolic cost is likely due to the added force demand on the plantar flexors, as walking on a more rigid foot/shoe surface compromises the plantar flexors’ mechanical advantage.
Adding Stiffness to the Foot Modulates Soleus Force-Velocity Behaviour during Human Walking.
Takahashi, Kota Z; Gross, Michael T; van Werkhoven, Herman; Piazza, Stephen J; Sawicki, Gregory S
2016-07-15
Previous studies of human locomotion indicate that foot and ankle structures can interact in complex ways. The structure of the foot defines the input and output lever arms that influences the force-generating capacity of the ankle plantar flexors during push-off. At the same time, deformation of the foot may dissipate some of the mechanical energy generated by the plantar flexors during push-off. We investigated this foot-ankle interplay during walking by adding stiffness to the foot through shoes and insoles, and characterized the resulting changes in in vivo soleus muscle-tendon mechanics using ultrasonography. Added stiffness decreased energy dissipation at the foot (p < 0.001) and increased the gear ratio (i.e., ratio of ground reaction force and plantar flexor muscle lever arms) (p < 0.001). Added foot stiffness also altered soleus muscle behaviour, leading to greater peak force (p < 0.001) and reduced fascicle shortening speed (p < 0.001). Despite this shift in force-velocity behaviour, the whole-body metabolic cost during walking increased with added foot stiffness (p < 0.001). This increased metabolic cost is likely due to the added force demand on the plantar flexors, as walking on a more rigid foot/shoe surface compromises the plantar flexors' mechanical advantage.
Dagar, Vikas Kumar; Adivitiya; Devi, Nirmala; Khasa, Yogender Pal
2016-10-01
Human interleukin-3 (hIL-3) is a therapeutically important cytokine involved in the maturation and differentiation of various cells of the immune system. The codon-optimized hIL-3 gene was cloned in fusion with the N-terminus α-mating factor signal peptide of Saccharomyces cerevisiae under an inducible alcohol oxidase 1 (AOX1) and constitutive glyceraldehyde-3-phosphate dehydrogenase (GAP) promoter. A Zeocin concentration up to 2000 mg/L was used to select hyper-producers. The shake flask cultivation studies in the Pichia pastoris GS115 host resulted a maximum recombinant hIL-3 expression level of 145 mg/L in the extracellular medium under the control of AOX1 promoter. The batch fermentation strategy allowed us to attain a fairly pure glycosylated hIL-3 protein in the culture supernatant at a final concentration of 475 mg/L with a high volumetric productivity of 4.39 mg/L/h. The volumetric product concentration achieved at bioreactor level was 3.28 folds greater than the shake flask results. The 6x His-tagged protein was purified using Ni-NTA affinity chromatography and confirmed further by western blot analysis using anti-6x His tag antibody. The glycosylation of recombinant hIL-3 protein was confirmed in a PNGase F deglycosylation reaction where it showed a molecular weight band pattern similar to E. coli produced non-glycosylated hIL-3 protein. The structural properties of recombinant hIL-3 protein were confirmed by CD and fluorescence spectroscopy where protein showed 40 % α-helix, 12 % β-sheets with an emission maxima at 343 nm. MALDI-TOF-TOF analysis was used to establish the protein identity. The biological activity of purified protein was confirmed by the human erythroleukemia TF-1 cell proliferation assay.
Epigenetic functions enriched in transcription factors binding to mouse recombination hotspots.
Wu, Min; Kwoh, Chee-Keong; Przytycka, Teresa M; Li, Jing; Zheng, Jie
2012-06-21
The regulatory mechanism of recombination is a fundamental problem in genomics, with wide applications in genome-wide association studies, birth-defect diseases, molecular evolution, cancer research, etc. In mammalian genomes, recombination events cluster into short genomic regions called "recombination hotspots". Recently, a 13-mer motif enriched in hotspots is identified as a candidate cis-regulatory element of human recombination hotspots; moreover, a zinc finger protein, PRDM9, binds to this motif and is associated with variation of recombination phenotype in human and mouse genomes, thus is a trans-acting regulator of recombination hotspots. However, this pair of cis and trans-regulators covers only a fraction of hotspots, thus other regulators of recombination hotspots remain to be discovered. In this paper, we propose an approach to predicting additional trans-regulators from DNA-binding proteins by comparing their enrichment of binding sites in hotspots. Applying this approach on newly mapped mouse hotspots genome-wide, we confirmed that PRDM9 is a major trans-regulator of hotspots. In addition, a list of top candidate trans-regulators of mouse hotspots is reported. Using GO analysis we observed that the top genes are enriched with function of histone modification, highlighting the epigenetic regulatory mechanisms of recombination hotspots.
Epigenetic functions enriched in transcription factors binding to mouse recombination hotspots
2012-01-01
The regulatory mechanism of recombination is a fundamental problem in genomics, with wide applications in genome-wide association studies, birth-defect diseases, molecular evolution, cancer research, etc. In mammalian genomes, recombination events cluster into short genomic regions called "recombination hotspots". Recently, a 13-mer motif enriched in hotspots is identified as a candidate cis-regulatory element of human recombination hotspots; moreover, a zinc finger protein, PRDM9, binds to this motif and is associated with variation of recombination phenotype in human and mouse genomes, thus is a trans-acting regulator of recombination hotspots. However, this pair of cis and trans-regulators covers only a fraction of hotspots, thus other regulators of recombination hotspots remain to be discovered. In this paper, we propose an approach to predicting additional trans-regulators from DNA-binding proteins by comparing their enrichment of binding sites in hotspots. Applying this approach on newly mapped mouse hotspots genome-wide, we confirmed that PRDM9 is a major trans-regulator of hotspots. In addition, a list of top candidate trans-regulators of mouse hotspots is reported. Using GO analysis we observed that the top genes are enriched with function of histone modification, highlighting the epigenetic regulatory mechanisms of recombination hotspots. PMID:22759569
Accelerators of Osteogenesis by Recombinant Human Bone Morphogenetic Protein-2
Okubo, Yasunori; Kusumoto, Kenji; Bessho, Kazuhisa
2007-01-01
Bone morphogenetic protein (BMP) appears to be one of the most promising cytokine and for clinical use in reconstructive surgery for bony defects and augmentation. To evaluate the effect of basic fibroblast growth factor (bFGF), FK506, elcatonin, and hyperbaric oxygenation (HBO) on osteoinduction by recombinant human bone morphogenetic protein-2 (rhBMP-2), 2 or 5 μg of rhBMP-2 was implanted into intramuscular sites of rats. At 21 days after implantation, the osteoinductive activity in the treatment group and control group was compared radiographically, biochemically, and histologically. The amount of new bone in the treatment group was significantly greater than that in the control group. The alkaline phosphatase activity and calcium content in the treatment group were significantly higher than those in the control group. These results suggest that bFGF, FK506, elcatonin, and HBO accelerated the activity and rate of osteoinduction by rhBMP2. These results may be useful when BMP is applied clinically in near future. PMID:21901062
Yang, Tai-Yun; Chiang, Nien-Yi; Tseng, Wen-Yi; Pan, Hsiao-Lin; Peng, Yen-Ming; Shen, Jiann-Jong; Wu, Kuo-An; Kuo, Ming-Ling; Chang, Gin-Wen; Lin, Hsi-Hsien
2015-05-01
GPR56 is a multi-functional adhesion-class G protein-coupled receptor involved in biological systems as diverse as brain development, male gonad development, myoblast fusion, hematopoietic stem cell maintenance, tumor growth and metastasis, and immune-regulation. Ectodomain shedding of human GPR56 receptor has been demonstrated previously, however the quantitative detection of GPR56 receptor shedding has not been investigated fully due to the lack of appropriate assays. Herein, an efficient system of expression and immune-affinity purification of the recombinant soluble extracellular domain of human GPR56 (sGPR56) protein from a stably transduced human melanoma cell line was established. The identity and functionality of the recombinant human sGPR56 protein were verified by Western blotting and mass spectrometry, and ligand-binding assays, respectively. Combined with the use of two recently generated anti-GPR56 monoclonal antibodies, a sensitive sandwich ELISA assay was successfully developed for the quantitative detection of human sGPR56 molecule. We found that GPR56 receptor shedding occurred constitutively and was further increased in activated human melanoma cells expressing endogenous GPR56. In conclusion, we report herein an efficient system for the production and purification of human sGPR56 protein for the establishment of a quantitative ELISA analysis of GPR56 receptor shedding. Copyright © 2014 Elsevier Inc. All rights reserved.
Ireno, Ivanildce C; Baumann, Cindy; Stöber, Regina; Hengstler, Jan G; Wiesmüller, Lisa
2014-05-01
In vitro genotoxicity tests are known to suffer from several shortcomings, mammalian cell-based assays, in particular, from low specificities. Following a novel concept of genotoxicity detection, we developed a fluorescence-based method in living human cells. The assay quantifies DNA recombination events triggered by DNA double-strand breaks and damage-induced replication fork stalling predicted to detect a broad spectrum of genotoxic modes of action. To maximize sensitivities, we engineered a DNA substrate encompassing a chemoresponsive element from the human genome. Using this substrate, we screened various human tumor and non-transformed cell types differing in the DNA damage response, which revealed that detection of genotoxic carcinogens was independent of the p53 status but abrogated by apoptosis. Cell types enabling robust and sensitive genotoxicity detection were selected for the generation of reporter clones with chromosomally integrated DNA recombination substrate. Reporter cell lines were scrutinized with 21 compounds, stratified into five sets according to the established categories for identification of carcinogenic compounds: genotoxic carcinogens ("true positives"), non-genotoxic carcinogens, compounds without genotoxic or carcinogenic effect ("true negatives") and non-carcinogenic compounds, which have been reported to induce chromosomal aberrations or mutations in mammalian cell-based assays ("false positives"). Our results document detection of genotoxic carcinogens in independent cell clones and at levels of cellular toxicities <60 % with a sensitivity of >85 %, specificity of ≥90 % and detection of false-positive compounds <17 %. Importantly, through testing cyclophosphamide in combination with primary hepatocyte cultures, we additionally provide proof-of-concept for the identification of carcinogens requiring metabolic activation using this novel assay system.
The Human Membrane Cofactor CD46 Is a Receptor for Species B Adenovirus Serotype 3
Sirena, Dominique; Lilienfeld, Benjamin; Eisenhut, Markus; Kälin, Stefan; Boucke, Karin; Beerli, Roger R.; Vogt, Lorenz; Ruedl, Christiane; Bachmann, Martin F.; Greber, Urs F.; Hemmi, Silvio
2004-01-01
Many human adenovirus (Ad) serotypes use the coxsackie B virus-Ad receptor (CAR). Recently, CD46 was suggested to be a receptor of species B Ad serotype 11 (Ad11), Ad14, Ad16, Ad21, Ad35, and Ad50. Using Sindbis virus-mediated cDNA library expression, we identify here the membrane cofactor protein CD46 as a surface receptor of species B Ad3. All four major CD46 transcripts and one minor CD46 transcript expressed in nucleated human cells were isolated. Rodent BHK cells stably expressing the BC1 form of CD46 bound radiolabeled Ad3 with a dissociation constant of 0.3 nM, identical to that of CD46-positive HeLa cells expressing twice as many Ad3 binding sites. Pull-down experiments with recombinant Ad3 fibers and a soluble form of the CD46 extracellular domain linked to the Fc portion of human immunoglobulin G (CD46ex-Fc) indicated direct interactions of the Ad3 fiber knob with CD46ex-Fc but not CARex-Fc (Fc-linked extracellular domain of CAR). Ad3 colocalized with cell surface CD46 in both rodent and human cells at the light and electron microscopy levels. Anti-CD46 antibodies and CD46ex-Fc inhibited Ad3 binding to CD46-expressing BHK cells more than 10-fold and to human cells 2-fold. In CD46-expressing BHK cells, wild-type Ad3 and a chimeric Ad consisting of the Ad5 capsid and the Ad3 fiber elicited dose-dependent cytopathic effects and transgene expression, albeit less efficiently than in human cells. Together, our results show that all of the major splice forms of CD46 are predominant and functional binding sites of Ad3 on CD46-expressing rodent and human cells but may not be the sole receptor of species B Ads on human cells. These results have implications for understanding viral pathogenesis and therapeutic gene delivery. PMID:15078926
The human membrane cofactor CD46 is a receptor for species B adenovirus serotype 3.
Sirena, Dominique; Lilienfeld, Benjamin; Eisenhut, Markus; Kälin, Stefan; Boucke, Karin; Beerli, Roger R; Vogt, Lorenz; Ruedl, Christiane; Bachmann, Martin F; Greber, Urs F; Hemmi, Silvio
2004-05-01
Many human adenovirus (Ad) serotypes use the coxsackie B virus-Ad receptor (CAR). Recently, CD46 was suggested to be a receptor of species B Ad serotype 11 (Ad11), Ad14, Ad16, Ad21, Ad35, and Ad50. Using Sindbis virus-mediated cDNA library expression, we identify here the membrane cofactor protein CD46 as a surface receptor of species B Ad3. All four major CD46 transcripts and one minor CD46 transcript expressed in nucleated human cells were isolated. Rodent BHK cells stably expressing the BC1 form of CD46 bound radiolabeled Ad3 with a dissociation constant of 0.3 nM, identical to that of CD46-positive HeLa cells expressing twice as many Ad3 binding sites. Pull-down experiments with recombinant Ad3 fibers and a soluble form of the CD46 extracellular domain linked to the Fc portion of human immunoglobulin G (CD46ex-Fc) indicated direct interactions of the Ad3 fiber knob with CD46ex-Fc but not CARex-Fc (Fc-linked extracellular domain of CAR). Ad3 colocalized with cell surface CD46 in both rodent and human cells at the light and electron microscopy levels. Anti-CD46 antibodies and CD46ex-Fc inhibited Ad3 binding to CD46-expressing BHK cells more than 10-fold and to human cells 2-fold. In CD46-expressing BHK cells, wild-type Ad3 and a chimeric Ad consisting of the Ad5 capsid and the Ad3 fiber elicited dose-dependent cytopathic effects and transgene expression, albeit less efficiently than in human cells. Together, our results show that all of the major splice forms of CD46 are predominant and functional binding sites of Ad3 on CD46-expressing rodent and human cells but may not be the sole receptor of species B Ads on human cells. These results have implications for understanding viral pathogenesis and therapeutic gene delivery.
Abbink, Peter; Lemckert, Angelique A C; Ewald, Bonnie A; Lynch, Diana M; Denholtz, Matthew; Smits, Shirley; Holterman, Lennart; Damen, Irma; Vogels, Ronald; Thorner, Anna R; O'Brien, Kara L; Carville, Angela; Mansfield, Keith G; Goudsmit, Jaap; Havenga, Menzo J E; Barouch, Dan H
2007-05-01
Recombinant adenovirus serotype 5 (rAd5) vector-based vaccines are currently being developed for both human immunodeficiency virus type 1 and other pathogens. The potential limitations associated with rAd5 vectors, however, have led to the construction of novel rAd vectors derived from rare Ad serotypes. Several rare serotype rAd vectors have already been described, but a detailed comparison of multiple rAd vectors from subgroups B and D has not previously been reported. Such a comparison is critical for selecting optimal rAd vectors for advancement into clinical trials. Here we describe the construction of three novel rAd vector systems from Ad26, Ad48, and Ad50. We report comparative seroprevalence and immunogenicity studies involving rAd11, rAd35, and rAd50 vectors from subgroup B; rAd26, rAd48, and rAd49 vectors from subgroup D; and rAd5 vectors from subgroup C. All six rAd vectors from subgroups B and D exhibited low seroprevalence in a cohort of 200 individuals from sub-Saharan Africa, and they elicited Gag-specific cellular immune responses in mice both with and without preexisting anti-Ad5 immunity. The rAd vectors from subgroup D were also evaluated using rhesus monkeys and were shown to be immunogenic after a single injection. The rAd26 vectors proved the most immunogenic among the rare serotype rAd vectors studied, although all rare serotype rAd vectors were still less potent than rAd5 vectors in the absence of anti-Ad5 immunity. These studies substantially expand the portfolio of rare serotype rAd vectors that may prove useful as vaccine vectors for the developing world.
Wen, Xiaobo; Cao, Dianjun; Jones, Ronald W; Li, Jianping; Szu, Shousun; Hoshino, Yasutaka
2012-09-21
Two currently licensed live oral rotavirus vaccines (Rotarix® and RotaTeq®) are highly efficacious against severe rotavirus diarrhea. However, the efficacy of such vaccines in selected low-income African and Asian countries is much lower than that in middle or high-income countries. Additionally, these two vaccines have recently been associated with rare case of intussusception in vaccinated infants. We developed a novel recombinant subunit parenteral rotavirus vaccine which may be more effective in low-income countries and also avert the potential problem of intussusception. Truncated recombinant VP8* (ΔVP8*) protein of human rotavirus strain Wa P[8], DS-1 P[4] or 1076 P[6] expressed in Escherichia coli was highly soluble and was generated in high yield. Guinea pigs hyperimmunized intramuscularly with each of the ΔVP8* proteins (i.e., P[8], P[4] or P[6]) developed high levels of homotypic as well as variable levels of heterotypic neutralizing antibodies. Moreover, the selected ΔVP8* proteins when administered to mice at a clinically relevant dosage, route and schedule, elicited high levels of serum anti-VP8* IgG and/or neutralizing antibodies. Our data indicated that the ΔVP8* proteins may be a plausible additional candidate as new parenteral rotavirus vaccines. Published by Elsevier Ltd.
Wen, Xiaobo; Cao, Dianjun; Jones, Ronald W.; Li, Jianping; Szu, Shousun; Hoshino, Yasutaka
2012-01-01
Two currently licensed live oral rotavirus vaccines (Rotarix® and RotaTeq®) are highly efficacious against severe rotavirus diarrhea. However, the efficacy of such vaccines in selected low-income African and Asian countries is much lower than that in middle or high-income countries. Additionally, these two vaccines have recently been associated with rare case of intussusception in vaccinated infants. We developed a novel recombinant subunit parenteral rotavirus vaccine which may be more effective in low-income countries and also avert the potential problem of intussusception. Truncated recombinant VP8* (ΔVP8*) protein of human rotavirus strain Wa P[8], DS-1 P[4] or 1076 P[6] expressed in E. coli was highly soluble and was generated in high yield. Guinea pigs hyperimmunized intramuscularly with each of the ΔVP8* proteins (i.e., (P[8], P[4] or P[6]) developed high levels of homotypic as well as variable levels of heterotypic neutralizing antibodies. Moreover, the selected ΔVP8* proteins when administered to mice at a clinically relevant dosage, route and schedule, elicited high levels of serum anti-VP8* IgG and/or neutralizing antibodies. Our data indicated that the ΔVP8* proteins may be a plausible additional candidate as new parenteral rotavirus vaccines. PMID:22885016
Sepsova, Vendula; Karasova, Jana Zdarova; Korabecny, Jan; Dolezal, Rafael; Zemek, Filip; Bennion, Brian J.; Kuca, Kamil
2013-01-01
Acetylcholinesterase (AChE) reactivators were developed for the treatment of organophosphate intoxication. Standard care involves the use of anticonvulsants (e.g., diazepam), parasympatolytics (e.g., atropine) and oximes that restore AChE activity. However, oximes also bind to the active site of AChE, simultaneously acting as reversible inhibitors. The goal of the present study is to determine how oxime structure influences the inhibition of human recombinant AChE (hrAChE). Therefore, 24 structurally different oximes were tested and the results compared to the previous eel AChE (EeAChE) experiments. Structural factors that were tested included the number of pyridinium rings, the length and structural features of the linker, and the number and position of the oxime group on the pyridinium ring. PMID:23959117
Evidence for mitochondrial DNA recombination in a human population of island Melanesia.
Hagelberg, E; Goldman, N; Lió, P; Whelan, S; Schiefenhövel, W; Clegg, J B; Bowden, D K
1999-01-01
Mitochondrial DNA (mtDNA) analysis has proved useful in studies of recent human evolution and the genetic affinities of human groups of different geographical regions. As part of an extensive survey of mtDNA diversity in present-day Pacific populations, we obtained sequence information of the hypervariable mtDNA control region of 452 individuals from various localities in the western Pacific. The mtDNA types fell into three major groups which reflect the settlement history of the area. Interestingly, we detected an extremely rare point mutation at high frequency in the small island of Nguna in the Melanesian archipelago of Vanuatu. Phylogenetic analysis of the mtDNA data indicated that the mutation was present in individuals of separate mtDNA lineages. We propose that the multiple occurrence of a rare mutation event in one isolated locality is highly improbable, and that recombination between different mtDNA types is a more likely explanation for our observation. If correct, this conclusion has important implications for the use of mtDNA in phylogenetic and evolutionary studies. PMID:10189712
Antibacterial activity of recombinant human lactoferrin from rice: effect of heat treatment.
Conesa, Celia; Rota, Carmen; Castillo, Eduardo; Pérez, María-Dolores; Calvo, Miguel; Sánchez, Lourdes
2009-06-01
The antibacterial activity of recombinant human lactoferrin from rice (rhLF) compared with that of human milk lactoferrin (hLF) was evaluated against Escherichia coli O157:H7, Salmonella Enteritidis and Listeria monocytogenes. The hydrolysates of rhLF and hLF were found to be more active than native proteins against E. coli O157:H7, and their activity was independent of their iron saturation. The effect of different heat treatments on the antibacterial activity of apo-rhLF was studied and compared with hLF. We observed that an HTST pasteurization treatment did not affect the antimicrobial activity of lactoferrin against the pathogens studied. Furthermore, the activity of apo-rhLF and hLF against E. coli O157:H7 and L. monocytogenes in UHT milk and whey was assayed, finding a decrease in the number of bacteria, although lower than that observed in a broth medium. This study shows the similar antibacterial activity of rhLF and hLF which is important in order to consider the addition of rhLF as a supplement in special products.
Evidence for mitochondrial DNA recombination in a human population of island Melanesia.
Hagelberg, E; Goldman, N; Lió, P; Whelan, S; Schiefenhövel, W; Clegg, J B; Bowden, D K
1999-03-07
Mitochondrial DNA (mtDNA) analysis has proved useful in studies of recent human evolution and the genetic affinities of human groups of different geographical regions. As part of an extensive survey of mtDNA diversity in present-day Pacific populations, we obtained sequence information of the hypervariable mtDNA control region of 452 individuals from various localities in the western Pacific. The mtDNA types fell into three major groups which reflect the settlement history of the area. Interestingly, we detected an extremely rare point mutation at high frequency in the small island of Nguna in the Melanesian archipelago of Vanuatu. Phylogenetic analysis of the mtDNA data indicated that the mutation was present in individuals of separate mtDNA lineages. We propose that the multiple occurrence of a rare mutation event in one isolated locality is highly improbable, and that recombination between different mtDNA types is a more likely explanation for our observation. If correct, this conclusion has important implications for the use of mtDNA in phylogenetic and evolutionary studies.
Yin, Xiaotao; Wang, Wei; Tian, Renli; Xu, Yuanji; Yan, Jinqi; Zhang, Wei; Gao, Jiangping; Yu, Jiyun
2013-08-01
To construct a prokaryotic expression plasmid pET28a-survivin, optimize the recombinant protein expression conditions in E.coli, and purify the survivin recombinant protein and identify its antigenicity. Survivin cDNA segment was amplified by PCR and cloned into prokaryotic expression vector pET28a(+) to construct the recombinant expression vector pET28a-survivin. The expression vector was transformed into BL21 (DE3) and the fusion protein survivin/His was induced by IPTG. The fusion protein was purified through Ni affinity chromatography. The antigenicity of the purified survivin protein was identified by Western blotting and ELISA. The recombinant expression vector was verified successfully by BamHI and HindIII. The fusion protein induced by IPTG was obtained with Mr; about 24 000. The purity of the purified protein reached 90% by SDS-PAGE analysis. And the antigenicity of the survivin protein was validated by Western blotting and ELISA. The prokaryotic expression plasmid pET28a-survivin was successfully constructed and the survivin protein was expressed and purified in E.coli. The antigenicity of the purified survivin protein was demonstrated desirable.
Saito, H; Hatake, K; Dvorak, A M; Leiferman, K M; Donnenberg, A D; Arai, N; Ishizaka, K; Ishizaka, T
1988-01-01
Effects of recombinant human interleukins on hematopoiesis were explored by using suspension cultures of mononuclear cells of human umbilical-cord blood and bone marrow. The results showed that interleukin 5 induced the selective differentiation and proliferation of eosinophils. After 3 weeks in culture with interleukin 5, essentially all nonadherent cells in both bone marrow and cord blood cell cultures became eosinophilic myelocytes. Culture of the same cells with interleukin 4 resulted in the selective growth of OKT3+ lymphocytes. However, OKT3+ cells did not develop if the bone marrow cells were depleted of OKT3+/OKT11+ cells prior to the culture, indicating that interleukin 4 induced the proliferation of a subpopulation of resting T cells present in cord blood and bone marrow cell preparations. In suspension cultures of bone marrow cells and cord blood cells grown in the presence of interleukin 3, basophilic, eosinophilic, and neutrophilic myelocytes and macrophages developed within 2 weeks. By 3 weeks, however, the majority of nonadherent cells became eosinophilic myelocytes. In contrast to mouse bone marrow cell cultures, neither interleukin 3 nor a combination of interleukins 3 and 4 induced the differentiation of mast cells in human bone marrow or cord blood cell cultures. Images PMID:3258425
Hansen-Hagge, T E; Yokota, S; Reuter, H J; Schwarz, K; Bartram, C R
1992-11-01
Rearrangements of the T-cell receptor (TCR) delta locus are observed in the majority of human B-cell precursor acute lymphoblastic leukemias (ALL) with a striking predominance of V delta 2(D)D delta 3 recombinations in common ALL (cALL) patients. Recently, we and others showed that almost 20% of cALL cases are characterized by further recombination of V delta 2(D)D delta 3 segments to J alpha elements, thereby deleting the TCR delta locus in analogy to the delta Rec/psi J alpha pathway in differentiating alpha/beta-positive T cells. We report here that two human cALL-derived cell lines, REH and Nalm-6, are competent to recombine the TCR delta/alpha locus under standard tissue culture conditions. Analysis of different REH subclones obtained by limiting dilution of the initial culture showed a biased recombination of V delta 2D delta 3 to distinct J alpha elements. During prolonged tissue culture, a subclone acquired growth advantage and displaced parental cells as well as other subclones. Frequently, the DJ junctions of REH subclones contained extended stretches of palindromic sequences derived from modified D delta 3 coding elements. The other cell line, Nalm-6, started the TCR delta/alpha recombination with an unusual signal joint of a cryptic recombinase signal sequence (RSS) upstream of D delta 3 to the 3' RSS of D delta 3. The RSS dimer was subsequently rearranged in all investigated subclones to an identical J alpha element. Both cell lines might become valuable tools to unravel the complex regulation of TCR delta/alpha recombination pathways in malignant and normal lymphopoiesis.
da Cunha, Nicolau B; Vianna, Giovanni R; da Almeida Lima, Thaina; Rech, Elíbio
2014-01-01
Plants have emerged as an attractive alternative to the traditional mammalian cell cultures or microbial cell-based systems system for the production of valuable recombinant proteins. Through recombinant DNA technology, plants can be engineered to produce large quantities of pharmaceuticals and industrial proteins of high quality at low costs. The recombinant production, by transgenic plants, of therapeutic proteins normally present in human plasma, such as cytokines, coagulation factors, anticoagulants, and immunoglobulins, represents a response to the ongoing challenges in meeting the demand for therapeutic proteins to treat serious inherited or acquired bleeding and immunological diseases. As the clinical utilization of fractionated plasma molecules is limited by high production costs, using recombinant biopharmaceuticals derived from plants represents a feasible alternative to provide efficient treatment. Plant-derived pharmaceuticals also reduce the potential risks to patients of infection with pathogens or unwanted immune responses due to immunogenic antigens. In this review, we summarize the recent advances in molecular farming of cytokines. We also examine the technological basis, upcoming challenges, and perspectives for the biosynthesis and detection of these molecules in different plant production platforms. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
The Ad5 [E1-, E2b-]-based vector: a new and versatile gene delivery platform
NASA Astrophysics Data System (ADS)
Jones, Frank R.; Gabitzsch, Elizabeth S.; Balint, Joseph P.
2015-05-01
Based upon advances in gene sequencing and construction, it is now possible to identify specific genes or sequences thereof for gene delivery applications. Recombinant adenovirus serotype-5 (Ad5) viral vectors have been utilized in the settings of gene therapy, vaccination, and immunotherapy but have encountered clinical challenges because they are recognized as foreign entities to the host. This recognition leads to an immunologic clearance of the vector that contains the inserted gene of interest and prevents effective immunization(s). We have reported on a new Ad5-based viral vector technology that can be utilized as an immunization modality to induce immune responses even in the presence of Ad5 vector immunity. We have reported successful immunization and immunotherapy results to infectious diseases and cancers. This improved recombinant viral platform (Ad5 [E1-, E2b-]) can now be utilized in the development of multiple vaccines and immunotherapies.
Tufail, Soban; Ismat, Fouzia; Imran, Muhammad; Iqbal, Mazhar; Mirza, Osman; Rhaman, Moazur
2016-01-01
Proteases are widely used to remove affinity and solubility tags from recombinant proteins to avoid potential interference of these tags with the structure and function of the fusion partner. In recent years, great interest has been seen in use of the human rhinovirus 3C protease owing to its stringent sequence specificity and enhanced activity. Like other proteases, activity of the human rhinovirus 3C protease can be affected in part by the buffer components and additives that are generally employed for purification and stabilization of proteins, hence, necessitate their removal by tedious and time-consuming procedures before proteolysis can occur. To address this issue, we examined the effect of elution buffers used for common affinity based purifications, salt ions, stability/solubility and reducing agents, and detergents on the activity of the human rhinovirus 3C protease using three different fusion proteins at 4°C, a temperature of choice for purification of many proteins. The results show that the human rhinovirus 3C protease performs better at 4°C than the frequently used tobacco etch virus protease and its activity was insensitive to most of the experimental conditions tested. Though number of fusion proteins tested is limited, we expect that these finding will facilitate the use of the human rhinovirus 3C protease in recombinant protein production for pharmaceutical and biotechnological applications. PMID:27093053
Ullah, Raheem; Shah, Majid Ali; Tufail, Soban; Ismat, Fouzia; Imran, Muhammad; Iqbal, Mazhar; Mirza, Osman; Rhaman, Moazur
2016-01-01
Proteases are widely used to remove affinity and solubility tags from recombinant proteins to avoid potential interference of these tags with the structure and function of the fusion partner. In recent years, great interest has been seen in use of the human rhinovirus 3C protease owing to its stringent sequence specificity and enhanced activity. Like other proteases, activity of the human rhinovirus 3C protease can be affected in part by the buffer components and additives that are generally employed for purification and stabilization of proteins, hence, necessitate their removal by tedious and time-consuming procedures before proteolysis can occur. To address this issue, we examined the effect of elution buffers used for common affinity based purifications, salt ions, stability/solubility and reducing agents, and detergents on the activity of the human rhinovirus 3C protease using three different fusion proteins at 4°C, a temperature of choice for purification of many proteins. The results show that the human rhinovirus 3C protease performs better at 4°C than the frequently used tobacco etch virus protease and its activity was insensitive to most of the experimental conditions tested. Though number of fusion proteins tested is limited, we expect that these finding will facilitate the use of the human rhinovirus 3C protease in recombinant protein production for pharmaceutical and biotechnological applications.
Xue, Haipeng; Wu, Sen; Papadeas, Sophia T; Spusta, Steve; Swistowska, Anna Maria; MacArthur, Chad C; Mattson, Mark P; Maragakis, Nicholas J; Capecchi, Mario R; Rao, Mahendra S; Zeng, Xianmin; Liu, Ying
2009-08-01
In this study, we targeted Olig2, a basic helix-loop-helix transcription factor that plays an important role in motoneuron and oligodendrocyte development, in human embryonic stem cell (hESC) line BG01 by homologous recombination. One allele of Olig2 locus was replaced by a green fluorescent protein (GFP) cassette with a targeting efficiency of 5.7%. Targeted clone R-Olig2 (like the other clones) retained pluripotency, typical hESC morphology, and a normal parental karyotype 46,XY. Most importantly, GFP expression recapitulated endogenous Olig2 expression when R-Olig2 was induced by sonic hedgehog and retinoic acid, and GFP-positive cells could be purified by fluorescence-activated cell sorting. Consistent with previous reports on rodents, early GFP-expressing cells appeared biased to a neuronal fate, whereas late GFP-expressing cells appeared biased to an oligodendrocytic fate. This was corroborated by myoblast coculture, transplantation into the rat spinal cords, and whole genome expression profiling. The present work reports an hESC reporter line generated by homologous recombination targeting a neural lineage-specific gene, which can be differentiated and sorted to obtain pure neural progenitor populations.
Cheong, Fei Wen; Lau, Yee Ling; Fong, Mun Yik; Mahmud, Rohela
2013-01-01
Plasmodium knowlesi is now known as the fifth Plasmodium species that can cause human malaria. The Plasmodium merozoite surface protein (MSP) has been reported to be potential target for vaccination and diagnosis of malaria. MSP-133 has been shown to be immunogenic and its T cell epitopes could mediate cellular immune protection. However, limited studies have focused on P. knowlesi MSP-133. In this study, an approximately 28-kDa recombinant P. knowlesi MSP-133 (pkMSP-133) was expressed by using an Escherichia coli system. The purified pkMSP-133 reacted with serum samples of patients infected with P. knowlesi (31 of 31, 100%) and non-P. knowlesi malaria (27 of 28, 96.43%) by Western blotting. The pkMSP-133 also reacted with P. knowlesi (25 of 31, 80.65%) and non-P. knowlesi malaria sera (20 of 28, 71.43%) in an enzyme-linked immunosorbent assay (ELISA). Most of the non-malarial infection (49 of 52 in by Western blotting and 46 of 52 in the ELISA) and healthy donor serum samples (65 of 65 by Western blotting and ELISA) did not react with recombinant pkMSP-133. PMID:23509118
Yamashita, Toshiharu; Okura, Masae; Ishii-Osai, Yasue; Hida, Tokimasa
2016-10-01
Because patients with xeroderma pigmentosum (XP) must avoid ultraviolet (UV) light from an early age, an early diagnosis of this disorder is essential. XP is composed of seven genetic complementation groups, XP-A to -G, and a variant type (XP-V). To establish an easy and accurate diagnosis of the eight disease groups, we constructed recombinant adenoviruses that expressed one of the XP cDNA. When fibroblasts derived from patients with XP-A, -B, -C, -D, -F or -G were infected with the adenovirus expressing XPA, XPB, XPC, XPD, XPF or XPG, respectively, and UV-C at 5-20 J/m 2 was irradiated, cell viability was clearly recovered by the corresponding recombinant adenoviruses. In contrast, XP-E and XP-V cells were not significantly sensitive to UV irradiation and were barely complemented by the matched recombinant adenoviruses. However, co-infection of Ad-XPA with Ad-XPE increased survival rate of XP-E cells after UV-C exposure. When XP-V cell strains, including one derived from a Japanese patient, were infected with Ad-XPV, exposed to UV-B and cultured with 1 mmol/L of caffeine, flow cytometry detected a characteristic decrease in the S phase in all the XP-V cell strains. From these results, the eight groups of XP could be differentiated by utilizing a set of recombinant adenoviruses, indicating that our procedure provides a convenient and correct diagnostic method for all the XP groups including XP-E and XP-V. © 2016 Japanese Dermatological Association.
Al-Ghobashy, Medhat A; Williams, Martin A K; Brophy, Brigid; Laible, Götz; Harding, David R K
2009-06-01
Downstream purification of a model recombinant protein (human myelin basic protein) from milk of transgenic cows is described. The recombinant protein was expressed as a His tagged fusion protein in the milk of transgenic cows and was found associated with the casein micellar phase. While difficulties in obtaining good recoveries were found when employing conventional micelle disruption procedures, direct capture using the cation exchanger SP Sepharose Big Beads was found successful in the extraction of the recombinant protein. Early breakthrough suggested a slow release of the recombinant protein from the micelles and dictated micelle disruption in order to obtain good yields. A new approach for deconstruction of the calcium core of the casein micelles, employing the interaction between the micellar calcium and the active sites of the cation exchanger resin was developed. Milk samples were loaded to the column in aliquots with a column washing step after each aliquot. This sequential loading approach successfully liberated the recombinant protein from the micelles and was found superior to the conventional sample loading approach. It increased the recovery by more than 25%, reduced fouling due to milk components and improved the column hydrodynamic properties as compared to the conventional sample loading approach. Hardware and software modifications to the chromatography system were necessary in order to keep the whole process automated. A second purification step using a Ni2+ affinity column was used to isolate the recombinant protein at purity more than 90% and a recovery percentage of 78%.
Tuppurainen, Laura; Sallinen, Hanna; Karvonen, Anni; Valkonen, Elina; Laakso, Hanne; Liimatainen, Timo; Hytönen, Elisa; Hämäläinen, Kirsi; Kosma, Veli-Matti; Anttila, Maarit; Ylä-Herttuala, Seppo
2017-06-01
Ovarian cancer is highly dependent on tumor microvessels and angiogenesis regulated by vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs) and angiopoietins (Ang) and their Tie receptors. We studied the efficacy of adenoviral (Ad) gene therapy with soluble VEGFR2 and Tie2 combined with paclitaxel and carboplatin for the treatment of ovarian cancer. An intraperitoneal human ovarian cancer xenograft model in nude mice (n = 44) was used in this study. Gene therapy was given intravenously when the presence of sizable tumors was confirmed in magnetic resonance imaging. The study groups were as follows: AdCMV as a control (group I), AdCMV with chemotherapy (group II), AdsVEGFR2 and AdsTie2 (group III), and AdsVEGFR2 and AdsTie2 with chemotherapy (group IV). Antitumor effectiveness was assessed by overall tumor growth, ascites, immunohistochemistry, microvessel density, and sequential magnetic resonance imaging analyses. AdsVEGFR2 and AdsTie2 gene therapy (group III) significantly reduced tumor weights as compared with group II (P = 0.007). Accumulation of ascites was significantly reduced when the mice were treated with AdsVEGFR2 and AdsTie2 gene therapy or with combined gene therapy and chemotherapy as compared with controls (P = 0.029 and P = 0.010, respectively). Vascular endothelial growth factor and Ang2 levels in ascites fluid were elevated after the gene therapy. Combined inhibition of VEGF/VEGFR2 and Ang/Tie2 pathways provided efficient therapy for ovarian cancer in mice. In addition, antiangiogenic gene therapy has potential as a treatment for the accumulation of ascites.
Xue, Haipeng; Wu, Jianbo; Li, Shenglan; Rao, Mahendra S; Liu, Ying
2016-01-01
Genetic modification is an indispensable tool to study gene function in normal development and disease. The recent breakthrough of creating human induced pluripotent stem cells (iPSCs) by defined factors (Takahashi et al., Cell 131:861-872, 2007) provides a renewable source of patient autologous cells that not only retain identical genetic information but also give rise to many cell types of the body including neurons and glia. Meanwhile, the rapid advancement of genome modification tools such as gene targeting by homologous recombination (Capecchi, Nat Rev Genet 6:507-512, 2005) and genome editing tools such as CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)/Cas (CRISPR-associated) system, TALENs (Transcription activator-like effector nucleases), and ZFNs (Zinc finger nucleases) (Wang et al., Cell 153:910-918, 2013; Mali et al., Science 339:823-826, 2013; Hwang et al., Nat Biotechnol 31:227-229, 2013; Friedland et al., Nat Methods 10(8):741-743, 2013; DiCarlo et al., Nucleic Acids Res 41:4336-4343, 2013; Cong et al., Science 339:819-823, 2013) has greatly accelerated the development of human genome manipulation at the molecular level. This chapter describes the protocols for making neural lineage reporter lines using homologous recombination and the CRISPR/Cas system-mediated genome editing, including construction of targeting vectors, guide RNAs, transfection into hPSCs, and selection and verification of successfully targeted clones. This method can be applied to various needs of hPSC genetic engineering at high efficiency and high reliability.
Mabashi-Asazuma, Hideaki; Shi, Xianzong; Geisler, Christoph; Kuo, Chu-Wei; Khoo, Kay-Hooi; Jarvis, Donald L
2013-02-01
Insect cells are widely used for recombinant glycoprotein production, but they cannot provide the glycosylation patterns required for some biotechnological applications. This problem has been addressed by genetically engineering insect cells to express mammalian genes encoding various glycoprotein glycan processing functions. However, for various reasons, the impact of a mammalian cytosine-5'-monophospho (CMP)-sialic acid transporter has not yet been examined. Thus, we transformed Spodoptera frugiperda (Sf9) cells with six mammalian genes to generate a new cell line, SfSWT-4, that can produce sialylated glycoproteins when cultured with the sialic acid precursor, N-acetylmannosamine. We then super-transformed SfSWT-4 with a human CMP-sialic acid transporter (hCSAT) gene to isolate a daughter cell line, SfSWT-6, which expressed the hCSAT gene in addition to the other mammalian glycogenes. SfSWT-6 cells had higher levels of cell surface sialylation and also supported higher levels of recombinant glycoprotein sialylation, particularly when cultured with low concentrations of N-acetylmannosamine. Thus, hCSAT expression has an impact on glycoprotein sialylation, can reduce the cost of recombinant glycoprotein production and therefore should be included in ongoing efforts to glycoengineer the baculovirus-insect cell system. The results of this study also contributed new insights into the endogenous mechanism and potential mechanisms of CMP-sialic acid accumulation in the Golgi apparatus of lepidopteran insect cells.
Houng, Huo-Shu H; Clavio, Sarah; Graham, Katherine; Kuschner, Robert; Sun, Wellington; Russell, Kevin L; Binn, Leonard N
2006-04-01
Ad4 is the principal etiological agent of acute respiratory disease (ARD) in the US military. Discovery of the novel 208bp inverted terminal repeated (ITR) sequence from a recent Ad4 Jax78 field isolate was totally distinct from the analogous 116bp ITR of Ad4 prototype. To investigate the origin and distribution of the novel Ad4 ITR sequence from ARD infections. Direct sequencing of ligated Ad ITR termini. The new Ad4 ITR was highly homologous with the ITRs of human Ad subgroup B. The left post-ITR region of Ad4 Jax78 was found to be highly homologous to the corresponding region of subgroup B Ads: 81% for Ad11 and 98% for Ad3 and Ad7. The right post-ITR region of Ad4 Jax78 contained a truncated classic ITR of the Ad4 prototype. The Ad4 Jax78 ITR most likely evolved from Ad4 prototype by substituting the Ad4 prototype ITR with the subgroup B Ads ITR. The ITR-based PCR assays developed from this study can be used to distinguish the new Ad4 genotype from the classical Ad4 prototype. The new Ad4 genotype was first detected in 1976 from Georgia, USA, and is the main causative agent of ARD infections in US military population.
Effects of Recombinant Human Lactoferrin on Osteoblast Growth and Bone Status in Piglets.
Li, Qiuling; Zhao, Jie; Hu, Wenping; Wang, Jianwu; Yu, Tian; Dai, Yunping; Li, Ning
2018-04-03
Lactoferrin (LF), an ~80 kDa iron-binding glycoprotein, modulates many biological effects, including antimicrobial and immunomodulatory activities. Recently, it was shown that LF also regulates bone cell activity, suggesting its therapeutic effect on postmenopausal bone loss. However, a minimal amount is known regarding the effects of recombinant human LF (rhLF) supplementation on bone status in young healthy infants. We found osteoblast cell differentiation was significantly promoted in vitro. Furthermore, treatment of human osteoblast cells with rhLF rapidly induced phosphorylation of p44/p42 mitogen-activated protein kinase (p44/p42 MAPK, ERK1/2). In order to investigate the effects of rhLF on bone status in vivo, we used a piglet model, which is a useful model for human infants. Piglets were supplemented with rhLF milk for 30 days. Bone formation markers, Serum calcium concentration, bone mineral density (BMD), bone mineral content (BMC), tibia bone strength, and the overall metabolite profile analysis showed that rhLF was advantageous to the bone growth in piglets. These findings suggest that rhLF supplementation benefits neonate bone health by modulating bone formation.
Recombinant Human Factor IX Produced from Transgenic Porcine Milk
Lee, Meng-Hwan; Lin, Yin-Shen; Tu, Ching-Fu; Yen, Chon-Ho
2014-01-01
Production of biopharmaceuticals from transgenic animal milk is a cost-effective method for highly complex proteins that cannot be efficiently produced using conventional systems such as microorganisms or animal cells. Yields of recombinant human factor IX (rhFIX) produced from transgenic porcine milk under the control of the bovine α-lactalbumin promoter reached 0.25 mg/mL. The rhFIX protein was purified from transgenic porcine milk using a three-column purification scheme after a precipitation step to remove casein. The purified protein had high specific activity and a low ratio of the active form (FIXa). The purified rhFIX had 11.9 γ-carboxyglutamic acid (Gla) residues/mol protein, which approached full occupancy of the 12 potential sites in the Gla domain. The rhFIX was shown to have a higher isoelectric point and lower sialic acid content than plasma-derived FIX (pdFIX). The rhFIX had the same N-glycosylation sites and phosphorylation sites as pdFIX, but had a higher specific activity. These results suggest that rhFIX produced from porcine milk is physiologically active and they support the use of transgenic animals as bioreactors for industrial scale production in milk. PMID:24955355
Vaccine platform recombinant measles virus.
Mühlebach, Michael D
2017-10-01
The classic development of vaccines is lengthy, tedious, and may not necessarily be successful as demonstrated by the case of HIV. This is especially a problem for emerging pathogens that are newly introduced into the human population and carry the inherent risk of pandemic spread in a naïve population. For such situations, a considerable number of different platform technologies are under development. These are also under development for pathogens, where directly derived vaccines are regarded as too complicated or even dangerous due to the induction of inefficient or unwanted immune responses causing considerable side-effects as for dengue virus. Among platform technologies are plasmid-based DNA vaccines, RNA replicons, single-round infectious vector particles, or replicating vaccine-based vectors encoding (a) critical antigen(s) of the target pathogens. Among the latter, recombinant measles viruses derived from vaccine strains have been tested. Measles vaccines are among the most effective and safest life-attenuated vaccines known. Therefore, the development of Schwarz-, Moraten-, or AIK-C-strain derived recombinant vaccines against a wide range of mostly viral, but also bacterial pathogens was quite straightforward. These vaccines generally induce powerful humoral and cellular immune responses in appropriate animal models, i.e., transgenic mice or non-human primates. Also in the recent first clinical phase I trial, the results have been quite encouraging. The trial indicated the expected safety and efficacy also in human patients, interestingly independent from the level of prevalent anti-measles immunity before the trial. Thereby, recombinant measles vaccines expressing additional antigens are a promising platform for future vaccines.
Genome-Wide Fine-Scale Recombination Rate Variation in Drosophila melanogaster
Song, Yun S.
2012-01-01
Estimating fine-scale recombination maps of Drosophila from population genomic data is a challenging problem, in particular because of the high background recombination rate. In this paper, a new computational method is developed to address this challenge. Through an extensive simulation study, it is demonstrated that the method allows more accurate inference, and exhibits greater robustness to the effects of natural selection and noise, compared to a well-used previous method developed for studying fine-scale recombination rate variation in the human genome. As an application, a genome-wide analysis of genetic variation data is performed for two Drosophila melanogaster populations, one from North America (Raleigh, USA) and the other from Africa (Gikongoro, Rwanda). It is shown that fine-scale recombination rate variation is widespread throughout the D. melanogaster genome, across all chromosomes and in both populations. At the fine-scale, a conservative, systematic search for evidence of recombination hotspots suggests the existence of a handful of putative hotspots each with at least a tenfold increase in intensity over the background rate. A wavelet analysis is carried out to compare the estimated recombination maps in the two populations and to quantify the extent to which recombination rates are conserved. In general, similarity is observed at very broad scales, but substantial differences are seen at fine scales. The average recombination rate of the X chromosome appears to be higher than that of the autosomes in both populations, and this pattern is much more pronounced in the African population than the North American population. The correlation between various genomic features—including recombination rates, diversity, divergence, GC content, gene content, and sequence quality—is examined using the wavelet analysis, and it is shown that the most notable difference between D. melanogaster and humans is in the correlation between recombination and
Use of recombinant human activated protein C in nonmenstrual staphylococcal toxic shock syndrome.
Nasa, Prashant; Sehrawat, Deepak; Kansal, Sudha; Chawla, Rajesh
2010-07-01
Toxic shock syndrome (TSS) is a serious, potentially life-threatening condition resulting from an overwhelming immunological response to an exotoxin released by Staphylococcus aureus and group A streptococci. High index of suspicion, early diagnosis and aggressive therapeutic measures must be instituted in view of high mortality of the TSS. In recent years, new agents have been tested to reduce morbidity and mortality in patients with severe sepsis, in addition to standard supportive measures. Among them, recombinant human activated protein C (rhAPC) has been reported to significantly reduce mortality and morbidity in patients with severe sepsis and two or more acute organ failures. We describe our experience with this drug in the early reversal of septic shock from TSS.
Heterotopic ossification after the use of recombinant human bone morphogenetic protein-7
Papanagiotou, Marianthi; Dailiana, Zoe H; Karachalios, Theophilos; Varitimidis, Sokratis; Hantes, Michael; Dimakopoulos, Georgios; Vlychou, Marianna; Malizos, Konstantinos N
2017-01-01
AIM To present the incidence of heterotopic ossification after the use of recombinant human bone morphogenetic protein-7 (rhBMP-7) for the treatment of nonunions. METHODS Bone morphogenetic proteins (BMPs) promote bone formation by auto-induction. Recombinant human BMP-7 in combination with bone grafts was used in 84 patients for the treatment of long bone nonunions. All patients were evaluated radiographicaly for the development of heterotopic ossification during the standard assessment for the nonunion healing. In all patients (80.9%) with radiographic signs of heterotopic ossification, a CT scan was performed. Nonunion site palpation and ROM evaluation of the adjacent joints were also carried out. Factors related to the patient (age, gender), the nonunion (location, size, chronicity, number of previous procedures, infection, surrounding tissues condition) and the surgical procedure (graft and fixation type, amount of rhBMP-7) were correlated with the development of heterotopic ossification and statistical analysis with Pearsons χ2 test was performed. RESULTS Eighty point nine percent of the nonunions treated with rhBMP-7, healed with no need for further procedures. Heterotopic bone formation occurred in 15 of 84 patients (17.8%) and it was apparent in the routine radiological evaluation of the nonunion site, in a mean time of 5.5 mo after the rhBMP-7 application (range 3-12). The heterotopic ossification was located at the femur in 8 cases, at the tibia in 6, and at the humerus in οne patient. In 4 patients a palpable mass was present and only in one patient, with a para-articular knee nonunion treated with rhBMP-7, the size of heterotopic ossification affected the knee range of motion. All the patients with heterotopic ossification were male. Statistical analysis proved that patient’s gender was the only important factor for the development of heterotopic ossification (P = 0.007). CONCLUSION Heterotopic ossification after the use of rhBMP-7 in nonunions was
Recombinant poxviruses as mucosal vaccine vectors.
Gherardi, M Magdalena; Esteban, Mariano
2005-11-01
The majority of infections initiate their departure from a mucosal surface, such as Human immunodeficiency virus (HIV), a sexually transmitted virus. Therefore, the induction of mucosal immunity is a high priority in the development of vaccines against mucosal pathogens. The selection of an appropriate antigen delivery system is necessary to induce an efficient mucosal immune response. Poxvirus vectors have been the most intensively studied live recombinant vector, and numerous studies have demonstrated their ability to induce mucosal immune responses against foreign expressed antigens. Previous studies have demonstrated that recombinants based on the attenuated modified vaccinia virus Ankara (MVA) vector were effective in inducing protective responses against different respiratory viruses, such as influenza and respiratory syncytial virus, following immunization via mucosal routes. Recent studies performed in the murine and macaque models have shown that recombinant MVA (rMVA) does not only stimulate HIV-specific immunity in the genital and rectal tracts following mucosal delivery, but can also control simian/human immunodeficiency viraemia and disease progression. In addition, a prime-boost vaccination approach against tuberculosis emphasized the importance of the intranasal rMVA antigen delivery to induce protective immunity against Mycobacterium tuberculosis. The aim of this review is to summarize the studies employing recombinant poxviruses, specifically rMVA as a mucosal delivery vector. The results demonstrate that rMVAs can activate specific immune responses at mucosal surfaces, and encourage further studies to characterize and improve the MVA mucosal immunogenicity of poxvirus vectors.
Human Immunodeficiency Virus Vaccine Trials
O’Connell, Robert J.; Kim, Jerome H.; Corey, Lawrence; Michael, Nelson L.
2012-01-01
More than 2 million AIDS-related deaths occurred globally in 2008, and more than 33 million people are living with HIV/AIDS. Despite promising advances in prevention, an estimated 2.7 million new HIV infections occurred in that year, so that for every two patients placed on combination antiretroviral treatment, five people became infected. The pandemic poses a formidable challenge to the development, progress, and stability of global society 30 years after it was recognized. Experimental preventive HIV-1 vaccines have been administered to more than 44,000 human volunteers in more than 187 separate trials since 1987. Only five candidate vaccine strategies have been advanced to efficacy testing. The recombinant glycoprotein (rgp)120 subunit vaccines, AIDSVAX B/B and AIDSVAX B/E, and the Merck Adenovirus serotype (Ad)5 viral-vector expressing HIV-1 Gag, Pol, and Nef failed to show a reduction in infection rate or lowering of postinfection viral set point. Most recently, a phase III trial that tested a heterologous prime-boost vaccine combination of ALVAC-HIV vCP1521 and bivalent rgp120 (AIDSVAX B/E) showed 31% efficacy in protection from infection among community-risk Thai participants. A fifth efficacy trial testing a DNA/recombinant(r) Ad5 prime-boost combination is currently under way. We review the clinical trials of HIV vaccines that have provided insight into human immunogenicity or efficacy in preventing HIV-1 infection. PMID:23209178
Ochi, Takeshi; Sakamoto, Masato; Minamida, Akira; Suzuki, Kenji; Ueda, Tomohiko; Une, Teruaki; Toda, Hiroshi; Matsumoto, Kazuya; Terauchi, Yoshiaki
2005-02-15
Two major metabolites in humans of blonanserin, 2-(4-ethyl-1-piperazinyl)-4-(4-fluorophenyl)-5,6,7,8,9,10-hexahydrocycloocta-[b]pyridine (code name AD-5423), were synthesized. The first, 7-hydroxylated AD-5423, was synthesized through a four-step process starting from 4-fluorobenzoylacetonitrile (1), and the second, 8-hydroxylated AD-5423, a nine-step process also from 1. The optical resolution, structures, and receptor binding properties of the metabolites were documented.
Bowalgaha, Kushari; Elliot, David J; Mackenzie, Peter I; Knights, Kathleen M; Swedmark, Stellan; Miners, John O
2005-01-01
Aims To characterize the kinetics of S-naproxen (‘naproxen’) acyl glucuronidation and desmethylnaproxen acyl and phenolic glucuronidation by human liver microsomes and identify the human UGT isoform(s) catalysing these reactions. Methods Naproxen and desmethylnaproxen glucuronidation were investigated using microsomes from six and five livers, respectively. Human recombinant UGTs were screened for activity towards naproxen and desmethylnaproxen. Where significant activity was observed, kinetic parameters were determined. Naproxen and desmethylnaproxen glucuronides were measured by separate high-performance liquid chromatography methods. Results Naproxen acyl glucuronidation by human liver microsomes followed biphasic kinetics. Mean apparent Km values (±SD, with 95% confidence interval in parentheses) for the high- and low-affinity components were 29 ± 13 µm (16, 43) and 473 ± 108 µm (359, 587), respectively. UGT 1A1, 1A3, 1A6, 1A7, 1A8, 1A9, 1A10 and 2B7 glucuronidated naproxen. UGT2B7 exhibited an apparent Km (72 µm) of the same order as the high-affinity human liver microsomal activity, which was inhibited by the UGT2B7 selective ‘probe’ fluconazole. Although data for desmethylnaproxen phenolic glucuronidation by human liver microsomes were generally adequately fitted to either the single- or two-enzyme Michaelis–Menten equation, model fitting was inconclusive for desmethylnaproxen acyl glucuronidation. UGT 1A1, 1A7, 1A9 and 1A10 catalysed both the phenolic and acyl glucuronidation of desmethylnaproxen, while UGT 1A3, 1A6 and 2B7 formed only the acyl glucuronide. Atypical glucuronidation kinetics were variably observed for naproxen and desmethylnaproxen glucuronidation by the recombinant UGTs. Conclusion UGT2B7 is responsible for human hepatic naproxen acyl glucuronidation, which is the primary elimination pathway for this drug. PMID:16187975
Expression of Recombinant Antibodies
Frenzel, André; Hust, Michael; Schirrmann, Thomas
2013-01-01
Recombinant antibodies are highly specific detection probes in research, diagnostics, and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transgenic plants and animals. Currently, almost all therapeutic antibodies are still produced in mammalian cell lines in order to reduce the risk of immunogenicity due to altered, non-human glycosylation patterns. However, recent developments of glycosylation-engineered yeast, insect cell lines, and transgenic plants are promising to obtain antibodies with “human-like” post-translational modifications. Furthermore, smaller antibody fragments including bispecific antibodies without any glycosylation are successfully produced in bacteria and have advanced to clinical testing. The first therapeutic antibody products from a non-mammalian source can be expected in coming next years. In this review, we focus on current antibody production systems including their usability for different applications. PMID:23908655
Zeng, Jia; Yi, Soojin V.
2014-01-01
Recombination clusters nonuniformly across mammalian genomes at discrete genomic loci referred to as recombination hotspots. Despite their ubiquitous presence, individual hotspots rapidly lose their activities, and the molecular and evolutionary mechanisms underlying such frequent hotspot turnovers (the so-called “recombination hotspot paradox”) remain unresolved. Even though some sequence motifs are significantly associated with hotspots, multiple lines of evidence indicate that factors other than underlying sequences, such as epigenetic modifications, may affect the evolution of recombination hotspots. Thus, identifying epigenetic factors that covary with recombination at fine-scale is a promising step for this important research area. It was previously reported that recombination rates correlate with indirect measures of DNA methylation in the human genome. Here, we analyze experimentally determined DNA methylation and histone modification of human sperms, and show that the correlation between DNA methylation and recombination in long-range windows does not hold with respect to the spatial and temporal variation of recombination at hotspots. On the other hand, two histone modifications (H3K4me3 and H3K27me3) overlap extensively with recombination hotspots. Similar trends were observed in mice. These results indicate that specific histone modifications rather than DNA methylation are associated with the rapid evolution of recombination hotspots. Furthermore, many human recombination hotspots occupy “bivalent” chromatin regions that harbor both active (H3K4me3) and repressive (H3K27me3) marks. This may explain why human recombination hotspots tend to occur in nongenic regions, in contrast to yeast and Arabidopsis hotspots that are characterized by generally active chromatins. Our results highlight the dynamic epigenetic underpinnings of recombination hotspot evolution. PMID:25326136
Dai, Qun; Aleksandrov, Andrei A.; Bajrami, Bekim; Diego, Pamela Ann; Wu, Xing; Ray, Marjorie; Naren, Anjaparavanda P.; Riordan, John R.; Yao, Xudong; DeLucas, Lawrence J.; Urbatsch, Ina L.; Kappes, John C.
2015-01-01
Recent human clinical trials results demonstrated successful treatment for certain genetic forms of cystic fibrosis (CF). To extend treatment opportunities to those afflicted with other genetic forms of CF disease, structural and biophysical characterization of CF transmembrane conductance regulator (CFTR) is urgently needed. In this study, CFTR was modified with various tags, including a His10 purification tag, the SUMOstar (SUMO*) domain, an extracellular FLAG epitope, or an enhanced green fluorescent protein (EGFP), each alone or in various combinations. Expressed in HEK293 cells, recombinant CFTR proteins underwent complex glycosylation, compartmentalized with the plasma membrane, and exhibited regulated chloride-channel activity with only modest alterations in channel conductance and gating kinetics. Surface CFTR expression level was enhanced by the presence of SUMO* on the N-terminus. Quantitative mass-spectrometric analysis indicated approximately 10% of the total recombinant CFTR (SUMO*-CFTRFLAG-EGFP) localized to the plasma membrane. Trial purification using dodecylmaltoside for membrane protein extraction reproducibly recovered 178 ± 56 μg SUMO*-CFTRFLAG-EGFP per billion cells at 80% purity. Fluorescence size-exclusion chromatography indicated purified CFTR was monodisperse. These findings demonstrate a stable mammalian cell expression system capable of producing human CFTR of sufficient quality and quantity to augment futrure CF drug discovery efforts, including biophysical and structural studies. PMID:25577540
Piano, Valentina; Nenci, Simone; Magnani, Francesca; Aliverti, Alessandro; Mattevi, Andrea
2016-12-02
Although the precise functions of ether phospholipids are still poorly understood, significant alterations in their physiological levels are associated either to inherited disorders or to aggressive metastatic cancer. The essential precursor, alkyl-dihydroxyacetone phosphate (DHAP), for all ether phospholipids species is synthetized in two consecutive reactions performed by two enzymes sitting on the inner side of the peroxisomal membrane. Here, we report the characterization of the recombinant human DHAP acyl-transferase, which performs the first step in alkyl-DHAP synthesis. By exploring several expression systems and designing a number of constructs, we were able to purify the enzyme in its active form and we found that it is tightly bound to the membrane through the N-terminal residues. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.
Fine-scale maps of recombination rates and hotspots in the mouse genome.
Brunschwig, Hadassa; Levi, Liat; Ben-David, Eyal; Williams, Robert W; Yakir, Benjamin; Shifman, Sagiv
2012-07-01
Recombination events are not uniformly distributed and often cluster in narrow regions known as recombination hotspots. Several studies using different approaches have dramatically advanced our understanding of recombination hotspot regulation. Population genetic data have been used to map and quantify hotspots in the human genome. Genetic variation in recombination rates and hotspots usage have been explored in human pedigrees, mouse intercrosses, and by sperm typing. These studies pointed to the central role of the PRDM9 gene in hotspot modulation. In this study, we used single nucleotide polymorphisms (SNPs) from whole-genome resequencing and genotyping studies of mouse inbred strains to estimate recombination rates across the mouse genome and identified 47,068 historical hotspots--an average of over 2477 per chromosome. We show by simulation that inbred mouse strains can be used to identify positions of historical hotspots. Recombination hotspots were found to be enriched for the predicted binding sequences for different alleles of the PRDM9 protein. Recombination rates were on average lower near transcription start sites (TSS). Comparing the inferred historical recombination hotspots with the recent genome-wide mapping of double-strand breaks (DSBs) in mouse sperm revealed a significant overlap, especially toward the telomeres. Our results suggest that inbred strains can be used to characterize and study the dynamics of historical recombination hotspots. They also strengthen previous findings on mouse recombination hotspots, and specifically the impact of sequence variants in Prdm9.
Avdeeva, S V; Khaĭdarova, N V; Logunov, D Iu; Neugodova, G L; Sevast'ianova, G A; Tarantul, V Z; Naroditskiĭ, B S
2003-01-01
A method was elaborated to evaluate the biological activity of expression products of gene in the plasmid vectors, which are crucial for the synthesis of growth factor of blood vessels. It was proven as possible that the chrioallantonic membrane (CAM) of chicken's embryos could be transfected by recombinant plasmids containing both the reporter and target genes. The efficiency of CAM transfection was assessed by a plasmid carrying the reporter gene of green fluorescent protein (GFP). Finally, it was demonstrated that, at an infiltration of the recombinant plasmid containing the human angiogenine gene, its expression products induce the neovascularization in the CAM cells of chicken's embryos and stimulate an accretion in vessels of the 1st, 2nd and 3d orders.
Holec-Gąsior, Lucyna; Ferra, Bartłomiej; Drapała, Dorota; Lautenbach, Dariusz
2012-01-01
This study presents an evaluation of the MIC1 (microneme protein 1)-MAG1 (matrix antigen 1) Toxoplasma gondii recombinant chimeric antigen for the serodiagnosis of human toxoplasmosis for the first time. The recombinant MIC1-MAG1 antigen was obtained as a fusion protein containing His tags at the N- and C-terminal ends using an Escherichia coli expression system. After purification by metal affinity chromatography, the chimeric protein was tested for usefulness in an enzyme-linked immunosorbent assay (ELISA) for the detection of anti-T. gondii immunoglobulin G (IgG). One hundred ten sera from patients at different stages of infection and 40 sera from seronegative patients were examined. The results obtained for the MIC1-MAG1 chimeric antigen were compared with those of IgG ELISAs using a Toxoplasma lysate antigen (TLA), a combination of recombinant antigens (rMIC1ex2-rMAG1) and single recombinant proteins (rMIC1ex2 and rMAG1). The sensitivity of the IgG ELISA calculated from all of the positive serum samples was similar for the MIC1-MAG1 chimeric antigen (90.8%) and the TLA (91.8%), whereas the sensitivities of the other antigenic samples used were definitely lower, at 69.1% for the mixture of antigens, 75.5% for the rMIC1ex2, and 60% for rMAG1. This study demonstrates that the MIC1-MAG1 recombinant chimeric antigen can be used instead of the TLA in the serodiagnosis of human toxoplasmosis. PMID:22116686
Nonmutagenic carcinogens induce intrachromosomal recombination in dividing yeast cells.
Schiestl, R H
1993-12-01
A large number of animal and human carcinogens without apparent genotoxic activity exist (nonmutagenic carcinogens) that are difficult or impossible to detect with the currently used short-term tests. Because of the association of carcinogenesis with genome rearrangement, a system selecting for intrachromosomal recombination (DEL recombination) that results in genome rearrangement has been constructed in the yeast Saccharomyces cerevisiae. Because DEL recombination is under different genetic control than interchromosomal recombination and meiotic recombination, it is probably due to a different mechanism. It has been found that DEL recombination is readily inducible by 10 mutagenic carcinogens and 17 nonmutagenic carcinogens that are not detectable (false negatives) with the Ames assay. In addition, three out of four mutagens that do not cause cancer (false positives in the Ames assay) do not induce DEL recombination. DEL recombination is inducible by UV only in dividing cells but not in cells synchronized in the G1 or G2 phase of the cell cycle. Interchromosomal recombination, on the other hand, is inducible in G1 but not in G2. The nonmutagenic carcinogens induce DEL recombination only in actively growing cells, which may give some indication as to their mechanism. Further characterization of the mechanism involved in induction of DEL recombination may contribute to the understanding of the biological activity of nonmutagenic carcinogens.
Seifert, Roland
2013-10-01
In the mid 1990s, it was assumed that a two-state model, postulating an inactive (R) state and an active (R*) state provides the molecular basis for GPCR activation. However, it became clear that this model could not accommodate many experimental observations. Accordingly, the two-state model was superseded by a multi-state model according to which any given ligand stabilizes a unique receptor conformation with distinct capabilities of activating down-stream G-proteins and β-arrestin. Much of this research was conducted with the β2-adrenoceptor in recombinant systems. At the molecular level, there is now no doubt anymore that ligand-specific receptor conformations, also referred to as functional selectivity, exist. This concept holds great potential for drug discovery in terms of developing drugs with higher selectivity for specific cells and/or cell functions and fewer side effects. A major challenge is the analysis for functional selectivity in native cells. Here, I discuss our current knowledge on functional selectivity of three representative GPCRs, the β2-adrenoceptor and the histamine H2- and H4-receptors, in recombinant systems and native human cells. Studies with human neutrophils and eosinophils support the concept of functional selectivity. A major strategy for the analysis of functional selectivity in native cells is to generate complete concentration/response curves with a large set of structurally diverse ligands for multiple parameters. Next, correlations of potencies and efficacies are analyzed, and deviations of the correlations from linearity are indicative for functional selectivity. Additionally, pharmacological inhibitors are used to dissect cell functions from each other. Copyright © 2013 Elsevier Inc. All rights reserved.
Recombinant Salmonella Bacteria Vectoring HIV/AIDS Vaccines
Chin’ombe, Nyasha; Ruhanya, Vurayai
2013-01-01
HIV/AIDS is an important public health problem globally. An affordable, easy-to-deliver and protective HIV vaccine is therefore required to curb the pandemic from spreading further. Recombinant Salmonella bacteria can be harnessed to vector HIV antigens or DNA vaccines to the immune system for induction of specific protective immunity. These are capable of activating the innate, humoral and cellular immune responses at both mucosal and systemic compartments. Several studies have already demonstrated the utility of live recombinant Salmonella in delivering expressed foreign antigens as well as DNA vaccines to the host immune system. This review gives an overview of the studies in which recombinant Salmonella bacteria were used to vector HIV/AIDS antigens and DNA vaccines. Most of the recombinant Salmonella-based HIV/AIDS vaccines developed so far have only been tested in animals (mainly mice) and are yet to reach human trials. PMID:24478808
Chitty, Jessica L; Blake, Kirsten L; Blundell, Ross D; Koh, Y Q Andre E; Thompson, Merinda; Robertson, Avril A B; Butler, Mark S; Cooper, Matthew A; Kappler, Ulrike; Williams, Simon J; Kobe, Bostjan; Fraser, James A
2017-07-14
There is significant clinical need for new antifungal agents to manage infections with pathogenic species such as Cryptococcus neoformans Because the purine biosynthesis pathway is essential for many metabolic processes, such as synthesis of DNA and RNA and energy generation, it may represent a potential target for developing new antifungals. Within this pathway, the bifunctional enzyme adenylosuccinate (ADS) lyase plays a role in the formation of the key intermediates inosine monophosphate and AMP involved in the synthesis of ATP and GTP, prompting us to investigate ADS lyase in C. neoformans. Here, we report that ADE13 encodes ADS lyase in C. neoformans. We found that an ade13 Δ mutant is an adenine auxotroph and is unable to successfully cause infections in a murine model of virulence. Plate assays revealed that production of a number of virulence factors essential for dissemination and survival of C. neoformans in a host environment was compromised even with the addition of exogenous adenine. Purified recombinant C. neoformans ADS lyase shows catalytic activity similar to its human counterpart, and its crystal structure, the first fungal ADS lyase structure determined, shows a high degree of structural similarity to that of human ADS lyase. Two potentially important amino acid differences are identified in the C. neoformans crystal structure, in particular a threonine residue that may serve as an additional point of binding for a fungal enzyme-specific inhibitor. Besides serving as an antimicrobial target, C. neoformans ADS lyase inhibitors may also serve as potential therapeutics for metabolic disease; rather than disrupt ADS lyase, compounds that improve the stability the enzyme may be used to treat ADS lyase deficiency disease. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.
Fuchs, Jonathan D; Bart, Pierre-Alexandre; Frahm, Nicole; Morgan, Cecilia; Gilbert, Peter B; Kochar, Nidhi; DeRosa, Stephen C; Tomaras, Georgia D; Wagner, Theresa M; Baden, Lindsey R; Koblin, Beryl A; Rouphael, Nadine G; Kalams, Spyros A; Keefer, Michael C; Goepfert, Paul A; Sobieszczyk, Magdalena E; Mayer, Kenneth H; Swann, Edith; Liao, Hua-Xin; Haynes, Barton F; Graham, Barney S; McElrath, M Juliana
2015-05-01
Recombinant adenovirus serotype 5 (rAd5)-vectored HIV-1 vaccines have not prevented HIV-1 infection or disease and pre-existing Ad5 neutralizing antibodies may limit the clinical utility of Ad5 vectors globally. Using a rare Ad serotype vector, such as Ad35, may circumvent these issues, but there are few data on the safety and immunogenicity of rAd35 directly compared to rAd5 following human vaccination. HVTN 077 randomized 192 healthy, HIV-uninfected participants into one of four HIV-1 vaccine/placebo groups: rAd35/rAd5, DNA/rAd5, and DNA/rAd35 in Ad5-seronegative persons; and DNA/rAd35 in Ad5-seropositive persons. All vaccines encoded the HIV-1 EnvA antigen. Antibody and T-cell responses were measured 4 weeks post boost immunization. All vaccines were generally well tolerated and similarly immunogenic. As compared to rAd5, rAd35 was equally potent in boosting HIV-1-specific humoral and cellular immunity and responses were not significantly attenuated in those with baseline Ad5 seropositivity. Like DNA, rAd35 efficiently primed rAd5 boosting. All vaccine regimens tested elicited cross-clade antibody responses, including Env V1/V2-specific IgG responses. Vaccine antigen delivery by rAd35 is well-tolerated and immunogenic as a prime to rAd5 immunization and as a boost to prior DNA immunization with the homologous insert. Further development of rAd35-vectored prime-boost vaccine regimens is warranted.
Reactions of chicken sera to recombinant Campylobacter jejuni flagellar proteins.
Yeh, Hung-Yueh; Hiett, Kelli L; Line, John E
2015-03-01
Campylobacter jejuni is a Gram-negative spiral rod bacterium and is the leading but underreported bacterial food-borne pathogen that causes human campylobacteriosis worldwide. Raw or undercooked poultry products are regarded as a major source for human infection. C. jejuni flagella have been implicated in colonization and adhesion to the mucosal surface of chicken gastrointestinal tracts. Therefore, flagellar proteins would be the excellent targets for further investigation. In this report, we used the recombinant technology to generate a battery of C. jejuni flagellar proteins, which were purified by His tag affinity chromatography and determined antigenic profiles of these recombinant flagellar proteins using sera from chickens older than 6 weeks of age. The immunoblot results demonstrate that each chicken serum reacted to various numbers of recombinant flagellar proteins. Among these recombinant proteins, chicken sera reacted predominantly to the FlgE1, FlgK, FlhF, FliG and FliY proteins. These antibody screening results provide a rationale for further evaluation of these recombinant flagellar proteins as potential vaccines for chickens to improve food safety as well as investigation of host immune response to C. jejuni.
Ruff, James S.; Suchy, Amanda K.; Hugentobler, Sara A.; Sosa, Mirtha M.; Schwartz, Bradley L.; Morrison, Linda C.; Gieng, Sin H.; Shigenaga, Mark K.; Potts, Wayne K.
2013-01-01
Consumption of added sugar has increased over recent decades and is correlated with numerous diseases. Rodent models have elucidated mechanisms of toxicity, but only at concentrations beyond typical human exposure. Here we show that comparatively low levels of added sugar consumption have substantial negative effects on mouse survival, competitive ability, and reproduction. Using Organismal Performance Assays (OPAs) – in which mice fed human-relevant concentrations of added sugar (25% Kcal from a mixture of fructose and glucose [F/G]) and control mice compete in seminatural enclosures for territories, resources and mates – we demonstrate that F/G-fed females experience a two-fold increase in mortality while F/G-fed males control 26% fewer territories and produce 25% less offspring. These findings represent the lowest level of sugar consumption shown to adversely affect mammalian health. Clinical defects of F/G-fed mice were decreased glucose clearance and increased fasting cholesterol. Our data highlight that physiological adversity can exist when clinical disruptions are minor, and suggest that OPAs represent a promising technique for unmasking negative effects of toxicants. PMID:23941916
Song, Yue; Shen, Keng; Yu, Jing-rong
2007-11-06
To construct recombinant adenoviral vector expressing autocatalysis caspase-3 driven by human telomerase reverse transcriptase promoter (hTERTp), and investigate its antitumor effect on ovarian cancer in vitro and in vivo. Recombinant adenovirus expressing autocatalytic caspase-3 (rev-csapase-3) driven by hTERTp, AdHT-rev-casp3, was constructed. Ad-rev-casp3 expressing rev-caspase-3 driven by cytomegalovirus promoter (CMVp) was used as a positive control. hTERT positive human ovarian cancer cells of the line AO and hTERT-negative human umbilical venous endothelial cells (HUVECs) were cultured and transfected with AdHT-rev-casp3, Ad-rev-casp3, or Ad-EGFG expressing enhanced green fluorescent protein as control group. Western blotting, Cell Counting Kit (CCK-8), flow cytometry, and TUNEL were used to detect the expression of p17, active subunit of caspase-3, and p85, a poly ADP-ribose polymerase (PARP) cleavage fragment, and they were also used to measure the cell survival rate and apoptotic rate. Western blotting was used to detect the expression of active caspase-3 and its substrate PARP in the AO cells and HUVECs. Twenty nude BALB/c mice were inoculated subcutaneously with AO cells to establish subcutaneous tumor models, when the tumor grew to the volume of 150 mm3 the rats were divided into 4 equal groups to undergo intra-tumor injection of AdHT-rev-casp3, Ad-rev-casp3, Ad-EGFG, and phosphate-buffered saline (PBS) respectively, the survival rate tumor inhibition rate was observed, 72 days later the mice were killed with their livers and tumors taken out, and Western blotting was used to detect the expression of active caspase-3. Another 40 mice underwent intraperitoneal injection of AO cells to establish intraperitoneal transplanted tumor models, 21 days later the rats were divided into 4 equal groups to be injected intraperitoneally with AdHT-rev-casp3, Ad-rev-casp3, Ad-EGFG, or PBS, the survival rate was observed, and the blood levels of alanine transaminase
Chen, Fanfan; Zhang, Guoqiang; Yu, Ling; Feng, Yanye; Li, Xianghui; Zhang, Zhijun; Wang, Yongting; Sun, Dapeng; Pradhan, Sriharsa
2016-07-30
Induced pluripotent mesenchymal stem cells (iPMSCs) are novel candidates for drug screening, regenerative medicine, and cell therapy. However, introduction of transcription factor encoding genes for induced pluripotent stem cell (iPSC) generation which could be used to generate mesenchymal stem cells is accompanied by the risk of insertional mutations in the target cell genome. We demonstrate a novel method using an inactivated viral particle to package and deliver four purified recombinant Yamanaka transcription factors (Sox2, Oct4, Klf4, and c-Myc) resulting in reprogramming of human primary fibroblasts. Whole genome bisulfite sequencing was used to analyze genome-wide CpG methylation of human iPMSCs. Western blot, quantitative PCR, immunofluorescence, and in-vitro differentiation were used to assess the pluripotency of iPMSCs. The resulting reprogrammed fibroblasts show high-level expression of stem cell markers. The human fibroblast-derived iPMSC genome showed gains in DNA methylation in low to medium methylated regions and concurrent loss of methylation in previously hypermethylated regions. Most of the differentially methylated regions are close to transcription start sites and many of these genes are pluripotent pathway associated. We found that DNA methylation of these genes is regulated by the four iPSC transcription factors, which functions as an epigenetic switch during somatic reprogramming as reported previously. These iPMSCs successfully differentiate into three embryonic germ layer cells, both in vitro and in vivo. Following multipotency induction in our study, the delivered transcription factors were degraded, leading to an improved efficiency of subsequent programmed differentiation. Recombinant transcription factor based reprogramming and derivatization of iPMSC offers a novel high-efficiency approach for regenerative medicine from patient-derived cells.
Kruzel, Marian L; Actor, Jeffrey K; Zimecki, Michał; Wise, Jasen; Płoszaj, Paulina; Mirza, Shaper; Kruzel, Mark; Hwang, Shen-An; Ba, Xueqing; Boldogh, Istvan
2013-12-01
Lactoferrin, an iron-binding protein found in high concentrations in mammalian exocrine secretions, is an important component of the host defense system. It is also a major protein of the secondary granules of neutrophils from which is released upon activation. Due to its potential clinical utility, recombinant human lactoferrin (rhLF) has been produced in various eukaryotic expression systems; however, none of these are fully compatible with humans. Most of the biopharmaceuticals approved by the FDA for use in humans are produced in mammalian expression systems. The Chinese hamster ovary cells (CHO) have become the system of choice for proteins that require post-translational modifications, such as glycoproteins. The aim of this study was to scale-up expression and purification of rhLF in a CHO expression system, verify its glycan primary structure, and assess its biological properties in cell culture models. A stable CHO cell line producing >200mg/L of rhLF was developed and established. rhLF was purified by a single-step cation-exchange chromatography procedure. The highly homogenous rhLF has a molecular weight of approximately 80 kDa. MALDI-TOF mass spectrometric analysis revealed N-linked, partially sialylated glycans at two glycosylation sites, typical for human milk LF. This novel rhLF showed a protective effect against oxidative stress in a similar manner to its natural counterpart. In addition, rhLF revealed a modulatory effect on cellular redox via upregulation of key antioxidant enzymes. These data imply that the CHO-derived rhLF is fully compatible with the native molecule, thus it has promise for human therapeutic applications. Copyright © 2013 Elsevier B.V. All rights reserved.
Zeng, Jia; Yi, Soojin V
2014-10-16
Recombination clusters nonuniformly across mammalian genomes at discrete genomic loci referred to as recombination hotspots. Despite their ubiquitous presence, individual hotspots rapidly lose their activities, and the molecular and evolutionary mechanisms underlying such frequent hotspot turnovers (the so-called "recombination hotspot paradox") remain unresolved. Even though some sequence motifs are significantly associated with hotspots, multiple lines of evidence indicate that factors other than underlying sequences, such as epigenetic modifications, may affect the evolution of recombination hotspots. Thus, identifying epigenetic factors that covary with recombination at fine-scale is a promising step for this important research area. It was previously reported that recombination rates correlate with indirect measures of DNA methylation in the human genome. Here, we analyze experimentally determined DNA methylation and histone modification of human sperms, and show that the correlation between DNA methylation and recombination in long-range windows does not hold with respect to the spatial and temporal variation of recombination at hotspots. On the other hand, two histone modifications (H3K4me3 and H3K27me3) overlap extensively with recombination hotspots. Similar trends were observed in mice. These results indicate that specific histone modifications rather than DNA methylation are associated with the rapid evolution of recombination hotspots. Furthermore, many human recombination hotspots occupy "bivalent" chromatin regions that harbor both active (H3K4me3) and repressive (H3K27me3) marks. This may explain why human recombination hotspots tend to occur in nongenic regions, in contrast to yeast and Arabidopsis hotspots that are characterized by generally active chromatins. Our results highlight the dynamic epigenetic underpinnings of recombination hotspot evolution. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for
Watanabe, M; Fukamachi, H; Uzumaki, H; Kabaya, K; Tsumura, H; Ishikawa, M; Matsuki, S; Kusaka, M
1991-05-15
A new mutant protein of recombinant human granulocyte colony-stimulating factor (rhG-CSF) was produced for the studies on receptors for human G-CSF. The mutant protein [(Tyr1, Tyr3]rhG-CSF), the biological activity of which was almost equal to that of rhG-CSF, was prepared by the replacement of threonine-1 and leucine-3 of rhG-CSF with tyrosine. The radioiodinated preparation of the mutant protein showed high specific radioactivity and retained full biological activity for at least 3 weeks. The binding capacity of the radioiodinated ligand was compared with that of [35S]rhG-CSF. Both radiolabeled ligands showed specific binding to murine bone marrow cells. Unlabeled rhG-CSF and human G-CSF purified from the culture supernatant of the human bladder carcinoma cell line 5637 equally competed for the binding of labeled rhG-CSFs in a dose-dependent manner, demonstrating that the sugar moiety of human G-CSF made no contribution to the binding of human G-CSF to target cells. In contrast, all other colony-stimulating factors and lymphokines examined did not affect the binding. Scatchard analysis of the specific binding of both labeled ligands revealed a single class of binding site with an apparent dissociation constant (Kd) of 20-30 pM and 100-200 maximal binding sites per cell. These data indicate that the radioiodinated preparation of the mutant protein binds the same specific receptor with the same affinity as [35S]rhG-CSF. The labeled mutant protein also showed specific binding to human circulating neutrophils.(ABSTRACT TRUNCATED AT 250 WORDS)
[A study of recombinant human sestrin 1 and sestrin 2 proteins produced in a prokaryotic system].
Rai, N; Kumar, R; Haque, Md A; Hassan, Md I; Dey, S
2017-01-01
Sestrins are highly conserved stress-inducible proteins capable of suppressing the production of ROS and signalling through mTORC1. Here we report a study of human sestrin1 (sesn1) and sestrin2 (sesn2) proteins produced in a pET28^(+) vector based prokaryotic system. Mass spectrometry analysis, western blot and surface plasmon resonance (SPR) of affinity purified sesn1 and sesn2 proteins confirmed their identity; biophysical characteristics were observed using circular dichroism (CD) showing that sesn1 and sesn2 have a predominant α-helical structure. Here we describe a simple, one step purification process to purify a large amount of sestrin proteins with significant yield. Further study of recombinant human sestrins may further facilitate the understanding of their roles in eukaryotic cells.
Oleson, Lauren; Court, Michael H.
2009-01-01
Glucuronidation studies using microsomes and recombinant UDP-glucuronosyltransferases (rUGTs) can be complicated by the presence of endogenous β-glucuronidases leading to underestimation of glucuronide formation rates. Saccharolactone is the most frequently used β-glucuronidase inhibitor, although as of yet it is not clear whether this reagent should be routinely added to glucuronidation incubations. Here we determined the effect of saccharolactone on eight different UGT probe activities using pooled human liver microsomes (pHLMs) and rUGTs. Despite the use of buffered incubation solutions it was necessary to adjust the pH of saccharolactone solutions to avoid effects (enhancement or inhibition) of lowered pH on UGT activity. Saccharolactone at concentrations ranging from 1 to 20 mM failed to show enhancement of any of the glucuronidation activities evaluated that could be considered consistent with inhibition of β-glucuronidase. However, for most activities, higher saccharolactone concentrations resulted in a modest degree of inhibition. The greatest inhibitory effect was observed for 5-hydroxytryptamine and estradiol glucuronidation by pHLMs with 35% decrease at 20 mM saccharolactone concentration. Endogenous β-glucuronidase activities were also measured using various human tissue microsomes and rUGTs with estradiol-3-glucuronide and estradiol-17-glucuronide as substrates. Glucuronide hydrolysis was observed for pHLMs, lung microsomes, and insect-cell expressed rUGTs, but not for kidney or intestinal microsomes, or HEK293 microsomes. However, the extent of hydrolysis was relatively small representing only 9 to 19% of the glucuronide formation rate measured in the same preparations. Consequently, these data do not support the routine inclusion of saccharolactone in glucuronidation incubations and, if used, saccharolactone concentrations should be titrated to achieve activity enhancement without inhibition. PMID:18718121
Recombinant Human DNase I Reduces the Viscosity of Cystic Fibrosis Sputum
NASA Astrophysics Data System (ADS)
Shak, Steven; Capon, Daniel J.; Hellmiss, Renate; Marsters, Scot A.; Baker, Carrie L.
1990-12-01
Respiratory distress and progressive lung destruction in cystic fibrosis can be attributed to bacterial persistence and the accumulation of viscous purulent secretions in the airways. More than 30 yr ago it was suggested that the large amounts of DNA in purulent secretions contribute to its viscosity and that bovine pancreatic DNase I could reduce the viscosity. To evaluate the potential clinical utility of recombinant human DNase I (rhDNase) in the treatment of cystic fibrosis, we have cloned, sequenced, and expressed rhDNase. Catalytic amounts of rhDNase greatly reduce the viscosity of purulent cystic fibrosis sputum, transforming it within minutes from a nonflowing viscous gel to a flowing liquid. The reduction in viscosity is associated with a decrease in size of DNA in the sputum. Inhalation of a rhDNase aerosol may be a simple direct approach that will help individuals with cystic fibrosis and other patients with pneumonia or bronchitis to clear their airways of purulent secretions.
Recombinant human DNase I reduces the viscosity of cystic fibrosis sputum.
Shak, S; Capon, D J; Hellmiss, R; Marsters, S A; Baker, C L
1990-12-01
Respiratory distress and progressive lung destruction in cystic fibrosis can be attributed to bacterial persistence and the accumulation of viscous purulent secretions in the airways. More than 30 yr ago it was suggested that the large amounts of DNA in purulent secretions contribute to its viscosity and that bovine pancreatic DNase I could reduce the viscosity. To evaluate the potential clinical utility of recombinant human DNase I (rhDNase) in the treatment of cystic fibrosis, we have cloned, sequenced, and expressed rhDNase. Catalytic amounts of rhDNase greatly reduce the viscosity of purulent cystic fibrosis sputum, transforming it within minutes from a nonflowing viscous gel to a flowing liquid. The reduction in viscosity is associated with a decrease in size of DNA in the sputum. Inhalation of a rhDNase aerosol may be a simple direct approach that will help individuals with cystic fibrosis and other patients with pneumonia or bronchitis to clear their airways of purulent secretions.
Manira, Maarof; Khairul Anuar, Khairoji; Seet, Wan Tai; Ahmad Irfan, Abd Wahab; Ng, Min Hwei; Chua, Kien Hui; Mohd Heikal, Mohd Yunus; Aminuddin, Bin Saim; Ruszymah, Bt Hj Idrus
2014-03-01
Animal-derivative free reagents are preferred in skin cell culture for clinical applications. The aim of this study was to compare the performance and effects between animal-derived trypsin and recombinant trypsin for skin cells culture and expansion. Full thickness human skin was digested in 0.6 % collagenase for 6 h to liberate the fibroblasts, followed by treatment with either animal-derived trypsin; Trypsin EDTA (TE) or recombinant trypsin; TrypLE Select (TS) to liberate the keratinocytes. Both keratinocytes and fibroblasts were then culture-expanded until passage 2. Trypsinization for both cell types during culture-expansion was performed using either TE or TS. Total cells yield was determined using a haemocytometer. Expression of collagen type I, collagen type III (Col-III), cytokeratin 10, and cytokeratin 14 genes were quantified via RT-PCR and further confirmed with immunocytochemical staining. The results of our study showed that the total cell yield for both keratinocytes and fibroblasts treated with TE or TS were comparable. RT-PCR showed that expression of skin-specific genes except Col-III was higher in the TS treated group compared to that in the TE group. Expression of proteins specific to the two cell types were confirmed by immunocytochemical staining in both TE and TS groups. In conclusion, the performance of the recombinant trypsin is comparable with the well-established animal-derived trypsin for human skin cell culture expansion in terms of cell yield and expression of specific cellular markers.
The Use of Recombinant Human Platelet-Derived Growth Factor for Maxillary Sinus Augmentation.
Kubota, Atsushi; Sarmiento, Hector; Alqahtani, Mohammed Saad; Llobell, Arturo; Fiorellini, Joseph P
The maxillary sinus augmentation procedure has become a predictable treatment to regenerate bone for implant placement. The purpose of this study was to evaluate the effect of recombinant human platelet-derived growth factor BB (rhPDGF-BB) combined with a deproteinized cancellous bovine bone graft for sinus augmentation. The lateral window approach was used for maxillary sinuses with minimal residual bone. After a healing period of 4 months, dental implants were placed and then restored following a 2-month osseointegration period. The result demonstrated increased bone height and ISQ values and a 100% survival rate. This study indicates that the addition of rhPDGF-BB to deproteinized cancellous bovine bone accelerated the healing period in maxillary sinuses with minimal native bone.
Use of recombinant human activated protein C in nonmenstrual staphylococcal toxic shock syndrome
Nasa, Prashant; Sehrawat, Deepak; kansal, Sudha; Chawla, Rajesh
2010-01-01
Toxic shock syndrome (TSS) is a serious, potentially life-threatening condition resulting from an overwhelming immunological response to an exotoxin released by Staphylococcus aureus and group A streptococci. High index of suspicion, early diagnosis and aggressive therapeutic measures must be instituted in view of high mortality of the TSS. In recent years, new agents have been tested to reduce morbidity and mortality in patients with severe sepsis, in addition to standard supportive measures. Among them, recombinant human activated protein C (rhAPC) has been reported to significantly reduce mortality and morbidity in patients with severe sepsis and two or more acute organ failures. We describe our experience with this drug in the early reversal of septic shock from TSS. PMID:21253349
2014-06-01
blind to the treatment , and the prevalence of damaged fibers was quantitated from 10 10x images from each muscle . Approximately 800 fibers were counted...therapeutic cell membrane repair in treatment of muscular dystrophy . Sci Transl Med. 2012; 4(139):139ra185. 11. Weisleder N, Lin P, Zhao X, Orange M, Zhu H...The effect of recombinant human MG53 protein on tourniquet- induced ischemia reperfusion injury in rat muscle Benjamin T. Corona, Ph.D.1, Koyal Garg
Doping in the recombinant era: strategies and counterstrategies.
Azzazy, Hassan M E; Mansour, Mai M H; Christenson, Robert H
2005-11-01
Advances in recombinant DNA technology have created one of the most powerful weapons in the current doping arsenal: recombinant proteins [Sweeney HL. Gene doping. Sci Am 2004;291:62-9; Unal M, Ozer Unal D. Gene doping in sports. Sports Med 2004;34:357-62]. Recombinant erythropoietin (EPO) and human growth hormone (hGH) are currently being abused but are fortunately detectable either directly by employing isoelectric focusing and immunoassays or indirectly by assessing changes in selected hematopoietic parameters. The detection is technically demanding due to the extent of similarity between the recombinant proteins and their endogenous counterparts. Another issue facing detection efforts is the speed and conditions at which blood samples are collected and analyzed in a sports setting. Recently, gene doping, which stemmed out of legitimate gene therapy trials, has emerged as the next level of doping. Erythropoietin (EPO), human growth hormone (hGH), insulin-like growth factor-1 (IGF-1), peroxisome proliferator-activated receptor-delta (PPAR delta), and myostatin inhibitor genes have been identified as primary targets for doping. Sports clinical scientists today are racing against the clock because assuring the continued integrity of sports competition depends on their ability to outpace the efforts of dopers by developing new detection strategies.
The Effects of the Recombinant CCR5 T4 Lysozyme Fusion Protein on HIV-1 Infection.
Jin, Qingwen; Chen, Hong; Wang, Xingxia; Zhao, Liandong; Xu, Qingchen; Wang, Huijuan; Li, Guanyu; Yang, Xiaofan; Ma, Hongming; Wu, Haoquan; Ji, Xiaohui
2015-01-01
Insertion of T4 lysozyme (T4L) into the GPCR successfully enhanced GPCR protein stability and solubilization. However, the biological functions of the recombinant GPCR protein have not been analyzed. We engineered the CCR5-T4L mutant and expressed and purified the soluble recombinant protein using an E.coli expression system. The antiviral effects of this recombinant protein in THP-1 cell lines, primary human macrophages, and PBMCs from different donors were investigated. We also explored the possible mechanisms underlying the observed antiviral effects. Our data showed the biphasic inhibitory and promotion effects of different concentrations of soluble recombinant CCR5-T4L protein on R5 tropic human immunodeficiency virus-1 (HIV-1) infection in THP-1 cell lines, human macrophages, and PBMCs from clinical isolates. We demonstrated that soluble recombinant CCR5-T4L acts as a HIV-1 co-receptor, interacts with wild type CCR5, down-regulates the surface CCR5 expression in human macrophages, and interacts with CCL5 to inhibit macrophage migration. Using binding assays, we further determined that recombinant CCR5-T4L and [125I]-CCL5 compete for the same binding site on wild type CCR5. Our results suggest that recombinant CCR5-T4L protein marginally promotes HIV-1 infection at low concentrations and markedly inhibits infection at higher concentrations. This recombinant protein may be helpful in the future development of anti-HIV-1 therapeutic agents.
Recombinant antibodies and their use in biosensors.
Zeng, Xiangqun; Shen, Zhihong; Mernaugh, Ray
2012-04-01
Inexpensive, noninvasive immunoassays can be used to quickly detect disease in humans. Immunoassay sensitivity and specificity are decidedly dependent upon high-affinity, antigen-specific antibodies. Antibodies are produced biologically. As such, antibody quality and suitability for use in immunoassays cannot be readily determined or controlled by human intervention. However, the process through which high-quality antibodies can be obtained has been shortened and streamlined by use of genetic engineering and recombinant antibody techniques. Antibodies that traditionally take several months or more to produce when animals are used can now be developed in a few weeks as recombinant antibodies produced in bacteria, yeast, or other cell types. Typically most immunoassays use two or more antibodies or antibody fragments to detect antigens that are indicators of disease. However, a label-free biosensor, for example, a quartz-crystal microbalance (QCM) needs one antibody only. As such, the cost and time needed to design and develop an immunoassay can be substantially reduced if recombinant antibodies and biosensors are used rather than traditional antibody and assay (e.g. enzyme-linked immunosorbant assay, ELISA) methods. Unlike traditional antibodies, recombinant antibodies can be genetically engineered to self-assemble on biosensor surfaces, at high density, and correctly oriented to enhance antigen-binding activity and to increase assay sensitivity, specificity, and stability. Additionally, biosensor surface chemistry and physical and electronic properties can be modified to further increase immunoassay performance above and beyond that obtained by use of traditional methods. This review describes some of the techniques investigators have used to develop highly specific and sensitive, recombinant antibody-based biosensors for detection of antigens in simple or complex biological samples.
USDA-ARS?s Scientific Manuscript database
Recombinant replication-defective human adenovirus type 5 (Ad5) vaccines containing capsid-coding regions from foot-and-mouth disease virus (FMDV) have been demonstrated to induce effective immune responses and provide homologous protective immunity against FMDV in cattle. However, basic mechanisms ...
Hu, Lulu; Gao, Chen-Hui; Hong, Chao; Zhong, Qiao; Dong, Hong-Liang; Gao, Xiao-Ming
2016-01-01
Lactoferrin (LTF), a multifunctional glycoprotein of the transferrin family mainly found in exotic secretions in mammals, is an important defense molecule against not only microbial invasion but also tumors. It folds into two globular domains (N- and C-lobes) each containing an iron-binding site. The cationic antimicrobial peptide in N-lobe is known to exert anti-tumor effect via a non-receptor-mediated pathway. However, whether LTF C-lobe also contributes to its anti-tumor activity remains to be investigated. In this study, a human LTF fragment (amino acid residues 343-682) covering the C-lobe was expressed with a histidine tag in E. coli and the purified polypeptide refolded through a series of buffer changing procedure. The resultant recombinant protein caused significant growth arrest of breast carcinoma cells MDA-MB-231 in a dose- and time-dependent manner, evidently via induction of apoptosis of the cell. Our data suggest a positive role for the C-lobe of human LTF in controlling tumors in vitro.
Logez, Christel; Berger, Sylvie; Legros, Céline; Banères, Jean-Louis; Cohen, William; Delagrange, Philippe; Nosjean, Olivier; Boutin, Jean A.; Ferry, Gilles
2014-01-01
The human melatonin MT1 receptor—belonging to the large family of G protein-coupled receptors (GPCRs)—plays a key role in circadian rhythm regulation and is notably involved in sleep disorders and depression. Structural and functional information at the molecular level are highly desired for fine characterization of this receptor; however, adequate techniques for isolating soluble MT1 material suitable for biochemical and biophysical studies remain lacking. Here we describe the evaluation of a panel of constructs and host systems for the production of recombinant human MT1 receptors, and the screening of different conditions for their solubilization and purification. Our findings resulted in the establishment of an original strategy using a mixture of Fos14 and CHAPS detergents to extract and purify a recombinant human MT1 from Pichia pastoris membranes. This procedure enabled the recovery of relatively pure, monomeric and ligand-binding active MT1 receptor in the near-milligram range. A comparative study based on extensive ligand-binding characterization highlighted a very close correlation between the pharmacological profiles of MT1 purified from yeast and the same receptor present in mammalian cell membranes. The high quality of the purified MT1 was further confirmed by its ability to activate its cognate Gαi protein partner when reconstituted in lipid discs, thus opening novel paths to investigate this receptor by biochemical and biophysical approaches. PMID:24959712
Logez, Christel; Berger, Sylvie; Legros, Céline; Banères, Jean-Louis; Cohen, William; Delagrange, Philippe; Nosjean, Olivier; Boutin, Jean A; Ferry, Gilles; Simonin, Frédéric; Wagner, Renaud
2014-01-01
The human melatonin MT1 receptor-belonging to the large family of G protein-coupled receptors (GPCRs)-plays a key role in circadian rhythm regulation and is notably involved in sleep disorders and depression. Structural and functional information at the molecular level are highly desired for fine characterization of this receptor; however, adequate techniques for isolating soluble MT1 material suitable for biochemical and biophysical studies remain lacking. Here we describe the evaluation of a panel of constructs and host systems for the production of recombinant human MT1 receptors, and the screening of different conditions for their solubilization and purification. Our findings resulted in the establishment of an original strategy using a mixture of Fos14 and CHAPS detergents to extract and purify a recombinant human MT1 from Pichia pastoris membranes. This procedure enabled the recovery of relatively pure, monomeric and ligand-binding active MT1 receptor in the near-milligram range. A comparative study based on extensive ligand-binding characterization highlighted a very close correlation between the pharmacological profiles of MT1 purified from yeast and the same receptor present in mammalian cell membranes. The high quality of the purified MT1 was further confirmed by its ability to activate its cognate Gαi protein partner when reconstituted in lipid discs, thus opening novel paths to investigate this receptor by biochemical and biophysical approaches.
Recombinant human hyaluronidase-enabled subcutaneous pediatric rehydration.
Allen, Coburn H; Etzwiler, Lisa S; Miller, Melissa K; Maher, George; Mace, Sharon; Hostetler, Mark A; Smith, Sharon R; Reinhardt, Neil; Hahn, Barry; Harb, George
2009-11-01
The Increased Flow Utilizing Subcutaneously-Enabled (INFUSE)-Pediatric Rehydration Study was designed to assess efficacy, safety, and clinical utility of recombinant human hyaluronidase (rHuPH20)-facilitated subcutaneous rehydration in children 2 months to 10 years of age. Patients with mild/moderate dehydration requiring parenteral treatment in US emergency departments were eligible for this phase IV, multicenter, single-arm study. They received subcutaneous injection of 1 mL rHuPH20 (150 U), followed by subcutaneous infusion of 20 mL/kg isotonic fluid over the first hour. Subcutaneous rehydration was continued as needed for up to 72 hours. Rehydration was deemed successful if it was attributed by the investigator primarily to subcutaneous fluid infusion and the child was discharged without requiring an alternative method of rehydration. Efficacy was evaluated in 51 patients (mean age: 1.9 years; mean weight: 11.2 kg). Initial subcutaneous catheter placement was achieved with 1 attempt for 46/51 (90.2%) of patients. Rehydration was successful for 43/51 (84.3%) of patients. Five patients (9.8%) were hospitalized but deemed to be rehydrated primarily through subcutaneous therapy, for a total of 48/51 (94.1%) of patients. No treatment-related systemic adverse events were reported, but 1 serious adverse event occurred (cellulitis at infusion site). Investigators found the procedure easy to perform for 96% of patients (49/51 patients), and 90% of parents (43/48 parents) were satisfied or very satisfied. rHuPH20-facilitated subcutaneous hydration seems to be safe and effective for young children with mild/moderate dehydration. Subcutaneous access is achieved easily, and the procedure is well accepted by clinicians and parents.
Recombinant antigens for immunodiagnosis of cystic echinococcosis
Li, Jun; Zhang, Wen-Bao
2004-01-01
Three cDNAs, termed EpC1, TPxEg and EgG5, were isolated by immunoscreening from an Echinococcus granulosus cDNA library. The recombinant phages exhibited strong reactivity with sera from humans with confirmed cystic echinococcosis (CE) and with sera from mice infected with E. granulosus oncospheres. The cDNAs were subcloned into a pET vector, expressed as fusion proteins tagged with GST and affinity purified against the GST tag. Of the three recombinant proteins, EpC1 achieved the highest performance for serodiagnosis of CE in Western blot analysis using a panel of clinically defined human sera to initially address the sensitivity and specificity of the molecules. The protein yielded an overall sensitivity of 92.2% and specificity of 95.6%, levels unprecedented taking into account the large panel of 896 human sera that were tested. The strategy used may also prove suitable for improved immunodiagnosis of other parasitic infections. PMID:15188015
Holmblat, Barbara; Jégouic, Sophie; Muslin, Claire; Blondel, Bruno; Joffret, Marie-Line; Delpeyroux, Francis
2014-08-05
Most of the circulating vaccine-derived polioviruses (cVDPVs) implicated in poliomyelitis outbreaks in Madagascar have been shown to be recombinants between the type 2 poliovirus (PV) strain of the oral polio vaccine (Sabin 2) and another species C human enterovirus (HEV-C), such as type 17 coxsackie A virus (CA17) in particular. We studied intertypic genetic exchanges between PV and non-PV HEV-C by developing a recombination model, making it possible to rescue defective type 2 PV RNA genomes with a short deletion at the 3' end by the cotransfection of cells with defective or infectious CA17 RNAs. We isolated over 200 different PV/CA17 recombinants, using murine cells expressing the human PV receptor (PVR) and selecting viruses with PV capsids. We found some homologous (H) recombinants and, mostly, nonhomologous (NH) recombinants presenting duplications of parental sequences preferentially located in the regions encoding proteins 2A, 2B, and 3A. Short duplications appeared to be stable, whereas longer duplications were excised during passaging in cultured cells or after multiplication in PVR-transgenic mice, generating H recombinants with diverse sites of recombination. This suggests that NH recombination events may be a transient, intermediate step in the generation and selection of the fittest H recombinants. In addition to the classical copy-choice mechanism of recombination thought to generate mostly H recombinants, there may also be a modular mechanism of recombination, involving NH recombinant precursors, shaping the genomes of recombinant enteroviruses and other picornaviruses. Importance: The multiplication of circulating vaccine-derived polioviruses (cVDPVs) in poorly immunized human populations can render these viruses pathogenic, causing poliomyelitis outbreaks. Most cVDPVs are intertypic recombinants between a poliovirus (PV) strain and another human enterovirus, such as type 17 coxsackie A viruses (CA17). For further studies of the genetic exchanges
Inference of Ancestral Recombination Graphs through Topological Data Analysis
Cámara, Pablo G.; Levine, Arnold J.; Rabadán, Raúl
2016-01-01
The recent explosion of genomic data has underscored the need for interpretable and comprehensive analyses that can capture complex phylogenetic relationships within and across species. Recombination, reassortment and horizontal gene transfer constitute examples of pervasive biological phenomena that cannot be captured by tree-like representations. Starting from hundreds of genomes, we are interested in the reconstruction of potential evolutionary histories leading to the observed data. Ancestral recombination graphs represent potential histories that explicitly accommodate recombination and mutation events across orthologous genomes. However, they are computationally costly to reconstruct, usually being infeasible for more than few tens of genomes. Recently, Topological Data Analysis (TDA) methods have been proposed as robust and scalable methods that can capture the genetic scale and frequency of recombination. We build upon previous TDA developments for detecting and quantifying recombination, and present a novel framework that can be applied to hundreds of genomes and can be interpreted in terms of minimal histories of mutation and recombination events, quantifying the scales and identifying the genomic locations of recombinations. We implement this framework in a software package, called TARGet, and apply it to several examples, including small migration between different populations, human recombination, and horizontal evolution in finches inhabiting the Galápagos Islands. PMID:27532298
Structural consistency analysis of recombinant and wild-type human serum albumin
NASA Astrophysics Data System (ADS)
Cao, Hui-Ling; Sun, Li-Hua; Liu, Li; Li, Jian; Tang, Lin; Guo, Yun-Zhu; Mei, Qi-Bing; He, Jian-Hua; Yin, Da-Chuan
2017-01-01
Recombinant human serum albumin (rHSA) is potential alternatives for human serum albumin (HSA) which may ease severe shortage of HSA worldwide. In theory, rHSA and HSA are the same. Structure decides function. Therefore, the 3D structural consistency analysis of rHSA and HSA is outmost importance, which is the base of their function consistency. In this paper, the crystal structures of rHSA at resolution limit of 2.22 Å and HSA at 2.30 Å were determined by X-ray diffraction (XRD), which were deposited in the Protein Data Bank (PDB) with accession codes 4G03 (rHSA) and 4G04 (HSA). The differences between rHSA and HSA were systematically analyzed from the crystallization behavior, diffraction data and three-dimensional (3D) structure. The superimposed contrasted analysis indicated that rHSA and HSA achieved a structural similarity of 99% with an r.m.s. deviation of 0.397 Å for the corresponding overall Cα atoms. In addition, the number of α-helices in the rHSA or HSA molecule was verified to be 30. As a result, rHSA can potentially replace HSA. The study provides a theoretical and experimental basis for the clinical and additional applications of rHSA. Meanwhile, it is also a good example for applications of genetic engineering.
Our objectives were to assess whether binding of chemicals differs significantly between recombinant estrogen receptors from fathead minnow (fhERα) and human (hERα) and to evaluate the performance of these receptors using two different in vitro assay systems: a COS whole cell bin...
Baranzini, Nicolò; Pedrini, Edoardo; Girardello, Rossana; Tettamanti, Gianluca; de Eguileor, Magda; Taramelli, Roberto; Acquati, Francesco; Grimaldi, Annalisa
2017-05-01
In recent years, several studies have demonstrated that the RNASET2 gene is involved in the control of tumorigenicity in ovarian cancer cells. Furthermore, a role in establishing a functional cross-talk between cancer cells and the surrounding tumor microenvironment has been unveiled for this gene, based on its ability to act as an inducer of the innate immune response. Although several studies have reported on the molecular features of RNASET2, the details on the mechanisms by which this evolutionarily conserved ribonuclease regulates the immune system are still poorly defined. In the effort to clarify this aspect, we report here the effect of recombinant human RNASET2 injection and its role in regulating the innate immune response after bacterial challenge in an invertebrate model, the medicinal leech. We found that recombinant RNASET2 injection induces fibroplasias, connective tissue remodeling and the recruitment of numerous infiltrating cells expressing the specific macrophage markers CD68 and HmAIF1. The RNASET2-mediated chemotactic activity for macrophages has been further confirmed by using a consolidated experimental approach based on injection of the Matrigel biomatrice (MG) supplemented with recombinant RNASET2 in the leech body wall. One week after injection, a large number of CD68 + and HmAIF-1 + macrophages massively infiltrated MG sponges. Finally, in leeches challenged with lipopolysaccharides (LPS) or with the environmental bacteria pathogen Micrococcus nishinomiyaensis, numerous macrophages migrating to the site of inoculation expressed high levels of endogenous RNASET2. Taken together, these results suggest that RNASET2 is likely involved in the initial phase of the inflammatory response in leeches.
A Recombinant Human Anti-Platelet scFv Antibody Produced in Pichia pastoris for Atheroma Targeting
Vallet-Courbin, Amelie; Larivière, Mélusine; Hocquellet, Agnès; Hemadou, Audrey; Parimala, Sarjapura-Nagaraja; Laroche-Traineau, Jeanny; Santarelli, Xavier; Clofent-Sanchez, Gisèle; Jacobin-Valat, Marie-Josée; Noubhani, Abdelmajid
2017-01-01
Cells of the innate and adaptive immune system are key factors in the progression of atherosclerotic plaque, leading to plaque instability and rupture, potentially resulting in acute atherothrombotic events such as coronary artery disease, cerebrovascular disease and peripheral arterial disease. Here, we describe the cloning, expression, purification, and immunoreactivity assessment of a recombinant single-chain variable fragment (scFv) derived from a human anti-αIIbβ3 antibody (HuAb) selected to target atheromatous lesions for the presence of platelets. Indeed, platelets within atheroma plaques have been shown to play a role in inflammation, in platelet-leucocyte aggregates and in thrombi formation and might thus be considered relevant biomarkers of atherosclerotic progression. The DNA sequence that encodes the anti-αIIbβ3 TEG4 scFv previously obtained from a phage-display selection on activated platelets, was inserted into the eukaryote vector (pPICZαA) in fusion with a tag sequence encoding 2 cysteines useable for specific probes grafting experiments. The recombinant protein was expressed at high yields in Pichia pastoris (30 mg/L culture). The advantage of P. pastoris as an expression system is the production and secretion of recombinant proteins in the supernatant, ruling out the difficulties encountered when scFv are produced in the cytoplasm of bacteria (low yield, low solubility and reduced affinity). The improved conditions allowed for the recovery of highly purified and biologically active scFv fragments ready to be grafted in a site-directed way to nanoparticles for the imaging of atherosclerotic plaques involving inflammatory processes and thus at high risk of instability. PMID:28125612
Wu, Haoming; Padhi, Abinash; Xu, Junqiang; Gong, Xiaoyan; Tien, Po
2016-01-01
The non-pathogenic Human Pegivirus (HPgV, formerly GBV-C/HGV), the most prevalent RNA virus worldwide, is known to be associated with reduced morbidity and mortality in HIV-infected individuals. Although previous studies documented its ubiquity and important role in HIV-infected individuals, little is known about the underlying genetic mechanisms that maintain high genetic diversity of HPgV within the HIV-infected individuals. To assess the within-host genetic diversity of HPgV and forces that maintain such diversity within the co-infected hosts, we performed phylogenetic analyses taking into account 229 HPgV partial E1-E2 clonal sequences representing 15 male and 8 female co-infected HIV patients from Hubei province of central China. Our results revealed the presence of eleven strongly supported clades. While nine clades belonged to genotype 3, two clades belonged to genotype 2. Additionally, four clades that belonged to genotype 3 exhibited inter-clade recombination events. The presence of clonal sequences representing multiple clades within the HIV-infected individual provided the evidence of co-circulation of HPgV strains across the region. Of the 23 patients, six patients (i.e., five males and one female) were detected to have HPgV recombinant sequences. Our results also revealed that while male patients shared the viral strains with other patients, viral strains from the female patients had restricted dispersal. Taken together, the present study revealed that multiple infections with divergent HPgV viral strains may have caused within-host genetic recombination, predominantly in male patients, and therefore, could be the major driver in shaping genetic diversity of HPgV.
Wu, Haoming; Padhi, Abinash; Xu, Junqiang; Gong, Xiaoyan; Tien, Po
2016-01-01
The non-pathogenic Human Pegivirus (HPgV, formerly GBV-C/HGV), the most prevalent RNA virus worldwide, is known to be associated with reduced morbidity and mortality in HIV-infected individuals. Although previous studies documented its ubiquity and important role in HIV-infected individuals, little is known about the underlying genetic mechanisms that maintain high genetic diversity of HPgV within the HIV-infected individuals. To assess the within-host genetic diversity of HPgV and forces that maintain such diversity within the co-infected hosts, we performed phylogenetic analyses taking into account 229 HPgV partial E1-E2 clonal sequences representing 15 male and 8 female co-infected HIV patients from Hubei province of central China. Our results revealed the presence of eleven strongly supported clades. While nine clades belonged to genotype 3, two clades belonged to genotype 2. Additionally, four clades that belonged to genotype 3 exhibited inter-clade recombination events. The presence of clonal sequences representing multiple clades within the HIV-infected individual provided the evidence of co-circulation of HPgV strains across the region. Of the 23 patients, six patients (i.e., five males and one female) were detected to have HPgV recombinant sequences. Our results also revealed that while male patients shared the viral strains with other patients, viral strains from the female patients had restricted dispersal. Taken together, the present study revealed that multiple infections with divergent HPgV viral strains may have caused within-host genetic recombination, predominantly in male patients, and therefore, could be the major driver in shaping genetic diversity of HPgV. PMID:27560699
Chan, Elizabeth S; Chen, Christopher; Soong, Tuck Wah; Wong, Boon-Seng
2018-03-01
Apolipoprotein E4 (ApoE4) is the strongest genetic risk factor for sporadic Alzheimer's disease (AD), where inheritance of this isoform predisposes development of AD in a gene dose-dependent manner. Although the mode of action of ApoE4 on AD onset and progression remains unknown, we have previously shown that ApoE4, and not ApoE3 expression, resulted in insulin signaling deficits in the presence of amyloid beta (Aβ). However, these reports were not conducted with clinical samples that more accurately reflect human disease. In this study, we investigated the effect of ApoE genotype on the insulin signaling pathway in control and AD human brain samples. We found that targets of the insulin signaling pathway were attenuated in AD cases, regardless of ApoE isoform. We also found a decrease in GluR1 subunit expression, and an increase NR2B subunit expression in AD cases, regardless of ApoE isoform. Lastly, we observed that more insulin receptor (IR) was immunoprecipitated in control cases, and more Aβ was immunoprecipitated with AD cases. But, when comparing among AD cases, we found that more IR was immunoprecipitated with ApoE3 than ApoE4, and more Aβ was immunoprecipitated with ApoE4 than ApoE3. Our results suggest that the difference in IR binding and effect on protein expression downstream of the IR may affect onset and progression of AD.
Recombinant follicle-stimulating hormone: new biotechnology for infertility.
Prevost, R R
1998-01-01
The frequency of infertility in developed countries is approximately 8-10%. New drugs are available for assisted reproduction techniques. Two recombinant follicle-stimulating hormone (FSH) products, follitropin-beta (Follistim in the United States, Puregon in Europe) and follitropin-alpha (Gonal-F), join compounds derived through transfecting nonhuman cell lines with genetic material capable of replicating identical amino acid sequences to human compounds. The cell line used for recombinant (r)-FSH production is the Chinese hamster ovary (CHO). Previously, the only agents that showed benefit in controlled ovulatory stimulation were derived from the urine of menopausal women. Those compounds contain additional substances, such as urinary proteins and various amounts of luteininzing hormone. The amino acid sequence of r-FSH is identical to that of human FSH, but the two recombinant products exist in many different isoforms and differ from each other and from human FSH due to varied carbohydrate side chains. Due to variation in the carbohydrate side chains, follitropin-beta in solution has a higher pH than urine-derived FSH, which enhances receptor affinity and therefore is a greater inducer of folliculogenesis. Follitropin-beta does not cause endogenous production of anti-CHO or anti-FSH antibodies, and is well tolerated.
Hansson, K M; Gustafsson, D; Skärby, T; Frison, L; Berntorp, E
2015-07-01
The present study was carried out to investigate the impact of FII levels, and their increase, on the hemostatic potential in plasma from hemophilia A and B patients with and without inhibitors. Recombinant human factor (F) II (rhFII) was added ex vivo to plasma from 68 patients with hemophilia A and B, with or without inhibitors. The hemostatic potential as measured by thrombin generation (calibrated automated thrombogram [CAT]) was focused on the endogenous thrombin potential (ETP) as it has been shown to correlate with the clinical phenotype of bleeding in hemophilia patients and has also been used to guide bypassing therapy in hemophilia patients with inhibitors before elective surgery. The factor eight inhibitor bypassing agent (FEIBA(®) ) was used as a reference to the clinical situation. The study shows that rhFII concentration-dependently increased ETP by a similar magnitude in hemophilia A and B, both with and without inhibitors. Compared with FEIBA, rhFII showed a shallower concentration-response curve. In both types of hemophilia 100 mg L(-1) of rhFII roughly doubled the ETP. A corresponding response was obtained by 0.5 U mL(-1) of FEIBA. These data support the theory that FII is one of the major components responsible for the efficacy of FEIBA. The data also indicate that rhFII may be useful, alone or in combination with other coagulation factors, in some of the conditions for which FEIBA is used today, although more data are needed to substantiate this. © 2015 International Society on Thrombosis and Haemostasis.
Cuppoletti, John; Chakrabarti, Jayati; Tewari, Kirti; Malinowska, Danuta H
2013-05-01
In clinical trials, methadone, but not morphine, appeared to prevent beneficial effects of lubiprostone, a ClC-2 Cl(-) channel activator, on opioid-induced constipation. Effects of methadone and morphine on lubiprostone-stimulated Cl(-) currents were measured by short circuit current (Isc) across T84 cells. Whole cell patch clamp of human ClC-2 (hClC-2) stably expressed in HEK293 cells and in a high expression cell line (HEK293EBNA) as well as human CFTR (hCFTR) stably expressed in HEK293 cells was used to study methadone and morphine effects on recombinant hClC-2 and hCFTR Cl(-) currents. Methadone but not morphine inhibited lubiprostone-stimulated Isc in T84 cells with half-maximal inhibition at 100 nM. Naloxone did not affect lubiprostone stimulation or methadone inhibition of Isc. Lubiprostone-stimulated Cl(-) currents in hClC-2/HEK293 cells, but not forskolin/IBMX-stimulated Cl(-) currents in hCFTR/HEK293 cells, were inhibited by methadone, but not morphine. HEK293EBNA cells expressing hClC-2 showed time-dependent, voltage-activated, CdCl2-inhibited Cl(-) currents in the absence (control) and the presence of lubiprostone. Methadone, but not morphine, inhibited control and lubiprostone-stimulated hClC-2 Cl(-) currents with half-maximal inhibition at 100 and 200-230 nM, respectively. Forskolin/IBMX-stimulated hClC-2 Cl(-) currents were also inhibited by methadone. Myristoylated protein kinase inhibitor (a specific PKA inhibitor) inhibited forskolin/IBMX- but not lubiprostone-stimulated hClC-2 Cl(-) currents. Methadone caused greater inhibition of lubiprostone-stimulated currents added before patching (66.1 %) compared with after patching (28.7 %). Methadone caused inhibition of lubiprostone-stimulated Cl(-) currents in T84 cells and control; lubiprostone- and forskolin/IBMX-stimulated recombinant hClC-2 Cl(-) currents may be the basis for reduced efficacy of lubiprostone in methadone-treated patients.
Determinants of High Titer in Recombinant Porcine Endogenous Retroviruses
Harrison, Ian; Takeuchi, Yasuhiro; Bartosch, Birke; Stoye, Jonathan P.
2004-01-01
Porcine endogenous retroviruses (PERVs) pose a potential stumbling block for therapeutic xenotransplantation, with the greatest threat coming from viruses generated by recombination between members of the PERV subgroup A (PERV-A) and PERV-C families (PERV-A/C recombinants). PERV-A and PERV-B have been shown to infect human cells in culture, albeit with low titers. PERV-C has a more restricted host range and cannot infect human cells. A recombinant PERV-A/C virus (PERV-A14/220) contains the PERV-A sequence between the end of pol and the middle of the SU region in env. The remaining sequence is derived from PERV-C. PERV-A14/220 is approximately 500-fold more infectious than PERV-A. To determine the molecular basis for the increased infectivity of PERV-A14/220, we have made a series of vector constructs. The primary determinant for the enhanced replicative potential of the recombinant virus appeared to be the env gene. Using a series of chimeric env genes, we could identify two determinants of high infectivity; one was an isoleucine to valine substitution at position 140 between variable regions A and B, and the other lies within the proline rich region. Taken together, these results show that the novel juxtaposition of env gene sequences enhanced the infectivity of PERV-A14/220 for human cells, perhaps by stabilization of the envelope glycoprotein or increased receptor binding. PMID:15564495
Song, Yue; Shen, Keng; He, Chun-Xia
2007-09-01
To construct recombinant adenoviral vector expressing autocatalysis caspase-3 driven by human telomerase reverse transcriptase promoter amplified by two-step transcription amplification (hTERTp-TSTA), and investigate its antitumor effect in ovarian cancer in vitro and in vivo. Recombinant adenoviruses expressing autocatalytic caspase-3 (rev-caspase-3) driven by hTERTp-TSTA were prepared, which were named as AdHTVP2G5-rev-casp3. AdHT-rev-casp3, Ad-rev-casp3 and AdHTVP2G5-EGEP, which express rev-caspase-3 driven by hTERTp, cytomegalovirus promoter (CMVp) and enhanced green fluorescent protein (EGFP), respectively, were used as controls. Western blot, cell counting kit (CCK-8), flow cytometry (FCM) and TdT-mediated dUTP-biotin nick end labeling (TUNEL) were used to detect the expression of p17, active subunit of caspase-3, and p85, and to measure cell survival rates, apoptotic rates and cell cycle distribution in ovarian cell line AO and normal human umbilical vein endothelial cell line HUVEC, following treatments of AdHTVP2G5-rev-casp3. subcutaneous tumor models and abdominally spread tumor models of human ovarian carcinoma using AO cells in BALB/c nude mice were established. Following treatments of AdHTVP2G5-rev-casp3, western blot was used to detect the expression of active caspase-3 in abdominally spread tumors and liver tissues, respectively, and the mouse survival rates and the volume of tumor nodules were measured, and the serum level of alanine transaminase (ALT) and aspartate transaminase (AST) were analyzed to monitor liver damages and HE staining was used to detect the histopathological changes of various organs. The levels of p17 expression in AdHTVP2G5-rev-casp3-treated AO cells were significantly higher than that in Ad-rev-casp3 or AdHT-rev-casp3 treated AO cells, while no expression was observed in AdHTVP2G5-rev-casp3-treated HUVEC. There was strong cell killing of AdHTVP2G5-rev-casp3 of hTERT positive AO cells, but not of the hTERT-negative HUVEC cells
Chen, X G; Liu, Y M; Lv, Q X; Ma, J
2017-01-01
We investigated the effects of recombinant adenovirus vectors that overexpress or silence PLCγ2 on the expression of this gene during hepatocyte proliferation. Hepatocytes were isolated, identified by immunofluorescent cytochemical staining and infected by previously constructed Ad-PLCγ2 and Ad-PLCγ2 siRNA1, siRNA2 and siRNA3. Green fluorescent protein (GFP) expression was observed by fluorescence microscopy. Infection percentage was calculated by flow cytometry. mRNA and protein levels of PLCγ2 were detected by quantitative reverse transcription-PCR (qRT-PCR) and western blotting, respectively. The viability of the infected hepatocytes was measured by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. We found that nearly 97% of cells were positive for the hepatocyte marker, CK18. After infection of Ad-PLCγ2 and Ad-PLCγ2 siRNA, more than 99% of hepatocytes expressed GFP significantly, and mRNA and protein expression of PLCγ2 was up-regulated significantly in Ad-PLCγ2 infected hepatocytes, but down-regulated in Ad-PLCγ2 siRNA2 infected cells. The cell proliferation rate decreased in PLCγ2-overexpressing cells, while the rate increased in PLCγ2-silencing cells. We verified that recombinant Ad-PLCγ2 and Ad-PLCγ2 siRNA2 were constructed successfully. These two recombinant vectors promoted or decreased the expression of PLCγ2 in rat hepatocytes and affected the cell proliferation rate, which provides a useful tool for further investigation of the role of PLCγ2 in hepatocyte apoptosis.
Zheng, Hongying; Nagaraja, Ganachari M; Kaur, Punit; Asea, Edwina E; Asea, Alexzander
2010-01-01
Extracellular heat shock protein 72 (Hsp72; inducible form of the 70-kDa heat shock protein) plays a critical role in innate and adaptive immune responses and has shown promise as an ideal adjuvant for the optimization of antigen-specific anti-tumor vaccines. Recent studies suggest that to correctly elucidate the mechanisms by which Hsp72 exerts its beneficial effects in vitro, great care must be taken to ensure that endotoxin by-products do not invalidate the findings. In this study, we have taken advantage of the baculovirus expression vector system for production of endotoxin-free recombinant Hsp72. The coding sequence of human hsp72 was recombined into the baculovirus immediately downstream of the strong polyhedron gene promoter. Ninety-six h post-infection of Sf9 insect cells with recombinant baculovirus, maximal levels of Hsp72 protein were detected. The recombinant human Hsp72 was purified by affinity chromatography from insect cells, and purity was confirmed by SDS-PAGE and mass spectrometry. The purified human recombinant Hsp72(bv) (Hsp72 produced using the BEVS) was demonstrated to have no endotoxin contamination and was shown to have stimulated potent calcium flux in the human monocytic cell line. Furthermore, recombinant Hsp72(bv) enhanced the tolerance of neuroblastoma cells to heat stress-induced cell death and displayed classical chaperokine functions including augmentation of inflammatory cytokine productions in mouse splenocytes. The production of functional, endotoxin-free recombinant human Hsp72(bv) in insect cells is inexpensive and convenient and eliminates the need of special procedures for endotoxin depletion. Endotoxin-free recombinant human Hsp72(bv) can now be used to unlock the important role Hsp72 plays in modulating immune function.
Zheng, Hongying; Nagaraja, Ganachari M.; Kaur, Punit; Asea, Edwina E.; Asea, Alexzander
2010-01-01
Extracellular heat shock protein 72 (Hsp72; inducible form of the 70-kDa heat shock protein) plays a critical role in innate and adaptive immune responses and has shown promise as an ideal adjuvant for the optimization of antigen-specific anti-tumor vaccines. Recent studies suggest that to correctly elucidate the mechanisms by which Hsp72 exerts its beneficial effects in vitro, great care must be taken to ensure that endotoxin by-products do not invalidate the findings. In this study, we have taken advantage of the baculovirus expression vector system for production of endotoxin-free recombinant Hsp72. The coding sequence of human hsp72 was recombined into the baculovirus immediately downstream of the strong polyhedron gene promoter. Ninety-six h post-infection of Sf9 insect cells with recombinant baculovirus, maximal levels of Hsp72 protein were detected. The recombinant human Hsp72 was purified by affinity chromatography from insect cells, and purity was confirmed by SDS-PAGE and mass spectrometry. The purified human recombinant Hsp72bv (Hsp72 produced using the BEVS) was demonstrated to have no endotoxin contamination and was shown to have stimulated potent calcium flux in the human monocytic cell line. Furthermore, recombinant Hsp72bv enhanced the tolerance of neuroblastoma cells to heat stress-induced cell death and displayed classical chaperokine functions including augmentation of inflammatory cytokine productions in mouse splenocytes. The production of functional, endotoxin-free recombinant human Hsp72bv in insect cells is inexpensive and convenient and eliminates the need of special procedures for endotoxin depletion. Endotoxin-free recombinant human Hsp72bv can now be used to unlock the important role Hsp72 plays in modulating immune function. PMID:19861412
USDA-ARS?s Scientific Manuscript database
The ability to rescue an infectious, recombinant, RNA virus from a cDNA clone, has led to new opportunities for measuring viral replication from a viral expressed reporter gene. In this protocol, the process of inserting enhanced green fluorescent protein (EGFP) gene into the human parainfluenza vi...
RTEL1 maintains genomic stability by suppressing homologous recombination.
Barber, Louise J; Youds, Jillian L; Ward, Jordan D; McIlwraith, Michael J; O'Neil, Nigel J; Petalcorin, Mark I R; Martin, Julie S; Collis, Spencer J; Cantor, Sharon B; Auclair, Melissa; Tissenbaum, Heidi; West, Stephen C; Rose, Ann M; Boulton, Simon J
2008-10-17
Homologous recombination (HR) is an important conserved process for DNA repair and ensures maintenance of genome integrity. Inappropriate HR causes gross chromosomal rearrangements and tumorigenesis in mammals. In yeast, the Srs2 helicase eliminates inappropriate recombination events, but the functional equivalent of Srs2 in higher eukaryotes has been elusive. Here, we identify C. elegans RTEL-1 as a functional analog of Srs2 and describe its vertebrate counterpart, RTEL1, which is required for genome stability and tumor avoidance. We find that rtel-1 mutant worms and RTEL1-depleted human cells share characteristic phenotypes with yeast srs2 mutants: lethality upon deletion of the sgs1/BLM homolog, hyperrecombination, and DNA damage sensitivity. In vitro, purified human RTEL1 antagonizes HR by promoting the disassembly of D loop recombination intermediates in a reaction dependent upon ATP hydrolysis. We propose that loss of HR control after deregulation of RTEL1 may be a critical event that drives genome instability and cancer.
The effects of genetic polymorphism on treatment response of recombinant human growth hormone.
Chen, Shi; You, Hanxiao; Pan, Hui; Zhu, Huijuan; Yang, Hongbo; Gong, Fengying; Wang, Linjie; Jiang, Yu; Yan, Chengsheng
2017-12-06
Recombinant human growth hormone (rhGH) has been widely used in clinical treatment of growth hormone deficiency (GHD) or non GHD since 1985 and technology have achieved a great development in different long-acting formulations. Although the mathematical models for predicting the growth hormone response could help clinicians get to an individual personalized growth dose, many patients just can't reach the target height and the growth hormone responses differed.Genetic polymorphisms may play a role in the varies of individual responses in this treatment process.This article gives an overview of the genetic polymorphisms research of growth hormone in recent years, in order to give some potential suggestion and guide for the dose titration during treatment. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Okada, Yuji; Kawagishi, Mayumi; Kusaka, Masaru
Single injection of recombinant human granulocyte colony-stimulating factor (rhG-CSF) immediately induced a decrease in the number of circulating neutrophils in rats. This neutropenia occurred 10 minutes after the injection but disappeared 40 minutes after injection. This transient neutropenia was dose-dependently induced by rhG-CSF and also induced by repeated injections. We studied the kinetics of circulating neutrophils in transient neutropenia. rhG-CSF markedly decreased the number of {sup 3}H-diisopropylfluorophosphate ({sup 3}H-DFP) labeled neutrophils in the circulation 10 minutes after injection but the labeled neutrophils recovered to near the control level 40 minutes after the injection. These results indicate that the neutrophil marginationmore » accounts for the neutrophenia and the marginated neutrophils return to the circulation.« less
Kukreja, Sunil; Ahmed, Osama I; Haydel, Justin; Nanda, Anil
2015-01-01
Objective There are several reports, which documented a high incidence of complications following the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in anterior cervical fusions (ACFs). The objective of this study is to share our experience with low-dose rhBMP-2 in anterior cervical spine. Methods We performed a retrospective analysis of 197 patients who underwent anterior cervical fusion (ACF) with the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) during 2007-2012. A low-dose rhBMP-2 (0.7mg/level) sponge was placed exclusively within the cage. In 102 patients demineralized bone matrix (DBM) was filled around the BMP sponge. Incidence and severity of dysphagia was determined by 5 points SWAL-QOL scale. Results Two patients had prolonged hospitalization due to BMP unrelated causes. Following the discharge, 13.2%(n=26) patients developed dysphagia and 8.6%(n=17) patients complained of neck swelling. More than half of the patients (52.9%, n=9) with neck swelling also had associated dysphagia; however, only 2 of these patients necessitated readmission. Both of these patients responded well to the intravenous dexamethasone. The use of DBM did not affect the incidence and severity of complications (p>0.05). Clinico-radiological evidence of fusion was not observed in 2 patients. Conclusion A low-dose rhBMP-2 in ACFs is not without risk. However, the incidence and severity of complications seem to be lower with low-dose BMP placed exclusively inside the cage. Packing DBM putty around the BMP sponge does not affect the safety profile of rhBMP-2 in ACFs. PMID:26217385
Ruderfer, Ilya; Shulman, Avidor; Kizhner, Tali; Azulay, Yaniv; Nataf, Yakir; Tekoah, Yoram; Shaaltiel, Yoseph
2018-05-16
The current treatment of Fabry disease by enzyme replacement therapy with commercially available recombinant human α-Galactosidase A shows a continuous deterioration of the disease patients. Human recombinant α-Galactosidase A is a homodimer with noncovalently bound subunits and is expressed in the ProCellEx plant cell-based protein expression platform to produce pegunigalsidase alfa. The effect of covalent bonding between two α-Galactosidase A subunits by PEG-based cross-linkers of various lengths was evaluated in this study. The results show that cross-linking by a bifunctional PEG polymer of 2000 Da produces a more stable protein with improved pharmacokinetic and biodistribution properties. The chemical modification did not influence the tertiary protein structure but led to an increased thermal stability and showed partial masking of immune epitopes. The developed pegunigalsidase alfa is currently tested in phase III clinical trials and has a potential to show superior efficacy versus the currently used enzyme replacement therapies in the treatment of Fabry disease patients.
Kim, Su-Mi; Kim, Se-Kyung; Park, Jong-Hyeon; Lee, Kwang-Nyeong; Ko, Young-Joon; Lee, Hyang-Sim; Seo, Min-Goo; Shin, Yeun-Kyung; Kim, Byounghan
2014-04-01
Foot-and-mouth disease (FMD) is a virulent and economically costly disease in domestic livestock. Since the current vaccine available against FMD provides no protection until 7days postvaccination, the only alternative method to halt the spread of the FMD virus (FMDV) during outbreaks is by the application of anti-viral agents. The combination of recombinant adenovirus expressing type I interferon (IFN-α) and adenovirus expressing type II IFN (IFN-γ) has been reported to be an effective anti-viral treatment strategy against FMDV. Nevertheless, the recombinant adenovirus mixture may be inefficient because of the low anti-viral efficiency of IFN-γ compared to that of IFN-α. In this study, we generated a recombinant adenovirus co-expressing porcine IFN-α and IFN-γ in tandem using an FMDV 2A sequence to mediate effective cleavage of the two proteins (referred to as Ad-porcine IFN-αγ). We demonstrated that both recombinant porcine IFN-α and IFN-γ were expressed and interferon stimulated gene (ISG)s related with IFN-α and IFN-γ were induced in porcine kidney (IBRS-2) cells infected with Ad-porcine IFN-αγ. Additionally, the anti-viral effects of Ad-porcine IFN-αγ against FMDV were enhanced both in IBRS-2 cells and in CD-1 (ICR) suckling mice compared to that of adenovirus expressing only a single protein. We propose that Ad-porcine IFN-αγ could be a rapid, highly efficient, convenient anti-viral agent against FMDV. Copyright © 2014 Elsevier B.V. All rights reserved.
Campos, J L; Qiu, S; Guirao-Rico, S; Bergero, R; Charlesworth, D
2017-01-01
The establishment of a region of suppressed recombination is a critical change during sex chromosome evolution, leading to such properties as Y (and W) chromosome genetic degeneration, accumulation of repetitive sequences and heteromorphism. Although chromosome inversions can cause large regions to have suppressed recombination, and inversions are sometimes involved in sex chromosome evolution, gradual expansion of the non-recombining region could potentially sometimes occur. We here test whether closer linkage has recently evolved between the sex-determining region and several genes that are partially sex-linked in Silene latifolia, using Silene dioica, a closely related dioecious plants whose XY sex chromosome system is inherited from a common ancestor. The S. latifolia pseudoautosomal region (PAR) includes several genes extremely closely linked to the fully Y-linked region. These genes were added to an ancestral PAR of the sex chromosome pair in two distinct events probably involving translocations of autosomal genome regions causing multiple genes to become partially sex-linked. Close linkage with the PAR boundary must have evolved since these additions, because some genes added in both events now show almost complete sex linkage in S. latifolia. We compared diversity patterns of five such S. latifolia PAR boundary genes with their orthologues in S. dioica, including all three regions of the PAR (one gene that was in the ancestral PAR and two from each of the added regions). The results suggest recent recombination suppression in S. latifolia, since its split from S. dioica. PMID:27827389
Zhai, Yifan; Yang, James C.; Spiess, Paul; Nishimura, Michael I.; Overwijk, Willem W.; Roberts, Bruce; Restifo, Nicholas P.; Rosenberg, Steven A.
2008-01-01
The recent identification of genes encoding melanoma-associated antigens has opened new possibilities for the development of cancer vaccines designed to cause the rejection of established tumors. To develop a syngeneic animal model for evaluating antigen-specific vaccines in cancer therapy, the murine homologues of the human melanoma antigens MART1 and gp 100, which were specifically recognized by tumor-infiltrating lymphocytes from patients with melanoma, were cloned and sequenced from a murine B16 melanoma cDNA library. The open reading frames of murine MART1 and gp 100 encode proteins of 113- and 626-amino acids with 68.8 and 77% identity to the respective human proteins. Comparison of the DNA sequences of the murine MART1 genes, derived from normal melanocytes, the immortalized nontumorgenic melanocyte line Melan-a and the B16 melanoma, showed all to be identical. Northern and Western blot analyses confirmed that both genes encoded products that were melanocyte lineage proteins. Mice immunized with murine MART1 or gp 100 using recombinant vaccinia virus failed to produce any detectable T-cell responses or protective immunity against B16 melanoma. In contrast, immunization of mice with human gp 100 using recombinant adenoviruses elicited T cells specific for hgp100, but these T cells also cross reacted with B16 tumor in vitro and induced significant but weak protection against B16 challenge. Immunization with human and mouse gp100 together [adenovirus type 2 (Ad2)-hep100 plus recombinant vaccinia virus (rVV)-mgp100], or immunization with human gp100 (Ad2-hgp100) and boosting with heterologous vector (rVV-hgp100 or rVV-mgp100) or homologous vector (Ad2-hgp100), did not significantly enhance the protective response against B16 melanoma. These results may suggest that immunization with heterologous tumor antigen, rather than self, may be more effective as an immunotherapeutic reagent in designing antigen-specific cancer vaccines. PMID:9101410
Expression of the functional recombinant human glycosyltransferase GalNAcT2 in Escherichia coli.
Lauber, Jennifer; Handrick, René; Leptihn, Sebastian; Dürre, Peter; Gaisser, Sabine
2015-01-13
Recombinant protein-based therapeutics have become indispensable for the treatment of many diseases. They are produced using well-established expression systems based on bacteria, yeast, insect and mammalian cells. The majority of therapeutic proteins are glycoproteins and therefore the post-translational attachment of sugar residues is required. The development of an engineered Escherichia coli-based expression system for production of human glycoproteins could potentially lead to increased yields, as well as significant decreases in processing time and costs. This work describes the expression of functional human-derived glycosyltransferase UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase 2 (GalNAcT2) in a recombinant E. coli strain. For expression, a codon-optimised gene encoding amino acids 52-571 of GalNAcT2 lacking the transmembrane N-terminal domain was inserted into a pET-23 derived vector encoding a polyhistidine-tag which was translationally fused to the N-terminus of the glycosyltransferase (HisDapGalNAcT2). The glycosyltransferase was produced in E. coli using a recently published expression system. Soluble HisDapGalNAcT2 produced in SHuffle® T7 host cells was purified using nickel affinity chromatography and was subsequently analysed by size exclusion chromatography coupled to multi-angle light scattering (SEC-MALS) and circular dichroism spectroscopy to determine molecular mass, folding state and thermal transitions of the protein. The activity of purified HisDapGalNAcT2 was monitored using a colorimetric assay based on the release of phosphate during transfer of glycosyl residues to a model acceptor peptide or, alternatively, to the granulocyte-colony stimulating growth factor (G-CSF). Modifications were assessed by Matrix Assisted Laser Desorption Ionization Time-of-flight Mass Spectrometry analysis (MALDI-TOF-MS) and Electrospray Mass Spectrometry analysis (ESI-MS). The results clearly indicate the glycosylation of the acceptor peptide and
Photoionization and Recombination
NASA Technical Reports Server (NTRS)
Nahar, Sultana N.
2000-01-01
Theoretically self-consistent calculations for photoionization and (e + ion) recombination are described. The same eigenfunction expansion for the ion is employed in coupled channel calculations for both processes, thus ensuring consistency between cross sections and rates. The theoretical treatment of (e + ion) recombination subsumes both the non-resonant recombination ("radiative recombination"), and the resonant recombination ("di-electronic recombination") processes in a unified scheme. In addition to the total, unified recombination rates, level-specific recombination rates and photoionization cross sections are obtained for a large number of atomic levels. Both relativistic Breit-Pauli, and non-relativistic LS coupling, calculations are carried out in the close coupling approximation using the R-matrix method. Although the calculations are computationally intensive, they yield nearly all photoionization and recombination parameters needed for astrophysical photoionization models with higher precision than hitherto possible, estimated at about 10-20% from comparison with experimentally available data (including experimentally derived DR rates). Results are electronically available for over 40 atoms and ions. Photoionization and recombination of He-, and Li-like C and Fe are described for X-ray modeling. The unified method yields total and complete (e+ion) recombination rate coefficients, that can not otherwise be obtained theoretically or experimentally.
Ong, Daniel; Wijaya, Linda; Laws, Simon M.; Taddei, Kevin; Newman, Morgan; Lardelli, Michael; Martins, Ralph N.; Verdile, Giuseppe
2013-01-01
We investigated the guinea pig, Cavia porcellus, as a model for Alzheimer’s disease (AD), both in terms of the conservation of genes involved in AD and the regulatory responses of these to a known AD risk factor - high cholesterol intake. Unlike rats and mice, guinea pigs possess an Aβ peptide sequence identical to human Aβ. Consistent with the commonality between cardiovascular and AD risk factors in humans, we saw that a high cholesterol diet leads to up-regulation of BACE1 (β-secretase) transcription and down-regulation of ADAM10 (α-secretase) transcription which should increase release of Aβ from APP. Significantly, guinea pigs possess isoforms of AD-related genes found in humans but not present in mice or rats. For example, we discovered that the truncated PS2V isoform of human PSEN2, that is found at raised levels in AD brains and that increases γ-secretase activity and Aβ synthesis, is not uniquely human or aberrant as previously believed. We show that PS2V formation is up-regulated by hypoxia and a high-cholesterol diet while, consistent with observations in humans, Aβ concentrations are raised in some brain regions but not others. Also like humans, but unlike mice, the guinea pig gene encoding tau, MAPT, encodes isoforms with both three and four microtubule binding domains, and cholesterol alters the ratio of these isoforms. We conclude that AD-related genes are highly conserved and more similar to human than the rat or mouse. Guinea pigs represent a superior rodent model for analysis of the impact of dietary factors such as cholesterol on the regulation of AD-related genes. PMID:23805206
Kieper, Jana; Lauber, Christiane; Gimadutdinow, Oleg; Urbańska, Anna; Cymerman, Iwona; Ghosh, Mahua; Szczesny, Bartosz; Meiss, Gregor
2010-09-01
Nuc1p, CPS-6, EndoG and EXOG are evolutionary conserved mitochondrial nucleases from yeast, Caenorhabditis elegans and humans, respectively. These enzymes play an important role in programmed cell death as well as mitochondrial DNA-repair and recombination. Whereas a significant interest has been given to the cell biology of these proteins, in particular their recruitment during caspase-independent apoptosis, determination of their biochemical properties has lagged behind. In part, biochemical as well as structural analysis of mitochondrial nucleases has been hampered by the fact that upon cloning and overexpression in Escherichia coli these enzymes can exert considerable toxicity and tend to aggregate and form inclusion bodies. We have, therefore, established a uniform E. coli expression system allowing us to obtain these four evolutionary related nucleases in active form from the soluble as well as insoluble fractions of E. coli cell lysates. Using preparations of recombinant Nuc1p, CPS-6, EndoG and EXOG we have compared biochemical properties and the substrate specificities of these related nucleases on selected substrates in parallel. Whereas Nuc1p and EXOG in addition to their endonuclease activity exert 5'-3'-exonuclease activity, CPS-6 and EndoG predominantly are endonucleases. These findings allow speculating that the mechanisms of action of these related nucleases in cell death as well as DNA-repair and recombination differ according to their enzyme activities and substrate specificities. Copyright 2010 Elsevier Inc. All rights reserved.
NASA Technical Reports Server (NTRS)
Powell, C.; Shansky, J.; Del Tatto, M.; Forman, D. E.; Hennessey, J.; Sullivan, K.; Zielinski, B. A.; Vandenburgh, H. H.
1999-01-01
Murine skeletal muscle cells transduced with foreign genes and tissue engineered in vitro into bioartificial muscles (BAMs) are capable of long-term delivery of soluble growth factors when implanted into syngeneic mice (Vandenburgh et al., 1996b). With the goal of developing a therapeutic cell-based protein delivery system for humans, similar genetic tissue-engineering techniques were designed for human skeletal muscle stem cells. Stem cell myoblasts were isolated, cloned, and expanded in vitro from biopsied healthy adult (mean age, 42 +/- 2 years), and elderly congestive heart failure patient (mean age, 76 +/- 1 years) skeletal muscle. Total cell yield varied widely between biopsies (50 to 672 per 100 mg of tissue, N = 10), but was not significantly different between the two patient groups. Percent myoblasts per biopsy (73 +/- 6%), number of myoblast doublings prior to senescence in vitro (37 +/- 2), and myoblast doubling time (27 +/- 1 hr) were also not significantly different between the two patient groups. Fusion kinetics of the myoblasts were similar for the two groups after 20-22 doublings (74 +/- 2% myoblast fusion) when the biopsy samples had been expanded to 1 to 2 billion muscle cells, a number acceptable for human gene therapy use. The myoblasts from the two groups could be equally transduced ex vivo with replication-deficient retroviral expression vectors to secrete 0.5 to 2 microg of a foreign protein (recombinant human growth hormone, rhGH)/10(6) cells/day, and tissue engineered into human BAMs containing parallel arrays of differentiated, postmitotic myofibers. This work suggests that autologous human skeletal myoblasts from a potential patient population can be isolated, genetically modified to secrete foreign proteins, and tissue engineered into implantable living protein secretory devices for therapeutic use.
Crank, Michelle C; Wilson, Eleanor M P; Novik, Laura; Enama, Mary E; Hendel, Cynthia S; Gu, Wenjuan; Nason, Martha C; Bailer, Robert T; Nabel, Gary J; McDermott, Adrian B; Mascola, John R; Koup, Richard A; Ledgerwood, Julie E; Graham, Barney S
2016-01-01
VRC 012 was a Phase I study of a prototype recombinant adenoviral-vector serotype-35 (rAd35) HIV vaccine, the precursor to two recently published clinical trials, HVTN 077 and 083. On the basis of prior evaluation of multiclade rAd5 HIV vaccines, Envelope A (EnvA) was selected as the standard antigen for a series of prototype HIV vaccines to compare various vaccine platforms. In addition, prior studies of rAd5-vectored vaccines suggested pre-existing human immunity may be a confounding factor in vaccine efficacy. rAd35 is less seroprevalent across human populations and was chosen for testing alone and in combination with a rAd5-EnvA vaccine in the present two-part phase I study. First, five subjects each received a single injection of 109, 1010, or 1011 particle units (PU) of rAd35-EnvA in an open-label, dose-escalation study. Next, 20 Ad5/Ad35-seronegative subjects were randomized to blinded, heterologous prime-boost schedules combining rAd5-EnvA and rAd35-EnvA with a three month interval. rAd35-EnvA was given at 1010 or 1011 PU to ten subjects each; all rAd5-EnvA injections were 1010 PU. EnvA-specific immunogenicity was assessed four weeks post-injection. Solicited reactogenicity and clinical safety were followed after each injection. Vaccinations were well tolerated at all dosages. Antibody responses measured by ELISA were detected at 4 weeks in 30% and 50% of subjects after single doses of 1010 or 1011 PU rAd35, respectively, and in 89% after a single rAd5-EnvA 1010 PU injection. EnvA-specific IFN-γ ELISpot responses were detected at four weeks in 0%, 70%, and 50% of subjects after the respective rAd35-EnvA dosages compared to 89% of subjects after rAd5. T cell responses were higher after a single rAd5-EnvA 1010 PU injection than after a single rAd35-EnvA 1010 PU injection, and humoral responses were low after a single dose of either vector. Of those completing the vaccine schedule, 100% of rAd5-EnvA recipients and 90% of rAd35-EnvA recipients had both T cell
Sex steroid levels and AD-like pathology in 3xTgAD mice
Ma, Chunqi; Taves, Matthew D.; Soma, Kiran K.; Mufson, Elliott J.
2014-01-01
Decreases in testosterone (T) and 17β-oestradiol (E2) are associated with an increased risk for Alzheimer's disease (AD), which has been attributed to an increase in beta amyloid (Aβ) and tau pathologic lesions. While recent studies have used transgenic animal models to test the effects of sex steroid manipulations on AD-like pathology, virtually none have systematically characterised the associations between AD lesions and sex steroid levels in the blood or brain in any mutant model. The present study evaluated age-related changes in T and E2 concentrations, as well as androgen receptor (AR) and oestrogen receptor (ER) α and β expression, in brain regions displaying AD pathology in intact male and female 3xTgAD and non-transgenic (ntg) mice. We report for the first time that circulating and brain T levels significantly increase in male 3xTgAD mice with age, but without changes in AR-immunoreactive (ir) cell number in either the hippocampal CA1 or medial amygdala. The age-related increase in hippocampal T levels correlated positively with increases in the conformational tau isoform, Alz50. These data suggest that the over-expression of human tau may up regulate the hypothalamic-pituitary-gonadal axis in these mice. Although circulating and brain E2 levels remained stable with age in both male and female 3xTgAD and ntg mice, ER-ir cell number in the hippocampus and medial amygdala decreased with age in female transgenic mice. Further, E2 levels were significantly higher in the hippocampus than in serum, suggesting local production of E2. Although triple transgenic mice mimic AD-like pathology, they do not fully replicate changes in human sex steroid levels, and may not be the best model for studying the effects of sex steroids on AD lesions. PMID:22889357
Soo, Benjamin P C; Tay, Julian; Ng, Shirelle; Ho, Steven C L; Yang, Yuansheng; Chao, Sheng-Hao
2017-08-01
Role of epigenetic regulation in the control of gene expression is well established. The impact of several epigenetic mechanisms, such as DNA methylation and histone acetylation, on recombinant protein production in mammalian cells has been investigated recently. Here we investigate the correlation between the selected epigenetic markers and five trastuzumab biosimilar-producing Chinese hamster ovary (CHO) cell lines in which the expression of trastuzumab is driven by human cytomegalovirus (HCMV) major immediate-early (MIE) promoter. We chose the producing clones in which transcription was the determinative step for the production of recombinant trastuzumab. We found that the abundance of trimethylation of histone 3 at lysine 4 (H3K4Me3) on the enhancer of HCMV MIE promoter correlated well with the relative titers of recombinant trastuzumab among the clones. Such close correlation was not observed between the recombinant protein and other epigenetic markers examined in our study. Our results demonstrate that the HCMV MIE enhancer-bound H3K4Me3 epigenetic marker may be used as the epigenetic indicator to predict the relative production of recombinant proteins between the producing CHO cell lines.
NASA Astrophysics Data System (ADS)
Wang, Feng; Wang, Riyuan; Wang, Yuancheng; Zhao, Ping; Xia, Qingyou
2015-11-01
With an increasing clinical demand for functional therapeutic proteins every year, there is an increasing requirement for the massive production of bioactive recombinant human acidic fibroblast growth factor (r-haFGF). In this present study, we delicately explore a strategy for the mass production of r-haFGF protein with biological activity in the transgenic silkworm cocoons. The sequence-optimized haFGF was inserted into an enhanced sericin-1 expression system to generate the original transgenic silkworm strain, which was then further crossed with a PIG jumpstarter strain to achieve the remobilization of the expression cassette to a “safe harbor” locus in the genome for the efficient expression of r-haFGF. In consequence, the expression of r-haFGF protein in the mutant line achieved a 5.6-fold increase compared to the original strain. The high content of r-haFGF facilitated its purification and large-scald yields. Furthermore, the r-haFGF protein bioactively promoted the growth, proliferation and migration of NIH/3T3 cells, suggesting the r-haFGF protein possessed native mitogenic activity and the potential for wound healing. These results show that the silk gland of silkworm could be an efficient bioreactor strategy for recombinant production of bioactive haFGF in silkworm cocoons.
Mostowy, Rafal; Croucher, Nicholas J; Hanage, William P; Harris, Simon R; Bentley, Stephen; Fraser, Christophe
2014-05-01
The bacterium Streptococcus pneumoniae (pneumococcus) is one of the most important human bacterial pathogens, and a leading cause of morbidity and mortality worldwide. The pneumococcus is also known for undergoing extensive homologous recombination via transformation with exogenous DNA. It has been shown that recombination has a major impact on the evolution of the pathogen, including acquisition of antibiotic resistance and serotype-switching. Nevertheless, the mechanism and the rates of recombination in an epidemiological context remain poorly understood. Here, we proposed several mathematical models to describe the rate and size of recombination in the evolutionary history of two very distinct pneumococcal lineages, PMEN1 and CC180. We found that, in both lineages, the process of homologous recombination was best described by a heterogeneous model of recombination with single, short, frequent replacements, which we call micro-recombinations, and rarer, multi-fragment, saltational replacements, which we call macro-recombinations. Macro-recombination was associated with major phenotypic changes, including serotype-switching events, and thus was a major driver of the diversification of the pathogen. We critically evaluate biological and epidemiological processes that could give rise to the micro-recombination and macro-recombination processes.
Hanage, William P.; Harris, Simon R.; Bentley, Stephen; Fraser, Christophe
2014-01-01
The bacterium Streptococcus pneumoniae (pneumococcus) is one of the most important human bacterial pathogens, and a leading cause of morbidity and mortality worldwide. The pneumococcus is also known for undergoing extensive homologous recombination via transformation with exogenous DNA. It has been shown that recombination has a major impact on the evolution of the pathogen, including acquisition of antibiotic resistance and serotype-switching. Nevertheless, the mechanism and the rates of recombination in an epidemiological context remain poorly understood. Here, we proposed several mathematical models to describe the rate and size of recombination in the evolutionary history of two very distinct pneumococcal lineages, PMEN1 and CC180. We found that, in both lineages, the process of homologous recombination was best described by a heterogeneous model of recombination with single, short, frequent replacements, which we call micro-recombinations, and rarer, multi-fragment, saltational replacements, which we call macro-recombinations. Macro-recombination was associated with major phenotypic changes, including serotype-switching events, and thus was a major driver of the diversification of the pathogen. We critically evaluate biological and epidemiological processes that could give rise to the micro-recombination and macro-recombination processes. PMID:24786281
Tran, Anh-Minh; Nguyen, Thanh-Thao; Nguyen, Cong-Thuan; Huynh-Thi, Xuan-Mai; Nguyen, Cao-Tri; Trinh, Minh-Thuong; Tran, Linh-Thuoc; Cartwright, Stephanie P; Bill, Roslyn M; Tran-Van, Hieu
2017-04-04
Recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) is a glycoprotein that has been approved by the FDA for the treatment of neutropenia and leukemia in combination with chemotherapies. Recombinant hGM-CSF is produced industrially using the baker's yeast, Saccharomyces cerevisiae, by large-scale fermentation. The methylotrophic yeast, Pichia pastoris, has emerged as an alternative host cell system due to its shorter and less immunogenic glycosylation pattern together with higher cell density growth and higher secreted protein yield than S. cerevisiae. In this study, we compared the pipeline from gene to recombinant protein in these two yeasts. Codon optimization in silico for both yeast species showed no difference in frequent codon usage. However, rhGM-CSF expressed from S. cerevisiae BY4742 showed a significant discrepancy in molecular weight from those of P. pastoris X33. Analysis showed purified rhGM-CSF species with molecular weights ranging from 30 to more than 60 kDa. Fed-batch fermentation over 72 h showed that rhGM-CSF was more highly secreted from P. pastoris than S. cerevisiae (285 and 64 mg total secreted protein/L, respectively). Ion exchange chromatography gave higher purity and recovery than hydrophobic interaction chromatography. Purified rhGM-CSF from P. pastoris was 327 times more potent than rhGM-CSF from S. cerevisiae in terms of proliferative stimulating capacity on the hGM-CSF-dependent cell line, TF-1. Our data support a view that the methylotrophic yeast P. pastoris is an effective recombinant host for heterologous rhGM-CSF production.
Sun, Chenjing; Zhang, Hongliang; Xu, Jiang; Gao, Jie
2013-01-01
Introduction Human myasthenia gravis (MG) is an autoimmune disorder of the neuromuscular system. Experimental autoimmune myasthenia gravis (EAMG) is a well-established animal model for MG that can be induced by active immunization with the Torpedo californica-derived acetylcholine receptor (AChR). Due to the expensive cost of purifying AChR from Torpedo californica, the development of an easier and more economical way of inducing EAMG remains critically needed. Material and methods Full-length cDNA of the human skeletal muscle AChR α1 subunit was obtained from TE671 cells. The DNA fragment encoding the extracellular domain (ECD) was then amplified by polymerase chain reaction (PCR) and inserted into pET-16b. The reconstructed plasmid was transformed into the host strain BL21(DE3)pLysS, which was derived from Escherichia coli. Isopropyl-β-D-thiogalactopyranoside (IPTG) was used to induce the expression of the N-terminal ECD. The produced protein was purified with immobilized Ni2+ affinity chromatography and refolded by dialysis. Results The recombinant protein was efficiently refolded to soluble active protein, which was verified by ELISA. After immunization with the recombinant ECD, all rats acquired clinical signs of EAMG. The titer of AChR antibodies in the serum was significantly higher in the EAMG group than in the control group, indicating successful induction of EAMG. Conclusions We describe an improved procedure for refolding recombinant ECD of human muscle AChR. This improvement allows for the generation of large quantities of correctly folded recombinant ECD of human muscle AChR, which provides for an easier and more economical way of inducing the animal model of MG. PMID:24904677
Recombinant Domain V of Human Perlecan Is a Bioactive Vascular Proteoglycan.
Rnjak-Kovacina, Jelena; Tang, Fengying; Lin, Xiaoting; Whitelock, John M; Lord, Megan S
2017-12-01
The C-terminal domain V of the extracellular matrix proteoglycan perlecan plays unique and often divergent roles in a number of biological processes, including angiogenesis, vascular cell interactions, wound healing, and autophagy. Recombinant forms of domain V have been proposed as therapeutic agents for the treatment of cancer, stroke, and the development of cardiovascular devices and bioartificial tissues. However, the effect of domain V appears to be related to the differences in domain V structure and function observed in different expression systems and environments and exactly how this occurs is not well understood. In this study, the sequence from amino acid 3626 to 4391 of the perlecan protein core, which includes domain V, is expressed in HEK-293 cells and purified as a secreted product from conditioned media. This recombinant domain V (rDV) is expressed as a proteoglycan decorated with heparan sulfate and chondroitin sulfate chains and supports endothelial cell interactions to the same extent as full-length perlecan. This expression system serves as an important model of recombinant proteoglycan expression, as well as a source of biologically active rDV for therapeutic applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
An att site-based recombination reporter system for genome engineering and synthetic DNA assembly.
Bland, Michael J; Ducos-Galand, Magaly; Val, Marie-Eve; Mazel, Didier
2017-07-14
Direct manipulation of the genome is a widespread technique for genetic studies and synthetic biology applications. The tyrosine and serine site-specific recombination systems of bacteriophages HK022 and ΦC31 are widely used for stable directional exchange and relocation of DNA sequences, making them valuable tools in these contexts. We have developed site-specific recombination tools that allow the direct selection of recombination events by embedding the attB site from each system within the β-lactamase resistance coding sequence (bla). The HK and ΦC31 tools were developed by placing the attB sites from each system into the signal peptide cleavage site coding sequence of bla. All possible open reading frames (ORFs) were inserted and tested for recombination efficiency and bla activity. Efficient recombination was observed for all tested ORFs (3 for HK, 6 for ΦC31) as shown through a cointegrate formation assay. The bla gene with the embedded attB site was functional for eight of the nine constructs tested. The HK/ΦC31 att-bla system offers a simple way to directly select recombination events, thus enhancing the use of site-specific recombination systems for carrying out precise, large-scale DNA manipulation, and adding useful tools to the genetics toolbox. We further show the power and flexibility of bla to be used as a reporter for recombination.
Prdm9 controls activation of mammalian recombination hotspots.
Parvanov, Emil D; Petkov, Petko M; Paigen, Kenneth
2010-02-12
Mammalian meiotic recombination, which preferentially occurs at specialized sites called hotspots, ensures the orderly segregation of meiotic chromosomes and creates genetic variation among offspring. A locus on mouse chromosome 17, which controls activation of recombination at multiple distant hotspots, has been mapped within a 181-kilobase interval, three of whose genes can be eliminated as candidates. The remaining gene, Prdm9, codes for a zinc finger containing histone H3K4 trimethylase that is expressed in early meiosis and whose deficiency results in sterility in both sexes. Mus musculus exhibits five alleles of Prdm9; human populations exhibit two predominant alleles and multiple minor alleles. The identification of Prdm9 as a protein regulating mammalian recombination hotspots initiates molecular studies of this important biological control system.
Stepwise detection of recombination breakpoints in sequence alignments.
Graham, Jinko; McNeney, Brad; Seillier-Moiseiwitsch, Françoise
2005-03-01
We propose a stepwise approach to identify recombination breakpoints in a sequence alignment. The approach can be applied to any recombination detection method that uses a permutation test and provides estimates of breakpoints. We illustrate the approach by analyses of a simulated dataset and alignments of real data from HIV-1 and human chromosome 7. The presented simulation results compare the statistical properties of one-step and two-step procedures. More breakpoints are found with a two-step procedure than with a single application of a given method, particularly for higher recombination rates. At higher recombination rates, the additional breakpoints were located at the cost of only a slight increase in the number of falsely declared breakpoints. However, a large proportion of breakpoints still go undetected. A makefile and C source code for phylogenetic profiling and the maximum chi2 method, tested with the gcc compiler on Linux and WindowsXP, are available at http://stat-db.stat.sfu.ca/stepwise/ jgraham@stat.sfu.ca.
The Role of Recombination in the Origin and Evolution of Alu Subfamilies
Teixeira-Silva, Ana; Silva, Raquel M.; Carneiro, João; Amorim, António; Azevedo, Luísa
2013-01-01
Alus are the most abundant and successful short interspersed nuclear elements found in primate genomes. In humans, they represent about 10% of the genome, although few are retrotransposition-competent and are clustered into subfamilies according to the source gene from which they evolved. Recombination between them can lead to genomic rearrangements of clinical and evolutionary significance. In this study, we have addressed the role of recombination in the origin of chimeric Alu source genes by the analysis of all known consensus sequences of human Alus. From the allelic diversity of Alu consensus sequences, validated in extant elements resulting from whole genome searches, distinct events of recombination were detected in the origin of particular subfamilies of AluS and AluY source genes. These results demonstrate that at least two subfamilies are likely to have emerged from ectopic Alu-Alu recombination, which stimulates further research regarding the potential of chimeric active Alus to punctuate the genome. PMID:23750218
The role of recombination in the origin and evolution of Alu subfamilies.
Teixeira-Silva, Ana; Silva, Raquel M; Carneiro, João; Amorim, António; Azevedo, Luísa
2013-01-01
Alus are the most abundant and successful short interspersed nuclear elements found in primate genomes. In humans, they represent about 10% of the genome, although few are retrotransposition-competent and are clustered into subfamilies according to the source gene from which they evolved. Recombination between them can lead to genomic rearrangements of clinical and evolutionary significance. In this study, we have addressed the role of recombination in the origin of chimeric Alu source genes by the analysis of all known consensus sequences of human Alus. From the allelic diversity of Alu consensus sequences, validated in extant elements resulting from whole genome searches, distinct events of recombination were detected in the origin of particular subfamilies of AluS and AluY source genes. These results demonstrate that at least two subfamilies are likely to have emerged from ectopic Alu-Alu recombination, which stimulates further research regarding the potential of chimeric active Alus to punctuate the genome.
Chen, Hao; Yang, Peng; Guo, Jing; Kwoh, Chee Keong; Przytycka, Teresa M; Zheng, Jie
2015-01-01
Meiotic recombination hotspots play important roles in various aspects of genomics, but the underlying mechanisms for regulating the locations and strengths of recombination hotspots are not yet fully revealed. Most existing algorithms for estimating recombination rates from sequence polymorphism data can only output average recombination rates of a population, although there is evidence for the heterogeneity in recombination rates among individuals. For genome-wide association studies (GWAS) of recombination hotspots, an efficient algorithm that estimates the individualized strengths of recombination hotspots is highly desirable. In this work, we propose a novel graph mining algorithm named ARG-walker, based on random walks on ancestral recombination graphs (ARG), to estimate individual-specific recombination hotspot strengths. Extensive simulations demonstrate that ARG-walker is able to distinguish the hot allele of a recombination hotspot from the cold allele. Integrated with output of ARG-walker, we performed GWAS on the phased haplotype data of the 22 autosome chromosomes of the HapMap Asian population samples of Chinese and Japanese (JPT+CHB). Significant cis-regulatory signals have been detected, which is corroborated by the enrichment of the well-known 13-mer motif CCNCCNTNNCCNC of PRDM9 protein. Moreover, two new DNA motifs have been identified in the flanking regions of the significantly associated SNPs (single nucleotide polymorphisms), which are likely to be new cis-regulatory elements of meiotic recombination hotspots of the human genome. Our results on both simulated and real data suggest that ARG-walker is a promising new method for estimating the individual recombination variations. In the future, it could be used to uncover the mechanisms of recombination regulation and human diseases related with recombination hotspots.
SPAR1/RTEL1 maintains genomic stability by suppressing homologous recombination
Barber, Louise J.; Youds, Jillian L.; Ward, Jordan D.; McIlwraith, Michael J.; O’Neil, Nigel J.; Petalcorin, Mark I.R.; Martin, Julie S.; Collis, Spencer J.; Cantor, Sharon B.; Auclair, Melissa; Tissenbaum, Heidi; West, Stephen C.; Rose, Ann M.; Boulton, Simon J.
2013-01-01
SUMMARY Inappropriate homologous recombination (HR) can cause gross chromosomal rearrangements that in mammalian cells may lead to tumorigenesis. In yeast, the Srs2 protein is an anti-recombinase that eliminates inappropriate recombination events, but the functional equivalent of Srs2 in higher eukaryotes has proven to be elusive. In this work, we identify C. elegans SPAR-1 as a functional analogue of Srs2 and describe its vertebrate counterpart, SPAR1/RTEL1, which is required for genome stability and tumour avoidance. We find that spar-1 mutant worms and SPAR1 knockdown human cells share characteristic phenotypes with yeast srs2 mutants, including inviability upon deletion of the sgs1/BLM homologue, hyper-recombination, and DNA damage sensitivity. In vitro, purified human SPAR1 antagonises HR by promoting the disassembly of D loop recombination intermediates in a reaction dependent upon ATP hydrolysis. We propose that loss of HR control following deregulation of SPAR1/RTEL1 may be a critical event that drives genome instability and cancer. PMID:18957201
Yang, Hai; Li, Qing-Wang; Han, Zeng-Sheng; Hu, Jian-Hong; Li, Wen-Ye; Liu, Zhi-Bin
2009-11-01
Plasma-derived antithrombin (pAT) is often used for the treatments of disseminated intravascular coagulation (DIC) patients. In this paper, the recombinant adenovirus vector encoding human antithrombin (AT) cDNA was constructed and directly infused into the mammary gland of two goats. The recombinant human antithrombin (rhAT) was purified by heparin affinity chromatography from the goat milk, and then used in the treatment of thirty lipopolysaccharide (LPS) induced DIC rats. A high expression level of rhAT up to 2.8 g/l was obtained in the milk of goats. After purification, the recovery rate and the purity of the rhAT were up to 54.7 +/- 3.2% and 96.2 +/- 2.7%, respectively. In blood of the DIC rat model treated with rhAT, the levels of antithrombin and thrombin-antithrombin (TAT) were augmented significantly; meanwhile the consumption of fibrinogen and platelet was reduced significantly, and the increase of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) concentration was restrained modest and non-significant. For the above DIC indexes, there were no differences between pAT and rhAT (P > 0.05). Our results demonstrated that the way we established is a pragmatic tool for large-scale production of rhAT, and the rhAT produced with this method has potential as a substitute for pAT in the therapy of DIC patients.
Sun, Yongke; Yang, Yuai; Zheng, Huanli; Xi, Dongmei; Lin, Mingxing; Zhang, Xiaomin; Yang, Linfu; Yan, Yulin; Chu, Xiaohui; Bi, Baoliang
2013-04-01
The objective of this study was to construct a recombinant adenovirus for future CSFV vaccines used in the pig industry for the reduction of losses involved in CSF outbreaks. The Erns and E2 genes of classical swine fever virus (CSFV), which encode the two main protective glycoproteins from the "Shimen" strain of CSFV, were combined and inserted into the replication-defective human adenovirus type-5 and named the rAd-Erns-E2. Nine pigs were randomly assigned to three treatment groups (three pigs in each group) including the rAd-Erns-E2, hAd-CMV control and DMEM control. Intramuscular vaccination with 2×10(6) TCID(50) of the rAd-Erns-E2 was administered two times with an interval of 21 days. At 42 days post inoculation, pigs in all groups were challenged with a lethal dose of 1×10(3) TCID(50) CSFV "Shimen" strain. Observation of clinical signs was made and the existence of CSFV RNA was detected. Animals in the hAd-CMV and DMEM groups showed severe clinical CSF symptoms and were euthanized from 7 to 10 days after the challenge. However, no adverse clinical CSF signs were observed in vaccinated pigs after the administration of rAd-Erns-E2 and even after CSFV challenge. Neither CSFV RNA nor pathological changes were detected in the tissues of interest of the above vaccinated pigs. These results implied that the recombination adenovirus carrying the Erns-E2 genes could be used to prevent swine from classical swine fever. Copyright © 2012 Elsevier Ltd. All rights reserved.
Martín, V; Pascual, E; Avia, M; Rangel, G; de Molina, A; Alejo, A; Sevilla, N
2016-01-06
Ovine interferon tau (IFN-τ) is a unique type I interferon with low toxicity and a broad host range in vivo. We report the generation of a nonreplicative recombinant adenovirus expressing biologically active IFN-τ. Using the B6.A2G-Mx1 mouse model, we showed that single-dose intranasal administration of recombinant Ad5-IFN-τ can effectively prevent lethality and disease induced by highly virulent hv-PR8 influenza virus by activating the interferon response and preventing viral replication. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
A simple approach for human recombinant apolipoprotein E4 expression and purification.
Argyri, Letta; Skamnaki, Vassiliki; Stratikos, Efstratios; Chroni, Angeliki
2011-10-01
We report a simple expression and purification procedure for the production of recombinant apolipoprotein E4 (apoE4), an important protein for the lipid homeostasis in humans that plays critical roles in the pathogenesis of cardiovascular and neurodegenerative diseases. Our approach is based on the expression of a thioredoxin-apoE4 fusion construct in bacterial cells and subsequent removal of the fused thioredoxin using the highly specific 3C protease, avoiding costly and laborious lipidation-delipidation steps used before. Our approach results in rapid, high-yield production of structurally and functionally competent apoE4 as evidenced by secondary structure measurements, thermal and chemical melting profiles and the kinetic profile of solubilization of dimyristoyl-phosphatidylcholine (DMPC) vesicles. This protocol is appropriate for laboratories with little experience in apolipoprotein biochemistry and will facilitate future studies on the role of apoE4 in the pathogenesis of cardiovascular disease and neurodegenerative diseases, including Alzheimer's disease. Copyright © 2011 Elsevier Inc. All rights reserved.
Razaghi, Ali; Owens, Leigh; Heimann, Kirsten
2016-12-20
Human interferon gamma is a cytokine belonging to a diverse group of interferons which have a crucial immunological function against mycobacteria and a wide variety of viral infections. To date, it has been approved for treatment of chronic granulomatous disease and malignant osteopetrosis, and its application as an immunotherapeutic agent against cancer is an increasing prospect. Recombinant human interferon gamma, as a lucrative biopharmaceutical, has been engineered in different expression systems including prokaryotic, protozoan, fungal (yeasts), plant, insect and mammalian cells. Human interferon gamma is commonly expressed in Escherichia coli, marketed as ACTIMMUNE ® , however, the resulting product of the prokaryotic expression system is unglycosylated with a short half-life in the bloodstream; the purification process is tedious and makes the product costlier. Other expression systems also did not show satisfactory results in terms of yields, the biological activity of the protein or economic viability. Thus, the review aims to synthesise available information from previous studies on the production of human interferon gamma and its glycosylation patterns in different expression systems, to provide direction to future research in this field. Copyright © 2016 Elsevier B.V. All rights reserved.
Freimuth, P; Anderson, C W
1993-03-01
The sequence of a 1158-base pair fragment of the human adenovirus serotype 12 (Ad12) genome was determined. This segment encodes the precursors for virion components Mu and VI. Both Ad12 precursors contain two sequences that conform to a consensus sequence motif for cleavage by the endoproteinase of adenovirus 2 (Ad2). Analysis of the amino terminus of VI and of the peptide fragments found in Ad12 virions demonstrated that these sites are cleaved during Ad12 maturation. This observation suggests that the recognition motif for adenovirus endoproteinases is highly conserved among human serotypes. The adenovirus 2 endoproteinase polypeptide requires additional co-factors for activity (C. W. Anderson, Protein Expression Purif., 1993, 4, 8-15). Synthetic Ad12 or Ad2 pVI carboxy-terminal peptides each permitted efficient cleavage of an artificial endoproteinase substrate by recombinant Ad2 endoproteinase polypeptide.
Zhang, Xiaoguang; Yang, Ren; Wang, Jiao; Wang, Xuan; Hou, Mieling; An, Lina; Zhu, Ying; Cao, Yuxi; Zeng, Yi
2016-01-01
We used 293 cells to express the recombinant membrane protein of the Ebola virus. Then, the immunogenicity of the recombinant protein was studied by immunized BALB/c mice. According to the codon use frequency of humans, the gene encoding the extracellular domain of the Ebola virus membrane protein was optimized, synthesized, and inserted into the eukaryotic expression plasmid pXG-Fc to construct the human IgG Fc and Ebola GP fusion protein expression plasmid pXG-modGP-Fc. To achieve expression, the fusion protein expression vector was transfected into high-density 293 cells using transient transfection technology. The recombinant protein was purified by protein A affinity chromatography. BALB/c mice were immunized with the purified fusion protein, and serum antibody titers evaluated by an indirect enzyme-linked immunosorbent assay (ELISA). Purification and analyses of the protein revealed that the eukaryotic expression vector could express the recombinant protein GP-Fc effectively, and that the recombinant protein in the supernatant of the cell culture was present as a dimer. After immunization with the purified recombinant protein, a high titer of antigen-specific IgG could be detected in the serum of immunized mice by indirect ELISA, showing that the recombinant protein had good immunogenicity. These data suggest that we obtained a recombinant protein with good immunogenicity. Our study is the basis for development of a vaccine against the Ebola virus and for screening of monoclonal antibodies.
Bolatti, Elisa M; Chouhy, Diego; Casal, Pablo E; Pérez, Germán R; Stella, Emma J; Sanchez, Adriana; Gorosito, Mario; Bussy, Ramón Fernandez; Giri, Adriana A
2016-08-01
Gammapapillomavirus (γ-PV) is a diverse and rapidly expanding genus, currently consisting of 79 fully characterized human PV (HPV) types. In this study, three novel types, HPV157, HPV158 and HPV205, obtained from healthy sun-exposed skin of two immunocompetent individuals, were amplified by the "Hanging droplet" long PCR technique, cloned, sequenced and characterized. HPV157, HPV158 and HPV205 genomes comprise 7154-bp, 7192-bp and 7298-bp, respectively, and contain four early (E1, E2, E6 and E7) and two late genes (L1 and L2). Phylogenetic analysis of the L1 ORF placed all novel types within the γ-PV genus: HPV157 was classified as a new member of species γ-12 while HPV158 and HPV205 belong to species γ-1. We then explored potential recombination events in genus γ-PV with the RDP4 program in a dataset of 74 viruses (71 HPV types with available full-length genomes and the 3 novel types). Two events, both located in the E1 ORF, met the inclusion criterion (p-values <0.05 with at least four methods) and persisted in different ORF combinations: an inter-species recombination in species γ-8 (major and minor parents: species γ-24 and γ-11, respectively), and an intra-species recombination in species γ-7 (recombinant strain: HPV170; major and minor parents: HPV-109 and HPV-149, respectively). These findings were confirmed by phylogenetic tree incongruence analysis. An additional incongruence was found in members of species γ-9 but it was not detected by the RDP4. This report expands our knowledge of the family Papillomaviridae and provides for the first time in silico evidence of recombination in genus γ-PV. Copyright © 2016 Elsevier B.V. All rights reserved.
Schäfer, Holger; Ramamoorthy, Siva; Wink, Michael
2017-01-01
Hairy root culture is a potential alternative to conventional mammalian cell culture to produce recombinant proteins due to its ease in protein recovery, low costs and absence of potentially human pathogenic contaminants. The current study focussed to develop a new platform of a hairy root culture system from Nicotiana tabacum for the production of recombinant human EPO (rhEPO), which is regularly produced in mammalian cells. The human EPO construct was amplified with C-terminal hexahistidine tag from a cDNA of Caco-2 cells. Two versions of rhEPO clones, with or without the N-terminal calreticulin (cal) fusion sequence, were produced by cloning the amplified construct into gateway binary vector pK7WG2D. Following Agrobacterium rhizogenes mediated transformation of tobacco explants; integration and expression of constructs in hairy roots were confirmed by several tests at DNA, RNA and protein levels. The amount of intracellular rhEPO from hairy root cultures with cal signal peptide was measured up to 66.75 ng g-1 of total soluble protein. The presence of the ER signal peptide (cal) was essential for the secretion of rhEPO into the spent medium; no protein was detected from hairy root cultures without ER signal peptide. The addition of polyvinylpyrrolidone enhanced the stabilization of secreted rhEPO leading to a 5.6 fold increase to a maximum concentration of 185.48 pg rhEPOHR g-1 FW hairy root cultures. The rhizo-secreted rhEPO was separated by HPLC and its biological activity was confirmed by testing distinct parameters for proliferation and survival in retinal pigment epithelial cells (ARPE). In addition, the rhEPO was detected to an amount 14.8 ng g-1 of total soluble leaf protein in transgenic T0 generation plantlets regenerated from hairy root cultures with cal signal peptide. PMID:28800637
Lee, Ji-Hye; Lee, Ji-Eun; Kang, Kyung-Jung; Jang, Young-Joo
2017-07-01
Fibroblast growth factor (FGF) is a multifunctional growth factor that induces cell proliferation, survival, migration, and differentiation in various cell types and tissues. With these biological functions, FGF-2 has been evaluated for clinical use in the regeneration of damaged tissues. The expression of hFGF-2 in Escherichia coli and a purification system using the immobilized metal affinity chromatography (IMAC) is well established to generate a continuous supply of FGF-2. Although hexa-histidine tag (H 6 ) is commonly used for IMAC purification, hexa-histidine-asparagine tag (HN 6 ) is also efficient for purification as it is easily exposed on the surface of the protein. In this study, four different tagging constructs of hFGF-2 based on tag positions and types (H 6 -FGF2, FGF2-H 6 , HN 6 -FGF2, and FGF2-HN 6 ) were designed and expressed under the inducible T7 expression system in E. coli. The experimental conditions of expression and purification of each recombinant protein were optimized. The effective dosages of the recombinant proteins were determined based on the increase of cell proliferation in human gingival fibroblast. ED50s of H 6 -FGF2, FGF2-H 6 , HN 6 -FGF2, and FGF2-HN 6 were determined (4.42 ng/ml, 3.55 ng/ml, 3.54 ng/ml, and 4.14 ng/ml, respectively) and found to be comparable to commercial FGF-2 (3.67 ng/ml). All the recombinant hFGF-2s inhibit the osteogenic induction and mineralization in human periodontal ligament-derived cells. Our data suggested that biological activities of the recombinant hFGF-2 are irrelevant to types and positions of tags, but may have an influence on the expression efficiency and solubility. Copyright © 2017 Elsevier Inc. All rights reserved.
Recombineering: A Homologous Recombination-Based Method of Genetic Engineering
Sharan, Shyam K.; Thomason, Lynn C.; Kuznetsov, Sergey G.; Court, Donald L.
2009-01-01
Recombineering is an efficient method of in vivo genetic engineering applicable to chromosomal as well as episomal replicons in E. coli. This method circumvents the need for most standard in vitro cloning techniques. Recombineering allows construction of DNA molecules with precise junctions without constraints being imposed by restriction enzyme site location. Bacteriophage homologous recombination proteins catalyze these recombineering reactions using double- and single-strand linear DNA substrates, so-called targeting constructs, introduced by electroporation. Gene knockouts, deletions and point mutations are readily made, gene tags can be inserted, and regions of bacterial artificial chromosomes (BACs) or the E. coli genome can be subcloned by gene retrieval using recombineering. Most of these constructs can be made within about a week's time. PMID:19180090
Mitchell, D H; James, G T; Kruse, C A
1990-06-01
The molecular integrity of human recombinant interleukin-2 (rIL-2), as measured by size exclusion chromatography, was not altered when exposed to high electrical field intensities. In addition, the biological activity was unaffected, as evidenced by the ability of the rIL-2 to stimulate the proliferation (by cell growth assays and tritiated thymidine uptake) and differentiation (by cytotoxicity assay) of human lymphocytes into killer cells. Electroporation conditions chosen for the loading of rIL-2, based upon those which provided for good recovery of carriers and minimal hemoglobin release, involved a lower field intensity (i.e., 6 kV/cm instead of 7 or 8 kV/cm) and multiple pulses (eight pulses, 5 microseconds) rather than a single pulse (40 microseconds). Human erythrocyte carriers consistently encapsulated 5-7.5% of the rIL-2 by electroporation (6 kV/cm, eight pulses, 5 microseconds duration). A rIL-2 concentration of 600,000 U/ml surrounding the erythrocytes during loading resulted in ca. 245,000 U/ml carriers, which represents a therapeutically significant quantity. Thus, rIL-2 shows potential as an encapsulated agent for slow release in the erythrocyte carrier system.
Gupta, Gaurav; Giannino, Viviana; Rishi, Narayan; Glueck, Reinhard
2016-09-07
Human papillomavirus (HPV) infection is the most common sexually transmitted disease worldwide. HPVs are oncogenic small double-stranded DNA viruses that are the primary causal agent of cervical cancer and other types of cancers, including in the anus, oropharynx, vagina, vulva, and penis. Prophylactic vaccination against HPV is an attractive strategy for preventing cervical cancer and some other types of cancers. However, there are few safe and effective vaccines against HPV infections. Current first-generation commercial HPV vaccines are expensive to produce and deliver. The goal of this study was to develop an alternate potent HPV recombinant L1-based vaccines by producing HPV virus-like particles into a vaccine that is currently used worldwide. Live attenuated measles virus (MV) vaccines have a well-established safety and efficacy record, and recombinant MV (rMV) produced by reverse genetics may be useful for generating candidate HPV vaccines to meet the needs of the developing world. We studied in non-human primate rMV-vectored HPV vaccine in parallel with a classical alum adjuvant recombinant HPV16L1 and 18L1 protein vaccine produced in Pichia pastoris. A combined prime-boost approach using both vaccines was evaluated, as well as immune interference due to pre-existing immunity against the MV. The humoral immune response induced by the MV, Pichia-expressed vaccine, and their combination as priming and boosting approaches was found to elicit HPV16L1 and 18L1 specific total IgG and neutralizing antibody titres. Pre-existing antibodies against measles did not prevent the immune response against HPV16L1 and 18L1. Copyright © 2016 Elsevier Ltd. All rights reserved.
Coelho, Eduardo Antonio Ferraz; Costa, Lourena Emanuele; Lage, Daniela Pagliara; Martins, Vívian Tamietti; Garde, Esther; de Jesus Pereira, Nathália Cristina; Lopes, Eliane Gonçalves Paiva; Borges, Luiz Felipe Nunes Menezes; Duarte, Mariana Costa; Menezes-Souza, Daniel; de Magalhães-Soares, Danielle Ferreira; Chávez-Fumagalli, Miguel Angel; Soto, Manuel; Tavares, Carlos Alberto Pereira
2016-01-15
Serological diagnostic tests for canine and human leishmaniasis present problems related with their sensitivity and/or specificity. Recently, an immunoproteomic approach performed with Leishmania infantum proteins identified new parasite antigens. In the present study, the diagnostic properties of two of these proteins, cytochrome c oxidase and IgE-dependent histamine-releasing factor, were evaluated for the serodiagnosis of canine visceral (CVL) and human tegumentary (HTL) leishmaniasis. For the CVL diagnosis, sera samples from non-infected dogs living in an endemic or non-endemic area of leishmaniasis, sera from asymptomatic or symptomatic visceral leishmaniasis (VL) dogs, from Leish-Tec(®)-vaccinated dogs, and sera from animals experimentally infected by Trypanosoma cruzi or Ehrlichia canis were used. For the HTL diagnosis, sera from non-infected subjects living in an endemic area of leishmaniasis, sera from active cutaneous or mucosal leishmaniasis patients, as well as those from T. cruzi-infected patients were employed. ELISA assays using the recombinant proteins showed both sensitivity and specificity values of 100% for the serodiagnosis of both forms of disease, with high positive and negative predictive values, showing better diagnostic properties than the parasite recombinant A2 protein or a soluble Leishmania antigen extract. In this context, the two new recombinant proteins could be considered to be used in the serodiagnosis of CVL and HTL. Copyright © 2015 Elsevier B.V. All rights reserved.
Pharmacological characterization of human recombinant melatonin mt1 and MT2 receptors
Browning, Christopher; Beresford, Isabel; Fraser, Neil; Giles, Heather
2000-01-01
We have pharmacologically characterized recombinant human mt1 and MT2 receptors, stably expressed in Chinese hamster ovary cells (CHO-mt1 and CHO-MT2), by measurement of [3H]-melatonin binding and forskolin-stimulated cyclic AMP (cAMP) production. [3H]-melatonin bound to mt1 and MT2 receptors with pKD values of 9.89 and 9.56 and Bmax values of 1.20 and 0.82 pmol mg−1 protein, respectively. Whilst most melatonin receptor agonists had similar affinities for mt1 and MT2 receptors, a number of putative antagonists had substantially higher affinities for MT2 receptors, including luzindole (11 fold), GR128107 (23 fold) and 4-P-PDOT (61 fold). In both CHO-mt1 and CHO-MT2 cells, melatonin inhibited forskolin-stimulated accumulation of cyclic AMP in a concentration-dependent manner (pIC50 9.53 and 9.74, respectively) causing 83 and 64% inhibition of cyclic AMP production at 100 nM, respectively. The potencies of a range of melatonin receptor agonists were determined. At MT2 receptors, melatonin, 2-iodomelatonin and 6-chloromelatonin were essentially equipotent, whilst at the mt1 receptor these agonists gave the rank order of potency of 2-iodomelatonin>melatonin>6-chloromelatonin. In both CHO-mt1 and CHO-MT2 cells, melatonin-induced inhibition of forskolin-stimulated cyclic AMP production was antagonized in a concentration-dependent manner by the melatonin receptor antagonist luzindole, with pA2 values of 5.75 and 7.64, respectively. Melatonin-mediated responses were abolished by pre-treatment of cells with pertussis toxin, consistent with activation of Gi/Go G-proteins. This is the first report of the use of [3H]-melatonin for the characterization of recombinant mt1 and MT2 receptors. Our results demonstrate that these receptor subtypes have distinct pharmacological profiles. PMID:10696085
Recombinant Bovine Growth Hormone Criticism Grows.
ERIC Educational Resources Information Center
Gaard, Greta
1995-01-01
Discusses concerns related to the use of recombinant bovine growth hormone in the United States and other countries. Analyses the issue from the perspectives of animal rights, human health, world hunger, concerns of small and organic farmers, costs to the taxpayer, and environmental questions. A sidebar discusses Canadian review of the hormone.…
Varlet-Marie, Emmanuelle; Audran, Michel; Lejeune, Mireille; Bonafoux, Béatrice; Sicart, Marie-Therese; Marti, Jacques; Piquemal, David; Commes, Thérèse
2004-08-01
Enhancement of oxygen delivery to tissues is associated with improved sporting performance. One way of enhancing oxygen delivery is to take recombinant human erythropoietin (rHuEpo), which is an unethical and potentially dangerous practice. However, detection of the use of rHuEpo remains difficult in situations such as: i) several days after the end of treatment ii) when a treatment with low doses is conducted iii) if the rHuEpo effect is increased by other substances. In an attempt to detect rHuEpo abuse, we selected erythroid gene markers from a SAGE library and analyzed the effects of rHuEpo administration on expression of the HBB, FTL and OAZ genes. Ten athletes were assigned to the rHuEpo or placebo group. The rHuEpo group received subcutaneous injections of rHuEpo (50 UI/kg three times a week, 4 weeks; 20 UI/kg three times a week, 2 weeks). HBB, FTL and OAZ gene profiles were monitored by real time-polymerase chain reaction (PCR) quantification during and for 3 weeks after drug administration. The global analysis of these targeted genes detected in whole blood samples showed a characteristic profile of subjects misusing rHuEpo with a increase above the threshold levels. The individual analysis of OAZ mRNA seemed indicative of rHuEpo treatment. The performance-enhancing effect of rHuEpo treatment is greater than the duration of hematologic changes associated with rHuEpo misuse. Although direct electrophoretic methods to detect rHuEpo have been developed, recombinant isoforms of rHuEpo are not detectable some days after the last subcutaneous injection. To overcome these limitations indirect OFF models have been developed. Our data suggest that, in the near future, it will be possible to consolidate results achievable with the OFF models by analyzing selected erythroid gene markers as a supplement to indirect methods.
Osman, Mohamed; Mistry, Anoop; Keding, Ada; Cook, Elizabeth; Wiggins, Rebecca; Di Marco, Stefania; Colloca, Stefano; Siani, Loredana; Smith, Deborah F.; Aebischer, Toni; Lacey, Charles J.
2017-01-01
Background Visceral leishmaniasis (VL or kala azar) is the most serious form of human leishmaniasis, responsible for over 20,000 deaths annually, and post kala azar dermal leishmaniasis (PKDL) is a stigmatizing skin condition that often occurs in patients after successful treatment for VL. Lack of effective or appropriately targeted cell mediated immunity, including CD8+ T cell responses, underlies the progression of VL and progression to PKDL, and can limit the therapeutic efficacy of anti-leishmanial drugs. Hence, in addition to the need for prophylactic vaccines against leishmaniasis, the development of therapeutic vaccines for use alone or in combined immuno-chemotherapy has been identified as an unmet clinical need. Here, we report the first clinical trial of a third-generation leishmaniasis vaccine, developed intentionally to induce Leishmania-specific CD8+ T cells. Methods We conducted a first-in-human dose escalation Phase I trial in 20 healthy volunteers to assess the safety, tolerability and immunogenicity of a prime-only adenoviral vaccine for human VL and PKDL. ChAd63-KH is a replication defective simian adenovirus expressing a novel synthetic gene (KH) encoding two Leishmania proteins KMP-11 and HASPB. Uniquely, the latter was engineered to reflect repeat domain polymorphisms and arrangements identified from clinical isolates. We monitored innate immune responses by whole blood RNA-Seq and antigen specific CD8+ T cell responses by IFNγ ELISPOT and intracellular flow cytometry. Findings ChAd63-KH was safe at intramuscular doses of 1x1010 and 7.5x1010 vp. Whole blood transcriptomic profiling indicated that ChAd63-KH induced innate immune responses characterized by an interferon signature and the presence of activated dendritic cells. Broad and quantitatively robust CD8+ T cell responses were induced by vaccination in 100% (20/20) of vaccinated subjects. Conclusion The results of this study support the further development of ChAd63-KH as a novel third
Osman, Mohamed; Mistry, Anoop; Keding, Ada; Gabe, Rhian; Cook, Elizabeth; Forrester, Sarah; Wiggins, Rebecca; Di Marco, Stefania; Colloca, Stefano; Siani, Loredana; Cortese, Riccardo; Smith, Deborah F; Aebischer, Toni; Kaye, Paul M; Lacey, Charles J
2017-05-01
Visceral leishmaniasis (VL or kala azar) is the most serious form of human leishmaniasis, responsible for over 20,000 deaths annually, and post kala azar dermal leishmaniasis (PKDL) is a stigmatizing skin condition that often occurs in patients after successful treatment for VL. Lack of effective or appropriately targeted cell mediated immunity, including CD8+ T cell responses, underlies the progression of VL and progression to PKDL, and can limit the therapeutic efficacy of anti-leishmanial drugs. Hence, in addition to the need for prophylactic vaccines against leishmaniasis, the development of therapeutic vaccines for use alone or in combined immuno-chemotherapy has been identified as an unmet clinical need. Here, we report the first clinical trial of a third-generation leishmaniasis vaccine, developed intentionally to induce Leishmania-specific CD8+ T cells. We conducted a first-in-human dose escalation Phase I trial in 20 healthy volunteers to assess the safety, tolerability and immunogenicity of a prime-only adenoviral vaccine for human VL and PKDL. ChAd63-KH is a replication defective simian adenovirus expressing a novel synthetic gene (KH) encoding two Leishmania proteins KMP-11 and HASPB. Uniquely, the latter was engineered to reflect repeat domain polymorphisms and arrangements identified from clinical isolates. We monitored innate immune responses by whole blood RNA-Seq and antigen specific CD8+ T cell responses by IFNγ ELISPOT and intracellular flow cytometry. ChAd63-KH was safe at intramuscular doses of 1x1010 and 7.5x1010 vp. Whole blood transcriptomic profiling indicated that ChAd63-KH induced innate immune responses characterized by an interferon signature and the presence of activated dendritic cells. Broad and quantitatively robust CD8+ T cell responses were induced by vaccination in 100% (20/20) of vaccinated subjects. The results of this study support the further development of ChAd63-KH as a novel third generation vaccine for VL and PKDL. This
Wang, Jishi; Ma, Dan; Li, Yan; Yang, Yuan; Hu, Xiaoyan; Zhang, Wei; Fang, Qin
2014-03-01
The aim of this study was to explore the effects of bone marrow-derived mesenchymal stem cells (BMSCs) as intermediate carriers on targeting of P450 gene recombinant adenovirus to malignant melanoma in vitro and in vivo. BMSCs were transduced with pAd5-CMV-CYP2E1 recombinant adenovirus. BMSC migration was detected by Transwell plates in vitro and by superparamagnetic iron oxide particles in vivo. Growth-inhibitory effect and apoptosis were determined by MTT and immunity fluorescence staining. Anticancer effects were examined by a human melanoma nude mouse model in vivo. BMSCs moved toward A375 cells in Transwell plates. Numerous superparamagnetic MSCs labeled with iron oxide were identified in the peripheral areas of the tumor, but were detected in primary organs by Prussian blue staining. BMSC-CYP2E1 cells mediated a bystander killing effect on CYP2E1-negative A375 cells during coculture (IC50 values for A375 cells cocultured with BMSC-EGFP and BMSC-CYP2E1 were 4.08 and 2.68 mmol/l, respectively). Intravenously injecting CYP2E1 recombinant adenovirus-loaded BMSCs in mice with established human melanoma managed to target the tumor site, and BMSCs with forced expression of CYP2E1 inhibited the growth of malignant cells in vivo by activating 5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide. BMSCs may serve as a platform of P450 gene-directed enzyme prodrug therapy for the delivery of chemotherapeutic prodrugs to tumors.
Aktaş, Doğukan; Demirel, Bilge; Gürsoy, Tuğba; Ovalı, Fahri
2015-06-01
To investigate the efficacy and safety of recombinant human granulocyte colony-stimulating factor, recombinant human granulocyte-macrophage colony-stimulating factor (rhG-CSF) to treat sepsis in neutropenic preterm infants. Fifty-six neutropenic preterm infants with suspected or culture-proven sepsis hospitalized in Zeynep Kamil Maternity and Children's Educational and Training Hospital, Kozyatağı/Istanbul, Turkey between January 2008 and January 2010 were enrolled. Patients were randomized either to receive rhG-CSF plus empirical antibiotics (Group I) or empirical antibiotics alone (Group II). Clinical features were recorded. Daily complete blood count was performed until neutropenia subsided. Data were analyzed using SPSS version 11.5. Thirty-three infants received rhG-CSF plus antibiotic treatment and 23 infants received antibiotic treatment. No drug-related adverse event was recorded. Absolute neutrophil count values were significantly higher on the 2(nd) study day and 3(rd) study day in Group I. Short-term mortality did not differ between the groups. Treatment with rhG-CSF resulted in a more rapid recovery of ANC in neutropenic preterm infants. However, no reduction in short-term mortality was documented. Copyright © 2014. Published by Elsevier B.V.
Isolation of recombinant antibodies directed against surface proteins of Clostridium difficile.
Shirvan, Ali Nazari; Aitken, Robert
2016-01-01
Clostridium difficile has emerged as an increasingly important nosocomial pathogen and the prime causative agent of antibiotic-associated diarrhoea and pseudomembranous colitis in humans. In addition to toxins A and B, immunological studies using antisera from patients infected with C. difficile have shown that a number of other bacterial factors contribute to the pathogenesis, including surface proteins, which are responsible for adhesion, motility and other interactions with the human host. In this study, various clostridial targets, including FliC, FliD and cell wall protein 66, were expressed and purified. Phage antibody display yielded a large panel of specific recombinant antibodies, which were expressed, purified and characterised. Reactions of the recombinant antibodies with their targets were detected by enzyme-linked immunosorbent assay; and Western blotting suggested that linear rather than conformational epitopes were recognised. Binding of the recombinant antibodies to surface-layer proteins and their components showed strain specificity, with good recognition of proteins from C. difficile 630. However, no reaction was observed for strain R20291-a representative of the 027 ribotype. Binding of the recombinant antibodies to C. difficile M120 extracts indicated that a component of a surface-layer protein of this strain might possess immunoglobulin-binding activities. The recombinant antibodies against FliC and FliD proteins were able to inhibit bacterial motility. Copyright © 2016. Published by Elsevier Editora Ltda.
Production of recombinant allergens in plants
2010-01-01
A large percentage of allergenic proteins are of plant origin. Hence, plant-based expression systems are considered ideal for the recombinant production of certain allergens. First attempts to establish production of plant-derived allergens in plants focused on transient expression in Nicotiana benthamiana infected with recombinant viral vectors. Accordingly, allergens from birch and mugwort pollen, as well as from apple have been expressed in plants. Production of house dust mite allergens has been achieved by Agrobacterium-mediated transformation of tobacco plants. Beside the use of plants as production systems, other approaches have focused on the development of edible vaccines expressing allergens or epitopes thereof, which bypasses the need of allergen purification. The potential of this approach has been convincingly demonstrated for transgenic rice seeds expressing seven dominant human T cell epitopes derived from Japanese cedar pollen allergens. Parallel to efforts in developing recombinant-based diagnostic and therapeutic reagents, different gene-silencing approaches have been used to decrease the expression of allergenic proteins in allergen sources. In this way hypoallergenic ryegrass, soybean, rice, apple, and tomato were developed. PMID:21258627
Production of recombinant allergens in plants.
Schmidt, Georg; Gadermaier, Gabriele; Pertl, Heidi; Siegert, Marc; Oksman-Caldentey, Kirsi-Marja; Ritala, Anneli; Himly, Martin; Obermeyer, Gerhard; Ferreira, Fatima
2008-10-01
A large percentage of allergenic proteins are of plant origin. Hence, plant-based expression systems are considered ideal for the recombinant production of certain allergens. First attempts to establish production of plant-derived allergens in plants focused on transient expression in Nicotiana benthamiana infected with recombinant viral vectors. Accordingly, allergens from birch and mugwort pollen, as well as from apple have been expressed in plants. Production of house dust mite allergens has been achieved by Agrobacterium-mediated transformation of tobacco plants. Beside the use of plants as production systems, other approaches have focused on the development of edible vaccines expressing allergens or epitopes thereof, which bypasses the need of allergen purification. The potential of this approach has been convincingly demonstrated for transgenic rice seeds expressing seven dominant human T cell epitopes derived from Japanese cedar pollen allergens. Parallel to efforts in developing recombinant-based diagnostic and therapeutic reagents, different gene-silencing approaches have been used to decrease the expression of allergenic proteins in allergen sources. In this way hypoallergenic ryegrass, soybean, rice, apple, and tomato were developed.
Alcantara, Luiz Carlos Junior; Cassol, Sharon; Libin, Pieter; Deforche, Koen; Pybus, Oliver G; Van Ranst, Marc; Galvão-Castro, Bernardo; Vandamme, Anne-Mieke; de Oliveira, Tulio
2009-07-01
Human immunodeficiency virus type-1 (HIV-1), hepatitis B and C and other rapidly evolving viruses are characterized by extremely high levels of genetic diversity. To facilitate diagnosis and the development of prevention and treatment strategies that efficiently target the diversity of these viruses, and other pathogens such as human T-lymphotropic virus type-1 (HTLV-1), human herpes virus type-8 (HHV8) and human papillomavirus (HPV), we developed a rapid high-throughput-genotyping system. The method involves the alignment of a query sequence with a carefully selected set of pre-defined reference strains, followed by phylogenetic analysis of multiple overlapping segments of the alignment using a sliding window. Each segment of the query sequence is assigned the genotype and sub-genotype of the reference strain with the highest bootstrap (>70%) and bootscanning (>90%) scores. Results from all windows are combined and displayed graphically using color-coded genotypes. The new Virus-Genotyping Tools provide accurate classification of recombinant and non-recombinant viruses and are currently being assessed for their diagnostic utility. They have incorporated into several HIV drug resistance algorithms including the Stanford (http://hivdb.stanford.edu) and two European databases (http://www.umcutrecht.nl/subsite/spread-programme/ and http://www.hivrdb.org.uk/) and have been successfully used to genotype a large number of sequences in these and other databases. The tools are a PHP/JAVA web application and are freely accessible on a number of servers including: http://bioafrica.mrc.ac.za/rega-genotype/html/, http://lasp.cpqgm.fiocruz.br/virus-genotype/html/, http://jose.med.kuleuven.be/genotypetool/html/.
Holmblat, Barbara; Jégouic, Sophie; Muslin, Claire; Blondel, Bruno; Joffret, Marie-Line
2014-01-01
ABSTRACT Most of the circulating vaccine-derived polioviruses (cVDPVs) implicated in poliomyelitis outbreaks in Madagascar have been shown to be recombinants between the type 2 poliovirus (PV) strain of the oral polio vaccine (Sabin 2) and another species C human enterovirus (HEV-C), such as type 17 coxsackie A virus (CA17) in particular. We studied intertypic genetic exchanges between PV and non-PV HEV-C by developing a recombination model, making it possible to rescue defective type 2 PV RNA genomes with a short deletion at the 3′ end by the cotransfection of cells with defective or infectious CA17 RNAs. We isolated over 200 different PV/CA17 recombinants, using murine cells expressing the human PV receptor (PVR) and selecting viruses with PV capsids. We found some homologous (H) recombinants and, mostly, nonhomologous (NH) recombinants presenting duplications of parental sequences preferentially located in the regions encoding proteins 2A, 2B, and 3A. Short duplications appeared to be stable, whereas longer duplications were excised during passaging in cultured cells or after multiplication in PVR-transgenic mice, generating H recombinants with diverse sites of recombination. This suggests that NH recombination events may be a transient, intermediate step in the generation and selection of the fittest H recombinants. In addition to the classical copy-choice mechanism of recombination thought to generate mostly H recombinants, there may also be a modular mechanism of recombination, involving NH recombinant precursors, shaping the genomes of recombinant enteroviruses and other picornaviruses. PMID:25096874
Characterization of the post-translational modification of recombinant human BMP-15 mature protein
Saito, Seiji; Yano, Keiichi; Sharma, Shweta; McMahon, Heather E.; Shimasaki, Shunichi
2008-01-01
Bone morphogenetic protein-15 (BMP-15) is an oocyte-secreted factor critical for the regulation of ovarian physiology. When recombinant human BMP-15 (rhBMP-15) produced in human embryonic kidney 293 cells was subjected to SDS-PAGE analysis, two mature protein forms corresponding to 16 kDa (P16) and 17 kDa (P17) were observed. Despite the physiological relevance and critical function of BMP-15 in female reproduction, little is known about the structure of rhBMP-15. Here, we have analyzed the structure of the rhBMP-15 mature proteins (P16 and P17) using state-of-the-art proteomics technology. Our findings are as follows: (1) the N-terminal amino acid of P16 and P17 is pyroglutamic acid; (2) the Ser residue at the sixth position of P16 is phosphorylated; (3) P17 is O-glycosylated at Thr10; and (4) the C-terminal amino acid of P16 and P17 is truncated. These findings are the first knowledge of the structure of rhBMP-15 mature protein toward understanding the molecular basis of BMP-15 function and could provide an important contribution to the rapidly progressing research area involving oocyte-specific growth factors in modulation of female fertility. PMID:18227435
Human Recombinant Peptide Sponge Enables Novel, Less Invasive Cell Therapy for Ischemic Stroke
Miyamoto, Michiyuki; Yamauchi, Tomohiro; Kawabori, Masahito; Osanai, Toshiya; Sasaki, Tasuku; Houkin, Kiyohiro; Kuroda, Satoshi
2018-01-01
Bone marrow stromal cell (BMSC) transplantation has the therapeutic potential for ischemic stroke. However, it is unclear which delivery routes would yield both safety and maximal therapeutic benefits. We assessed whether a novel recombinant peptide (RCP) sponge, that resembles human collagen, could act as a less invasive and beneficial scaffold in cell therapy for ischemic stroke. BMSCs from green fluorescent protein-transgenic rats were cultured and Sprague–Dawley rats were subjected to permanent middle cerebral artery occlusion (MCAo). A BMSC-RCP sponge construct was transplanted onto the ipsilateral intact neocortex 7 days after MCAo. A BMSC suspension or vehicle was transplanted into the ipsilateral striatum. Rat motor function was serially evaluated and histological analysis was performed 5 weeks after transplantation. The results showed that BMSCs could proliferate well in the RCP sponge and the BMSC-RCP sponge significantly promoted functional recovery, compared with the vehicle group. Histological analysis revealed that the RCP sponge provoked few inflammatory reactions in the host brain. Moreover, some BMSCs migrated to the peri-infarct area and differentiated into neurons in the BMSC-RCP sponge group. These findings suggest that the RCP sponge may be a promising candidate for animal protein-free scaffolds in cell therapy for ischemic stroke in humans. PMID:29765415
Human Recombinant Peptide Sponge Enables Novel, Less Invasive Cell Therapy for Ischemic Stroke.
Miyamoto, Michiyuki; Nakamura, Kentaro; Shichinohe, Hideo; Yamauchi, Tomohiro; Ito, Masaki; Saito, Hisayasu; Kawabori, Masahito; Osanai, Toshiya; Sasaki, Tasuku; Houkin, Kiyohiro; Kuroda, Satoshi
2018-01-01
Bone marrow stromal cell (BMSC) transplantation has the therapeutic potential for ischemic stroke. However, it is unclear which delivery routes would yield both safety and maximal therapeutic benefits. We assessed whether a novel recombinant peptide (RCP) sponge, that resembles human collagen, could act as a less invasive and beneficial scaffold in cell therapy for ischemic stroke. BMSCs from green fluorescent protein-transgenic rats were cultured and Sprague-Dawley rats were subjected to permanent middle cerebral artery occlusion (MCAo). A BMSC-RCP sponge construct was transplanted onto the ipsilateral intact neocortex 7 days after MCAo. A BMSC suspension or vehicle was transplanted into the ipsilateral striatum. Rat motor function was serially evaluated and histological analysis was performed 5 weeks after transplantation. The results showed that BMSCs could proliferate well in the RCP sponge and the BMSC-RCP sponge significantly promoted functional recovery, compared with the vehicle group. Histological analysis revealed that the RCP sponge provoked few inflammatory reactions in the host brain. Moreover, some BMSCs migrated to the peri-infarct area and differentiated into neurons in the BMSC-RCP sponge group. These findings suggest that the RCP sponge may be a promising candidate for animal protein-free scaffolds in cell therapy for ischemic stroke in humans.
Recombination activity of human RAG2 mutations and correlation with the clinical phenotype.
Tirosh, Irit; Yamazaki, Yasuhiro; Frugoni, Francesco; Ververs, Francesca A; Allenspach, Eric J; Zhang, Yu; Burns, Siobhan; Al-Herz, Waleed; Noroski, Lenora; Walter, Jolan E; Gennery, Andrew R; van der Burg, Mirjam; Notarangelo, Luigi D; Lee, Yu Nee
2018-05-14
Mutations in the Recombinase Activating Gene 1 and 2 (RAG1, RAG2) are associated with a broad range of clinical and immunological phenotypes in humans. Using a flow cytometry-based assay, we aimed to measure the recombinase activity of naturally occurring RAG2 mutant proteins, and to correlate results with the severity of the clinical and immunological phenotype. Abelson virus-transformed Rag2 -/- pro-B cells engineered to contain an inverted GFP cassette flanked by recombination signal sequences (RSS) were transduced with retroviruses encoding either wild-type or 41 naturally occurring RAG2 variants. Bicistronic vectors were used to introduce compound heterozygous RAG2 variants.The percentage of GFP-expressing cells was evaluated by flow cytometry, and high throughput sequencing was used to analyze rearrangements at the endogenous Igh locus.. The RAG2 variants showed a wide range of recombination activity. Mutations associated with severe combined immune deficiency (SCID) and Omenn syndrome had significantly lower activity than those detected in patients with less severe clinical presentations. Four variants (P253R, F386L, N474S, and M502V) previously thought to be pathogenic were found to have wild-type levels of activity. Use of bicistronic vectors permitted to assess more carefully the effect of compound heterozygous mutations, with good correlation between GFP expression and number and diversity of Igh rearrangements. Our data support genotype-phenotype correlation in RAG2 deficiency. The assay described can be used to define the possible disease-causing role of novel RAG2 variants and may help predict the severity of the clinical phenotype. Copyright © 2018 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
[Advances of consolidated bioprocessing based on recombinant strategy].
Zheng, Zongbao; Zhao, Meina; Chen, Tao; Zhao, Xueming
2013-10-01
Lignocellulosic biomass represents an abundant, low-cost and renewable source of potentially fermentable sugars. It is acandidate besides petroleum as feedstock for fuel and chemical production. Recent researches on utilizing lignocellulosicsas feedstock boost development of numerous-promising processes for a variety of fuels and chemicals, such as biodiesel, biohydrogen and ethanol. However, high cost in depolymerization is a primary obstacle preventing the use of lignocellulosic biomass as feedstock. Consolidated bioprocessing (CBP), refers to the bioprocess without any exogenous cellulolyotic enzymes added, converting the lignocellulosic material into biochemicals directly, which could potentially avoid the cost of the dedicated enzyme generation step by incorporating enzyme-generating, biomass-degrading and bioproduct-producing capabilities into a single organism through genetic engineering. There are two CBP strategies, native strategy and recombinant strategy. We mainly introduce the recombinant strategy, including its principle, the two responding styles, the contributions of synthetic biology and metabolic engineering and the future challenges.
Effect of increased HoxB4 on human megakaryocytic development
Zhong, Yiming; Sullenbarger, Brent; Lasky, Larry C.
2010-01-01
In order to ex vivo produce clinically useful quantity of platelets, we may need to firstly enhance early self-renewal of hematopoietic stem cells (HSCs) and/or megakaryocyte (Mk) progenitors. The homeodomain transcription factor HoxB4 has been shown to be an important regulator of stem cell renewal and hematopoiesis; however, its effect on megakaryopoiesis is unclear. In this study, we investigated the effect of HoxB4 overexpression or RNA silencing on megakaryocytic development in the human TF1 progenitor cell line; we then used recombinant tPTD-HoxB4 fusion protein to study the effect of exogenous HoxB4 on megakaryocytic development of human CD34 positively-selected cord blood cells. We found that ectopic HoxB4 in TF1 cells increased the antigen expression of CD61and CD41a, increased the gene expression of thrombopoietin receptor (TpoR), Scl-1, Cyclin D1, Fog-1 and Fli-1 while it decreased c-Myb expression. HoxB4 RNA silencing in TF1 cells decreased the expression of CD61 and CD41a and decreased Fli-1 expression while it increased the expression of c-Myb. Recombinant tPTD-HoxB4 fusion protein increased the percentages and absolute numbers of CD41a and CD61 positive cells during megakaryocytic differentiation of CD34 positively-selected cord blood cells and increased the numbers of colony forming unit-megakaryocyte (CFU-Mk). Adding tPTD-HoxB4 fusion protein increased the gene expression of TpoR, Cyclin D1, Fog-1 and Fli-1 while it inhibited c-Myb expression. Our data indicate that increased HoxB4 enhanced early megakaryocytic development in human TF1 cells and CD34 positively-selected cord blood cells primarily by upregulating Tpo R and Fli-1 expression and downregulating c-Myb expression. Increasing HoxB4 expression or adding recombinant HoxB4 protein might be a way to expand Mks for the production of platelets for use in transfusion medicine. PMID:20599537
Grinenko, N F; Savitskaia, N V; Pashvykina, G V; Al'tshteĭn, A D
2003-06-01
A highly oncogenic monkey adenovirus SA7(C8) facilitates the reproduction of human adenovirus type 2 (Ad2) in monkey cells. Upon mixed infection of monkey cells with both viruses, these viruses recombine producing defective adeno-adeno hybrids Ad2C8 serologically identical to Ad2 and capable of assisting Ad2 to reproduce in monkey cells. Ad2C8 and Ad2 form an intercomplementary pair inseparable in monkey cells. Unlike oncogenic SA7(C8), Ad2C8 is a nononcogenic virus for hamsters but is able to induce tumor antigens of this virus (T and TSTA). Molecular genetic analysis of 68 clones of adeno-adeno hybrids revealed that the left part of their genome consists of Ad2 DNA, and the right part contains no less than 40% of the viral SA7(C8) genome where E2A, E3, and E4 genes are located. Apparently, the products of these genes contribute to the composition of adenoviral tumor antigens, while the E4 gene is involved in complementation of monkey and human adenoviruses and makes a contribution to host range determination of these viruses.
Pharmacological profiling of the TRPV3 channel in recombinant and native assays.
Grubisha, Olivera; Mogg, Adrian J; Sorge, Jessica L; Ball, Laura-Jayne; Sanger, Helen; Ruble, Cara L A; Folly, Elizabeth A; Ursu, Daniel; Broad, Lisa M
2014-05-01
Transient receptor potential vanilloid subtype 3 (TRPV3) is implicated in nociception and certain skin conditions. As such, it is an attractive target for pharmaceutical research. Understanding of endogenous TRPV3 function and pharmacology remains elusive as selective compounds and native preparations utilizing higher throughput methodologies are lacking. In this study, we developed medium-throughput recombinant and native cellular assays to assess the detailed pharmacological profile of human, rat and mouse TRPV3 channels. Medium-throughput cellular assays were developed using a Ca(2+) -sensitive dye and a fluorescent imaging plate reader. Human and rat TRPV3 pharmacology was examined in recombinant cell lines, while the mouse 308 keratinocyte cell line was used to assess endogenous TRPV3 activity. A recombinant rat TRPV3 cellular assay was successfully developed after solving a discrepancy in the published rat TRPV3 protein sequence. A medium-throughput, native, mouse TRPV3 keratinocyte assay was also developed and confirmed using genetic approaches. Whereas the recombinant human and rat TRPV3 assays exhibited similar agonist and antagonist profiles, the native mouse assay showed important differences, namely, TRPV3 activity was detected only in the presence of potentiator or during agonist synergy. Furthermore, the native assay was more sensitive to block by some antagonists. Our findings demonstrate similarities but also notable differences in TRPV3 pharmacology between recombinant and native systems. These findings offer insights into TRPV3 function and these assays should aid further research towards developing TRPV3 therapies. © 2013 The British Pharmacological Society.
NASA Astrophysics Data System (ADS)
Sato, M.; Ito, Y.; Kameyama, K.; Imai, M.; Ishikawa, N.; Takagi, T.
1995-02-01
The overall and internal structure of recombinant yeast-derived human hepatitis B virus surface antigen vaccine particles was investigated by small-angle neutron scattering using the contrast variation method. The vaccine is a nearly spherical particle, and its contrast-matching point was determined to be at about 24% D 2O content, indicating that a large part of the vaccine particle is occupied by lipids and carbohydrates from the yeast. The Stuhrmann plot suggests that the surface antigens exist predominantly in the peripheral region of the particle, which is favorable to the induction of anti-virus antibodies.
On-column refolding of recombinant human interleukin-4 from inclusion bodies.
Razeghifard, M Reza
2004-09-01
Interleukin-4 (IL4) is a multifunctional cytokine which plays a key role in the immune system. Several antagonists/agonists of IL4 are reported through mutagenesis studies, but their solution structural studies using nuclear magnetic resonance (NMR) spectroscopy are hindered as milligram quantities of isotopically labeled protein are required for structural refinements. In this work, a His-tagged recombinant form of human IL4 was overexpressed in Escherichia coli under the control of a T7 promoter. The resulting inclusion bodies were separated from cellular debris by centrifugation and solubilized by 6M guanidine-HCl in the presence of reducing agents. The denatured IL4 was immobilized on Ni2+-fractogel beads and refolded in a single chromatographic step by gradual removal of denaturant. This protocol yielded 15-20 mg of isotope-enriched protein from 1L of culture grown in minimal medium. The refolded protein was highly pure and was correctly folded as judged by its two-dimensional NMR spectrum. To show the successful application of this refolding protocol to IL4 variants, 15N-labeled Y124D-IL4 was also prepared and its first two-dimensional NMR spectrum was presented.
Kim, Nam-Hee; Kim, Yeong-Su; Kim, Hye-Jung; Oh, Deok-Kun
2008-01-01
The formation of beta-carotene detergent micelles and their conversion into retinal by recombinant human beta,beta-carotene 15,15'-monooxygenase was optimized under aqueous conditions. Toluene was the most hydrophobic among the organic solvents tested; thus, it was used to dissolve beta-carotene, which is a hydrophobic compound. Tween 80 was selected as the detergent because it supported the highest level of retinal production among all of the detergents tested. The maximum production of retinal was achieved in detergent micelles containing 200 mg/L of beta-carotene and 2.4% (w/v) Tween 80. Under these conditions, the recombinant enzyme produced 97 mg/L of retinal after 16 h with a conversion yield of 48.5% (w/w). The amount of retinal produced, which is the highest ever reported, is a result of the ability of our system to dissolve large amounts of beta-carotene.
Applications and challenges of multivalent recombinant vaccines
Naim, Hussein Y.
2013-01-01
The exceptional discoveries of antigen/gene delivery systems have allowed the development of novel prophylactic and therapeutic vaccine candidates. The vaccine candidates employ various antigen-delivery systems, particularly recombinant viral vectors. Recombinant viral vectors are experimental vaccines similar to DNA vaccines, but they use attenuated viruses or bacterium as a carrier “vector” to introduce microbial DNA to cells of the body. They closely mimic a natural infection and therefore can efficiently stimulate the immune system. Although such recombinant vectors may face extensive preclinical testing and will possibly have to meet stringent regulatory requirements, some of these vectors (e.g. measles virus vectors) may benefit from the profound industrial and clinical experience of the parent vaccine. Most notably, novel vaccines based on live attenuated viruses combine the induction of broad, strong and persistent immune responses with acceptable safety profiles. We assess certain technologies in light of their use against human immunodeficiency virus (HIV). PMID:23249651
Toro, H; Zhang, J F; Gallardo, R A; van Santen, V L; van Ginkel, F W; Joiner, K S; Breedlove, C
2014-06-01
Protective properties of three distinct infectious bronchitis virus (IBV) Ark Delmarva poultry industry (ArkDPI) S1 proteins encoded from replication-defective recombinant adenovirus vectors were investigated. Using a suboptimal dose of each recombinant virus, we demonstrated that IBV S1 amino acid sequences showing > or = 95.8% amino acid identity to the S1 of the challenge strain differed in their ability at conferring protection. Indeed, the S1 sequence of the IBV population previously designated C4 (AdIBVS1.C4), which protected the most poorly, differs from the S1 sequence of population C2 (AdIBVS1.C2), which provided the highest protection, only at amino acid position 56. The fact that a change in one amino acid in this region significantly altered the induction of a protective immune response against this protein provides evidence that the first portion of S1 displays relevant immunoprotective epitopes. Use of an optimal dose of AdIBVS1.C2 effectively protected chickens from clinical signs and significantly reduced viral load after IBV Ark virulent challenge. Moreover, increased numbers of both IgA and IgG IBV-specific antibody secreting lymphocytes were detected in the spleen after challenge. The increased response detected for both IgA and IgG lymphocytes after challenge might be explained by vaccine-induced B memory cells. The fact that a single vaccination with Ad/IBVS1.C2 provides protection against IBV challenge is promising, because Ad-vectored vaccines can be mass delivered by in ovo inoculation using automated in ovo injectors.
Frahm, Grant E; Smith, Daryl G S; Kane, Anita; Lorbetskie, Barry; Cyr, Terry D; Girard, Michel; Johnston, Michael J W
2014-01-01
The use of different expression systems to produce the same recombinant human protein can result in expression-dependent chemical modifications (CMs) leading to variability of structure, stability and immunogenicity. Of particular interest are recombinant human proteins expressed in plant-based systems, which have shown particularly high CM variability. In studies presented here, recombinant human serum albumins (rHSA) produced in Oryza sativa (Asian rice) (OsrHSA) from a number of suppliers have been extensively characterized and compared to plasma-derived HSA (pHSA) and rHSA expressed in yeast (Pichia pastoris and Saccharomyces cerevisiae). The heterogeneity of each sample was evaluated using size exclusion chromatography (SEC), reversed-phase high-performance liquid chromatography (RP-HPLC) and capillary electrophoresis (CE). Modifications of the samples were identified by liquid chromatography-mass spectrometry (LC-MS). The secondary and tertiary structure of the albumin samples were assessed with far U/V circular dichroism spectropolarimetry (far U/V CD) and fluorescence spectroscopy, respectively. Far U/V CD and fluorescence analyses were also used to assess thermal stability and drug binding. High molecular weight aggregates in OsrHSA samples were detected with SEC and supplier-to-supplier variability and, more critically, lot-to-lot variability in one manufactures supplied products were identified. LC-MS analysis identified a greater number of hexose-glycated arginine and lysine residues on OsrHSA compared to pHSA or rHSA expressed in yeast. This analysis also showed supplier-to-supplier and lot-to-lot variability in the degree of glycation at specific lysine and arginine residues for OsrHSA. Both the number of glycated residues and the degree of glycation correlated positively with the quantity of non-monomeric species and the chromatographic profiles of the samples. Tertiary structural changes were observed for most OsrHSA samples which correlated well
Microbial production of value-added nutraceuticals.
Wang, Jian; Guleria, Sanjay; Koffas, Mattheos Ag; Yan, Yajun
2016-02-01
Nutraceuticals are important natural bioactive compounds that confer health-promoting and medical benefits to humans. Globally growing demands for value-added nutraceuticals for prevention and treatment of human diseases have rendered nutraceuticals a multi-billion dollar market. However, supply limitations and extraction difficulties from natural sources such as plants, animals or fungi, restrict the large-scale use of nutraceuticals. Metabolic engineering via microbial production platforms has been advanced as an eco-friendly alternative approach for production of value-added nutraceuticals from simple carbon sources. Microbial platforms like the most widely used Escherichia coli and Saccharomyces cerevisiae have been engineered as versatile cell factories for production of diverse and complex value-added chemicals such as phytochemicals, prebiotics, polysaccaharides and poly amino acids. This review highlights the recent progresses in biological production of value-added nutraceuticals via metabolic engineering approaches. Copyright © 2015 Elsevier Ltd. All rights reserved.
Shepelev, Mikhail V; Korobko, Elena V; Vinogradova, Tatiana V; Kopantsev, Eugene P; Korobko, Igor V
2013-03-04
Adenovirus-based drugs are efficient when combined with other anticancer treatments. Here we show that treatment with LY294002 and LY303511 upregulates expression of recombinant proteins encoded by replication-defective adenoviruses, including expression of therapeutically valuable combination of herpes simplex virus thymidine kinase controlled by human telomerase reverse transcriptase promoter (Ad-hTERT-HSVtk). In line with this, treatment with LY294002 synergized with Ad-hTERT-HSVtk infection in the presence of gancyclovir prodrug on Calu-I lung cancer cell death. The effect of LY294002 and LY303511 on adenovirus-delivered transgene expression was demonstrated in 4 human lung cancer cell lines. LY294002-induced upregulation of adenovirally delivered transgene is mediated in part by direct inhibition of mTOR protein kinase in mTORC2 signaling complex thus suggesting that anticancer drugs targeting mTOR will also enhance expression of transgenes delivered with adenoviral vectors. As both LY294002 and LY303511 are candidate prototypic anticancer drugs, and many mTOR inhibitors for cancer treatment are under development, our results have important implication for development of future therapeutic strategies with adenoviral gene delivery.
Duez, C; Gras-Masse, H; Hammad, H; Akoum, H; Didierlaurent, A; André, C; Tonnel, A B; Pestel, J
2001-01-01
We have previously established a model to study the in vivo human IgE response using humanized SCID mice. Allergic SCID mice were obtained following intraperitoneal injection with mononuclear cells from Dermatophagoides pteronyssinus (Dpt)-sensitive patients, and sensitization by Dpt allergen intraperitoneal injection (immunization) or Dpt aerosol (inhalation). Human serum IgE was measured in allergic SCID mice after administration of human recombinant IFN-gamma or the lipopeptide LP 52-71 (derived from peptide p52-71 from Der p 1, Dpt major allergen, coupled to a lipophilic moiety), during the immunization or the inhalation phase. IFN-gamma inhibited human IgE production when given at the time of immunization, but not during inhalation. This effect was long-lasting as Dpt aerosol, given one month after immunization and IFN-gamma administration, failed to increase IgE levels. Unlike Dpt or p52-71, LP 52-71 failed to induce human IgE production at day 14 and 21 after its injection, but did inhibit the development of the IgE response after a secondary Dpt-challenge. Moreover, LP 52-71 administration 14 days after Dpt inhalation decreased IgE levels, in contrast to peptide 52-71, which increased IgE levels. Thus, taken together these results indicate that the development of the human IgE response in allergic SCID mice can be modulated by modified allergen and a Th1 cytokine.
Wu, Shipo; Zhang, Zhe; Yu, Rui; Zhang, Jun; Liu, Ying; Song, Xiaohong; Yi, Shaoqiong; Liu, Ju; Chen, Jianqin; Yin, Ying; Xu, Junjie; Hou, Lihua; Chen, Wei
2014-02-01
Developing an effective anthrax vaccine that can induce a rapid and sustained immune response is a priority for the prevention of bioterrorism-associated anthrax infection. Here, we developed a recombinant replication-deficient adenovirus serotype 5-based vaccine expressing the humanized protective antigen (Ad5-PAopt). A single intramuscular injection of Ad5-PAopt resulted in rapid and robust humoral and cellular immune responses in Fisher 344 rats. Animals intramuscularly inoculated with a single dose of 10⁸ infectious units of Ad5-PAopt achieved 100% protection from challenge with 10 times the 50% lethal dose (LD₅₀) of anthrax lethal toxin 7 days after vaccination. Although preexisting intranasally induced immunity to Ad5 slightly weakened the humoral and cellular immune responses to Ad5-PAopt via intramuscular inoculation, 100% protection was achieved 15 days after vaccination in Fisher 344 rats. The protective efficacy conferred by intramuscular vaccination in the presence of preexisting intranasally induced immunity was significantly better than that of intranasal delivery of Ad5-PAopt and intramuscular injection with recombinant PA and aluminum adjuvant without preexisting immunity. As natural Ad5 infection often occurs via the mucosal route, the work here largely illuminates that intramuscular inoculation with Ad5-PAopt can overcome the negative effects of immunity induced by prior adenovirus infection and represents an efficient approach for protecting against emerging anthrax.
Wu, Shipo; Zhang, Zhe; Yu, Rui; Zhang, Jun; Liu, Ying; Song, Xiaohong; Yi, Shaoqiong; Liu, Ju; Chen, Jianqin; Yin, Ying; Xu, Junjie
2014-01-01
Developing an effective anthrax vaccine that can induce a rapid and sustained immune response is a priority for the prevention of bioterrorism-associated anthrax infection. Here, we developed a recombinant replication-deficient adenovirus serotype 5-based vaccine expressing the humanized protective antigen (Ad5-PAopt). A single intramuscular injection of Ad5-PAopt resulted in rapid and robust humoral and cellular immune responses in Fisher 344 rats. Animals intramuscularly inoculated with a single dose of 108 infectious units of Ad5-PAopt achieved 100% protection from challenge with 10 times the 50% lethal dose (LD50) of anthrax lethal toxin 7 days after vaccination. Although preexisting intranasally induced immunity to Ad5 slightly weakened the humoral and cellular immune responses to Ad5-PAopt via intramuscular inoculation, 100% protection was achieved 15 days after vaccination in Fisher 344 rats. The protective efficacy conferred by intramuscular vaccination in the presence of preexisting intranasally induced immunity was significantly better than that of intranasal delivery of Ad5-PAopt and intramuscular injection with recombinant PA and aluminum adjuvant without preexisting immunity. As natural Ad5 infection often occurs via the mucosal route, the work here largely illuminates that intramuscular inoculation with Ad5-PAopt can overcome the negative effects of immunity induced by prior adenovirus infection and represents an efficient approach for protecting against emerging anthrax. PMID:24307239
Recombination-Mediated Host Adaptation by Avian Staphylococcus aureus
Murray, Susan; Pascoe, Ben; Méric, Guillaume; Mageiros, Leonardos; Yahara, Koji; Hitchings, Matthew D.; Friedmann, Yasmin; Wilkinson, Thomas S.; Gormley, Fraser J.; Mack, Dietrich; Bray, James E.; Lamble, Sarah; Bowden, Rory; Jolley, Keith A.; Maiden, Martin C.J.; Wendlandt, Sarah; Schwarz, Stefan; Corander, Jukka; Fitzgerald, J. Ross
2017-01-01
Staphylococcus aureus are globally disseminated among farmed chickens causing skeletal muscle infections, dermatitis, and septicaemia. The emergence of poultry-associated lineages has involved zoonotic transmission from humans to chickens but questions remain about the specific adaptations that promote proliferation of chicken pathogens. We characterized genetic variation in a population of genome-sequenced S. aureus isolates of poultry and human origin. Genealogical analysis identified a dominant poultry-associated sequence cluster within the CC5 clonal complex. Poultry and human CC5 isolates were significantly distinct from each other and more recombination events were detected in the poultry isolates. We identified 44 recombination events in 33 genes along the branch extending to the poultry-specific CC5 cluster, and 47 genes were found more often in CC5 poultry isolates compared with those from humans. Many of these gene sequences were common in chicken isolates from other clonal complexes suggesting horizontal gene transfer among poultry associated lineages. Consistent with functional predictions for putative poultry-associated genes, poultry isolates showed enhanced growth at 42 °C and greater erythrocyte lysis on chicken blood agar in comparison with human isolates. By combining phenotype information with evolutionary analyses of staphylococcal genomes, we provide evidence of adaptation, following a human-to-poultry host transition. This has important implications for the emergence and dissemination of new pathogenic clones associated with modern agriculture. PMID:28338786
Leopol'd, A V; Baklaushev, V P; Korchagina, A A; Shein, S A; Grinenko, N F; Pavlov, K A; Ryabukhin, I A; Chekhonin, V P
2012-04-01
cDNA encoding VEGF and Ig-like extracellular domains 2-4 of VEGFR-1 (sFlt-1(2-4)) were cloned into prokaryotic expression vectors pET32a and pQE60. Recombinant proteins were purified (metal affinity chromatography) and renatured. Chemiluminescent study for the interaction of recombinant VEGF and sFlt-1(2-4) showed that biotinylated VEGF specifically binds to the polystyrene-immobilized receptor extracellular fragment. Biotinylated recombinant sFlt-1 interacts with immobilized VEGF. Analysis of the interaction of immobilized recombinant VEGFR-1 and VEGF with C6 glioma cells labeled with CFDA-SE (vital fluorescent dye) showed that recombinant VEGFR-1 also binds to native membrane-associated VEGF. Recombinant VEGF was shown to bind to specific receptors expressed on the surface of C6 glioma cells. Functional activity of these proteins was confirmed by ligand-receptor assay for VEGF and VEGFR-1 (sFlt-1) and quantitative chemiluminescent detection.
Recombinant aequorin and recombinant semi-synthetic aequorins. Cellular Ca2+ ion indicators.
Shimomura, O; Inouye, S; Musicki, B; Kishi, Y
1990-01-01
Properties of a recombinant aequorin were investigated in comparison with those of natural aequorin. In chromatographic behaviour the recombinant aequorin did not match any of ten isoaequorins tested, although it was very similar to aequorin J. Its sensitivity to Ca2+ was found to be higher than that of any isoaequorin except aequorin D. The recombinant aequorin exhibited no toxicity when tested in various kinds of cells, even where samples of natural aequorin had been found to be toxic. Properties of four recombinant semi-synthetic aequorins (fch-, hcp-, e- and n-types), prepared from the recombinant apo-aequorin and synthetic analogues of coelenterazine, were approximately parallel with those of corresponding semi-synthetic aequorins prepared from natural apo-aequorin. Both recombinant e-aequorin and natural e-aequorin J luminesced with high values of the luminescence intensity ratio I400/I465, although the ratios were not pCa-dependent. The recombinant aequorin and recombinant semi-synthetic aequorins are highly suited for monitoring cellular Ca2+. PMID:2400391
Bagherpour, Ghasem; Ghasemi, Hosnie; Zand, Bahare; Zarei, Najmeh; Roohvand, Farzin; Ardakani, Esmat M.; Azizi, Mohammad; Khalaj, Vahid
2018-01-01
Saccharomyces boulardii, a subspecies of Saccharomyces cerevisiae, is a well-known eukaryotic probiotic with many benefits for human health. In the present study, a recombinant strain of S. boulardii was prepared to use as a potential oral vaccine delivery vehicle. In this sense, a ura3 auxotroph strain of S. boulardii CNCM I-745 (known as S. cerevisiae HANSEN CBS 5926, Yomogi®) was generated using CRISPR/Cas9 methodology. Then a gene construct encoding a highly immunogenic protein, ovalbumin (OVA), was prepared and transformed into the ura3- S. boulardii. To facilitate the transport of the recombinant immunogen across the intestinal barrier, a claudin-targeting sequence from Clostridium perfringens enterotoxin (CPE) was added to the C-terminus of the expression cassette. The recombinant S. boulardii strain expressing the OVA-CPE fusion protein was then administered orally to a group of mice, and serum IgG and fecal IgA levels were evaluated by ELISA. Our results demonstrated that anti-OVA IgG in serum significantly increased in test group (P < 0.001) compared to control groups (receiving wild type S. boulardii or PBS), and the fecal IgA titer was significantly higher in test group (P < 0.05) than control groups. In parallel, a recombinant S. boulardii strain expressing the similar construct lacking C-terminal CPE was also administered orally. The result showed an increased level of serum IgG in group receiving yeasts expressing the CPE negative construct compared to control groups; however, the fecal IgA levels did not increase significantly. In conclusion, our findings indicated that the yeast S. boulardii, as a delivery vehicle with possible immunomodulatory effects, and c-CPE, as a targeting tag, synergistically assist to stimulate systemic and local immunity. This proposed recombinant S. boulardii system might be useful in the expression of other antigenic peptides, making it as a promising tool for oral delivery of vaccines or therapeutic proteins. PMID
Bagherpour, Ghasem; Ghasemi, Hosnie; Zand, Bahare; Zarei, Najmeh; Roohvand, Farzin; Ardakani, Esmat M; Azizi, Mohammad; Khalaj, Vahid
2018-01-01
Saccharomyces boulardii , a subspecies of Saccharomyces cerevisiae , is a well-known eukaryotic probiotic with many benefits for human health. In the present study, a recombinant strain of S. boulardii was prepared to use as a potential oral vaccine delivery vehicle. In this sense, a ura3 auxotroph strain of S. boulardii CNCM I-745 (known as S. cerevisiae HANSEN CBS 5926, Yomogi ® ) was generated using CRISPR/Cas9 methodology. Then a gene construct encoding a highly immunogenic protein, ovalbumin (OVA), was prepared and transformed into the ura3 - S. boulardii . To facilitate the transport of the recombinant immunogen across the intestinal barrier, a claudin-targeting sequence from Clostridium perfringens enterotoxin (CPE) was added to the C-terminus of the expression cassette. The recombinant S. boulardii strain expressing the OVA-CPE fusion protein was then administered orally to a group of mice, and serum IgG and fecal IgA levels were evaluated by ELISA. Our results demonstrated that anti-OVA IgG in serum significantly increased in test group ( P < 0.001) compared to control groups (receiving wild type S. boulardii or PBS), and the fecal IgA titer was significantly higher in test group ( P < 0.05) than control groups. In parallel, a recombinant S. boulardii strain expressing the similar construct lacking C-terminal CPE was also administered orally. The result showed an increased level of serum IgG in group receiving yeasts expressing the CPE negative construct compared to control groups; however, the fecal IgA levels did not increase significantly. In conclusion, our findings indicated that the yeast S. boulardii , as a delivery vehicle with possible immunomodulatory effects, and c-CPE, as a targeting tag, synergistically assist to stimulate systemic and local immunity. This proposed recombinant S. boulardii system might be useful in the expression of other antigenic peptides, making it as a promising tool for oral delivery of vaccines or therapeutic proteins.
Ladoukakis, E D; Zouros, E
2001-07-01
The assumption that animal mitochondrial DNA (mtDNA) does not undergo homologous recombination is based on indirect evidence, yet it has had an important influence on our understanding of mtDNA repair and mutation accumulation (and thus mitochondrial disease and aging) and on biohistorical inferences made from population data. Recently, several studies have suggested recombination in primate mtDNA on the basis of patterns of frequency distribution and linkage associations of mtDNA mutations in human populations, but others have failed to produce similar evidence. Here, we provide direct evidence for homologous mtDNA recombination in mussels, where heteroplasmy is the rule in males. Our results indicate a high rate of mtDNA recombination. Coupled with the observation that mammalian mitochondria contain the enzymes needed for the catalysis of homologous recombination, these findings suggest that animal mtDNA molecules may recombine regularly and that the extent to which this generates new haplotypes may depend only on the frequency of biparental inheritance of the mitochondrial genome. This generalization must, however, await evidence from animal species with typical maternal mtDNA inheritance.
Balamurugan, Appakalai N; Green, Michael L; Breite, Andrew G; Loganathan, Gopalakrishnan; Wilhelm, Joshua J; Tweed, Benjamin; Vargova, Lenka; Lockridge, Amber; Kuriti, Manikya; Hughes, Michael G; Williams, Stuart K; Hering, Bernhard J; Dwulet, Francis E; McCarthy, Robert C
2016-01-01
Isolation following a good manufacturing practice-compliant, human islet product requires development of a robust islet isolation procedure where effective limits of key reagents are known. The enzymes used for islet isolation are critical but little is known about the doses of class I and class II collagenase required for successful islet isolation. We used a factorial approach to evaluate the effect of high and low target activities of recombinant class I (rC1) and class II (rC2) collagenase on human islet yield. Consequently, 4 different enzyme formulations with divergent C1:C2 collagenase mass ratios were assessed, each supplemented with the same dose of neutral protease. Both split pancreas and whole pancreas models were used to test enzyme targets (n = 20). Islet yield/g pancreas was compared with historical enzymes (n = 42). Varying the Wunsch (rC2) and collagen degradation activity (CDA, rC1) target dose, and consequently the C1:C2 mass ratio, had no significant effect on tissue digestion. Digestions using higher doses of Wunsch and CDA resulted in comparable islet yields to those obtained with 60% and 50% of those activities, respectively. Factorial analysis revealed no significant main effect of Wunsch activity or CDA for any parameter measured. Aggregate results from 4 different collagenase formulations gave 44% higher islet yield (>5000 islet equivalents/g) in the body/tail of the pancreas (n = 12) when compared with those from the same segment using a standard natural collagenase/protease mixture (n = 6). Additionally, islet yields greater than 5000 islet equivalents/g pancreas were also obtained in whole human pancreas. A broader C1:C2 ratio can be used for human islet isolation than has been used in the past. Recombinant collagenase is an effective replacement for the natural enzyme and we have determined that high islet yield can be obtained even with low doses of rC1:rC2, which is beneficial for the survival of islets.
Green factory: plants as bioproduction platforms for recombinant proteins.
Xu, Jianfeng; Dolan, Maureen C; Medrano, Giuliana; Cramer, Carole L; Weathers, Pamela J
2012-01-01
Molecular farming, long considered a promising strategy to produce valuable recombinant proteins not only for human and veterinary medicine, but also for agriculture and industry, now has some commercially available products. Various plant-based production platforms including whole-plants, aquatic plants, plant cell suspensions, and plant tissues (hairy roots) have been compared in terms of their advantages and limits. Effective recombinant strategies are summarized along with descriptions of scalable culture systems and examples of commercial progress and success. Copyright © 2011 Elsevier Inc. All rights reserved.
Schein, Ophir; Westreich, Melvyn; Shalom, Avshalom
2013-09-01
Studies have focused on enhancing flap viability using superoxide dismutase (SOD), but only a few used SOD from human origin, and most gave the compound systemically. We evaluated the ability of SOD to improve random skin flap survival using human recombinant copper-zinc superoxide dismutase (Hr-CuZnSOD) in variable doses, injected intradermally into the flap. Seventy male Sprague Dawley rats were randomly assigned into 4 groups. Cephalic random pattern flaps were elevated on their backs and intradermal injections of different dosages of Hr-CuZnSOD were given 15 minutes before surgery. Flap survival was evaluated by fluorescein fluorescence. Analysis of variance (ANOVA) and t test statistical analyses were performed. Flap survival in all treated groups was significantly better than in the controls. The beneficial effect of HR-CuZnSOD on flap survival is attained when it is given intradermally into the flap tissue. Theoretically, Hr-CuZnSOD delivered with local anesthetics used in flap elevation may be a valuable clinical tool. Copyright © 2012 Wiley Periodicals, Inc.
Jia, Junting; Ma, Yuyuan; Zhao, Xiong; Huangfu, Chaoji; Zhong, Yadi; Fang, Chi; Fan, Rui; Lv, Maomin; Zhang, Jingang
2016-09-17
Human parvovirus B19 (B19V) is a frequent contaminant of blood and plasma-derived medicinal products. Three distinct genotypes of B19V have been identified. The distribution of the three B19V genotypes has been investigated in various regions or countries. However, in China, data on the existence of different B19V genotypes are limited. One hundred and eighteen B19V-DNA positive source plasma pool samples collected from three Chinese blood products manufacturers were analyzed. The subgenomic NS1/VP1u region junction of B19V was amplified by nested PCR. These amplified products were then cloned and subsequently sequenced. For genotyping, their phylogenetic inferences were constructed based on the NS1/VP1-unique region. Then putative recombination events were analyzed and identified. Phylogenetic analysis of 118 B19V sequences attributed 61.86 % to genotype 1a, 10.17 % to genotype 1b, and 17.80 % to genotype 3b. All the genotype 3b sequences obtained in this study grouped as a specific, closely related cluster with B19V strain D91.1. Four 1a/3b recombinants and 5 new atypical B19V variants with no recombination events were identified. There were at least 3 subtypes (1a, 1b and 3b) of B19V circulating in China. Furthermore, putative B19V 1a/3b recombinants and unclassified strains were identified as well. Such recombinant and unclassified strains may contribute to the genetic diversity of B19V and consequently complicate the B19V infection diagnosis and NAT screening. Further studies will be required to elucidate the biological significance of the recombinant and unclassified strains.
Recombinant Immunotoxin Therapy of Solid Tumors: Challenges and Strategies.
Shan, Liang; Liu, Yuanyi; Wang, Paul
2013-01-01
Immunotoxins are a group of protein-based therapeutics, basically comprising two functional moieties: one is the antibody or antibody Fv fragment that allows the immunotoxin to bind specifically to target cells; another is the plant or bacterial toxin that kills the cells upon internalization. Immunotoxins have several unique features which are superior to conventional chemotherapeutics, including high specificity, extraordinary potency, and no known drug resistance. Development of immunotoxins evolves with time and technology, but significant progress has been achieved in the past 20 years after introduction of recombinant DNA technique and generation of the first single-chain variable fragment of monoclonal antibodies. Since then, more than 1,000 recombinant immunotoxins have been generated against cancer. However, most success in immunotoxin therapy has been achieved against hematological malignancies, several issues persist to be significant barriers for effective therapy of human solid tumors. Further development of immunotoxins will largely focus on the improvement of penetration capability to solid tumor mass and elimination of immunogenicity occurred when given repeatedly to patients. Promising strategies may include construction of recombinant antibody fragments with higher binding affinity and stability, elimination of immunodominant T- and B-cell epitopes of toxins, modification of immunotoxins with macromolecules like poly(ethylene glycol) and liposomes, and generation of immunotoxins with humanized antibody fragments and human endogenous cytotoxic enzymes. In this paper, we briefly reviewed the evolution of immunotoxin development and then discussed the challenges of immunotoxin therapy for human solid tumors and the potential strategies we may seek to overcome the challenges.
Recombinant human prion protein fragment 90-231, a useful model to study prion neurotoxicity.
Corsaro, Alessandro; Thellung, Stefano; Villa, Valentina; Nizzari, Mario; Aceto, Antonio; Florio, Tullio
2012-01-01
Transmissible spongiform encephalopathies (TSE), or prion diseases, are a group of fatal neurodegenerative disorders of animals and humans. Human diseases include Creutzfeldt-Jakob (CJD) and Gerstmann-Straussler-Scheinker (GSSD) diseases, fatal familial insomnia, and Kuru. Human and animal TSEs share a common histopathology with a pathognomonic triad: spongiform vacuolation of the grey matter, neuronal death, glial proliferation, and, more inconstantly, amyloid deposition. According to the "protein only" hypothesis, TSEs are caused by a unique post-translational conversion of normal, host-encoded, protease-sensitive prion protein (PrP(sen) or PrP(C)) to an abnormal disease-associated isoform (PrP(res) or PrP(Sc)). To investigate the molecular mechanism of neurotoxicity induced by PrP(Sc) we developed a protocol to obtain millimolar amounts of soluble recombinant polypeptide encompassing the amino acid sequence 90-231 of human PrP (hPrP90-231). This protein corresponds to the protease-resistant prion protein fragment that originates after amino-terminal truncation. Importantly, hPrP90-231 has a flexible backbone that, similar to PrP(C), can undergo to structural rearrangement. This peptide, structurally resembling PrP(C), can be converted in a PrP(Sc)-like conformation, and thus represents a valuable model to study prion neurotoxicity. In this article we summarized our experimental evidence on the molecular and structural mechanisms responsible of hPrP90-231 neurotoxicity on neuroectodermal cell line SHSY5Y and the effects of some PrP pathogen mutations identified in familial TSE.
Xu, Weidong; Neill, Thomas; Yang, Yuefeng; ...
2014-12-11
In an effort to develop a new therapy for prostate cancer bone metastases, we have created Ad.dcn, a recombinant oncolytic adenovirus carrying the human decorin gene. Infection of PC-3 and DU-145, the human prostate tumor cells, with Ad.dcn or a non-replicating adenovirus Ad(E1-).dcn resulted in decorin expression; Ad.dcn produced high viral titers and cytotoxicity in human prostate tumor cells. Adenoviral-mediated decorin expression inhibited Met, the Wnt/β- catenin signaling axis, vascular endothelial growth factor A, reduced mitochondrial DNA levels, and inhibited tumor cell migration. To examine the anti-tumor response of Ad.dcn, PC-3-luc cells were inoculated in the left heart ventricle tomore » establish bone metastases in nude mice. Ad.dcn, in conjunction with control replicating and non-replicating vectors were injected via tail vein. The real-time monitoring of mice, once a week, by bioluminescence imaging and X-ray radiography showed that Ad.dcn produced significant inhibition of skeletal metastases. Analyses of the mice at the terminal time point indicated a significant reduction in the tumor burden, osteoclast number, serum TRACP 5b levels, osteocalcin levels, hypercalcemia, inhibition of cancer cachexia, and an increase in the animal survival. Finally, based on these studies, we believe that Ad.dcn can be developed as a potential new therapy for prostate cancer bone metastasis.« less
Recombination in Eukaryotic Single Stranded DNA Viruses
Martin, Darren P.; Biagini, Philippe; Lefeuvre, Pierre; Golden, Michael; Roumagnac, Philippe; Varsani, Arvind
2011-01-01
Although single stranded (ss) DNA viruses that infect humans and their domesticated animals do not generally cause major diseases, the arthropod borne ssDNA viruses of plants do, and as a result seriously constrain food production in most temperate regions of the world. Besides the well known plant and animal-infecting ssDNA viruses, it has recently become apparent through metagenomic surveys of ssDNA molecules that there also exist large numbers of other diverse ssDNA viruses within almost all terrestrial and aquatic environments. The host ranges of these viruses probably span the tree of life and they are likely to be important components of global ecosystems. Various lines of evidence suggest that a pivotal evolutionary process during the generation of this global ssDNA virus diversity has probably been genetic recombination. High rates of homologous recombination, non-homologous recombination and genome component reassortment are known to occur within and between various different ssDNA virus species and we look here at the various roles that these different types of recombination may play, both in the day-to-day biology, and in the longer term evolution, of these viruses. We specifically focus on the ecological, biochemical and selective factors underlying patterns of genetic exchange detectable amongst the ssDNA viruses and discuss how these should all be considered when assessing the adaptive value of recombination during ssDNA virus evolution. PMID:21994803
Hack, C Erik; Mannesse, Maurice; Baboeram, Aartie; Oortwijn, Beatrijs; Relan, Anurag
2012-10-01
Recombinant human C1-inhibitor (rhC1INH) is used to treat acute angioedema attacks in hereditary angioedema (HAE) due to a genetic C1INH deficiency. Recombinant proteins in general may induce antibody responses and therefore evaluation of such responses in the target population is an essential step in the clinical development program of a recombinant protein. Here we report the assessment of the immunogenicity of rhC1INH in symptomatic HAE patients. Blood samples collected before and after administration of rhC1INH were tested for antibodies against plasma-derived (pd) or rhC1INH, or against host-related impurities (HRI). Above cut-off screening results were confirmed with displacement assays, and also tested for neutralizing anti-C1INH antibodies. Finally, the relation of antibodies to clinical efficacy and safety of rhC1INH was analyzed. Data from 155 HAE patients who received 424 treatments with rhC1INH were analyzed. 1.5% of all pre-exposure tests and 1.3% of all post-exposure tests were above the cut-off level in the screening assay for anti-C1INH antibodies. Six patients (3.9%) had anti-rhC1INH antibodies positive in the confirmatory assay. In two patients, confirmed antibodies were pre-existing with no increase post-exposure; in three patients, the antibodies occurred on a single occasion post-exposure; and in one patient, on subsequent occasions post-exposure. Neutralizing anti-pdC1INH antibodies were not found. Anti-HRI antibodies in the screening assay occurred in <0.7% of the tests before exposure to rhC1INH, in <1.9% after first exposure and in <3.1% after repeat treatment with rhC1INH. Five patients had anti-HRI antibodies positive in the confirmatory assay. In one patient, the antibodies were pre-existing, whereas in three of the 155 rhC1INH-treated patients (1.9%), confirmed anti-HRI antibodies occurred at more time points. Antibody findings were not associated with altered efficacy of rhC1INH or adverse events. These results indicate a reassuring
Exploiting persistent infection for selection of bovine herpesvirus 4 recombinants.
Donofrio, G; Martignani, E; Cavirani, S; Flammini, C F
2005-09-01
Bovine herpesvirus 4 (BoHV-4) is a gamma-herpesvirus with no clear disease association, and due to its biological characteristics, has been suggested as a gene delivery vector. It was demonstrated previously that recombinant BoHV-4 carrying a neomycin-resistance gene was able to infect a human rhabdomyosarcoma cell line (RD-4), resulting in no detectable cytopathic effect (CPE) and allowing selection of G418-resistant persistently-infected cells containing circular episomal viral DNA [Donofrio, G., Cavirani, S., van Santen, V.L., 2000a. Establishment of a cell line persistently infected with recombinant BoHV-4. J. Gen. Virol. 81, 1807-1814.]. Those cells produce infectious virus and infection is predominantly non-permissive and non-cytopathic. Starting from these results, the ability of RD-4 cells to sustain persistent infection was combined with positive selection activity conferred by the neomycin-expression cassette insert, as an easier way to select recombinants of BoHV-4 following homologous recombination in permissive cells. A tool for selecting BoHV-4 recombinants was developed by drug positive selection.
Effects of Recombinant Human Growth Hormone for Osteoporosis: Systematic Review and Meta-Analysis.
Atkinson, Hayden F; Moyer, Rebecca F; Yacoub, Daniel; Coughlin, Dexter; Birmingham, Trevor B
2017-03-01
Our objective was to evaluate the efficacy of recombinant human growth hormone (GH) on bone mineral density (BMD) in persons age 50 and older, with normal pituitary function, with or at risk for developing osteoporosis. We systematically reviewed randomized clinical trials (RCTs), searching six databases, and conducted meta-analyses to examine GH effects on BMD of the lumbar spine and femoral neck. Data for fracture incidence, bone metabolism biomarkers, and adverse events were also extracted and analysed. Thirteen RCTs met the eligibility criteria. Pooled effect sizes suggested no significant GH effect on BMD. Pooled effect sizes were largest, but nonsignificant, when compared to placebo. GH had a significant effect on several bone metabolism biomarkers. A significantly higher rate of adverse events was observed in the GH groups. Meta-analysis of RCTs suggests that GH treatment for persons with or at risk for developing osteoporosis results in very small, nonsignificant increases in BMD.
Peters, Esther; Schirris, Tom; van Asbeck, Alexander H; Gerretsen, Jelle; Eymael, Jennifer; Ashikov, Angel; Adjobo-Hermans, Merel J W; Russel, Frans; Pickkers, Peter; Masereeuw, Rosalinde
2017-02-05
Sepsis-associated acute kidney injury is a multifactorial syndrome in which inflammation and renal microcirculatory dysfunction play a profound role. Subsequently, renal tubule mitochondria reprioritize cellular functions to prevent further damage. Here, we investigated the putative protective effects of human recombinant alkaline phosphatase (recAP) during inhibition of mitochondrial respiration in conditionally immortalized human proximal tubule epithelial cells (ciPTEC). Full inhibition of mitochondrial oxygen consumption was obtained after 24h antimycin A treatment, which did not affect cell viability. While recAP did not affect the antimycin A-induced decreased oxygen consumption and increased hypoxia-inducible factor-1α or adrenomedullin gene expression levels, the antimycin A-induced increase of pro-inflammatory cytokines IL-6 and IL-8 was attenuated. Antimycin A tended to induce the release of detrimental purines ATP and ADP, which reached statistical significance when antimycin A was co-incubated with lipopolysaccharide, and were completely converted into cytoprotective adenosine by recAP. As the adenosine A 2A receptor was up-regulated after antimycin A exposure, an adenosine A 2A receptor knockout ciPTEC cell line was generated in which recAP still provided protection. Together, recAP did not affect oxygen consumption but attenuated the inflammatory response during impaired mitochondrial function, an effect suggested to be mediated by dephosphorylating ATP and ADP into adenosine. Copyright © 2016 Elsevier B.V. All rights reserved.
Tateno, Hiroaki; Saito, Sayoko
2017-07-10
The use of human pluripotent stem cells (hPSCs) such as human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs) in regenerative medicine is hindered by their tumorigenic potential. Previously, we developed a recombinant lectin-toxin fusion protein of the hPSC-specific lectin rBC2LCN, which has a 23 kDa catalytic domain (domain III) of Pseudomonas aeruginosa exotoxin A (rBC2LCN-PE23). This fusion protein could selectively eliminate hPSCs following its addition to the cell culture medium. Here we conjugated rBC2LCN lectin with a 38 kDa domain of exotoxin A containing domains Ib and II in addition to domain III (PE38). The developed rBC2LCN-PE38 fusion protein could eliminate 50% of 201B7 hPSCs at a concentration of 0.003 μg/mL (24 h incubation), representing an approximately 556-fold higher activity than rBC2LCN-PE23. Little or no effect on human fibroblasts, human mesenchymal stem cells, and hiPSC-derived hepatocytes was observed at concentrations lower than 1 μg/mL. Finally, we demonstrate that rBC2LCN-PE38 selectively eliminates hiPSCs from a mixed culture of hiPSCs and hiPSC-derived hepatocytes. Since rBC2LCN-PE38 can be prepared from soluble fractions of E. coli culture at a yield of 9 mg/L, rBC2LCN-PE38 represents a practical reagent to remove human pluripotent stem cells residing in cultured cells destined for transplantation.
Furimsky, Anna M; Green, Carol E; Sharp, Lewanne E Hunt; Catz, Paul; Adjei, Araba A; Parman, Toufan; Kapetanovic, Izet M; Weinshilboum, Richard M; Iyer, Lalitha V
2008-01-01
The purpose of this study was to investigate the sulfation of resveratrol (3,5,4'-trihydroxystilbene) and its potential to exhibit drug-drug interactions via sulfation. The possible interaction of resveratrol with 17beta-estradiol (E2), a major estrogen hormone and prototypic substrate for sulfate conjugation, was studied. Resveratrol and E2 are both known to undergo sulfate conjugation catalyzed by human sulfotransferases (SULTs). Resveratrol is a phytoestrogen with mixed estrogen agonist/antagonist properties that is being developed as a chemopreventive agent. The sulfate conjugation of E2 and resveratrol were studied individually using S9 fractions from human liver and jejunum as well as recombinant human SULT isoforms. The sulfation of E2 (3-20 nM) was then investigated in the presence of various concentrations (0, 0.5, 1, and 2 microM) of resveratrol using the two S9 preparations as well as recombinant SULT1E1, the major isoform responsible for E2 sulfation. Resveratrol inhibited E2 sulfation with estimated K(i) values of 1.1 microM (liver), 0.6 microM (jejunum), and 2.3 microM (SULT1E1), concentrations that could be pharmacologically relevant. The results suggest that these phytoestrogens can potentially alter the homeostasis of estrogen levels. These findings also imply that resveratrol may inhibit the metabolism of other estrogen analogs or therapeutic agents such as ethinylestradiol or dietary components that are also substrates for SULT1E1.
2008-02-01
The Effect of Recombinant Activated Factor VII on Mortality in Combat-Related Casualties With Severe Trauma and Massive Transfusion Philip C...REPORT TYPE 3. DATES COVERED 00-00-2007 to 00-00-2007 4. TITLE AND SUBTITLE The Effect of Recombinant Activated Factor VII on Mortality in Combat...Boffard study,17 the effect of rFVIIa on 24-hour blood product ad- ministration was only determined for patients who lived for at least 24 hours
Cutaneous wound healing after treatment with plant-derived human recombinant collagen flowable gel.
Shilo, Shani; Roth, Sigal; Amzel, Tal; Harel-Adar, Tamar; Tamir, Eran; Grynspan, Frida; Shoseyov, Oded
2013-07-01
Chronic wounds, particularly diabetic ulcers, represent a main public health concern with significant costs. Ulcers often harbor an additional obstacle in the form of tunneled or undermined wounds, requiring treatments that can reach the entire wound tunnel, because bioengineered grafts are typically available only in a sheet form. While collagen is considered a suitable biodegradable scaffold material, it is usually extracted from animal and human cadaveric sources, and accompanied by potential allergic and infectious risks. The purpose of this study was to test the performance of a flowable gel made of human recombinant type I collagen (rhCollagen) produced in transgenic tobacco plants, indicated for the treatment of acute, chronic, and tunneled wounds. The performance of the rhCollagen flowable gel was tested in an acute full-thickness cutaneous wound-healing rat model and compared to saline treatment and two commercial flowable gel control products made of bovine collagen and cadaver human skin collagen. When compared to the three control groups, the rhCollagen-based gel accelerated wound closure and triggered a significant jumpstart to the healing process, accompanied by enhanced re-epithelialization. In a cutaneous full-thickness wound pig model, the rhCollagen-based flowable gel induced accelerated wound healing compared to a commercial product made of bovine tendon collagen. By day 21 post-treatment, 95% wound closure was observed with the rhCollagen product compared to 68% closure in wounds treated with the reference product. Moreover, rhCollagen treatment induced an early angiogenic response and induced a significantly lower inflammatory response than in the control group. In summary, rhCollagen flowable gel proved to be efficacious in animal wound models and is expected to be capable of reducing the healing time of human wounds.
Cutaneous Wound Healing After Treatment with Plant-Derived Human Recombinant Collagen Flowable Gel
Roth, Sigal; Amzel, Tal; Harel-Adar, Tamar; Tamir, Eran; Grynspan, Frida; Shoseyov, Oded
2013-01-01
Chronic wounds, particularly diabetic ulcers, represent a main public health concern with significant costs. Ulcers often harbor an additional obstacle in the form of tunneled or undermined wounds, requiring treatments that can reach the entire wound tunnel, because bioengineered grafts are typically available only in a sheet form. While collagen is considered a suitable biodegradable scaffold material, it is usually extracted from animal and human cadaveric sources, and accompanied by potential allergic and infectious risks. The purpose of this study was to test the performance of a flowable gel made of human recombinant type I collagen (rhCollagen) produced in transgenic tobacco plants, indicated for the treatment of acute, chronic, and tunneled wounds. The performance of the rhCollagen flowable gel was tested in an acute full-thickness cutaneous wound-healing rat model and compared to saline treatment and two commercial flowable gel control products made of bovine collagen and cadaver human skin collagen. When compared to the three control groups, the rhCollagen-based gel accelerated wound closure and triggered a significant jumpstart to the healing process, accompanied by enhanced re-epithelialization. In a cutaneous full-thickness wound pig model, the rhCollagen-based flowable gel induced accelerated wound healing compared to a commercial product made of bovine tendon collagen. By day 21 post-treatment, 95% wound closure was observed with the rhCollagen product compared to 68% closure in wounds treated with the reference product. Moreover, rhCollagen treatment induced an early angiogenic response and induced a significantly lower inflammatory response than in the control group. In summary, rhCollagen flowable gel proved to be efficacious in animal wound models and is expected to be capable of reducing the healing time of human wounds. PMID:23259631
Breaks in the 45S rDNA Lead to Recombination-Mediated Loss of Repeats.
Warmerdam, Daniël O; van den Berg, Jeroen; Medema, René H
2016-03-22
rDNA repeats constitute the most heavily transcribed region in the human genome. Tumors frequently display elevated levels of recombination in rDNA, indicating that the repeats are a liability to the genomic integrity of a cell. However, little is known about how cells deal with DNA double-stranded breaks in rDNA. Using selective endonucleases, we show that human cells are highly sensitive to breaks in 45S but not the 5S rDNA repeats. We find that homologous recombination inhibits repair of breaks in 45S rDNA, and this results in repeat loss. We identify the structural maintenance of chromosomes protein 5 (SMC5) as contributing to recombination-mediated repair of rDNA breaks. Together, our data demonstrate that SMC5-mediated recombination can lead to error-prone repair of 45S rDNA repeats, resulting in their loss and thereby reducing cellular viability. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.
Rubinstein, I; Iwamoto, I; Ueki, I F; Borson, D B; Nadel, J A
1990-01-01
To determine whether exogenously administered neutral endopeptidase (NEP; enkephalinase, EC 3.4.24.11) inhibits the substance P-induced increase in vascular permeability in the skin, we examined the effects of recombinant human NEP on plasma extravasation induced by intradermal injection of substance P in guinea pig skin. Injection of substance P (2.5 X 10(-8) M) induced significant plasma extravasation in the skin (53 +/- 4 mm2 of Evans blue extravasation; mean +/- 1 SEM). In vitro incubation of substance P with recombinant human NEP prior to injection prevented the substance P-induced plasma extravasation in the skin in a dose-dependent fashion. Intradermal preinjection of recombinant human NEP partially inhibited plasma extravasation induced by subsequent injection of substance P (52 +/- 9% of the control without NEP). The H1 and H2 histamine antagonists pyrilamine and cimetidine, and a muscarinic antagonist, atropine, had no effects on substance P-induced responses. Two products of substance P degradation by NEP containing the carboxy-terminal portion, substance P7-11 and substance P8-11, were also without effect. These findings suggest that recombinant human NEP can attenuate substance P-induced increases in vascular permeability in guinea pig skin and, therefore, may be useful in treating dermatologic disorders in which abnormal responses to substance P or other neuropeptides cleaved by NEP may occur.
Genome-wide recombination rate variation in a recombination map of cotton.
Shen, Chao; Li, Ximei; Zhang, Ruiting; Lin, Zhongxu
2017-01-01
Recombination is crucial for genetic evolution, which not only provides new allele combinations but also influences the biological evolution and efficacy of natural selection. However, recombination variation is not well understood outside of the complex species' genomes, and it is particularly unclear in Gossypium. Cotton is the most important natural fibre crop and the second largest oil-seed crop. Here, we found that the genetic and physical maps distances did not have a simple linear relationship. Recombination rates were unevenly distributed throughout the cotton genome, which showed marked changes along the chromosome lengths and recombination was completely suppressed in the centromeric regions. Recombination rates significantly varied between A-subgenome (At) (range = 1.60 to 3.26 centimorgan/megabase [cM/Mb]) and D-subgenome (Dt) (range = 2.17 to 4.97 cM/Mb), which explained why the genetic maps of At and Dt are similar but the physical map of Dt is only half that of At. The translocation regions between A02 and A03 and between A04 and A05, and the inversion regions on A10, D10, A07 and D07 indicated relatively high recombination rates in the distal regions of the chromosomes. Recombination rates were positively correlated with the densities of genes, markers and the distance from the centromere, and negatively correlated with transposable elements (TEs). The gene ontology (GO) categories showed that genes in high recombination regions may tend to response to environmental stimuli, and genes in low recombination regions are related to mitosis and meiosis, which suggested that they may provide the primary driving force in adaptive evolution and assure the stability of basic cell cycle in a rapidly changing environment. Global knowledge of recombination rates will facilitate genetics and breeding in cotton.
Genome-wide recombination rate variation in a recombination map of cotton
Shen, Chao; Li, Ximei; Zhang, Ruiting
2017-01-01
Recombination is crucial for genetic evolution, which not only provides new allele combinations but also influences the biological evolution and efficacy of natural selection. However, recombination variation is not well understood outside of the complex species’ genomes, and it is particularly unclear in Gossypium. Cotton is the most important natural fibre crop and the second largest oil-seed crop. Here, we found that the genetic and physical maps distances did not have a simple linear relationship. Recombination rates were unevenly distributed throughout the cotton genome, which showed marked changes along the chromosome lengths and recombination was completely suppressed in the centromeric regions. Recombination rates significantly varied between A-subgenome (At) (range = 1.60 to 3.26 centimorgan/megabase [cM/Mb]) and D-subgenome (Dt) (range = 2.17 to 4.97 cM/Mb), which explained why the genetic maps of At and Dt are similar but the physical map of Dt is only half that of At. The translocation regions between A02 and A03 and between A04 and A05, and the inversion regions on A10, D10, A07 and D07 indicated relatively high recombination rates in the distal regions of the chromosomes. Recombination rates were positively correlated with the densities of genes, markers and the distance from the centromere, and negatively correlated with transposable elements (TEs). The gene ontology (GO) categories showed that genes in high recombination regions may tend to response to environmental stimuli, and genes in low recombination regions are related to mitosis and meiosis, which suggested that they may provide the primary driving force in adaptive evolution and assure the stability of basic cell cycle in a rapidly changing environment. Global knowledge of recombination rates will facilitate genetics and breeding in cotton. PMID:29176878
Wang, Yin-Jue; Liu, Yong-Dong; Chen, Jing; Hao, Su-Juan; Hu, Tao; Ma, Guang-Hui; Su, Zhi-Guo
2010-02-15
Recombinant human erythropoietin produced by mammalian cells contains about 40% carbohydrates which maintain its stability and long residence in body. However, mammalian derived Epo has low yields and high costs of production. In this article, a cost-effective strategy of producing non-glycosylated Epo from Escherichia coli and then PEGylating it to replace the role of sugar chains was investigated. Recombinant human non-glycosylated erythropoietin (rh-ngEpo) was overexpressed as inclusion body in E. coli. As the routine inclusion body washing step resulted in poor protein recovery and purity, a new process scheme of using strong ion-exchange chromatography to purify denatured rh-ngEpo from inclusion body before refolding was developed. The purity of the denatured rh-ngEpo was increased from 59% to over 90%. Rh-ngEpo was then refolded and subsequently purified by one step of weak cation-exchange chromatography to 98% pure. Final protein yield was 129 mg/l, a significant improvement from 49 mg/l obtained via the conventional practice. The in vitro bioactivity of purified rh-ngEpo was comparable with the CHO-expressed Epo and the formation of native secondary structure was also confirmed by CD spectra. Rh-ngEpo was then modified by a 20 kDa methoxy polyethylene glycol (PEG) succinimidyl carbonate. The monoPEGylated protein, which retained 68% bioactivity, had enhanced thermal stability and a remarkably prolonged circulating half-life in rats as compared with that of the unmodified protein. These studies demonstrated the feasibility of PEGylating rh-ngEpo as a promising way for the development of new Epo drugs. Copyright 2009 Elsevier B.V. All rights reserved.
Stukenbrock, Eva H.; Dutheil, Julien Y.
2018-01-01
Meiotic recombination is an important driver of evolution. Variability in the intensity of recombination across chromosomes can affect sequence composition, nucleotide variation, and rates of adaptation. In many organisms, recombination events are concentrated within short segments termed recombination hotspots. The variation in recombination rate and positions of recombination hotspot can be studied using population genomics data and statistical methods. In this study, we conducted population genomics analyses to address the evolution of recombination in two closely related fungal plant pathogens: the prominent wheat pathogen Zymoseptoria tritici and a sister species infecting wild grasses Z. ardabiliae. We specifically addressed whether recombination landscapes, including hotspot positions, are conserved in the two recently diverged species and if recombination contributes to rapid evolution of pathogenicity traits. We conducted a detailed simulation analysis to assess the performance of methods of recombination rate estimation based on patterns of linkage disequilibrium, in particular in the context of high nucleotide diversity. Our analyses reveal overall high recombination rates, a lack of suppressed recombination in centromeres, and significantly lower recombination rates on chromosomes that are known to be accessory. The comparison of the recombination landscapes of the two species reveals a strong correlation of recombination rate at the megabase scale, but little correlation at smaller scales. The recombination landscapes in both pathogen species are dominated by frequent recombination hotspots across the genome including coding regions, suggesting a strong impact of recombination on gene evolution. A significant but small fraction of these hotspots colocalize between the two species, suggesting that hotspot dynamics contribute to the overall pattern of fast evolving recombination in these species. PMID:29263029
Stukenbrock, Eva H; Dutheil, Julien Y
2018-03-01
Meiotic recombination is an important driver of evolution. Variability in the intensity of recombination across chromosomes can affect sequence composition, nucleotide variation, and rates of adaptation. In many organisms, recombination events are concentrated within short segments termed recombination hotspots. The variation in recombination rate and positions of recombination hotspot can be studied using population genomics data and statistical methods. In this study, we conducted population genomics analyses to address the evolution of recombination in two closely related fungal plant pathogens: the prominent wheat pathogen Zymoseptoria tritici and a sister species infecting wild grasses Z. ardabiliae We specifically addressed whether recombination landscapes, including hotspot positions, are conserved in the two recently diverged species and if recombination contributes to rapid evolution of pathogenicity traits. We conducted a detailed simulation analysis to assess the performance of methods of recombination rate estimation based on patterns of linkage disequilibrium, in particular in the context of high nucleotide diversity. Our analyses reveal overall high recombination rates, a lack of suppressed recombination in centromeres, and significantly lower recombination rates on chromosomes that are known to be accessory. The comparison of the recombination landscapes of the two species reveals a strong correlation of recombination rate at the megabase scale, but little correlation at smaller scales. The recombination landscapes in both pathogen species are dominated by frequent recombination hotspots across the genome including coding regions, suggesting a strong impact of recombination on gene evolution. A significant but small fraction of these hotspots colocalize between the two species, suggesting that hotspot dynamics contribute to the overall pattern of fast evolving recombination in these species. Copyright © 2018 Stukenbrock and Dutheil.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhang, S. Y.; Blaskiewicz, M.
This is a brief report on LEReC recombination monitor design considerations. The recombination produced Au 78+ ion rate is reviewed. Based on this two designs are discussed. One is to use the large dispersion lattice. It is shown that even with the large separation of the Au 78+ beam from the Au 79+ beam, the continued monitoring of the recombination is not possible. Accumulation of Au 78+ ions is needed, plus collimation of the Au79+ beam. In another design, it is shown that the recombination monitor can be built based on the proposed scheme with the nominal lattice. From machinemore » operation point of view, this design is preferable. Finally, possible studies and the alternative strategies with the basic goal of the monitor are discussed.« less
Xu, Yunbin; Li, Yong; Bao, Weiguo; Qiu, Shi
2018-03-01
The aim of the present study was to evaluate the protective effects and safety aspects of recombinant human brain natriuretic peptide (rhBNP) on cardiac functions of patients undergoing open-heart surgery during perioperative period. In total, 150 patients undergoing open heart surgery in the Second Hospital of Shandong Universty from August 2015 to July 2016 were randomly divided into control group and observation group each with 75 cases. Patients in control group were treated by routine rehabilitation while patients in the observation group were treated by both the routine rehabilitation and rhBNP. All the observations were made before operation, after operation and 7 days after operation. The changes of N-terminal pro-brain natriuretic peptide (NT-proBNP) of patients, the left ventricular ejection fraction (LVEF), cardiac function [Cardiac output (CO), pulmonary capillary wedge pressure (PAWP) and central venous pressure (CVP)] of patients were measured. Further, respirator support time, ICU stay time, incidence of complications and vital signs (BP, HR, SaO2) of patients in the two groups were also compared. NT-proBNP levels of all patients improved after operation but it decreased in both groups after 7 days of operation. The decrease of NT-proBNP levels in observation group was significantly higher than that of control group. Whereas, LVEF, CO, PAWP and CVP of patients in both the groups increased after operation but effects were significantly higher in the observation group after 7 days of medication. Respirator support time and ICU stay time of patients in observation group were significantly shorter than those in control group, and the incidence of postoperative complications of patients in the observation group were significantly lower than the control group. Moreover, BP, HR and SaO2 of patients in observation group were significantly elevated in comparison to control group (P<0.05). Recombinant human brain natriuretic peptide (rhBNP) could significantly
Zhang, Kao; Jin, Huijun; Zhong, Fei; Li, Xiujin; Neng, Changai; Chen, Huihui; Li, Wenyan; Wen, Jiexia
2012-11-04
To construct recombinant adenovirus containing canine interferon-gamma (cIFN-gamma) gene and to investigate its antiviral activity against canine parvovirus in Madin-Darby canine kidney cells (MDCK). [Methods] The cIFN-gamma gene was inserted into adenovirus shuttle plasmid to construct pShuttle3-cIFN-gamma expression vector, from which the cIFN-gamma expression cassette was transferred into the adenovirus genomic plasmid pAdeno-X by specific restriction sites to generate recombinant adenovirus genomic plasmid pAd-cIFN-gamma. The pAd-cIFN-gamma plasmid was linearized by digestion and transfected into human embryonic kidney (HEK) 293T cells to generate the replication-defective cIFN-gamma recombinant adenovirus (Ad-cIFN-gamma). To analyze its anti-canine parvovirus activity, the MDCK cells were pre-infected by Ad-cIFN-gamma recombinant adenovirus, and then infected by canine parvovirus. The antiviral activity of the Ad-cIFN-gamma recombinant adenovirus against parvovirus was analyzed. The recombinant adenovirus containing cIFN-gamma gene was constructed by the ligation method. The recombinant adenovirus could mediates recombinant cIFN-gamma secretory expression in MDCK cells. The Ad-cIFN-gamma recombinant adenovirus could significantly inhibit canine parvovirus replication in MDCK cells pre-infected with the recombinant adenovirus. These results indicate that the Ad-cIFN-gamma recombinant adenovirus has the potent antiviral activity against canine parvovirus. The Ad-cIFN-gamma recombinant adenovirus was successfully constructed by the ligation method and possessed a powerful antiviral activity against canine parvovirus.
New Technologies in Using Recombinant Attenuated Salmonella Vaccine Vectors
Curtiss, Roy; Xin, Wei; Li, Yuhua; Kong, Wei; Wanda, Soo-Young; Gunn, Bronwyn; Wang, Shifeng
2014-01-01
Recombinant attenuated Salmonella vaccines (RASVs) have been constructed to deliver antigens from other pathogens to induce immunity to those pathogens in vaccinated hosts. The attenuation means should ensure that the vaccine survives following vaccination to colonize lymphoid tissues without causing disease symptoms. This necessitates that attenuation and synthesis of recombinant gene encoded protective antigens do not diminish the ability of orally administered vaccines to survive stresses encountered in the gastrointestinal tract. We have eliminated these problems by using RASVs with regulated delayed expression of attenuation and regulated delayed synthesis of recombinant antigens. These changes result in RASVs that colonize effector lymphoid tissues efficiently to serve as “factories” to synthesize protective antigens that induce higher protective immune responses than achieved when using previously constructed RASVs. We have devised a biological containment system with regulated delayed lysis to preclude RASV persistence in vivo and survival if excreted. Attributes were added to reduce the mild diarrhea sometimes experienced with oral live RASVs and to ensure complete safety in newborns. These collective technologies have been used to develop a novel, low-cost, RASV-synthesizing, multiple-protective Streptococcus pneumoniae antigens that will be safe for newborns/infants and will induce protective immunity to diverse S. pneumoniae serotypes after oral immunization. PMID:20370633
Role of Recombinant DNA Technology to Improve Life.
Khan, Suliman; Ullah, Muhammad Wajid; Siddique, Rabeea; Nabi, Ghulam; Manan, Sehrish; Yousaf, Muhammad; Hou, Hongwei
2016-01-01
In the past century, the recombinant DNA technology was just an imagination that desirable characteristics can be improved in the living bodies by controlling the expressions of target genes. However, in recent era, this field has demonstrated unique impacts in bringing advancement in human life. By virtue of this technology, crucial proteins required for health problems and dietary purposes can be produced safely, affordably, and sufficiently. This technology has multidisciplinary applications and potential to deal with important aspects of life, for instance, improving health, enhancing food resources, and resistance to divergent adverse environmental effects. Particularly in agriculture, the genetically modified plants have augmented resistance to harmful agents, enhanced product yield, and shown increased adaptability for better survival. Moreover, recombinant pharmaceuticals are now being used confidently and rapidly attaining commercial approvals. Techniques of recombinant DNA technology, gene therapy, and genetic modifications are also widely used for the purpose of bioremediation and treating serious diseases. Due to tremendous advancement and broad range of application in the field of recombinant DNA technology, this review article mainly focuses on its importance and the possible applications in daily life.
Role of Recombinant DNA Technology to Improve Life
Khan, Suliman; Ullah, Muhammad Wajid; Siddique, Rabeea; Nabi, Ghulam; Manan, Sehrish; Yousaf, Muhammad
2016-01-01
In the past century, the recombinant DNA technology was just an imagination that desirable characteristics can be improved in the living bodies by controlling the expressions of target genes. However, in recent era, this field has demonstrated unique impacts in bringing advancement in human life. By virtue of this technology, crucial proteins required for health problems and dietary purposes can be produced safely, affordably, and sufficiently. This technology has multidisciplinary applications and potential to deal with important aspects of life, for instance, improving health, enhancing food resources, and resistance to divergent adverse environmental effects. Particularly in agriculture, the genetically modified plants have augmented resistance to harmful agents, enhanced product yield, and shown increased adaptability for better survival. Moreover, recombinant pharmaceuticals are now being used confidently and rapidly attaining commercial approvals. Techniques of recombinant DNA technology, gene therapy, and genetic modifications are also widely used for the purpose of bioremediation and treating serious diseases. Due to tremendous advancement and broad range of application in the field of recombinant DNA technology, this review article mainly focuses on its importance and the possible applications in daily life. PMID:28053975
Patro, Sunita; Maiti, Soumitra; Panda, Santosh Kumar; Dey, Nrisingha
2015-04-01
We describe the use of plant-made β-defensins as effective antimicrobial substances for controlling salmonellosis, a deadly infection caused by Salmonella typhimurium (referred to further as S. typhi). Human β-defensin-1 (hBD-1) and -2 (hBD-2) were expressed under the control of strong constitutive promoters in tobacco plants, and bio-active β-defensins were successfully extracted. In the in vitro studies, enriched recombinant plant-derived human β-defensin-1 (phBD-1) and -2 (phBD-2) obtained from both T1 and T2 transgenic plants showed significant antimicrobial activity against Escherichia coli and S. typhi when used individually and in various combinations. The 2:1 peptide combination of phBD-1:phBD-2 with peptides isolated from T1-and T2-generation plants reduced the growth of S. typhi by 96 and 85 %, respectively. In vivo studies employing the mouse model (Balb/c) of Salmonella infection clearly demonstrated that the administration of plant-derived defensins individually and in different combinations enhanced the mean survival time of Salmonella-infected animals. When treatment consisted of the 2:1 phBD-1:phBD-2 combination, approximately 50 % of the infected mice were still alive at 206 h post-inoculation; the lowest number of viable S. typhi was observed in the liver and spleen of infected animals. We conclude that plant-made recombinant β-defensins (phBD-1 and phBD-2) are promising antimicrobial substances and have the potential to become additional tools against salmonellosis, particularly when used in combination.
Saavedra, Soledad L; Martínez Ceron, María C; Giudicessi, Silvana L; Forno, Guillermina; Bosco, María Belén; Marani, Mariela M; Erra-Balsells, Rosa; Albericio, Fernando; Cascone, Osvaldo; Camperi, Silvia A
2018-04-25
Recombinant human growth hormone (rhGH) is used for the treatment of several pathologies, most of them related to growth. Although different expression systems can be used for its production, the milk from transgenic cows is one of the most interesting due to the high rhGH level achieved (5 g/L). We have designed and synthesized short peptides (9 or 10 amino acid long) using Fmoc chemistry and studied their ability to purify rhGH from milk once immobilized on an agarose support. Using spiked milk with the hormone as a sample, rhGH was purified with 88% yield and 92% purity in a single step with a fold purification of 4.5. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018. © 2018 American Institute of Chemical Engineers.
2010-01-01
Background Baculovirus comprise the largest group of insect viruses most studied worldwide, mainly because they efficiently kill agricutural insect pests. In this study, two recombinant baculoviruses containing the ScathL gene from Sarcophaga peregrina (vSynScathL), and the Keratinase gene from the fungus Aspergillus fumigatus (vSynKerat), were constructed. and their insecticidal properties analysed against Spodoptera frugiperda larvae. Results Bioassays of third-instar and neonate S. frugiperda larvae with vSynScathL and vSynKerat showed a decrease in the time needed to kill the infected insects when compared to the wild type virus. We have also shown that both recombinants were able to increase phenoloxidase activity in the hemolymph of S. frugiperda larvae. The expression of proteases in infected larvae resulted in destruction of internal tissues late in infection, which could be the reason for the increased viral speed of kill. Conclusions Baculoviruses and their recombinant forms constitute viable alternatives to chemical insecticides. Recombinant baculoviruses containing protease genes can be added to the list of engineered baculoviruses with great potential to be used in integrated pest management programs. PMID:20587066
Arita, Minetaro; Zhu, Shuang-Li; Yoshida, Hiromu; Yoneyama, Tetsuo; Miyamura, Tatsuo; Shimizu, Hiroyuki
2005-01-01
Outbreaks of poliomyelitis caused by circulating vaccine-derived polioviruses (cVDPVs) have been reported in areas where indigenous wild polioviruses (PVs) were eliminated by vaccination. Most of these cVDPVs contained unidentified sequences in the nonstructural protein coding region which were considered to be derived from human enterovirus species C (HEV-C) by recombination. In this study, we report isolation of a Sabin 3-derived PV recombinant (Cambodia-02) from an acute flaccid paralysis (AFP) case in Cambodia in 2002. We attempted to identify the putative recombination counterpart of Cambodia-02 by sequence analysis of nonpolio enterovirus isolates from AFP cases in Cambodia from 1999 to 2003. Based on the previously estimated evolution rates of PVs, the recombination event resulting in Cambodia-02 was estimated to have occurred within 6 months after the administration of oral PV vaccine (99.3% nucleotide identity in VP1 region). The 2BC and the 3Dpol coding regions of Cambodia-02 were grouped into the genetic cluster of indigenous coxsackie A virus type 17 (CAV17) (the highest [87.1%] nucleotide identity) and the cluster of indigenous CAV13-CAV18 (the highest [94.9%] nucleotide identity) by the phylogenic analysis of the HEV-C isolates in 2002, respectively. CAV13-CAV18 and CAV17 were the dominant HEV-C serotypes in 2002 but not in 2001 and in 2003. We found a putative recombination between CAV13-CAV18 and CAV17 in the 3CDpro coding region of a CAV17 isolate. These results suggested that a part of the 3Dpol coding region of PV3(Cambodia-02) was derived from a HEV-C strain genetically related to indigenous CAV13-CAV18 strains in 2002 in Cambodia. PMID:16188967
Yuan, X L; Li, Y; Pan, X H; Zhou, M; Gao, Q Y; Li, M C
2016-01-01
Interleukin (IL)-38 is the latest member of the IL-1 cytokine family. However, as a result of lacking efficient method to generate relatively large quantity of IL-38, its precise functions are poorly understood. In the present study, the cloning, expression, purification, and activity analysis of recombinant human IL-38 was described. Human IL-38 cDNA was cloned into the prokaryotic expression vector pET-44. The recombinant IL-38 containing a C-hexahistidine tag was expressed in Escherichia coli BL21 (DE3) which induced by isopropyl-β-D-thiogalactoside. The expressed fusion protein was purified by Ni-NTA affinity chromatography. IL-38 protein was largely found in the soluble fraction. The purified IL-38 appeared a single band on SDS-PAGE, the yield of IL-38 was 4 mg from 1 L of bacterial culture, and the purity was more than 98% with low endotoxin level (<0.1 EU/μg). Western blotting confirmed the identity of the purified protein. Activity analysis showed that IL-38 can inhibit effectively the expression of proinflammatory cytokines, such as tumor necrosis factor-α, IL-1β, IL-17, and monocyte chemoattractant protein-1 in lipopolysaccharide-activated THP-1 cells. The production and characterization of biologically active IL-38 will be beneficial for its potential role in clinical applications.
Asano, Ryutaro; Kawaguchi, Hiroko; Watanabe, Yasuhiro; Nakanishi, Takeshi; Umetsu, Mitsuo; Hayashi, Hiroki; Katayose, Yu; Unno, Michiaki; Kudo, Toshio; Kumagai, Izumi
2008-10-01
Recently, recombinant antibodies have been dissected into antigen-binding regions and rebuilt into multivalent high-avidity formats. These new structural designs are expected to improve in vivo pharmacokinetics and efficacy in clinical use. Here, we designed effective recombinant bispecific antibody (BsAb) formats based on hEx3, a humanized bispecific diabody with epidermal growth factor receptor and CD3 retargeting. The bispecific and bivalent IgG-like antibodies engineered from hEx3 (or its single-chain form, hEx3-scDb) and the human Fc region showed stronger binding to each target cell than did monovalent diabody formats, and their affinity was identical to that of the corresponding parent IgG. The bivalent effect of the constructed IgG-like BsAbs resulted in cell cytotoxicity 10 times that of monovalent diabodies, and further, the fusion of Fc portion contributed intense cytotoxicity in peripheral blood mononuclear cells by the induction of the antibody-dependent cellular cytotoxicity. The growth-inhibition effects of IgG-like BsAbs were superior to those of the approved therapeutic antibody cetuximab, which recognizes the same epidermal growth factor receptor antigen, even when peripheral blood mononuclear cells were used as effector cells. We thus demonstrated a critical improvement in the effect of hEx3 by the bottom-up construction of IgG-like BsAbs; in adoptive immunotherapy, monotherapy without supplemental molecules may be able to induce antibody-dependent cellular cytotoxicity.
Tanabe, Y; Dan, K; Kuriya, S; Nomura, T
1989-10-01
The effects of recombinant human interferon (IFN) alpha-2b and gamma on the bone marrow megakaryocyte progenitors (CFU-Meg) were compared between eight patients in the chronic phase of Ph1-positive chronic myelocytic leukemia (CML) and five hematologically normal patients. CFU-Meg was assayed in plasma clot culture added with phytohemagglutinin-stimulated leukocyte-conditioned medium as a source of colony stimulating activity. The average count of CFU-Meg colonies formed from the bone marrow of CML patients was 5.5 times that of normal controls. Spontaneous CFU-Meg colonies were grown in seven of eight CML patients, but in none of five controls. Colony formation by CFU-Meg in CML as well as normal bone marrow was suppressed by the two preparations of IFN in a dose dependent fashion. Their suppressive influence on colonies from CFU-Meg was comparable between CML and normal bone marrow at lower concentrations, but was less marked for CML than normal bone marrow at higher concentrations. The formation of CFU-Meg colonies from CML bone marrow was more severely suppressed by IFN-gamma than IFN-alpha-2b. Depletion of either T lymphocytes or adherent cells from the CML bone marrow cells diminished the suppressive effects of IFN-gamma, but had no influence on the effects of IFN-alpha-2b.
Yang, Zhi-Kai; Luo, Hao; Zhang, Yanming; Wang, Baijing; Gao, Feng
2018-05-03
The budding yeast Saccharomyces cerevisiae is a model species powerful for studying the recombination of eukaryotes. Although many recombination studies have been performed for this species by experimental methods, the population genomic study based on bioinformatics analyses is urgently needed to greatly increase the range and accuracy of recombination detection. Here, we carry out the population genomic analysis of recombination in S. cerevisiae to reveal the potential rules between recombination and evolution in eukaryotes. By population genomic analysis, we discover significantly more and longer recombination events in clinical strains, which indicates that adverse environmental conditions create an obviously wider range of genetic combination in response to the selective pressure. Based on the analysis of recombinational DSBs-intersected genes (RDIGs), we find that RDIGs significantly converge on specific disease- and adaptability-related pathways, indicating that recombination plays a biologically key role in the repair of DSBs related to diseases and environmental adaptability, especially the human neurological disorders (NDs). By evolutionary analysis of RDIGs, we find that the RDIGs highly prevailing in populations of yeast tend to be more evolutionarily conserved, indicating the accurate repair of DSBs in these RDIGs is critical to ensure the eukaryotic survival or fitness. fgao@tju.edu.cn. Supplementary data are available at Bioinformatics online.
The kinetochore prevents centromere-proximal crossover recombination during meiosis
Vincenten, Nadine; Kuhl, Lisa-Marie; Lam, Isabel; Oke, Ashwini; Kerr, Alastair RW; Hochwagen, Andreas; Fung, Jennifer; Keeney, Scott; Vader, Gerben; Marston, Adèle L
2015-01-01
During meiosis, crossover recombination is essential to link homologous chromosomes and drive faithful chromosome segregation. Crossover recombination is non-random across the genome, and centromere-proximal crossovers are associated with an increased risk of aneuploidy, including Trisomy 21 in humans. Here, we identify the conserved Ctf19/CCAN kinetochore sub-complex as a major factor that minimizes potentially deleterious centromere-proximal crossovers in budding yeast. We uncover multi-layered suppression of pericentromeric recombination by the Ctf19 complex, operating across distinct chromosomal distances. The Ctf19 complex prevents meiotic DNA break formation, the initiating event of recombination, proximal to the centromere. The Ctf19 complex independently drives the enrichment of cohesin throughout the broader pericentromere to suppress crossovers, but not DNA breaks. This non-canonical role of the kinetochore in defining a chromosome domain that is refractory to crossovers adds a new layer of functionality by which the kinetochore prevents the incidence of chromosome segregation errors that generate aneuploid gametes. DOI: http://dx.doi.org/10.7554/eLife.10850.001 PMID:26653857
Wang, Furong; Wu, Min; Liu, Wenhui; Shen, Qi; Sun, Hongying; Chen, Shuqing
2013-01-01
Human growth hormone (hGH) can mobilize lipid and inhibit the synthesis of triglycerides. However, it is not a potentially useful drug for treating obesity because it has many other actions resulting in several side effects. Here, we report a novel approach to develop the lipolytic function of hGH. The amino terminus of hGH was replaced by an inactive protein so that the actions unrelated to lipolytic function would be avoided. The fusion genes encoding human serum albumin (HSA) and lipolytic domain of hGH were constructed and expressed in Pichia pastoris. The recombinant proteins were purified and characterized by SDS-PAGE and Western blot. The preliminary stability tests demonstrated that HSA-hGH166-191 and HSA-hGH177-191 were stable at different pH levels after four days at 37°C. Lipolytic activity assay revealed that fusion proteins could increase the amounts of glycerol released from the isolated adipocytes. The HSA fusion proteins constructed in this work can be further developed as antiobesity agents. © 2013 International Union of Biochemistry and Molecular Biology, Inc.
Ethanol precipitation for purification of recombinant antibodies.
Tscheliessnig, Anne; Satzer, Peter; Hammerschmidt, Nikolaus; Schulz, Henk; Helk, Bernhard; Jungbauer, Alois
2014-10-20
Currently, the golden standard for the purification of recombinant humanized antibodies (rhAbs) from CHO cell culture is protein A chromatography. However, due to increasing rhAbs titers alternative methods have come into focus. A new strategy for purification of recombinant human antibodies from CHO cell culture supernatant based on cold ethanol precipitation (CEP) and CaCl2 precipitation has been developed. This method is based on the cold ethanol precipitation, the process used for purification of antibodies and other components from blood plasma. We proof the applicability of the developed process for four different antibodies resulting in similar yield and purity as a protein A chromatography based process. This process can be further improved using an anion-exchange chromatography in flowthrough mode e.g. a monolith as last step so that residual host cell protein is reduced to a minimum. Beside the ethanol based process, our data also suggest that ethanol could be replaced with methanol or isopropanol. The process is suited for continuous operation. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.
Fine-scale variation in meiotic recombination in Mimulus inferred from population shotgun sequencing
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hellsten, Uffe; Wright, Kevin M.; Jenkins, Jerry
2013-11-13
Meiotic recombination rates can vary widely across genomes, with hotspots of intense activity interspersed among cold regions. In yeast, hotspots tend to occur in promoter regions of genes, whereas in humans and mice hotspots are largely defined by binding sites of the PRDM9 protein. To investigate the detailed recombination pattern in a flowering plant we use shotgun resequencing of a wild population of the monkeyflower Mimulus guttatus to precisely locate over 400,000 boundaries of historic crossovers or gene conversion tracts. Their distribution defines some 13,000 hotspots of varying strengths, interspersed with cold regions of undetectably low recombination. Average recombination ratesmore » peak near starts of genes and fall off sharply, exhibiting polarity. Within genes, recombination tracts are more likely to terminate in exons than in introns. The general pattern is similar to that observed in yeast, as well as in PRDM9-knockout mice, suggesting that recombination initiation described here in Mimulus may reflect ancient and conserved eukaryotic mechanisms« less
Recent updates on recombinant human growth hormone outcomes and adverse events.
Watson, Sara E; Rogol, Alan D
2013-02-01
To provide up-to-date information on outcomes and adverse events associated with the use of recombinant human growth hormone (rhGH). We will focus on patients with Prader Willi Syndrome and Idiopathic Short Stature. We will also discuss recent reports on long-term adverse events from the European database. Prader Willi Syndrome is associated with hypogonadism, which does not appear to be affected by treatment with rhGH. However, there is new evidence that treatment may improve cognition. For patients with Idiopathic Short Stature, the gain in near adult height with treatment with rhGH appears to be 3-4 cm. Although a recent analysis of this group shows that certain patient characteristics may help identify those most likely to have a good response to treatment. Additionally, the safety and appropriateness of growth hormone treatments in Europe study released preliminary data from patients treated in two separate locations that showed conflicting information on risk of mortality from treatment with rhGH. Although we will continue to receive new information regarding the safety and effects of treatment with rhGH, it is important to discuss the risks and benefits with our patients. Additionally, it is incumbent on us to help guide the treatment to those most likely to benefit.
ERIC Educational Resources Information Center
Whitehouse, H. L. K.
1973-01-01
Discusses the mechanisms of genetic recombination with particular emphasis on the study of the fungus Sordaria brevicollis. The study of recombination is facilitated by the use of mutants of this fungus in which the color of the ascospores is affected. (JR)
Ohkuri, Takatoshi; Murase, Eri; Sun, Shu-Lan; Sugitani, Jun; Ueda, Tadashi
2013-10-01
A method was previously established for evaluating Asn deamidation by matrix-assisted laser desorption/ionization time of flight-mass spectrometry using endoproteinase Asp-N. In this study, we demonstrated that this method could be applied to the identification of the deamidation site of the humanized fragment antigen-binding (Fab). First, a system for expressing humanized Fab from methylotrophic yeast Pichia pastoris was constructed, resulting in the preparation of ∼30 mg of the purified humanized Fab from 1 l culture. Analysis of the L-chain derived from recombinant humanized Fab that was heated at pH 7 and 100°C for 1 h showed the deamidation at Asn138 in the constant region. Then, we prepared L-N138D Fab and L-N138A Fab and examined their properties. The circular dichroism (CD) spectrum of the L-N138D Fab was partially different from that of the wild-type Fab. The measurement of the thermostability showed that L-N138D caused a significant decrease in the thermostability of Fab. On the other hand, the CD spectrum and thermostability of L-N138A Fab showed the same behaviour as the wild-type Fab. Thus, it was suggested that the introduction of a negative charge at position 138 in the L-chain by the deamidation significantly affected the stability of humanized Fab.
Turki, Imène; Hammami, Akil; Kharmachi, Habib; Mousli, Mohamed
2014-02-01
Human and equine rabies immunoglobulins are currently available for passive immunization against rabies. However, these are hampered by the limited supply and some drawbacks. Advances in antibody engineering have led to overcome issues of clinical applications and to improve the protective efficacy. In the present study, we report the generation of a trivalent single-chain Fv (scFv50AD1-Fd), that recognizes the rabies virus glycoprotein, genetically fused to the trimerization domain of the bacteriophage T4 fibritin, termed 'foldon' (Fd). scFv50AD1-Fd was expressed as soluble recombinant protein in bacterial periplasmic space and purified through affinity chromatography. The molecular integrity and stability were analyzed by polyacrylamide gradient-gel electrophoresis, size-exclusion chromatography and incubation in human sera. The antigen-binding properties of the trimeric scFv were analyzed by direct and competitive-ELISA. Its apparent affinity constant was estimated at 1.4 ± 0.25 × 10(9)M(-1) and was 75-fold higher than its monovalent scFv (1.9 ± 0.68 × 10(7)M(-1)). The scFv50AD1-Fd neutralized rabies virus in a standard in vitro and in vivo neutralization assay. We showed a high neutralization activity up to 75-fold compared with monovalent format and the WHO standard serum. The gain in avidity resulting from multivalency along with an improved biological activity makes the trivalent scFv50AD1-Fd construct an important reagent for rabies protection. The antibody engineering approach presented here may serve as a strategy for designing a new generation of anti-rabies for passive immunotherapy. Copyright © 2013 Elsevier Ltd. All rights reserved.
Immunoglobulin class-switch recombination deficiencies.
Durandy, Anne; Kracker, Sven
2012-07-30
Immunoglobulin class-switch recombination deficiencies (Ig-CSR-Ds) are rare primary immunodeficiencies characterized by defective switched isotype (IgG/IgA/IgE) production. Depending on the molecular defect in question, the Ig-CSR-D may be combined with an impairment in somatic hypermutation (SHM). Some of the mechanisms underlying Ig-CSR and SHM have been described by studying natural mutants in humans. This approach has revealed that T cell-B cell interaction (resulting in CD40-mediated signaling), intrinsic B-cell mechanisms (activation-induced cytidine deaminase-induced DNA damage), and complex DNA repair machineries (including uracil-N-glycosylase and mismatch repair pathways) are all involved in class-switch recombination and SHM. However, several of the mechanisms required for full antibody maturation have yet to be defined. Elucidation of the molecular defects underlying the diverse set of Ig-CSR-Ds is essential for understanding Ig diversification and has prompted better definition of the clinical spectrum of diseases and the development of increasingly accurate diagnostic and therapeutic approaches.
Ezcurra, Diego; Humaidan, Peter
2014-10-03
Gonadotropins extracted from the urine of post-menopausal women have traditionally been used to stimulate folliculogenesis in the treatment of infertility and in assisted reproductive technology (ART). Products, such as human menopausal gonadotropin (hMG), consist not only of a mixture of the hormones, follicle-stimulating hormone (FSH), luteinising hormone (LH) and human chorionic gonadotropin (hCG), but also other biologically active contaminants, such as growth factors, binding proteins and prion proteins. The actual amount of molecular LH in hMG preparations varies considerably due to the purification process, thus hCG, mimicking LH action, is added to standardise the product. However, unlike LH, hCG plays a different role during the natural human menstrual cycle. It is secreted by the embryo and placenta, and its main role is to support implantation and pregnancy. More recently, recombinant gonadotropins (r-hFSH and r-hLH) have become available for ART therapies. Recombinant LH contains only LH molecules. In the field of reproduction there has been controversy in recent years over whether r-hLH or hCG should be used for ART. This review examines the existing evidence for molecular and functional differences between LH and hCG and assesses the clinical implications of hCG-supplemented urinary therapy compared with recombinant therapies used for ART.
Attenuating homologous recombination stimulates an AID-induced antileukemic effect
Lamont, Kristin R.; Hasham, Muneer G.; Donghia, Nina M.; Branca, Jane; Chavaree, Margaret; Chase, Betsy; Breggia, Anne; Hedlund, Jacquelyn; Emery, Ivette; Cavallo, Francesca; Jasin, Maria; Rüter, Jens
2013-01-01
Activation-induced cytidine deaminase (AID) is critical in normal B cells to initiate somatic hypermutation and immunoglobulin class switch recombination. Accumulating evidence suggests that AID is also prooncogenic, inducing cancer-promoting mutations or chromosome rearrangements. In this context, we find that AID is expressed in >40% of primary human chronic lymphocytic leukemia (CLL) cases, consistent with other reports. Using a combination of human B lymphoid leukemia cells and mouse models, we now show that AID expression can be harnessed for antileukemic effect, after inhibition of the RAD51 homologous recombination (HR) factor with 4,4′-diisothiocyanatostilbene-2-2′-disulfonic acid (DIDS). As a proof of principle, we show that DIDS treatment inhibits repair of AID-initiated DNA breaks, induces apoptosis, and promotes cytotoxicity preferentially in AID-expressing human CLL. This reveals a novel antineoplastic role of AID that can be triggered by inhibition of HR, suggesting a potential new paradigm to treat AID-expressing tumors. Given the growing list of tumor types with aberrant AID expression, this novel therapeutic approach has potential to impact a significant patient population. PMID:23589568
Pharmacological profiling of the TRPV3 channel in recombinant and native assays
Grubisha, Olivera; Mogg, Adrian J; Sorge, Jessica L; Ball, Laura-Jayne; Sanger, Helen; Ruble, Cara L A; Folly, Elizabeth A; Ursu, Daniel; Broad, Lisa M
2014-01-01
Background and Purpose Transient receptor potential vanilloid subtype 3 (TRPV3) is implicated in nociception and certain skin conditions. As such, it is an attractive target for pharmaceutical research. Understanding of endogenous TRPV3 function and pharmacology remains elusive as selective compounds and native preparations utilizing higher throughput methodologies are lacking. In this study, we developed medium-throughput recombinant and native cellular assays to assess the detailed pharmacological profile of human, rat and mouse TRPV3 channels. Experimental Approach Medium-throughput cellular assays were developed using a Ca2+-sensitive dye and a fluorescent imaging plate reader. Human and rat TRPV3 pharmacology was examined in recombinant cell lines, while the mouse 308 keratinocyte cell line was used to assess endogenous TRPV3 activity. Key Results A recombinant rat TRPV3 cellular assay was successfully developed after solving a discrepancy in the published rat TRPV3 protein sequence. A medium-throughput, native, mouse TRPV3 keratinocyte assay was also developed and confirmed using genetic approaches. Whereas the recombinant human and rat TRPV3 assays exhibited similar agonist and antagonist profiles, the native mouse assay showed important differences, namely, TRPV3 activity was detected only in the presence of potentiator or during agonist synergy. Furthermore, the native assay was more sensitive to block by some antagonists. Conclusions and Implications Our findings demonstrate similarities but also notable differences in TRPV3 pharmacology between recombinant and native systems. These findings offer insights into TRPV3 function and these assays should aid further research towards developing TRPV3 therapies. Linked Articles This article is part of a themed section on the pharmacology of TRP channels. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-10 PMID:23848361
Site-Specific N-Glycosylation of Recombinant Pentameric and Hexameric Human IgM
NASA Astrophysics Data System (ADS)
Moh, Edward S. X.; Lin, Chi-Hung; Thaysen-Andersen, Morten; Packer, Nicolle H.
2016-07-01
Glycosylation is known to play an important role in IgG antibody structure and function. Polymeric IgM, the largest known antibody in humans, displays five potential N-glycosylation sites on each heavy chain monomer. IgM can exist as a pentamer with a connecting singly N-glycosylated J-chain (with a total of 51 glycosylation sites) or as a hexamer (60 glycosylation sites). In this study, the N-glycosylation of recombinant pentameric and hexameric IgM produced by the same human cell type and culture conditions was site-specifically profiled by RP-LC-CID/ETD-MS/MS using HILIC-enriched tryptic and GluC glycopeptides. The occupancy of all putative N-glycosylation sites on the pentameric and hexameric IgM were able to be determined. Distinct glycosylation differences were observed between each of the five N-linked sites on the IgM heavy chains. While Asn171, Asn332, and Asn395 all had predominantly complex type glycans, differences in glycan branching and sialylation were observed between the sites. Asn563, a high mannose-rich glycosylation site that locates in the center of the IgM polymer, was only approximately 60% occupied in both the pentameric and hexameric IgM forms, with a difference in relative abundance of the glycan structures between the pentamer and hexamer. This study highlights the information obtained by characterization of the site-heterogeneity of a highly glycosylated protein of high molecular mass with quaternary structure, revealing differences that would not be seen by global glycan or deglycosylated peptide profiling.
Nishiyama, U; Kuwaki, T; Akahori, H; Kato, T; Ikeda, Y; Miyazaki, H
2005-02-01
Previous in vitro studies demonstrated that thrombopoietin (TPO) acts on platelets to activate a variety of intracellular signaling pathways and to enhance platelet sensitivity to multiple agonists. Little is known, however, about whether TPO exerts prothrombotic effects in vivo. The aim of this study was to examine the effects of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF), a pegylated N-terminal domain of human TPO, in a rat model of venous thrombosis. A microthrombus was photochemically induced on the vessel wall of a mesenteric venule, but the vessel was not occluded by it. A single intravenous injection of PEG-rHuMGDF (3 microg kg(-1)) after the thrombus generation into normal rats enhanced the thrombus size, resulting in transient thrombotic occlusion in the majority of rats. Stimulatory effects on thrombus growth were also observed following administration of glycosylated recombinant human full-length TPO (6 microg kg(-1)). In rats rendered thrombocytopenic by total body irradiation, however, PEG-rHuMGDF, even at 300 microg kg(-1), did not induce a significant increase in thrombus size or thrombotic occlusion. Platelets from thrombocytopenic rats had decreased surface levels of c-Mpl and decreased sensitivity to PEG-rHuMGDF in an in vitro aggregation response. Thus, decreased prothrombotic effects of PEG-rHuMGDF in thrombocytopenic rats might be the result not only of low platelet counts but also of decreased platelet reactivity to PEG-rHuMGDF. These results indicate that PEG-rHuMGDF has little effect on venous thrombus formation in thrombocytopenic states associated with high endogenous TPO levels.
Iron Oxidation and Core Formation in Recombinant Heteropolymeric Human Ferritins.
Mehlenbacher, Matthew; Poli, Maura; Arosio, Paolo; Santambrogio, Paolo; Levi, Sonia; Chasteen, N Dennis; Bou-Abdallah, Fadi
2017-08-01
In animals, the iron storage and detoxification protein, ferritin, is composed of two functionally and genetically distinct subunit types, H (heavy) and L (light), which co-assemble in various ratios with tissue specific distributions to form shell-like protein structures of 24 subunits within which a mineralized iron core is stored. The H-subunit possesses a ferroxidase center (FC) that catalyzes Fe(II) oxidation, whereas the L-subunit does not. To assess the role of the L-subunit in iron oxidation and core formation, two human recombinant heteropolymeric ferritins, designated H-rich and L-rich with ratios of ∼20H:4L and ∼22L:2H, respectively, were employed and compared to the human homopolymeric H-subunit ferritin (HuHF). These heteropolymeric ferritins have a composition similar to the composition of those found in hearts and brains (i.e., H-rich) and in livers and spleens (i.e., L-rich). As for HuHF, iron oxidation in H-rich ferritin was found to proceed with a 2:1 Fe(II):O 2 stoichiometry at an iron level of 2 Fe(II) atoms/H-subunit with the generation of H 2 O 2 . The H 2 O 2 reacted with additional Fe(II) in a 2:1 Fe(II):H 2 O 2 ratio, thus avoiding the production of hydroxyl radical. A μ-1,2-peroxo-diFe(III) intermediate was observed at the FC of H-rich ferritin as for HuHF. Importantly, the H-rich protein regenerated full ferroxidase activity more rapidly than HuHF did and additionally formed larger iron cores, indicating dual roles for the L-subunit in facilitating iron turnover at the FC and in mineralization of the core. The L-rich ferritin, while also facilitating iron oxidation at the FC, additionally promoted oxidation at the mineral surface once the iron binding capacity of the FC was exceeded.
p53: traffic cop at the crossroads of DNA repair and recombination.
Sengupta, Sagar; Harris, Curtis C
2005-01-01
p53 mutants that lack DNA-binding activities, and therefore, transcriptional activities, are among the most common mutations in human cancer. Recently, a new role for p53 has come to light, as the tumour suppressor also functions in DNA repair and recombination. In cooperation with its function in transcription, the transcription-independent roles of p53 contribute to the control and efficiency of DNA repair and recombination.
Yun, Ye-Rang; Kim, Hae-Won; Kang, Wonmo; Jeon, Eunyi; Lee, Sujin; Lee, Hye-Young; Kim, Cheol-Hwan; Jang, Jun-Hyeog
2012-05-01
Dentin sialoprotein (DSP) is cleaved from dentin sialophosphoprotein (DSPP) and most abundant dentinal non-collagenous proteins in dentin. DSP is believed to participate in differentiation and mineralization of cells. In this study, we first constructed recombinant human DSP (rhDSP) in Escherichia coli (E. coli) and investigated its odontoblastic differentiation effects on human dental pulp cells (hDPCs). Cell adhesion activity was measured by crystal violet assay and cell proliferation activity was measured by MTT assay. To assess mineralization activity of rhDSP, Alizarin Red S staining was performed. In addition, the mRNA levels of collagen type І (Col І), alkaline phosphatase (ALP), and osteocalcin (OCN) were measured due to their use as mineralization markers for odontoblast-/osteoblast-like differentiation of hDPCs. The obtained rhDSP in E. coli was approximately identified by SDS-PAGE and Western blot. Initially, rhDSP significantly enhanced hDPCs adhesion activity and proliferation (p<0.05). In Alizarin Red S staining, stained hDPCs increased in a time-dependent manner. This odontoblastic differentiation activity was also verified through mRNA levels of odontoblast-related markers. Here, we first demonstrated that rhDSP may be an important regulatory ECM in determining the hDPCs fate including cell adhesion, proliferation, and odontoblastic differentiation activity. These findings indicate that rhDSP can induce growth and differentiation on hDPCs, leading to improve tooth repair and regeneration. Copyright © 2012 Elsevier Inc. All rights reserved.
Wang, Yuhang; Ding, Fangrong; Wang, Tao; Liu, Wenjie; Lindquist, Susanne; Hernell, Olle; Wang, Jianwu; Li, Jing; Li, Ling; Zhao, Yaofeng; Dai, Yunping; Li, Ning
2017-01-01
Bile salt-stimulated lipase (BSSL) is a lipolytic digestive enzyme with broad substrate specificity secreted from exocrine pancreas into the intestinal lumen in all species and from the lactating mammary gland into the milk of some species, notably humans but not cows. BSSL in breast milk facilitates digestion and absorption of milk fat and promotes growth of small for gestational age preterm infants. Thus, purified recombinant human BSSL (rhBSSL) can be used for treatment of patients with fat malabsorption and expressing rhBSSL in the milk of transgenic cloned cows would therefore be a mean to meet a medical need. In the present study, a vector pBAC-hLF-hBSSL was constructed, which efficiently expressed active rhBSSL in milk of transgenic cloned cows to a concentration of 9.8 mg/ml. The rhBSSL purified from cow milk had the same enzymatic activity, N-terminal amino acid sequence, amino acid composition and isoelectric point and similar physicochemical characteristics as human native BSSL. Our study supports the use of transgenic cattle for the cost-competitive, large-scale production of therapeutic rhBSSL.
Ding, Fangrong; Wang, Tao; Liu, Wenjie; Lindquist, Susanne; Hernell, Olle; Wang, Jianwu; Li, Jing; Li, Ling; Zhao, Yaofeng; Dai, Yunping; Li, Ning
2017-01-01
Bile salt-stimulated lipase (BSSL) is a lipolytic digestive enzyme with broad substrate specificity secreted from exocrine pancreas into the intestinal lumen in all species and from the lactating mammary gland into the milk of some species, notably humans but not cows. BSSL in breast milk facilitates digestion and absorption of milk fat and promotes growth of small for gestational age preterm infants. Thus, purified recombinant human BSSL (rhBSSL) can be used for treatment of patients with fat malabsorption and expressing rhBSSL in the milk of transgenic cloned cows would therefore be a mean to meet a medical need. In the present study, a vector pBAC-hLF-hBSSL was constructed, which efficiently expressed active rhBSSL in milk of transgenic cloned cows to a concentration of 9.8 mg/ml. The rhBSSL purified from cow milk had the same enzymatic activity, N-terminal amino acid sequence, amino acid composition and isoelectric point and similar physicochemical characteristics as human native BSSL. Our study supports the use of transgenic cattle for the cost-competitive, large-scale production of therapeutic rhBSSL. PMID:28475629
Aerosolized recombinant human DNase I for the treatment of cystic fibrosis.
Shak, S
1995-02-01
Respiratory symptoms, recurrent infectious exacerbations, and progressive lung destruction in cystic fibrosis can be attributed to bacterial persistence and the accumulation of viscous purulent secretions in the airways. Purulent secretions contain high concentrations of extracellular DNA, a viscous material released by leukocytes. To evaluate the potential clinical utility of recombinant human DNase I (rhDNase or Pulmozyme), the human enzyme was cloned, sequenced, and expressed. In in vitro studies, rhDNase has been shown to reduce the viscoelasticity, reduce the adhesiveness, and improve the mucociliary transportability of cystic fibrosis sputum. In short-term phase 1 and phase 2 clinical trials, rhDNase has been shown to be safely tolerated and to improve the FEV1, FVC, and symptoms of dyspnea. A long-term placebo-controlled phase 3 study was performed in 968 adults and children (> or = 5 years) with cystic fibrosis to determine the effect of rhDNase on the risk of respiratory exacerbations requiring parenteral antibiotics and on the FEV1. Compared with placebo-treated patients, patients treated with rhDNase once daily or twice daily experienced a reduced risk of respiratory exacerbations by 28% (p = 0.04) and 37% (p = 0.01), respectively, and had a mean improvement in FEV1 of 5.8% (p < 0.01) and 5.6% (p < 0.01), respectively. Compared with placebo-treated patients, patients treated with rhDNase spent 2.7 fewer days receiving parenteral antibiotics (p = 0.04) and spent 1.3 fewer days in the hospital (p = 0.06) over the 6-month treatment period. Inhalation of rhDNase did not cause anaphylaxis but was associated with upper airway symptoms (ie, voice alteration, hoarseness, pharyngitis) that were generally mild and transient. In conclusion, aerosol administration of rhDNase was safely tolerated, reduced the risk of infectious exacerbations requiring parenteral antibiotics, and improved pulmonary function and patient well-being.
Zhang, Yong; Zhang, Fan; Zhu, Shuangli; Chen, Li; Yan, Dongmei; Wang, Dongyan; Tang, Ruiyan; Zhu, Hui; Hou, Xiaohui; An, Hongqiu; Zhang, Hong; Xu, Wenbo
2010-02-01
A type 2 vaccine-related poliovirus (strain CHN3024), differing from the Sabin 2 strain by 0.44% in the VP1 coding region was isolated from a patient with vaccine-associated paralytic poliomyelitis. Sequences downstream of nucleotide position 6735 (3D(pol) coding region) were derived from an unidentified sequence; no close match for a potential parent was found, but it could be classified into a non-polio human enteroviruses species C (HEV-C) phylogeny. The virus differed antigenically from the parental Sabin strain, having an amino acid substitution in the neutralizing antigenic site 1. The similarity between CHN3024 and Sabin 2 sequences suggests that the recombination was recent; this is supported by the estimation that the initiating OPV dose was given only 36-75 days before sampling. The patient's clinical manifestations, intratypic differentiation examination, and whole-genome sequencing showed that this recombinant exhibited characteristics of neurovirulent vaccine-derived polioviruses (VDPV), which may, thus, pose a potential threat to a polio-free world.
Jourdier, T-M; Moste, C; Bonnet, M-C; Delisle, F; Tafani, J-P; Devauchelle, P; Tartaglia, J; Moingeon, P
2003-12-01
We tested the canarypox virus vector ALVAC and the genetically attenuated vaccinia virus vector NYVAC as vehicles for achieving local immunomodulation in domestic animals bearing spontaneous tumours. Following intratumoral administration of ALVAC-, or NYVAC-luciferase in dogs with melanoma, it was demonstrated that viral recombinants remained localized along the needle track, with no virus detectable in the periphery of the tumour. Given these distribution characteristics and their well-documented safety profile, ALVAC- or NYVAC-based recombinants expressing feline or human IL2, respectively, were administered to domestic cats, in order to prevent the recurrence of spontaneous fibrosarcomas. In the absence of immunotherapy, tumour recurrence was observed in 61% of animals within a 12-month follow-up period after treatment with surgery and iridium-based radiotherapy. In contrast, only 39 and 28% of cats receiving either NYVAC-human IL2 or ALVAC-feline IL2, respectively, exhibited tumour recurrences. Based on such results, and in the context of ongoing clinical studies conducted in humans, we discuss the utilization of ALVAC- or NYVAC-based recombinants as viable therapeutic modalities for local immunotherapy or therapeutic vaccination against cancer, both in humans and companion animals.
Evaluation of the Recombinant Protein TpF1 of Treponema pallidum for Serodiagnosis of Syphilis
Jiang, Chuanhao; Zhao, Feijun; Xiao, Jinhong; Zeng, Tiebing; Yu, Jian; Ma, Xiaohua; Wu, Haiying
2013-01-01
Syphilis is a chronic infection caused by Treponema pallidum subsp. pallidum, and diagnosis with sensitive and specific methods is a challenging process that is important for its prevention and treatment. In the present study, we established a recombinant protein TpF1-based indirect immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) and a Western blot assay for human and rabbit sera. The 20-kDa recombinant protein TpF1 was detected by Western blotting performed with sera from rabbits immunized with recombinant TpF1 and infected with the T. pallidum Nichols strain and T. pallidum clinical isolates but was not detected by Western blotting with sera from uninfected rabbits. The sensitivity of the recombinant protein was determined by screening sera from individuals with primary, secondary, latent, and congenital syphilis (n = 82). The specificity of the recombinant protein was determined by screening sera from uninfected controls (n = 30) and individuals with potentially cross-reactive infections, including Lyme disease (n = 30) and leptospirosis (n = 5). The sensitivities of TpF1-based ELISAs were 93.3%, 100%, 100%, and 100% for primary, secondary, latent, and congenital syphilis, respectively, and the specificities were all 100% for sera from uninfected controls and individuals with potentially cross-reactive infections. In Western blot assays, the sensitivities and specificities of TpF1 for human sera were all 100%. The reactivities of TpF1 with syphilitic sera were proportional to the titers of the T. pallidum particle agglutination (TPPA) assay. These data indicate that the recombinant protein TpF1 is a highly immunogenic protein in human and rabbit infections and a promising marker for the screening of syphilis. PMID:23945159
Chen, Xin Jie
2013-09-01
Homologous recombination is a universal process, conserved from bacteriophage to human, which is important for the repair of double-strand DNA breaks. Recombination in mitochondrial DNA (mtDNA) was documented more than 4 decades ago, but the underlying molecular mechanism has remained elusive. Recent studies have revealed the presence of a Rad52-type recombination system of bacteriophage origin in mitochondria, which operates by a single-strand annealing mechanism independent of the canonical RecA/Rad51-type recombinases. Increasing evidence supports the notion that, like in bacteriophages, mtDNA inheritance is a coordinated interplay between recombination, repair, and replication. These findings could have profound implications for understanding the mechanism of mtDNA inheritance and the generation of mtDNA deletions in aging cells.
2013-01-01
SUMMARY Homologous recombination is a universal process, conserved from bacteriophage to human, which is important for the repair of double-strand DNA breaks. Recombination in mitochondrial DNA (mtDNA) was documented more than 4 decades ago, but the underlying molecular mechanism has remained elusive. Recent studies have revealed the presence of a Rad52-type recombination system of bacteriophage origin in mitochondria, which operates by a single-strand annealing mechanism independent of the canonical RecA/Rad51-type recombinases. Increasing evidence supports the notion that, like in bacteriophages, mtDNA inheritance is a coordinated interplay between recombination, repair, and replication. These findings could have profound implications for understanding the mechanism of mtDNA inheritance and the generation of mtDNA deletions in aging cells. PMID:24006472
The Time Scale of Recombination Rate Evolution in Great Apes
Stevison, Laurie S.; Woerner, August E.; Kidd, Jeffrey M.; Kelley, Joanna L.; Veeramah, Krishna R.; McManus, Kimberly F.; Bustamante, Carlos D.; Hammer, Michael F.; Wall, Jeffrey D.
2016-01-01
Abstract We present three linkage-disequilibrium (LD)-based recombination maps generated using whole-genome sequence data from 10 Nigerian chimpanzees, 13 bonobos, and 15 western gorillas, collected as part of the Great Ape Genome Project (Prado-Martinez J, et al. 2013. Great ape genetic diversity and population history. Nature 499:471–475). We also identified species-specific recombination hotspots in each group using a modified LDhot framework, which greatly improves statistical power to detect hotspots at varying strengths. We show that fewer hotspots are shared among chimpanzee subspecies than within human populations, further narrowing the time scale of complete hotspot turnover. Further, using species-specific PRDM9 sequences to predict potential binding sites (PBS), we show higher predicted PRDM9 binding in recombination hotspots as compared to matched cold spot regions in multiple great ape species, including at least one chimpanzee subspecies. We found that correlations between broad-scale recombination rates decline more rapidly than nucleotide divergence between species. We also compared the skew of recombination rates at centromeres and telomeres between species and show a skew from chromosome means extending as far as 10–15 Mb from chromosome ends. Further, we examined broad-scale recombination rate changes near a translocation in gorillas and found minimal differences as compared to other great ape species perhaps because the coordinates relative to the chromosome ends were unaffected. Finally, on the basis of multiple linear regression analysis, we found that various correlates of recombination rate persist throughout the African great apes including repeats, diversity, and divergence. Our study is the first to analyze within- and between-species genome-wide recombination rate variation in several close relatives. PMID:26671457