scholarly journals Influence of Codon Bias on Heterologous Production of Human Papillomavirus Type 16 Major Structural Protein L1 in Yeast

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Milda Norkiene ◽  
Alma Gedvilaite
Keyword(s):  
Gene Expression ◽  
Human Papillomavirus ◽  
Codon Bias ◽  
Heterologous Gene Expression ◽  
Heterologous Production ◽  
Structural Protein ◽  
Hpv 16 ◽  
Major Structural Protein ◽  
Human Papillomavirus Type 16 ◽  
L1 Protein

Heterologous gene expression is dependent on multistep processes involving regulation at the level of transcription, mRNA turnover, protein translation, and posttranslational modifications. Codon bias has a significant influence on protein yields. However, sometimes it is not clear which parameter causes observed differences in heterologous gene expression as codon adaptation typically optimizes many sequence properties at once. In the current study, we evaluated the influence of codon bias on heterologous production of human papillomavirus type 16 (HPV-16) major structural protein L1 in yeast by expressing five variants of codon-modified open reading frames (OFRs) encoding HPV-16 L1 protein. Our results showed that despite the high toleration of various codons used throughout the length of the sequence of heterologously expressed genes in transformed yeast, there was a significant positive correlation between the gene's expression level and the degree of its codon bias towards the favorable codon usage. The HPV-16 L1 protein expression in yeast can be optimized by adjusting codon composition towards the most preferred codon adaptation, and this effect most probably is dependent on the improved translational elongation.

scholarly journals Polypyrimidine Tract Binding Protein Induces Human Papillomavirus Type 16 Late Gene Expression by Interfering with Splicing Inhibitory Elements at the Major Late 5′ Splice Site, SD3632

2008 ◽  
Vol 82 (7) ◽  
pp. 3665-3678 ◽  
Author(s):  
Monika Somberg ◽  
Xiaomin Zhao ◽  
Monika Fröhlich ◽  
Magnus Evander ◽  
Stefan Schwartz
Keyword(s):  
Gene Expression ◽  
Human Papillomavirus ◽  
Splice Site ◽  
Late Gene ◽  
Polypyrimidine Tract ◽  
Late Gene Expression ◽  
Hpv 16 ◽  
Human Papillomavirus Type 16 ◽  
Polypyrimidine Tract Binding Protein ◽  
Cellular Factors

ABSTRACT We have initiated a screen for cellular factors that can induce human papillomavirus type 16 (HPV-16) late gene expression in human cancer cells. We report that the overexpression of polypyrimidine tract binding protein (PTB), also known as heterologous nuclear ribonucleoprotein I (hnRNP I), induces HPV-16 late gene expression in cells transfected with subgenomic HPV-16 plasmids or with full-length HPV-16 genomes and in persistently HPV-16-infected cells. In contrast, other hnRNPs such as hnRNP B1/A2, hnRNP F, and hnRNP Q do not induce HPV-16 late gene expression. PTB activates SD3632, the only 5′ splice site on the HPV-16 genome that is used exclusively by late mRNAs. PTB interferes with splicing inhibitory sequences located immediately upstream and downstream of SD3632, thereby activating late gene expression. One AU-rich PTB-responsive element was mapped to a 198-nucleotide sequence located downstream of SD3632. The deletion of this element induced HPV-16 late gene expression in the absence of PTB. Our results suggest that the overexpression of PTB interferes with cellular factors that interact with the inhibitory sequences. One may speculate that an increase in PTB levels or a reduction in the concentration of a PTB antagonist is required for the activation of HPV-16 late gene expression during the viral life cycle.

scholarly journals Production of Human Papillomavirus Type 16 L1 Virus-Like Particles by Recombinant Lactobacillus casei Cells

2006 ◽  
Vol 72 (1) ◽  
pp. 745-752 ◽  
Author(s):  
Karina Araujo Aires ◽  
Aurora Marques Cianciarullo ◽  
Sylvia Mendes Carneiro ◽  
Luisa Lina Villa ◽  
Enrique Boccardo ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Lactobacillus Casei ◽  
Enzyme Linked Immunosorbent Assay ◽  
Hpv 16 ◽  
Virus Like Particles ◽  
Human Papillomavirus Type 16 ◽  
Common Causes ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
L1 Protein

ABSTRACT Infections with human papillomavirus type 16 (HPV-16) are closely associated with the development of human cervical carcinoma, which is one of the most common causes of cancer death in women worldwide. At present, the most promising vaccine against HPV-16 infection is based on the L1 major capsid protein, which self-assembles in virus-like particles (VLPs). In this work, we used a lactose-inducible system based on the Lactobacillus casei lactose operon promoter (plac) for expression of the HPV-16 L1 protein in L. casei. Expression was confirmed by Western blotting, and an electron microscopy analysis of L. casei expressing L1 showed that the protein was able to self-assemble into VLPs intracellularly. The presence of conformational epitopes on the L. casei-produced VLPs was confirmed by immunofluorescence using the anti-HPV-16 VLP conformational antibody H16.V5. Moreover, sera from mice that were subcutaneously immunized with L. casei expressing L1 reacted with Spodoptera frugiperda-produced HPV-16 L1 VLPs, as determined by an enzyme-linked immunosorbent assay. The production of L1 VLPs by Lactobacillus opens the possibility for development of new live mucosal prophylactic vaccines.

scholarly journals A Downstream Polyadenylation Element in Human Papillomavirus Type 16 L2 Encodes Multiple GGG Motifs and Interacts with hnRNP H

2005 ◽  
Vol 79 (14) ◽  
pp. 9254-9269 ◽  
Author(s):  
Daniel Öberg ◽  
Joanna Fay ◽  
Helen Lambkin ◽  
Stefan Schwartz
Keyword(s):  
Gene Expression ◽  
Human Papillomavirus ◽  
Polyadenylation Signal ◽  
Late Gene ◽  
Coding Region ◽  
Late Gene Expression ◽  
Hpv 16 ◽  
Virus Particles ◽  
Human Papillomavirus Type 16 ◽  
L1 And L2

ABSTRACT Production of human papillomavirus type 16 (HPV-16) virus particles is totally dependent on the differentiation-dependent induction of viral L1 and L2 late gene expression. The early polyadenylation signal in HPV-16 plays a major role in the switch from the early to the late, productive stage of the viral life cycle. Here, we show that the L2 coding region of HPV-16 contains RNA elements that are necessary for polyadenylation at the early polyadenylation signal. Consecutive mutations in six GGG motifs located 174 nucleotides downstream of the polyadenylation signal resulted in a gradual decrease in polyadenylation at the early polyadenylation signal. This caused read-through into the late region, followed by production of the late mRNAs encoding L1 and L2. Binding of hnRNP H to the various triple-G mutants correlated with functional activity of the HPV-16 early polyadenylation signal. In addition, the polyadenylation factor CStF-64 was also found to interact specifically with the region in L2 located 174 nucleotides downstream of the early polyadenylation signal. Staining of cervix epithelium with anti-hnRNP H-specific antiserum revealed high expression levels of hnRNP H in the lower layers of cervical epithelium and a loss of hnRNP H production in the superficial layers, supporting a model in which a differentiation-dependent down regulation of hnRNP H causes a decrease in HPV-16 early polyadenylation and an induction of late gene expression.

Genetic variability in the major capsid L1 protein of human papillomavirus type 16 (HPV-16) and 18 (HPV-18)

2011 ◽  
Vol 11 (8) ◽  
pp. 2119-2124 ◽  
Author(s):  
E. Frati ◽  
S. Bianchi ◽  
D. Colzani ◽  
A. Zappa ◽  
G. Orlando ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Genetic Variability ◽  
Hpv 16 ◽  
Human Papillomavirus Type 16 ◽  
L1 Protein ◽  
Hpv 18

scholarly journals A Splicing Enhancer in the E4 Coding Region of Human Papillomavirus Type 16 Is Required for Early mRNA Splicing and Polyadenylation as Well as Inhibition of Premature Late Gene Expression

2005 ◽  
Vol 79 (18) ◽  
pp. 12002-12015 ◽  
Author(s):  
Margaret Rush ◽  
Xiaomin Zhao ◽  
Stefan Schwartz
Keyword(s):  
Gene Expression ◽  
Human Papillomavirus ◽  
Splice Site ◽  
Late Gene ◽  
Coding Region ◽  
Late Gene Expression ◽  
Hpv 16 ◽  
Human Papillomavirus Type 16 ◽  
Early Region ◽  
Splicing Enhancer

ABSTRACT Successful inhibition of human papillomavirus type 16 (HPV-16) late gene expression early in the life cycle is essential for persistence of infection, the highest risk factor for cervical cancer. Our study aimed to locate regulatory RNA elements in the early region of HPV-16 that influence late gene expression. For this purpose, subgenomic HPV-16 expression plasmids under control of the strong human cytomegalovirus immediate early promoter were used. An exonic splicing enhancer that firmly supported the use of the E4 3′ splice site at position 3358 in the early region of the HPV-16 genome was identified. The enhancer was mapped to a 65-nucleotide AC-rich sequence located approximately 100 nucleotides downstream of the position 3358 3′ splice site. Deletion of the enhancer caused loss of both splicing at the upstream position 3358 3′ splice site and polyadenylation at the early polyadenylation signal, pAE. Direct splicing occurred at the competing L1 3′ splice site at position 5639 in the late region. Optimization of the position 3358 3′ splice site restored splicing to that site and polyadenylation at pAE. Additionally, a sequence of 40 nucleotides with a negative effect on late mRNA production was located immediately downstream of the enhancer. As the E4 3′ splice site is employed by both early and late mRNAs, the enhancer constitutes a key regulator of temporal HPV-16 gene expression, which is required for early mRNA production as well as for the inhibition of premature late gene expression.

scholarly journals Heterologous production of human papillomavirus type-16 L1 protein by a lactic acid bacterium

2009 ◽  
Vol 2 (1) ◽  
pp. 167 ◽  
Author(s):  
Naima G Cortes-Perez ◽  
Pascale Kharrat ◽  
Philippe Langella ◽  
Luis G Bermúdez-Humarán
Keyword(s):  
Lactic Acid ◽  
Human Papillomavirus ◽  
Lactic Acid Bacterium ◽  
Heterologous Production ◽  
Human Papillomavirus Type 16 ◽  
L1 Protein

Human Papillomavirus Type 16 Exists in Bacteria Isolated from Cervical Cancer Biopsies

2009 ◽  
Vol 37 (4) ◽  
pp. 1065-1074 ◽  
Author(s):  
Zhenghai Ma ◽  
Lihong Liu ◽  
Fuchun Zhang ◽  
Meng Yu ◽  
Kai Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cervical Cancer ◽  
Human Papillomavirus ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Hpv 16 ◽  
Human Papillomavirus Type 16 ◽  
Reverse Transcription Pcr ◽  
Bacterial Rna ◽  
L1 Protein

This study investigated the association between infectious microbes and persistent infection with human papillomavirus type 16 (HPV-16) in cervical cancer. Bacterial strains (identified as Enterococcus, Staphylococcus, Bacillus and Corynebacterium, based on their partial 16S rDNA sequence) were HPV-16 positive from 12 out of 14 cervical cancer biopsies. Total DNA was isolated from the four bacterial strains, and HPV-16 genes and genome were detected using polymerase chain reaction (PCR) and Southern blotting. RNA transcripts for HPV-16 E6 and L1 genes were detected in total bacterial RNA samples using reverse transcription-PCR, and HPV-16 L1 protein expression was detected in bacterial cells by Western blotting and immunocolloidal gold electron microscopy. The presence of virus particles in bacterial cells was demonstrated by transmission electron microscopy. The results suggest that bacteria carrying HPV-16 could provide a potential explanation for how infectious microbes contribute to the progression from HPV-16 infection to cervical cancer.

scholarly journals Nuclear Matrix Attachment Regions of Human Papillomavirus Type 16 Repress or Activate the E6 Promoter, Depending on the Physical State of the Viral DNA

2000 ◽  
Vol 74 (6) ◽  
pp. 2489-2501 ◽  
Author(s):  
Walter Stünkel ◽  
Zhonghui Huang ◽  
Shyh-Han Tan ◽  
Mark J. O'Connor ◽  
Hans-Ulrich Bernard
Keyword(s):  
Gene Expression ◽  
Human Papillomavirus ◽  
Reporter Gene ◽  
Hela Cells ◽  
Nuclear Matrix ◽  
Binding Sites ◽  
Matrix Attachment Regions ◽  
Hpv 16 ◽  
Human Papillomavirus Type 16 ◽  
E6 Gene

ABSTRACT Two nuclear matrix attachment regions (MARs) bracket a 550-bp segment of the long control region (LCR) containing the epithelial cell-specific enhancer and the E6 promoter of human papillomavirus type 16 (HPV-16). One of these MARs is located in the 5′ third of the LCR (5′-LCR-MAR); the other lies within the E6 gene (E6-MAR). To study their function, we linked these MARs in various natural or artificial permutations to a chimeric gene consisting of the HPV-16 enhancer-promoter segment and a reporter gene. In transient transfections of HeLa cells, the presence of either of these two MARs strongly represses reporter gene expression. In contrast to this, but similar to the published behavior of cellular MARs, reporter gene expression is stimulated strongly by the E6-MAR and moderately by the 5′-LCR-MAR in stable transfectants of HeLa or C33A cells. To search for binding sites of soluble nuclear proteins which may be responsible for repression during transient transfections, we performed electrophoretic mobility shift assays (EMSAs) of overlapping oligonucleotides that represented all sequences of these two MARs. Both MARs contain multiple sites for two strongly binding proteins and weak binding sites for additional factors. The strongest complex, with at least five binding sites in each MAR, is generated by the CCAAT displacement factor (CDP)/Cut, as judged by biochemical purification, by EMSAs with competing oligonucleotides and with anti-CDP/Cut oligonucleotides, and by mutations. CDP/Cut, a repressor that is down-regulated during differentiation, apparently represses HPV-16 transcription in undifferentiated epithelials cells and in HeLa cells, which are rich in CDP/Cut. In analogy to poorly understood mechanisms acting on cellular MARs, activation after physical linkage to chromosomal DNA may result from competition between the nuclear matrix and CDP/Cut. Our observations show that cis-responsive elements that regulate the HPV-16 E6 promoter are tightly clustered over at least 1.3 kb and occur throughout the E6 gene. HPV-16 MARs are context dependent transcriptional enhancers, and activated expression of HPV-16 oncogenes dependent on chromosomal integration may positively select tumorigenic cells during the multistep etiology of cervical cancer.

scholarly journals Nasal Immunization of Mice with Human Papillomavirus Type 16 (HPV-16) Virus-Like Particles or with the HPV-16 L1 Gene Elicits Specific Cytotoxic T Lymphocytes in Vaginal Draining Lymph Nodes

1999 ◽  
Vol 73 (11) ◽  
pp. 9063-9071 ◽  
Author(s):  
Catherine Dupuy ◽  
Dominique Buzoni-Gatel ◽  
Antoine Touzé ◽  
Daniel Bout ◽  
Pierre Coursaget
Keyword(s):  
T Cells ◽  
Human Papillomavirus ◽  
Immune Responses ◽  
Self Assembly ◽  
Genital Tract ◽  
Hpv 16 ◽  
Virus Like Particles ◽  
Mammalian Expression ◽  
Human Papillomavirus Type 16 ◽  
L1 Protein

ABSTRACT Human papillomavirus type 16 (HPV-16) infects the genital tract and is closely associated with the development of cervical cancer. HPV-16 initiates infection at the genital mucosal surface; thus, mucosal immune responses are likely to contribute to defense against HPV-16 infection. However, little information is available regarding the induction of immune responses in the genital tract mucosa. In this study, we evaluated the potential of intranasally administered papillomavirus vaccines to elicit both systemic and vaginal immune responses. HPV-16 virus-like particles (VLPs) produced by self-assembly of L1 protein and the HPV-16 L1 gene cloned into a mammalian expression vector were used as vaccines. Intranasally administered VLPs induced serum immunoglobulin G (IgG) and vaginal IgA secretory antibodies. Very weak serum IgG and vaginal IgA responses were found after DNA immunization. Both splenic and vaginal lymphocytes could be activated by intranasal immunization with VLPs and the HPV-16 L1 gene. Activated CD4+ Th1-like T cells were shown to synthesize gamma interferon, and activated CD8+ T cells were demonstrated to be cytotoxic.

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