http://www.gvt-journal.com The most accessed research articles published by Genetic Vaccines and Therapy 2012-01-30T00:00:00Z The complexity of parasitic infections requires novel approaches to vaccine design. The versatility of DNA vaccination provides new perspectives. This review discusses the use of prime-boost immunizations, genetic adjuvants, multivalent vaccines and codon optimization for optimal DNA vaccine design against parasites. http://www.gvt-journal.com/content/2/1/17 Catherine Ivory Kris Chadee Genetic Vaccines and Therapy 2004, null:17 2004-12-03T00:00:00Z doi:10.1186/1479-0556-2-17 /content/figures/1479-0556-2-17-toc.gif Genetic Vaccines and Therapy 1479-0556 ${item.volume} 17 2004-12-03T00:00:00Z XML Tattooing is one of a number of DNA delivery methods which results in an efficient expression of an introduced gene in the epidermal and dermal layers of the skin. The tattoo procedure causes many minor mechanical injuries followed by hemorrhage, necrosis, inflammation and regeneration of the skin and thus non-specifically stimulates the immune system. DNA vaccines delivered by tattooing have been shown to induce higher specific humoral and cellular immune responses than intramuscularly injected DNA. In this study, we focused on the comparison of DNA immunization protocols using different routes of administrations of DNA (intradermal tattoo versus intramuscular injection) and molecular adjuvants (cardiotoxin pre-treatment or GM-CSF DNA co-delivery). For this comparison we used the major capsid protein L1 of human papillomavirus type 16 as a model antigen. L1-specific immune responses were detected after three and four immunizations with 50 μg plasmid DNA. Cardiotoxin pretreatment or GM-CSF DNA co-delivery substantially enhanced the efficacy of DNA vaccine delivered intramuscularly by needle injection but had virtually no effect on the intradermal tattoo vaccination. The promoting effect of both adjuvants was more pronounced after three rather than four immunizations. However, three DNA tattoo immunizations without any adjuvant induced significantly higher L1-specific humoral immune responses than three or even four intramuscular DNA injections supported by molecular adjuvants. Tattooing also elicited significantly higher L1-specific cellular immune responses than intramuscularly delivered DNA in combination with adjuvants. In addition, the lymphocytes of mice treated with the tattoo device proliferated more strongly after mitogen stimulation suggesting the presence of inflammatory responses after tattooing. The tattoo delivery of DNA is a cost-effective method that may be used in laboratory conditions when more rapid and more robust immune responses are required. http://www.gvt-journal.com/content/6/1/4 Dana Pokorna Ivonne Rubio Martin Muller Genetic Vaccines and Therapy 2008, null:4 2008-02-07T00:00:00Z doi:10.1186/1479-0556-6-4 DNA tattoos boost vaccine delivery The tattoo delivery of DNA vaccines is cost effective, induces a greater immune response, and is a more efficient delivery strategy for laboratory studies than intramuscular injection. /content/figures/1479-0556-6-4-toc.gif Genetic Vaccines and Therapy 1479-0556 ${item.volume} 4 2008-02-07T00:00:00Z XML Background: Hepatitis C virus (HCV) is one of the leading causes of viral hepatitis worldwide and its genotype 3a is predominant in vast areas of Pakistan.FindingsThe present study reports the first full sequence of HCV 3a isolate PK-1 from Pakistan. This nucleotide sequence was compared with six other HCV genotype 3a full length sequences from different regions of the world by using statistical methods of phylogenetic analysis. Conclusion: The nucleotide difference of these seven sequences shows that HCV genotype 3a of phylogenetically distinct origin is circulating in Pakistan. http://www.gvt-journal.com/content/9/1/2 Irshad-ur Rehman Muhammad Idrees Muhammad Ali Liaqat Ali Sadia Butt Abrar Hussain Haji Akbar Samia Afzal Genetic Vaccines and Therapy 2011, null:2 2011-01-06T00:00:00Z doi:10.1186/1479-0556-9-2 /content/figures/1479-0556-9-2-toc.gif Genetic Vaccines and Therapy 1479-0556 ${item.volume} 2 2011-01-06T00:00:00Z XML DNA vaccination is a relatively recent development in vaccine methodology. It is now possible to undertake a rational step-by-step approach to DNA vaccine design. Strategies may include the incorporation of immunostimulatory sequences in the backbone of the plasmid, co-expression of stimulatory molecules, utilisation of localisation/secretory signals, and utilisation of the appropriate delivery system, for example. However, another important consideration is the utilisation of methods designed to optimise transgene expression. In this review we discuss the importance of regulatory elements, kozak sequences and codon optimisation in transgene expression. http://www.gvt-journal.com/content/1/1/2 Helen Garmory Katherine Brown Richard Titball Genetic Vaccines and Therapy 2003, null:2 2003-09-16T00:00:00Z doi:10.1186/1479-0556-1-2 DNA vaccines: improving expression of antigens. /content/figures/1479-0556-1-2-toc.gif Genetic Vaccines and Therapy 1479-0556 ${item.volume} 2 2003-09-16T00:00:00Z XML Solid tumours account for 90% of all cancers. Gene therapy represents a potential new modality for their treatment. Up to now, several approaches have been developed, but the most efficient ones are the viral vector based gene therapy systems. However, viral vectors suffer from several deficiencies: firstly most vectors currently in use require intratumoural injection to elicit an effect. This is far from ideal as many tumours are inaccessible and many may have already spread to other parts of the body, making them difficult to locate and inject gene therapy vectors into. Second, because of cell heterogeneity within a given cancer, the vectors do not efficiently enter and kill every cancer cell. Third, hypoxia, a prevalent characteristic feature of most solid tumours, reduces the ability of the viral vectors to function and decreases viral gene expression and production. Consequently, a proportion of the tumour is left unaffected, from which tumour regrowth occurs. Thus, cancer gene therapy has yet to realise its full potential.The facultative or obligate anaerobic bacteria have been shown to selectively colonise and regerminate in solid tumours when delivered systemically. Among them, the clostridial spores were easy to produce, stable to store and safe to use as well as having extensive oncolytic ability. However, research in animals and humans has shown that oncolysis was almost always interrupted sharply at the outer rim of the viable tumour tissue where the blood supply was sufficient. These clostridial spores, though, could serve as "Trojan horse" for cancer gene therapy. Indeed, various spores harbouring genes for cancerstatic factors, prodrug enzymes, or proteins or cytokines had endowed with additional tumour-killing capability. Furthermore, combination of these "Trojan horses" with conventional chemotherapy or radiation therapies often significantly perform better, resulting in the "cure" of solid tumours in a high percentage of animals.It is, thus, not too difficult to predict the potential outcomes for the use of clostridial spores as "Trojan horse" vectors for oncolytic therapy when compared with viral vector-mediated cancer therapy for it be replication-deficient or competent. However, to move the "Trojan horse" to a clinic, though, additional requirements need to be satisfied (i) target tumours only and not anywhere else, and (ii) be able to completely kill primary tumours as well as metastases. Current technologies are in place to achieve these goals. http://www.gvt-journal.com/content/6/1/8 Ming Wei Ruimei Ren David Good Jozef Anne Genetic Vaccines and Therapy 2008, null:8 2008-02-17T00:00:00Z doi:10.1186/1479-0556-6-8 /content/figures/1479-0556-6-8-toc.gif Genetic Vaccines and Therapy 1479-0556 ${item.volume} 8 2008-02-17T00:00:00Z XML Retroviral vector-mediated gene transfer has been central to the development of gene therapy. Retroviruses have several distinct advantages over other vectors, especially when permanent gene transfer is the preferred outcome. The most important advantage that retroviral vectors offer is their ability to transform their single stranded RNA genome into a double stranded DNA molecule that stably integrates into the target cell genome. This means that retroviral vectors can be used to permanently modify the host cell nuclear genome. Recently, retroviral vector-mediated gene transfer, as well as the broader gene therapy field, has been re-invigorated with the development of a new class of retroviral vectors which are derived from lentiviruses. These have the unique ability amongst retroviruses of being able to infect non-cycling cells. Vectors derived from lentiviruses have provided a quantum leap in technology and seemingly offer the means to achieve significant levels of gene transfer in vivo.The ability of retroviruses to integrate into the host cell chromosome also raises the possibility of insertional mutagenesis and oncogene activation. Both these phenomena are well known in the interactions of certain types of wild-type retroviruses with their hosts. However, until recently they had not been observed in replication defective retroviral vector-mediated gene transfer, either in animal models or in clinical trials. This has meant the potential disadvantages of retroviral mediated gene therapy have, until recently, been seen as largely, if not entirely, hypothetical. The recent clinical trial of γc mediated gene therapy for X-linked severe combined immunodeficiency (X-SCID) has proven the potential of retroviral mediated gene transfer for the treatment of inherited metabolic disease. However, it has also illustrated the potential dangers involved, with 2 out of 10 patients developing T cell leukemia as a consequence of the treatment. A considered review of retroviral induced pathogenesis suggests these events were qualitatively, if not quantitatively, predictable. In addition, it is clear that the probability of such events can be greatly reduced by relatively simple vector modifications, such as the use of self-inactivating vectors and vectors derived from non-oncogenic retroviruses. However, these approaches remain to be fully developed and validated. This review also suggests that, in all likelihood, there are no other major retroviral pathogenetic mechanisms that are of general relevance to replication defective retroviral vectors. These are important conclusions as they suggest that, by careful design and engineering of retroviral vectors, we can continue to use this gene transfer technology with confidence. http://www.gvt-journal.com/content/2/1/9 Donald Anson Genetic Vaccines and Therapy 2004, null:9 2004-08-13T00:00:00Z doi:10.1186/1479-0556-2-9 /content/figures/1479-0556-2-9-toc.gif Genetic Vaccines and Therapy 1479-0556 ${item.volume} 9 2004-08-13T00:00:00Z XML Hepatitis C virus (HCV) infection is a major worldwide problem causes acute and chronic HCV infection. Current treatment of HCV includes pegylated interferon-α (PEG IFN- α) plus ribavirin (RBV) which has significant side effects depending upon the type of genotype. Currently, there is a need to develop antiviral agents, both from synthetic chemistry and Herbal sources. In the last decade, various novel HCV replication, helicase and entry inhibitors have been synthesized and some of which have been entered in different phases of clinical trials. Successful results have been acquired by executing combinational therapy of compounds with standard regime in different HCV replicons. Even though, diverse groups of compounds have been described as antiviral targets against HCV via Specifically Targeted Antiviral Therapy for hepatitis C (STAT-C) approach (in which compounds are designed to directly block HCV or host proteins concerned in HCV replication), still there is a need to improve the properties of existing antiviral compounds. In this review, we sum up potent antiviral compounds against entry, unwinding and replication of HCV and discussed their activity in combination with standard therapy. Conclusively, further innovative research on chemical compounds will lead to consistent standard therapy with fewer side effects. http://www.gvt-journal.com/content/9/1/11 Sidra Rehman Usman Ashfaq Tariq Javed Genetic Vaccines and Therapy 2011, null:11 2011-06-23T00:00:00Z doi:10.1186/1479-0556-9-11 /content/figures/1479-0556-9-11-toc.gif Genetic Vaccines and Therapy 1479-0556 ${item.volume} 11 2011-06-23T00:00:00Z XML Background: Countrywide 5.9 million, 0-11 Month old children are immunized annually by EPI (Expended Program on Immunization) against 8 vaccine preventable diseases including measles and so on. Unfortunately the basic immunity centers are not uniform throughout the country. Each center provides services to about 27000 people which is inadequate. The purpose of this study was to explore the development of EPI Pakistan in terms of immunization of measles. Methods: Nucleotide sequences were analyzed by neighbor joining method (bootstrap test) using Bio- edit and MEGA-5 software to find evolutionary relationship between wild type measles strain and vaccine strain (Edmonston strain) used in Pakistan. For statistical analysis of data SPSS 16 was used. Results: Currently 1.3 vaccinators are working at each U C (union council) which according to national EPI policy should be at least 2. About 56% and 44% children of age 0-11 months did not received second dose of measles in the last two years respectively. Out of these 4231 cases which were reported last year, 1370 have received their first dose of measles vaccine. Conclusion: Seroconversion and seroprevalence study of the vaccine and field strain of measles virus is needed to confirm whether its failure is due to service unavailability or vaccine in-affectivity.Key words: Measles, EPI, Outbreaks, Immunization, vaccines, Pakistan. http://www.gvt-journal.com/content/10/1/1 Masaud Shah Sulaiman Shams Ziaur Rahman Genetic Vaccines and Therapy 2012, null:1 2012-01-30T00:00:00Z doi:10.1186/1479-0556-10-1 /content/figures/1479-0556-10-1-toc.gif Genetic Vaccines and Therapy 1479-0556 ${item.volume} 1 2012-01-30T00:00:00Z PDF Background: Hepatitis C virus (HCV) infection is the leading cause of chronic hepatitis which progresses to hepatocellular carcinoma (HCC) afflicting > 170 million people worldwide. HCV 3a is the most common genotype (about 70% of all genotypes) circulating in Pakistan. Expression of HCV individual gene of 3a would facilitate therapeutic and vaccines strategies against chronic HCV and liver Cirrhosis. The aim of the present study was the establishment of stable Huh-7 cell lines expressing structural and non structural proteins of HCV Genotype 3a Pakistani isolate obtained from chronic HCV patients. Methods: Blood samples were obtained from chronic HCV-3a positive patients. HCV individual genes were amplified using PCR with gene specific primers having restriction sites. These gene amplicons were cloned in mammalian expression vector PcDNA3.1+. Huh-7 cell lines were transfected with these constructed plasmids having structural or non-structural HCV genes in confluent cells with lipofectamine. Positive clones were selected with G418 and then confirmed by genome PCR. Subsequently, transcription and expression of the integrated genes were demonstrated by RT-PCR, sequencing and Western blot analysis. Results: We successfully cloned and express five HCV-3a genes in PcDNA3.1+ mammalian expression vector. Results of western blot and sequencing PCR confirmed the stable expression of these five genes. Conclusion: The stable cell-lines expressing HCV-3a individual genes would be a useful tool to investigate the role of various HCV proteins on HCV disease outcome and testing of new therapeutic strategies against HCV. http://www.gvt-journal.com/content/9/1/12 Sadia Butt Muhammad Idrees Irshad-ur Rehman Liaqat Ali Abrar Hussain Muhammad Ali Naveed Ahmad Sana Saleem Madiha Fayyaz Genetic Vaccines and Therapy 2011, null:12 2011-06-28T00:00:00Z doi:10.1186/1479-0556-9-12 /content/figures/1479-0556-9-12-toc.gif Genetic Vaccines and Therapy 1479-0556 ${item.volume} 12 2011-06-28T00:00:00Z XML Hepatitis C virus (HCV) is a major cause of chronic liver diseases including steatosis, cirrhosis and hepatocellular carcinoma. Currently, there is no vaccine available for prevention of HCV infection due to high degree of strain variation. The current treatment of care, Pegylated interferon α in combination with ribavirin is costly, has significant side effects and fails to cure about half of all infections. The development of in-vitro models such as HCV infection system, HCV sub-genomic replicon, HCV producing pseudoparticles (HCVpp) and infectious HCV virion provide an important tool to develop new antiviral drugs of different targets against HCV. These models also play an important role to study virus lifecycle such as virus entry, endocytosis, replication, release and HCV induced pathogenesis. This review summarizes the most important in-vitro models currently used to study future HCV research as well as drug design. http://www.gvt-journal.com/content/9/1/7 Usman Ashfaq Shaheen Khan Zafar Nawaz Sheikh Riazuddin Genetic Vaccines and Therapy 2011, null:7 2011-04-06T00:00:00Z doi:10.1186/1479-0556-9-7 /content/figures/1479-0556-9-7-toc.gif Genetic Vaccines and Therapy 1479-0556 ${item.volume} 7 2011-04-06T00:00:00Z XML