• IMMUNE NETWORK
• /
• v.5 no.1
• /
• pp.1-10
• /
• 2005

Background: Chronic infection with hepatitis B virus (HBV) affects about 350 million people worldwide, which have a high risk of development of cirrhosis and hepatocellular carcinoma. Treatment of chronic HBV infection relies on IFN-${\alpha}$ or lamivudine. However, interferon-${\alpha}$ is effective in only about 30% of patients. Also, the occurrence of escape mutations limits the usage of lamivudine. Therefore, the development and evaluation of new compounds or approaches are urgent. Methods: We comparatively evaluated DNA and adenoviral vaccines expressing HBV antigens, either alone or in combined regimens, for their ability to elicit Th1-type immune responses in Balb / c mice which are believed to be suited to resolve HBV infection. The vaccines were tested with or without a genetically engineered IL-12 (mIL-12 N220L) which was shown to enhance sustained Th1-type immune responses in HCV E2 DNA vaccine. Results: Considering the Th1-type cytokine secretion and the IgG2a titers, the strongest Th1-type immune response was elicited by the DNA prime-adenovirus boost regimen in the presence of mIL-12 N220L. In addition, the codelivery of mIL-12 N220L modulated differentially the immune responses by different vaccination regimens. Conclusion: Our results suggest that the DNA prime-adenovirus boost regimen in the presence of mIL-12 N220L may be the best candidate for HBV vaccine therapy of the regimens tested in this study and will be worthwhile being evaluated in chronic HBV patients.

• Parasites, Hosts and Diseases
• /
• v.60 no.6
• /
• pp.379-391
• /
• 2022

Leishmaniasis is a serious parasitic disease caused by Leishmania spp. transmitted through sandfly bites. This disease is a major public health concern worldwide. It can occur in 3 different clinical forms: cutaneous, mucocutaneous, and visceral leishmaniasis (CL, MCL, and VL, respectively), caused by different Leishmania spp. Currently, licensed vaccines are unavailable for the treatment of human leishmaniasis. The treatment and prevention of this disease rely mainly on chemotherapeutics, which are highly toxic and have an increasing resistance problem. The development of a safe, effective, and affordable vaccine for all forms of vector-borne disease is urgently needed to block transmission of the parasite between the host and vector. Immunological mechanisms in the pathogenesis of leishmaniasis are complex. IL-12-driven Th1-type immune response plays a crucial role in host protection. The essential purpose of vaccination is to establish a protective immune response. To date, numerous vaccine studies have been conducted using live/attenuated/killed parasites, fractionated parasites, subunits, recombinant or DNA technology, delivery systems, and chimeric peptides. Most of these studies were limited to animals. In addition, standardization has not been achieved in these studies due to the differences in the virulence dynamics of the Leishmania spp. and the feasibility of the adjuvants. More studies are needed to develop a safe and effective vaccine, which is the most promising approach against Leishmania infection.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.7
• /
• pp.3061-3063
• /
• 2016

Exploiting the immune system to abolish cancer growth via vaccination is a promising strategy but that is limited by many clinical issues. For DNA vaccines, viral vectors as a delivery system mediate a strong immune response due to their protein structure, which could afflect the cellular uptake of the genetic vector or even induce cytotoxic immune responses against transfected cells. Recently, synthetic DNA delivery systems have been developed and recommended as much easier and simple approaches for DNA delivery compared with viral vectors. These are based on the attraction of the positively charged cationic transfection reagents to negatively charged DNA molecules, which augments the cellular DNA uptake. In fact, there are three major cellular barriers which hinder successful DNA delivery systems: low uptake across the plasma membrane; inadequate release of DNA molecules with limited stability; and lack of nuclear targeting. Recently, a polysaccharide polymer produced by microalgae has been synthesized in a form of polymeric fiber material poly-N-acetyl glucosamine (p-GlcNAc). Due its unique properties, the F2 gel matrix was suggested as an effective delivery system for immune and gene vaccinations.

• Journal of Microbiology and Biotechnology
• /
• v.19 no.11
• /
• pp.1408-1414
• /
• 2009

The obtention of high yields of purified plasmid DNA is viewed as an essential issue to be considered towards efficient production of DNA vaccines and therapeutic plasmids. In this work, Escherichia coli $DH5\alpha$. bearing the pVAXI-LacZ plasmid was grown in a developed semi-defined medium at different temperatures and tryptone concentrations. Analysis of pDNA yields and E. coli morphology revealed that at higher temperatures (37 and $40^{\circ}C$), higher specific yields and E. coli filamentation were obtained. However, the best results were achieved when a lower tryptone concentration was used. This approach was shown to be a powerful tool to promote plasmid amplification, keeping the desirable plasmid structure, and favoring the attainment of quality. Our results suggest that by using tryptone alone as an amino acid source, pDNA amplification was improved and a specific yield of 20.43 mg pDNA/g dcw was achieved, proving that this strategy can improve pDNA yield even at a small scale.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.18
• /
• pp.8019-8029
• /
• 2016

The development of new strategies for vaccine delivery for generating protective and long-lasting immune responses has become an expanding field of research. In the last years, it has been recognized that bacteriophages have several potential applications in the biotechnology and medical fields because of their intrinsic advantages, such as ease of manipulation and large-scale production. Over the past two decades, bacteriophages have gained special attention as vehicles for protein/peptide or DNA vaccine delivery. In fact, whole phage particles are used as vaccine delivery vehicles to achieve the aim of enhanced immunization. In this strategy, the carried vaccine is protected from environmental damage by phage particles. In this review, phage-based vaccine categories and their development are presented in detail, with discussion of the potential of phage-based vaccines for protection against microbial diseases and cancer treatment. Also reviewed are some recent advances in the field of phagebased vaccines.

• Korean Journal of Poultry Science
• /
• v.28 no.2
• /
• pp.165-172
• /
• 2001

Vaccination is one of the most important and cost-effective methods of preventing infectious diseases. Over the past decade, scientific in molecular biology and immunology have improved understanding of many diseases and led to the development of novel strategies for vaccination. An ideal vaccine would induce effective immunity specific for the type of infection, have long duration, require minimal or no boosters, have safety, would not induce adverse reaction, and be easy to administer. The desire to meet these criteria has resulted in the development of vaccines that do not depend on the use of the viable disease agent. It is not the intent of this review to give an extensive review of the field of vaccinology, but rather to address characteristics of conventional and genetically engineered vaccines.

• 한국생물공학회:학술대회논문집
• /
• 2002.04a
• /
• pp.543-547
• /
• 2002

DNA vaccines use eukaryote expression vectors to produce immunizing proteins in the vaccinated host and it represents a novel approach to vaccine and immuno-therapeutic development. We constructed a 2.9 kb compact plasmid vector (pVAC) which contains CMV promoter, polycloning site, BGH poly A terminator, ampicillin resistance gene and PBR322 origin. Enriched unmathlyated CpG motifs have introduced into pVAC-ISS1 and pVAC-ISS2 which are derived from pVAC for enhancing Thl responses. These plasmid DNAs rapidly induced interleukin 6 secretion in vivo. It is expected that these vectors will contribute to the DNA inoculation against infectious disease and various cancers without adjuvant.

• Proceedings of the Korean Society of Toxicology Conference
• /
• 2003.10b
• /
• pp.89-90
• /
• 2003

Biological products are composed of vaccines, antitoxin, blood products, DNA recombinant protein drugs, monoclonal antibody, cell therapy and gene therapy. Biological products are divided into traditional (i.e. recombinant proteins and monoclonal antibodies) and novel biological products (gene and cell therapy) and will require a similar re-evaluation of the approaches taken during each development program.(omitted)

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.20
• /
• pp.9039-9043
• /
• 2014

There is a continuing need for innovative alternative therapies for liver cancer. DNA vaccines for hormone/growth factor immune deprivation represent a feasible and attractive approach for cancer treatment. We reported a preventive effect of a DNA vaccine based on six copies of the B cell epitope GRP18-27 with optimized adjuvants against H22 hepatocarcinoma. Vaccination with pCR3.1-VS-HSP65-TP-GRP6-M2 (vaccine) elicited much higher level of anti-GRP antibodies and proved efficacious in preventing growth of transplanted hepatocarcinoma cells. The tumor size and weight were significantly lower (p<0.05) in the vaccine subgroup than in the control pCR3.1-VS-TP-HSP65-TP-GRP6, pCR3.1-VS-TP-HSP65-TP-M2 or saline subgroups. In addition, significant reduction of tumor-induced angiogenesis associated with intradermal tumors of H22 cells was observed. These potent effects may open ways towards the development of new immunotherapeutic approaches in the treatment of liver cancer.

• Molecules and Cells
• /
• v.22 no.2
• /
• pp.175-181
• /
• 2006

Delivery of DNA vaccines to airway mucosa would be an ideal method for mucosal immunization. However, there have been few reports of a suitable gene delivery system. In this study we used a cationic emulsion to immunize mice via the intranasal route with pCMV-S coding for Hepatitis B virus surface antigen (HBsAg). Complexing pCMV-S with a cationic emulsion dramatically enhanced HBsAg expression in both nasal tissue and lung, and was associated with increases in the levels of HBs-specific Abs in serum and mucosal fluids, of cytotoxic T lymphocytes (CTL) in the spleen and cervical and iliac lymph nodes, and of delayed-type hypersensitivity (DTH) against HBsAg. In contrast, very weak humoral and cellular immunities were observed following immunization with naked DNA. In support of these observations, a higher proliferative response of spleenocytes was detected in the group immunized with the emulsion/pCMV-S complex than in the group immunized with naked pCMV-S. These findings may facilitate development of an emulsion-mediated gene vaccination technique for use against intracellular pathogens that invade mucosal surfaces.