Protection against tuberculosis by a single intranasal administration of DNA-hsp65 vaccine complexed with cationic liposomes

Núcleo de Pesquisas em Tuberculose, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, São Paulo,
BMC Immunology (Impact Factor: 2.48). 07/2008; 9(1):38. DOI: 10.1186/1471-2172-9-38
Source: PubMed


The greatest challenges in vaccine development include optimization of DNA vaccines for use in humans, creation of effective single-dose vaccines, development of delivery systems that do not involve live viruses, and the identification of effective new adjuvants. Herein, we describe a novel, simple technique for efficiently vaccinating mice against tuberculosis (TB). Our technique consists of a single-dose, genetic vaccine formulation of DNA-hsp65 complexed with cationic liposomes and administered intranasally.
We developed a novel and non-toxic formulation of cationic liposomes, in which the DNA-hsp65 vaccine was entrapped (ENTR-hsp65) or complexed (COMP-hsp65), and used to immunize mice by intramuscular or intranasal routes. Although both liposome formulations induced a typical Th1 pattern of immune response, the intramuscular route of delivery did not reduce the number of bacilli. However, a single intranasal immunization with COMP-hsp65, carrying as few as 25 microg of plasmid DNA, leads to a remarkable reduction of the amount of bacilli in lungs. These effects were accompanied by increasing levels of IFN-gamma and lung parenchyma preservation, results similar to those found in mice vaccinated intramuscularly four times with naked DNA-hsp65 (total of 400 microg).
Our objective was to overcome the significant obstacles currently facing DNA vaccine development. Our results in the mouse TB model showed that a single intranasal dose of COMP-hsp65 elicited a cellular immune response that was as strong as that induced by four intramuscular doses of naked-DNA. This formulation allowed a 16-fold reduction in the amount of DNA administered. Moreover, we demonstrated that this vaccine is safe, biocompatible, stable, and easily manufactured at a low cost. We believe that this strategy can be applied to human vaccines to TB in a single dose or in prime-boost protocols, leading to a tremendous impact on the control of this infectious disease.

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Available from: Simone G Ramos
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    • "Although DNA vaccines have been shown to induce a potent CTL responses (Srivastava and Liu, 2003), but they are not capable enough in eliciting antibody responses (Wang et al., 1998), and low immunogenicity has been observed in human clinical trials as well (Bivas-Benita et al., 2009). This low immunogenicity of DNA vaccines may be addressed by the use of various novel delivery systems coupled with suitable adjuvants for DNA vaccines (Bivas-Benita et al., 2004, 2009; de la Torre et al., 2009; Meerak et al., 2013; Rosada et al., 2008, 2012; Wang et al., 2010; Yu et al., 2012) (Table 4). Thus strategies are needed to enhance the immunogenicity of DNA vaccines (Yu et al., 2012). "
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    ABSTRACT: Despite worldwide availability of the vaccines against most of the infectious diseases, BCG and various programs such as Directly Observed Treatment Short course (DOTS) to prevent tuberculosis still remains one of the most deadly forms of the disease affecting millions of people globally. The evolution of multi drug resistant strains (MDR) has increased the complexity further. Although currently available marketed BCG vaccine has shown sufficient protection against childhood tuberculosis, it has failed to prevent the most common form of disease i.e., pulmonary tuberculosis in adults. However, various vaccine candidates have already entered phase I clinical trials and have shown promising outcomes. The most prominent amongst them is the heterologous prime-boost approach, which shows a great promise towards designing and development of a new efficacious tuberculosis vaccine. It has also been shown that the use of various viral and non-viral vectors as carriers for the potential vaccine candidates will further boost their effect on subsequent immunization. In this review, we briefly summarize the potential of a few novel nano-carriers for developing effective vaccination strategies against tuberculosis.
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    • "DNA-lipid complexes were prepared as described by Rosada [43] and Torchilin [44]. The required amounts of all lipid stock solutions in chloroform (PC/CH/ODA 5:4:1 molar) were mixed and dried to a thin film using a rotary evaporator in vacuum for 1 h. "
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    ABSTRACT: Background A eukaryotic expression plasmid encoding glycoprotein C (gC) of Anatid herpesvirus 1 (AnHV-1) (pcDNA3.1-gC) was constructed and validated. The tissue distribution of chitosan/DNA complexes, liposome/DNA complexes and pcDNA3.1-gC alone were evaluated using a quantitative real-time PCR based TaqMan™ probe following intramuscular administration in ducklings. Results Compared with pcDNA3.1-gC alone, liposomes universally increased the plasmid DNA copy number at the injection sites, liver, spleen, heart, brain, bursa of Fabricius, and especially in the enteron (esophagus, duodenum, rectum, and cecum). Chitosan also universally increased the plasmid DNA copy number at the injection sites, liver, spleen, heart, brain and esophagus. Compared with lipoplex-gC, higher chitosan-gC plasmid DNA copy numbers were detected at the injection sites, liver, spleen, heart, brain and esophagus. In contrast, compared with lipoplex-gC, lower copy numbers of chitosan-gC plasmid DNA were detected in the duodenum, rectum and cecum. Conclusions The results of this study demonstrated that chitosan and liposomes mediated rapid and extensive plasmid distribution in duck tissues, with low levels maintained from 1 d after DNA vaccination.
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    • "M. tuberculosis. As observed in Figure 8, the modified process did not alter the formulation's ability to induce effective immune response in mice against M. tuberculosis, at similar levels to BCG immunisation and sustain the pattern observed in previous results reported by our group using the conventional process (DRV-CP) (Figure 8, inset; Rosada et al., 2008). Therefore, the modifications studied allow a simpler and more economical process for production of cationic liposomes useful for gene vaccine, which is promising for further scale-up studies. "
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    ABSTRACT: We developed cationic liposomes containing DNA through a conventional process involving steps of (i) preformation of liposomes, (ii) extrusion, (iii) drying and rehydration and (iv) DNA complexation. Owing to its high prophylactic potentiality against tuberculosis, which had already been demonstrated in preclinical assays, we introduced modifications into the conventional process towards getting a simpler and more economical process for further scale-up. Elimination of the extrusion step, increasing the lipid concentration (from 16 to 64 mM) of the preformed liposomes and using good manufacturing practice bulk lipids (96-98% purity) instead of analytical grade purity lipids (99.9-100%) were the modifications studied. The differences in the physico-chemical properties, such as average diameter, zeta potential, melting point and morphology of the liposomes prepared through the modified process, were not as significant for the biological properties, such as DNA loading on the cationic liposomes, and effective immune response in mice after immunisation as the control liposomes prepared through the conventional process. Beneficially, the modified process increased productivity by 22% and reduced the cost of raw material by 75%.
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