pJW4303-SjC23-mHSP70, 7. produced higher level of protection compare with naked DNA vaccines against contamination in a mouse model. Futhermore,antibodies from mice immunized with PAMAM-Lys combined DNA vaccines were significantly higher than those of mice immunized with the naked DNA vaccines. The PAMAM-Lys vector elicited a predominantly IgG2a antibody response and a tremendously increase in the production of IL-2 and IFN-. Conclusion/Significance Lysine-modified PAMAM-Lys is an excellent vector. PAMAM-Lys may enhance the immunoreactivity of DNA vaccine and increase the protective effect of the SjC23 DNA vaccine against contamination. Introduction Schistosomiasis remains a major public health problem throughout the world, with more than 200 million people in 76 countries or regions from Africa, Asia and South America being affected, with an additional 779 million individuals at risk of contamination [1]C[3]. In China, schistosomiasis japonica is one of the four key infectious diseases [4] that have been given priority control by the central government. Currently, there are more than 286,000 people infected with the parasite, with 238 million at risk of contamination [5]. Despite numerous strategies that have been devised to combat this infectious disease, including the use of chemotherapeutic drugs, such as praziquantel, schistosomiasis still cannot be effectively Rabbit polyclonal to ACTA2 controlled [6]. It is generally agreed that chemotherapy has certain limitations and drug resistance hampers its effectiveness [7]C[8]. Furthermore, re-infection occurs frequently in endemic areas. Therefore, development of effective vaccine is usually urgently needed to control and prevent the disease. With the discovery of potential protective antigens and improved understanding of immune mechanisms for the control of schistosomiasis contamination, P005091 the development of subunit-based vaccines may be possible. Several potential protective antigens from have been reported and used for vaccine development. Some of them have been recommended by WHO/TDR as vaccine candidates, including glutathione S-transferase (Sj26GST) [9], [10], triose-phosphate isomerase (SjTPI) [11]C[13], paramyosin (Sj97) [14], [15], fatty acid binding protein (FABP, Sj14) [16], and 23 kDa membrane protein (Sj23) [10], [12], [16], [17]. Such antigens have been shown to produce partial protection in the mouse model when used as subunit-based vaccines, such as peptide vaccines, recombinant protein vaccines, and DNA vaccines [18], [19]. However, most of these antigens only produce worm reductions of less than 40% in mouse models [14], [15], [17], [20]. Although partial protection may reduce the pathogenesis, morbidity, transmission rates [21], and improve the control of schistosomiasis when combined with praziquantel treatment in humans and livestock [22], [23], it is also important to improve the protective efficacy for an independent prophylactic vaccine. DNA vaccination was introduced in 1990 when it was demonstrated that protein expression could be induced upon direct intramuscular injection of plasmid DNA into myocytes [24]. The advantages of DNA vaccines over traditional, attenuated or subunit vaccines are the low cost of production, thermal stability, and their ability to induce a wide variety of long-lived cellular and humoral immune responses [25]. In our laboratory, the coding region for (Chinese mainland strain) 23-kDa membrane P005091 protein (SjC23) was cloned into the eukaryotic expression plasmid, pcDNA3.1, as a DNA vaccine vector. Several different research groups have shown that each of these DNA vaccines induces partial protection P005091 in animals, with worm reductions ranging from 20% to 50%, depending on the animal species challenged and the group performing the study [26]C[28]. It has been reported that DNA vaccination, using unformulated plasmid DNA (pDNA), shows low gene transfer efficiency in the host cell and hence, low antigen expression [29]. Recently, cationic polymers carriers, such as polyamidoamine (PAMAM) dendrimers, have been used to deliver pDNA. PAMAM carriers bind the pDNA electrostatically and condense it into positively charged nanoparticles that are more easily taken up by host cells. Furthermore, they protect pDNA against extracellular nucleases [30]. Several studies have already shown that PAMAM dendrimers can enhance the transfection efficiency leading to improved gene expression and contamination. Materials and P005091 Methods Cercaria snails, infected with Chinese strain were obtained from Jiangsu Institute of Parasitic Diseases, China. Cercariae of were P005091 collected from infected snails for subsequent experiments. Construction of PJW4303/SjC23 Vaccine A pair of primers (P1: 5-GC AAC ATT CTG ATA ATCG-3) were designed and synthesized based.