Efficacy of Leishmania donovani ribosomal P1 gene as DNA vaccine in experimental visceral leishmaniasis

Department of Immunopathology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
Experimental Parasitology (Impact Factor: 1.64). 05/2011; 129(1):55-64. DOI: 10.1016/j.exppara.2011.05.014
Source: PubMed


The acidic ribosomal proteins of the protozoan parasites have been described as prominent antigens during human disease. We present here data showing the molecular cloning and protective efficacy of P1 gene of Leishmania donovani as DNA vaccine. The PCR amplified complete ORF cloned in either pQE or pVAX vector was used either as peptide or DNA vaccine against experimentally induced visceral leishmaniasis in hamsters. The recombinant protein rLdP1 was given along with Freund's adjuvant and the plasmid DNA vaccine, pVAX-P1 was used alone either as single dose or double dose (prime and boost) in different groups of hamsters which were subsequently challenged with a virulent dose of 1×10(7) L. donovani (MHOM/IN/DD8/1968 strain) promastigotes by intra-cardiac route. While the recombinant protein rLdP1 or DNA vaccine pVAX-P1 in single dose format were not found to be protective, DNA vaccine in a prime-boost mode was able to induce protection with reduced mortality, a significant (75.68%) decrease in splenic parasite burden and increased expression of Th1 type cytokines in immunized hamsters. Histopathology of livers and spleens from these animals showed formation of mature granulomas with compact arrangement of lymphocytes and histiocytes, indicating its protective potential as vaccine candidate.

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    • "The direct injection of a naked plasmid DNA vaccine encoding a foreign antigen results in plasmid uptake and protein expression, leading to the induction of antigen-specific cell-mediated immune responses (CMI) and antibody-mediated immune responses (AMI) (Tang et al. 1992). The ability of DNA vaccines elicited immune responses had been proved to be effectively against some parasitic infections (Alarcon et al. 1999; Masih et al. 2011; Chen et al. 2012). DNA vaccine encoding H. contortus cysteine protease (HC58), glutathione peroxidase (Hc29), glyceraldehyde-3- phosphate dehydrogenase (GAPDH) and aminopeptidase (H11) (Muleke et al. 2007a; Sun et al. 2011; Han et al. 2012; *Corresponding author: "
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    ABSTRACT: Actin is a globular multi-functional protein that forms microfilaments, and participates in many important cellular processes. Previous study found that Haemonchus contortus actin could be recognized by the serum of goats infected with the homology parasite. This indicated that H. contortus actin could be a potential candidate for vaccine. In this study, DNA vaccine encoding H. contortus actin was tested for protection against experimental H. contortus infections in goats. Fifteen goats were allocated into three trial groups. The animals of Actin group were vaccinated with the DNA vaccine on day 0 and 14, and challenged with 5000 infective H. contortus third stage larval (L3) on day 28. An unvaccinated positive control group was challenged with L3 at the same time. An unvaccinated negative control group was not challenged with L3. The results showed that DNA vaccine were transcribed at local injection sites and expressed in vivo post immunizations respectively. For goats in Actin vaccinated group, higher levels of serum IgG, serum IgA and mucosal IgA were produced, the percentages of CD4+ T lymphocytes, CD8+ T lymphocytes and B lymphocytes and the concentrations of TGF-β were increased significantly (PH. contortus Actin DNA vaccine induced partial immune response and has protective potential against goat haemonchosis.
    Acta Parasitologica 10/2014; 59(4). DOI:10.2478/s11686-014-0298-z · 0.91 Impact Factor
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    • "We evaluated the impact of parasite load in two compartments (spleen and liver) after infection by L. infantum strains. The development of molecular approaches to quantify the parasite load in the spleen and liver from experimentally infected hamsters is extremely relevant because this animal model has been used to evaluated potential drugs and candidate vaccines against VL [30], [31], [32], [33], [34], [35], [36], [37], [38]. The LDU index, as described by Stauber [19], has the disadvantage of low sensitivity for detecting amastigotes by optical microscopy. "
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    ABSTRACT: To develop and test new therapeutics and immune prophylaxis strategies for visceral leishmaniasis (VL), understanding tissue parasitism evolution after experimental infection with Leishmania infantum is important. Experimental infection in a hamster model (Mesocricetus auratus) reproduces several typical aspects of canine and human VL that are closely related to the inoculum's route. We quantified the parasitism in the liver and spleen of hamsters experimentally infected by various routes (intradermal, intraperitoneal, and intracardiac [IC]) and different strains of L. infantum (MHOM/BR/74/PP75 and Wild) and compared two different methodologies to evaluate tissue parasitism (Leishman Donovan units [LDU] and real-time qPCR). In addition, the quantification of specific total-IgG in the serum of uninfected and infected hamsters was determined by ELISA. The animals were followed for 1, 3, 6 and 9 months post-infection for survival analysis. We found that infection with the Wild strain by the IC route resulted in higher mortality. Positive antibody (IgG) responses were detected with higher peaks at 6 and 9 months in the IC group inoculated with PP75 strain. However, in animals infected with the Wild strain the IgG levels were elevated in all infected groups during all the time evaluated. We also observed by LDU analysis that the IC route lead to higher parasitism in the liver and spleen with both strains. Furthermore, qPCR showed higher sensitivity for identifying animals with low parasitic burden. In conclusion, qPCR can be useful for assessing parasitism in the spleen and liver of a hamster model infected with L. infantum independent of the route of infection, and this technique may become an essential tool for assessing parasite density in the hamster model after experimental treatment or immunization with potential vaccine candidates.
    PLoS ONE 10/2012; 7(10):e47907. DOI:10.1371/journal.pone.0047907 · 3.23 Impact Factor
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    • "In addition, DNA vaccines mimic the protective effects of live vaccines without the potential danger of disease development, they are relatively easy and cheap to produce and unlike protein or live-attenuated vaccines , does not require the maintenance of " cold chain " sequence (Gurunathan et al., 2000b). Several experimental studies have shown that DNA vaccines confer strong protection against cutaneous (Doroud et al., 2011a,b) and visceral (Fragaki et al., 2001; Tewary et al., 2004; Saldarriaga et al., 2006; Masih et al., 2011; Mazumder et al., 2011) leishmaniases. However, although DNA vaccination is considered a promising technology, it still remains an experimental practice because no development of such vaccines for use in humans has been reported so far. "
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    ABSTRACT: Although a great deal of knowledge has been gained from studies on the immunobiology of leishmaniasis, there is still no universally acceptable, safe, and effective vaccine against the disease. This strongly suggests that we still do not completely understand the factors that control and/or regulate the development and sustenance of anti-Leishmania immunity, particularly those associated with secondary (memory) immunity. Such an understanding is critically important for designing safe, effective, and universally acceptable vaccine against the disease. Here we review the literature on the correlate of protective anti-Leishmania immunity and vaccination strategies against leishmaniasis with a bias emphasis on experimental cutaneous leishmaniasis.
    Frontiers in Immunology 05/2012; 3:128. DOI:10.3389/fimmu.2012.00128
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