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 Hypericum perforatum is well known for its antidepressant and anti-inflammatory activities, for which hypericin and its derivatives are indicated to be the most active compounds. Hypericin synthase (Hyp-1) is the only protein proven to catalyze the synthesis of hypericin. In this study, the full-length cDNA of Hyp-1 was chemically synthesized according to the Hyp-1 sequence in GenBank (accession no. AY148090) and then cloned into the plasmid pET22b. Hyp-1 was expressed in Escherichia coli BL21 (DE3) and purified with a Ni-NTA column. The purified protein was used to immunize New Zealand white rabbits, from which an antiserum was purified by protein G affinity chromatography. The polyclonal antibody against Hyp-1 provides a valuable tool for the study of hypericin biosynthesis in H. perforatum. Expression of Hyp-1 and the cellular distribution of hypericin were analyzed in different organs of red-pigmented H. perforatum plantlets. The black glands were not the only site of hypericin accumulation and the results indicated that hypericin might be synthesized in mesophyll cells or in tissues of the root and/or stem and then transported to the glands. This work provides a foundation for further investigation of the regulatory mechanism of hypericin synthesis during the development of H. perforatum.
In the present study we determined whether CpG motifs could be used as an immune adjuvant for the Omp-1 DNA vaccine against Chlamydophila psittaci, based on the major outer membrane protein (MOMP), to induce the protection in specific pathogen free chickens against an intranasal challenge. Six sequences of phosphorothioate-CpG oligodeoxynucleotides (CpG ODNs) with strong immunostimulatory activity were designed to be examined. The CpG ODN with three GTCGTT repeats significantly promoted splenic lymphocyte proliferation and increased macrophage nitric oxide in a in vitro study. Birds vaccinated with CpG ODN and pcDNA3.1:MOMP induced moderate antibody response and higher lymphoproliferative stimulation while chickens primed-boosted with DNA alone did not. Furthermore, DNA vaccine plus CpG ODN accelerated chlamydial clearance in the spleen and lungs, and decreased inflammatory cellular infiltration. All above evidences show that CpG ODN can be used as an effective adjuvant with a DNA vaccine and this immunisation protocol resulted in an enhanced clearance of Chlamydophila psittaci.
In the presented study, omp-1 gene coding main outer membrane protein of Chlamydophila abortus was cloned into pCI-neo and pcDNA3.1 as delivery vehicles for DNA vaccination. Thirty-six BALB/c mice were randomly assigned to three groups and inoculated intramuscularly with: 1) 100 µg of pCI-neo, 2) 100 µg of pCI-neo::MOMP, and 3) 100 µg of pcDNA3.1::MOMP. All animals were vaccinated three times at 14 d intervals. The results showed that mice given pCI-neo::MOMP developed a higher IgG antibody level, high T lymphocytes proliferations, and high titres of IFN-γ and IL-2, than mice given pcDNA3.1::MOMP, which induced moderate antibody levels, less T lymphocyte proliferations and lower cytokine levels. No significant difference of TNF-α was observed in above groups. Additionally, IgG2a and Ig2b were the predominant isotypes on day 44, suggesting a high level of Th1 stimulation. Mice given the pCI-neo::MOMP also elicited a higher chlamydial clearance and a better protection than mice with pcDNA3.1::MOMP did. Immunisation with pCI-neo::MOMP vaccine may provide novel ways for active immunisation strategy against Chlamydophila abortus.
Physiological and ecological adaptations of altitudinal gradients reveal alpine plants’ ecological and evolutionary responses to environmental changes. Here we quantitatively investigated the variation in the foliar physiological and morphological traits of alpine tree species (Abies fargesii) along the altitudinal gradient in the Taibai Mountains, China. We collected the needle samples of Taibai fir (A. fargesii) from seven sites at altitudes of 2550, 2650, 2750, 2850, 2950, 3050 and 3150 m, respectively, and measured the 12 foliar physiological and morphological traits. Each set of needle sample (100 needles) was randomly selected from the upper- third of A. fargesii canopies. The results showed that leaf mass per unit area (LMA), stable carbon isotope composition (δ13C), stomatal rows (SR), leaf carbon concentration per unit area (Carea), leaf nitrogen concentration per unit leaf mass (Nmass) and area (Narea) linearly increase significantly while stomatal density (SD), number of stomata per unit nitrogen concentration (St/N) and per unit leaf mass (St/LM) decrease with the altitudes raise. Moreover, all measured traits presented both strong correlations and significantly linear relationships with the main climate factors such as the mean temperature, rainfall and relative humidity during the growing season as well as the altitudes, except for leaf free water concentration (LWC), leaf carbon concentration per unit leaf mass (Cmass) and C: N ratio. The patterns of foliar traits in response to altitudes imply that the alpine plants need higher cost (e.g. higher nutrient concentration) to adapt to the harsher environments along altitudinal gradient. Moreover, our results show that the variation patterns of the leaf traits for A. fargesii plants should be driven by the interactions of multi-climate factors because the abiotic factors that directly influence the growth of plants covary with the increasing altitudes.
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