Comparison of the antibody responses to Plasmodium vivax and Plasmodium falciparum antigens in residents of Mandalay, Myanmar

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to investigate the profile of antibodies against several antigens of <it>Plasmodium vivax </it>and <it>Plasmodium falciparum </it>in Mandalay, Myanmar.</p> <p>Methods</p> <p>Malaria parasites were identified by microscopic examination. To test the antibodies against <it>P. vivax </it>and <it>P. falciparum </it>in sera, an indirect immunofluorescence antibody test (IFAT) was performed using asexual blood parasite antigens. An enzyme-linked immunosorbent assay (ELISA) was performed with circumsporozoite protein (CSP), Pvs25 and Pvs28 recombinant proteins of transmission-blocking vaccine candidates for <it>P. vivax</it>, and liver stage specific antigen-1 and -3 (PfLSA-1, PfLSA-3) for <it>P. falciparum</it>.</p> <p>Results</p> <p>Fourteen patients among 112 were found to be infected with <it>P. vivax </it>and 26 with <it>P. falciparum </it>by thick smear examination. Twenty-three patients were found to be infected with <it>P. vivax</it>, 19 with <it>P. falciparum </it>and five with both by thin smear examination. Blood samples were divided into two groups: Group I consisted of patients who were positive for infection by microscopic examination, and Group II consisted of those who showed symptoms, but were negative in microscopic examination. In <it>P. falciparum</it>, IgG against the blood stage antigen in Group I (80.8%) was higher than in Group II (70.0%). In <it>P. vivax</it>, IgG against the blood stage antigen in Group I (53.8%) was higher than in Group II (41.7%). However, the positivity rate of the PvCSP VK210 subtype in Group II (40.0%) was higher than in Group I (23.1%). Similarly for the PvCSP VK247 subtype, Group II (21.7%) was higher than that for Group I (9.6%). A similar pattern was observed in the ELISA using Pvs25 and Pvs28: positive rates of Group II were higher than those for Group I. However, those differences were not shown significant in statistics.</p> <p>Conclusions</p> <p>The positive rates for blood stage antigens of <it>P. falciparum </it>were higher in Group I than in Group II, but the positive rates for antigens of other stages (PfLSA-1 and -3) showed opposite results. Similar to <it>P. falciparum</it>, the positive rate of pre-blood stage (CSP VK210 and 247 subtype) and post-blood stage (Pvs25 and 28) antigens of <it>P. vivax </it>were higher in Group II than in Group I. Therefore, sero-diagnosis is not helpful to discriminate between malaria patients and symptomatic individuals during the epidemic season in Myanmar.</p

Relationships between land use and multi-dimensional characteristics of streams and rivers at two different scales

Despite numerous previous studies, relationships between watershed land use and adjacent streams and rivers at various scales in Korea remain unclear. This study investigated the relationships between land uses and the physical, chemical, and biological characteristics of 720 sites of streams and rivers across the country. The land uses at two spatial scales, including a 1-km buffer and the base watershed management region (BWMR), were computed in a geographical information system (GIS) with a digital land use/land cover map. Characteristics of land uses at two spatial scales were then correlated with the monitored multidimensional characteristics of the streams and rivers. The results of this study indicate that land use types have significant effects on stream and river characteristics. Specifically, most characteristics were negatively correlated with the proportions of urban, rice paddy, agricultural, and bare soil areas and positively correlated with the amount of forest. The site-scale and BWMR-scale analyses suggest that BWMR land use patterns were more strongly related to ecological integrity than they were to site land use patterns. Improving our understanding of land use effects will largely depend on relating the results of site-specific studies that use similar response techniques and measures to evaluate ecological integrity. In addition, our results clearly indicate that the characteristics of streams and rivers are closely linked and that land use types differentially affect those characteristics. Thus, effective restoration and management for ecological integrity of lotic system should consider the physical, chemical, and biological factors in combination

Fully Elastic Conductive Films from Viscoelastic Composites

We investigated, for the first time, the conditions where a thermoplastic conductive composite can exhibit completely reversible stretchability at high elongational strains (epsilon = 1.8). We studied a composite of Au nanosheets and a polystyrene-block-polybutadiene-block-polystyrene block copolymer as an example. The composite had an outstandingly low sheet resistance (0.45 Omega/sq). We found that when a thin thermoplastic composite film is placed on a relatively thicker chemically cross-linked elastomer film, it can follow the reversible elastic behavior of the bottom elastomer. Such elasticity comes from the restoration of the block copolymer microstructure. The strong adhesion of the thermoplastic polymer to the metallic fillers is advantageous in the fabrication of mechanically robust, highly conductive, stretchable electrodes. The chemical stability of the Au composite was used to fabricate high luminescence, stretchable electrochemiluminescence displays with a conventional top-bottom electrode setup and with a horizontal electrode setup

Direct Interaction of CD40 on Tumor Cells with CD40L on T Cells Increases the Proliferation of Tumor Cells by Enhancing TGF-β Production and Th17 Differentiation.

It has recently been reported that the CD40-CD40 ligand (CD40L) interaction is important in Th17 development. In addition, transforming growth factor-beta (TGF-β) promotes tumorigenesis as an immunosuppressive cytokine and is crucial in the development of Th17 cells. This study investigated the role of CD40 in breast cancer cells and its role in immunosuppressive function and tumor progression. CD40 was highly expressed in the breast cancer cell line MDA-MB231, and its stimulation with CD40 antibodies caused the up-regulation of TGF-β. Direct CD40-CD40L interaction between MDA-MB231 cells and activated T cells also increased TGF-β production and induced the production of IL-17, which accelerated the proliferation of MDA-MB231 cells through the activation of STAT3. Taken together, the direct CD40-CD40L interaction of breast tumor cells and activated T cells increases TGF-β production and the differentiation of Th17 cells, which promotes the proliferation of breast cancer cells

IL-17 production via direct interaction of CD40 and CD40L increases STAT3 activation and the proliferation of MDA-MD231 cells.

<p>(A) MDA-MB231 cells and activated T cells were directly co-cultured at the ratio of 1:5 for 24 hrs in the presence of anti-IL-17 neutralizing antibody or anti-CD40 neutralizing antibody (2 μg/ml/each) on 96-well plate, and then cells were cultured for 24 hrs. After the addition of 1 μCi/mL of [³H]-thymidine, cells were culture for another 18 hrs. And the proliferation of cells was measured as described in <i>Materials and Methods</i>. Data represents mean ± S.D. The assay was performed in quadruplicate and result is the representative of three independent experiments. (B) MDA-MB231 cells were cultured in the presence of recombinant IL-17 (rIL-17, 50 ng/ml) for 15, 30 and 60 min. In addition, cells were cultured with direct co-culture supernatant of MDA-MB231 cells and activated T cells in the presence or absence of anti-IL-17 neutralizing antibody (nAb). And then, the activation of STAT3 was examined by western blot as described in <i>Materials and Methods</i>. Lane 1: Control, Lane 2: rIL-17 (50 ng/ml), Lane 3: Direct co-culture supernatant of MDA-MB231 cells and activated T cells, Lane 4: Direct co-culture supernatant of MDA-MB231 cells and activated T cells with IL-17 nAb, Lane 5: Indirect co-culture supernatant of MDA-MB231 cells and activated T cells. β-actin was used as a loading control. Result is the representative of three independent experiments. (C) MDA-MB231 cells and activated T cells were directly co-cultured at the ratio of 1:5 for 24 hrs in the presence of 20 μM of AG490 (STAT3 inhibitor) or anti-IL-17 nAb (2 μg/ml) on 96-well plate, and then cells were cultured for 24 hrs. After the addition of 1 μCi/mL of [³H]-thymidine, cells were culture for another 18 hrs. Direct co-culture supernatant of CD40-non expressing breast cancer cell line, Hs578T and activated T cells was used as a negative control. The proliferation of cells was measured as described in <i>Materials and Methods</i>. Data represents mean ± S.D. The assay was performed in quadruplicate and result is the representative of three independent experiments.</p

CD40 ligand stimulation on the activated T cells induces Th17 differentiation.

<p>(A) Human T cells (2.5x10⁶/ml) purified from human PBMCs were activated as described in <i>Materials and Methods</i>. After increase of CD40L expression on activated T cells was confirmed by flow cytometry analysis, they were co-cultured with MDA-MB231 cells in the same well on 6-well plate at the ratio of 5:1 for 24 hrs. Th17 differentiation was confirmed by staining of intracellular IL-17 in CD4⁺ T cells with Alexa Fluor 647-conjugated anti-human IL-17A antibody (1 μg/ml) and FITC-conjugated anti-human CD4 antibody (1 μg/ml). To confirm the role of CD40 on Th17 differentiation, the interaction between CD40 and CD40L was interfered with the addition of anti-CD40 neutralizing antibody (2 μg/ml) for 1 hr. Result is the representative of three independent experiments. (B-D) Culture supernatant from the experiment described in Fig 3A were collected and the amount of IL-1β (B), IL-6 (C) and IL-21 (D) were measured by ELISA, according to manufacturer’s instruction. Data represents mean ± S.D. Result is the representative of three independent experiments and each experiment was performed in triplicate. *p < 0.05. (E) Human T cells (2.5x10⁶/ml) purified from human PBMCs were activated as described in <i>Materials and Methods</i>. After increase of CD40L expression on activated T cells was confirmed by flow cytometry analysis, activated T cells were stimulated by anti-CD40L agonistic antibody (1 μg/ml) or isotype (1 μg/ml) for 24 and 36 hrs. The expression of ROR gamma t (RORγt), the orphan nuclear receptor for IL-17 transcription and Th17 differentiation was determined by intracellular flow cytometry analysis, after staining with PE-conjugated anti- RORγt antibody (1 μg/ml) and PE-conjugated Rat IgG (1 μg/ml) as described in <i>Materials and Methods</i>. Result is the representative of three independent experiments.</p