Distribution of Onchocerciasis Showing Current Status of Global Onchocerciasis Control.

<p>Red shading represents areas receiving ivermectin treatment. Yellow shading represents areas requiring further epidemiological surveys. Green shading indicates the area covered by the OCP in West Africa. Pink zones indicate the special intervention zones, i.e., previous OCP areas receiving ivermectin and some vector control. Figure from <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0000076#pntd.0000076-Basez1" target="_blank">[10]</a>.</p

cDNA clones isolated from the mL3 cDNA library.

a<p>, % abundance of clone in the <i>O. volvulus</i> EST dataset as reported previously <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0000800#pntd.0000800-LizotteWaniewski1" target="_blank">[12]</a>.</p

Effect of mono-specific human anti-<i>Ov</i>-CPI-2 antibodies on L3 molting and viability in the presence of normal human neutrophils.

a<p><i>O. volvulus</i> L3 were cultured in complete medium alone or in complete medium containing negative control antibodies purified from the same serum donor using a λgt11 lysate column or mono-specific antibodies to r<i>Ov</i>-CPI-2 in the presence of 2×10⁵ normal human neutrophils per well for 6 days. Larval molting and viability were determined as described under the “<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0000800#s2" target="_blank">Materials & Methods</a>” section. Three experiments were performed, where each consisted of a total of 10 wells per treatment group with 5 larvae per well. The results are the mean ± SEM and the range of the three experiments.</p><p>*Significance between groups was determined by unpaired t test with Welch's correction with <i>p</i> = 0.007 between medium control and the anti-<i>Ov</i>-CPI-2 group and <i>p</i> = 0.028 between the negative antibodies and the anti-<i>Ov</i>-CPI-2 group.</p><p>**There is no significant difference between the three groups.</p

cDNA clones isolated from the L3 cDNA library.

a<p>, % abundance of clone in the <i>O. volvulus</i> EST dataset as reported previously <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0000800#pntd.0000800-LizotteWaniewski1" target="_blank">[12]</a>.</p

Human IgG sub-classes and IgE class antibody responses to recombinant <i>Ov</i>-CPI-2 in the PI and the INF.

<p>The median IgG1, IgG3, IgG4 and IgE responses to r<i>Ov</i>-CPI-2 in the PI (N = 21) and INF subjects (N = 21) are indicated with short, solid horizontal lines. The median IgG1 and IgG4 responses are significantly higher in the INF (<i>P</i> = 0.03 and 0.04 respectively) than in the PI.</p

The correlation of IgG sub-classes and IgE class responses to r<i>Ov</i>-CPI-2 in infected patients with age: Maintenance of high IgG1 (a) and IgE (c) responses regardless of age; (b) Positive correlation between IgG3 levels and age (r = 0.241; <i>P</i> = 0.0013).

<p>The correlation of IgG sub-classes and IgE class responses to r<i>Ov</i>-CPI-2 in infected patients with age: Maintenance of high IgG1 (a) and IgE (c) responses regardless of age; (b) Positive correlation between IgG3 levels and age (r = 0.241; <i>P</i> = 0.0013).</p

Dual Protonophore–Chitinase Inhibitors Dramatically Affect O. volvulus Molting

The L3-stage-specific chitinase OvCHT1 has been implicated in the development of Onchocerca volvulus, the causative agent of onchocerciasis. Closantel, a known anthelmintic drug, was previously discovered as a potent and specific OvCHT1 inhibitor. As closantel is also a known protonophore, we performed a simple scaffold modulation to map out the structural features that are relevant for its individual or dual biochemical roles. Furthermore, we present that either OvCHT1 inhibition or protonophoric activity was capable of affecting O. volvulus L3 molting and that the presence of both activities in a single molecule yielded more potent inhibition of the nematode’s developmental process

Phylogeny of the major taxa of human helminths—nematodes and platyhelminths—as established by maximum likelihood (ML) analysis of 18S ribosomal RNA from 18 helminth species.

<p>Sequences were aligned using ClustalX <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0000538#pntd.0000538-Chenna1" target="_blank">[93]</a>. The topology of the tree was derived from a consensus tree by neighbor-joining–based bootstrapping, its branch lengths were computed using a ML-based method, and it was rooted with the orthologue from the brewer's yeast, <i>Saccharomyces cerevisiae</i>. The branch lengths of the phylogenetic tree were computed using DNAML (PHYLIP package <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0000538#pntd.0000538-Felsenstein1" target="_blank">[94]</a>) by allowing rate variation among sites. The headings Chromadorea, Enoplea, Trematoda, and Cestoda are major classes of the phyla Nematoda and Platyhelminthes. The GenBank accession numbers of aligned sequences are DQ118536.1 (<i>Trichuris trichiura</i>), AY851265.1 (<i>Trichuris suis</i>), AF036637.1 (<i>Trichuris muris</i>), AY497012.1 (<i>Trichinella spiralis</i>), U94366.1 (<i>Ascaris lumbricoides</i>), AF036587.1 (<i>Ascaris suum</i>), AF036588.1 (<i>Brugia malayi</i>), AJ920348.1 (<i>Necator americanus</i>), AJ920347.2 (<i>Ancylostoma caninum</i>), AF036597.1 (<i>Nippostrongylus brasiliensis</i>), X03680.1 (<i>Caenorhabditis elegans</i>), AF036605.1 (<i>Strongyloides ratti</i>), U81581.1 (<i>Strongyloides ratti</i>), AB453329.1 (<i>Strongyloides ratti</i>), AF279916.2 (<i>Strongyloides stercoralis</i>), AB453315.1 (<i>Strongyloides stercoralis</i>), M84229.1 (<i>Strongyloides stercoralis</i>), EU011664.1 (<i>Saccharomyces cerevisiae</i>), , U27015.1 (<i>Saccharomyces cerevisiae</i>), DQ157224.1 (<i>Taenia solium</i>), AF229852.1 (<i>Clonorchis sinensis</i>), Z11590.1 (<i>Schistosoma japonicum</i>), Z11976.1 (<i>Schistosoma haematobium</i>), U65657.1 (<i>Schistosoma mansoni</i>).</p

Some recent approaches to expressing transgenes in human helminths.

<p>(A) Luciferase activity in <i>Schistosoma mansoni</i> larvae (schistosomules) after transduction with a pseudotyped retrovirus that expresses the luciferase reporter gene. Anti-luciferase antibody staining of schistosomules three days after exposure to pseudotyped lentivirus carrying the firefly luciferase transgene. Schistosomules examined by confocal laser microscopy; (i) bright field, (ii) fluorescence red channel, (iii) merged images. Control non-transformed worms showed only background levels of fluorescence (not shown; see <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0000538#pntd.0000538-Morales2" target="_blank">[34]</a>–<a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0000538#pntd.0000538-Kines2" target="_blank">[36]</a> for relevant hypotheses and experimental methods). (B) Recent studies on transgenic <i>Strongyloides stercoralis</i> indicated that morphogenesis of the infective L3 stage larva requires the DAF-16 orthologue FKTF-1 <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0000538#pntd.0000538-Castelletto1" target="_blank">[38]</a>. L3s of this parasitic nematode were transfected with plasmids carrying the transgene fktf-1<i>b</i>::gfp::fktf-1b and examined by fluorescence microscopy. (i, ii) Transgenic first-stage larvae express green fluorescent protein (GFP) in the procorpus (arrow) of the pharynx. (iii, iv) A first-stage larva (L1) expresses the GFP::FKTF-1b(wt) transgene in the hypodermis. (v, vi) An infective L3 expresses the GFP::FKTF-1b(wt) fusion protein in the hypodermis and in a narrow band in the pharynx (arrow). Scale bars, 10 µm. Adapted from <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0000538#pntd.0000538-Castelletto1" target="_blank">[38]</a>.</p

Montage of some of the major human helminth parasites, their developmental stages, and disease pathology.

<p>(A) Microfilaria of <i>Brugia malayi</i> in a thick blood smear, stained with Giemsa (<a href="http://www.dpd.cdc.gov/dpdx/html/frames/a-f/filariasis/body_Filariasis_mic1.htm" target="_blank">http://www.dpd.cdc.gov/dpdx/html/frames/a-f/filariasis/body_Filariasis_mic1.htm</a>); the microfilaria is about 250 µm in length. (B) Patient with lymphedema of the left leg due to lymphatic filariasis (<a href="http://www.cdc.gov/ncidod/dpd/parasites/lymphaticfilariasis/index.htm" target="_blank">http://www.cdc.gov/ncidod/dpd/parasites/lymphaticfilariasis/index.htm</a>). (C) Hookworm egg passed in the stool of an infected person; the microscopic egg, barrel-shaped with a thin wall, is about 70×40 µm in dimension. (D) longitudinal section through an adult hookworm attached to wall of small intestine, ingesting host blood and mucosal wall. The parasite is about 1 cm in length. (E) Eggs of <i>Schistosoma mansoni</i>. The egg is about 150×50 µm in dimension; the lateral spine is diagnostic for <i>S. mansoni</i> in comparison to the other human schistosome species. Fibrotic responses to schistosome eggs trapped in the intestines, liver, and other organs of the infected person are the cause of the schistosomiasis pathology and morbidity. (F) A pair of adult worms of the blood fluke <i>Schistosoma mansoni</i>; the more slender female worm resides in the gynecophoral canal of the thicker male. The worms are about 1.5 cm in length, and live for many years (<a href="http://www.dpd.cdc.gov/dpdx/HTML/ImageLibrary/Schistosomiasis_il.htm" target="_blank">http://www.dpd.cdc.gov/dpdx/HTML/ImageLibrary/Schistosomiasis_il.htm</a> ).</p