11 research outputs found
Life Cycle of the Human Hookworm N. americanus
<p>The BZA anthelminthics albendazole and mebendazole remove adult hookworms from the gastrointestinal tract. In contrast, the <i>Na</i>-ASP-2 Hoookworm Vaccine is designed to target third-stage infective larvae (filariform larvae). Humoral immunity to the vaccine inhibits the entry of larvae into the gastrointestinal tract and thereby prevents their development into blood-feeding adult parasites. (Illustration: Sapna Khandwala, Public Library of Science, adapted from [<a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0020067#pmed-0020067-b3" target="_blank">3</a>] and [<a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0020067#pmed-0020067-b33" target="_blank">33</a>])</p
Scheme for the Development and Quality-Control Testing of the <i>Na</i>-ASP-2 Hookworm Vaccine, and Its Transition from the Laboratory into the Clinic
<p>After the selection of ASP-2 from N. americanus (<i>Na</i>-ASP-2) as the lead candidate antigen based on a series of research and development (R&D) tests—which included immunoepidemiology studies identifying human correlates of immunity to hookworm and confirmatory laboratory animal vaccine trials—the recombinant antigen was expressed in yeast and then developed as a biologic through a well-defined product development strategy (PDS). By following the product development strategy, process development (PD) and manufacturing led to the generation of pilot batches at different scales prior to technology transfer to a cGMP manufacturing facility. Both process development and manufacturing rely on developing assays for the product's identity, color and appearance, purity, immunological recognition, and potency, as well as qualification of the assays for sensitivity, specificity, accuracy, and reproducibility. Each of these processes must maintain a high level of quality control by following a set of policies, protocols, and standard operating procedures. After the manufacturing of a cGMP product and the required pre-clinical animal testing, a clinical development plan (CDP) was generated. Because the <i>Na</i>-ASP-2 Hookworm Vaccine is a product destined for the world's poorest, it is being developed almost exclusively in the non-profit sector, along with government manufacturers in middle-income countries.</p
Global Distribution of Human Hookworm Infection
<p>(Illustration: Margaret Shear, Public Library of Science, adapted from [<a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0020067#pmed-0020067-b4" target="_blank">4</a>])</p
Sequence and structural alignment of Nu class GSTs with a Sigma Class GST (HsGST, human GST or hematopoietic prostagladin D synthase 37) and other parasite GSTs (SjGST, 43, (-GST-1) 42
<p><b>Copyright information:</b></p><p>Taken from "X-ray structures of -GST-1 and -GST-2 two glutathione s-transferase from the human hookworm "</p><p>http://www.biomedcentral.com/1472-6807/7/42</p><p>BMC Structural Biology 2007;7():42-42.</p><p>Published online 26 Jun 2007</p><p>PMCID:PMC1924862.</p><p></p> (a) The alignment reveals that firstly N-terminal alpha beta domain is more conserved than the C-terminal alpha domain. Furthermore, -GST-1 has higher sequence identity with HpolGST than -GST-2 and the lowest similarity is with the HsGST. This figure was generated with ESPript [55, 56]. (b) Structural alignment of monomers of Nu class GSTs (-GST-1, magenta; -GST-2, gold; HpolGST, green) with a sigma class GST (HsGST, cyan)
Nu class GSTs a) -GST-2, c) HpolGST have larger binding cavity than sigma class GST b) HsGST
<p><b>Copyright information:</b></p><p>Taken from "X-ray structures of -GST-1 and -GST-2 two glutathione s-transferase from the human hookworm "</p><p>http://www.biomedcentral.com/1472-6807/7/42</p><p>BMC Structural Biology 2007;7():42-42.</p><p>Published online 26 Jun 2007</p><p>PMCID:PMC1924862.</p><p></p> d) Overlay of the cavities reveals the considerable reduction in the active site size between sigma class (blue) and nu class (cyan). The structure of HpolGST is missing a loop in close proximity to the binding cavity and we modeled it as cartoon from the -GST-2 structure. The glutathione in the G-site is shown as red stick model
P. pastoris Secrete <i>Ac-</i>APR-1 Zymogen that Autoactivates at Low pH and Degrades Canine Hb
<div><p>SDS-PAGE gel stained with Coomassie Brilliant Blue showing purification of recombinant APR-1 zymogen from <i>P. pastoris</i> culture supernatant.</p>
<p>(A) Lane 1, molecular weight markers; lane 2, concentrated culture supernatant; lane 3, flow-through from a nickel-IDA column; lane 4, 5 mM imidazole wash; lane 5, 20 mM imidazole column eluate; lane 6, 60 mM imidazole eluate; and lane 7, 1 M imidazole eluate. Purified recombinant APR-1 zymogen was activated by buffer exchange into 0.1 M sodium formate/0.1 M NaCl (pH 3.6).</p>
<p>(B) Lane 1, molecular weight markers; lane 2, 5.0 μg of canine Hb (pH 3.6); and lane 3, 5.0 μg of canine Hb (pH 3.6) incubated with 0.2 μg of recombinant APR-1.</p></div
Vaccination of Dogs with APR-1 Reduces Blood Loss and Protects against Anemia
<p>Hb concentrations of vaccinated dogs were significantly (<i>p</i> = 0.049) greater than those of control dogs when blood was drawn after larval challenge (0 and 7 d before necropsy [post]) but not when blood was drawn 5 d before larval challenge (pre).</p
Vaccination with APR-1 Reduces Adult Worm Burdens of Dogs after Challenge Infection with Hookworms
<p>Statistically significant reduction at the <i>p</i> < 0.1 level (<i>p</i> = 0.065) in median adult worm (both sexes) burdens of dogs vaccinated with APR-1 compared to dogs that received adjuvant alone (A). Reductions are also shown when only male (B) (<i>p</i> = 0.111) and only female (C) (<i>p</i> = 0.1905) worms were considered; however, statistically significant reductions were not achieved for single sex analyses. Bars represent the median value for each group.</p
Vaccination with APR-1 Reduces Fecal Egg Counts of Dogs after Challenge Infection with Hookworms
<div><p>Statistically significant reduction (<i>p</i> = 0.018) in median fecal egg counts sampled on days 21, 23, and 26 of dogs vaccinated with APR-1 compared to dogs that received adjuvant alone.</p>
<p>(A). Geometric mean values of fecal egg counts from vaccinated and control dogs between challenge infection and necropsy.</p>
<p>(B). Error bars refer to the standard error of the mean.</p></div