Oral Peptide Vaccine against Hookworm Infection: Correlation of Antibody Titers with Protective Efficacy
3区 · 医学
作者: Shalash, Ahmed O. ; Becker, Luke ; Yang, Jieru ; Giacomin, Paul ; Pearson, Mark ; Hussein, Waleed M. ; Loukas, Alex ; Skwarczynski, Mariusz ; Toth, Istvan
Approximately 0.4 billion individuals worldwide are infected with hookworm. An effective vaccine is needed to not only improve the health of those affected and at high risk, but also to improve economic growth in disease-endemic areas. An ideal anti-hookworm therapeutic strategy for mass administration is a stable and orally administered vaccine. Oral vaccines are advantageous as they negate the need for trained medical staff for administration and do not require strict sterility conditions. Vaccination, therefore, can be carried out at a significantly reduced cost. One of the most promising current antigenic targets for hookworm vaccine development is the aspartic protease digestive enzyme (APR-1). Antibody-mediated neutralization of APR-1 deprives the worm of nourishment, leading to reduced worm burdens in vaccinated hosts. Previously, we demonstrated that, when incorporated into vaccine delivery systems, the APR-1-derived p3 epitope (TSLIAGPKAQVEAIQKYIGAEL) was able to greatly reduce worm burdens (≥90%) in BALB/c mice; however, multiple, large doses of the vaccine were required. Here, we investigated a variety of p3-antigen conjugates to optimize antigen delivery and establish immune response/protective efficacy relationships. We synthesized, purified, and characterized four p3 peptide-based vaccine candidates with: (a) lipidic (lipid core peptide (LCP)); (b) classical polymeric (polymethylacrylate (PMA)); and (c) novel polymeric (polyleucine in a branched or linear arrangement, BL10 or LL10, respectively) groups as self-adjuvanting moieties. BL10 and LL10 induced the highest serum anti-p3 and anti-APR-1 IgG titers. Upon challenge with rodent hookworms, the highest significant reduction in worm burden was observed in mice immunized with LL10. APR-1-specific serum IgG titers correlated with worm burden reduction. Thus, we provide the first vaccine-triggered immune response-protection relationship for hookworm infection.
2021-03-26·Animals : an open access journal from MDPI2区 · 农林科学
Introducing Mediterranean Lupins in Lambs' Diets: Effects on Growth and Digestibility.
2区 · 农林科学
作者: Mariana Almeida ; Sofia Garcia-Santos ; Ana Nunes ; Sara Rito ; Jorge Azevedo ; Cristina Guedes ; Severiano Silva ; Luís Ferreira
Lupins are suitable candidates to replace soybean meal in livestock feeding in the Mediterranean area, presenting a solution for the European Union's dependence on soybean importations. This study aimed to assess the effect of incorporating Lupinus albus and Lupinus luteus into Churra da Terra Quente lambs' diets on growth performance and digestibility. Two trials were conducted over two years. In trial 1, two experimental diets containing 50 g/kg Lupinus albus and 50 g/kg Lupinus luteus were tested. In trial 2, lambs were fed with diets containing higher incorporations of Lupinus luteus (100, 150, and 200 g/kg: LL10, LL15, and LL20, respectively). Total dry matter, hay dry matter, and crude protein intake were calculated, as well as average daily gains. At the end of the growth trials, dry matter, organic matter, and NDF digestibility was determined. Incorporating 50 g/kg of lupins did not affect (p > 0.05) the performance. Lambs fed on LL20 diets presented the lowest HDMI and CPI values (p < 0.05). The highest intakes (p < 0.05) were observed from LL15 lambs. No differences were found in apparent digestibility coefficients between diets (p > 0.05), except for NDF digestibility which was highest (p < 0.05) for LL20. The optimum level of lupin inclusion in lambs' diets seems to be 150 g/kg.