Lacroux Caroline, Nguyen Thi Hai Chi, Andreoletti Olivier, Prevot Françoise, Grisez Christelle, Bergeaud Jean-Paul, Gruner Lucas, Brunel Jean-Claude, Francois Dominique, Dorchies Philippe, Jacquiet Philippe
UMR INRA-ENVT 1225 Interactions Hôtes Agents Pathogènes, Ecole Nationale Vétérinaire de Toulouse, 23 chemin des Capelles, 31076 Toulouse Cedex 03, France.
Vet Res. 2006 Jul-Aug;37(4):607-22. doi: 10.1051/vetres:2006022. Epub 2006 May 16.
Selection of resistant animals and host immunization have been proposed as alternative methods for the control of gastrointestinal nematode parasites. However, a better knowledge of the mechanisms involved in protective immunity against these parasites is required for the development of optimal strategies. In this study, 3 month old INRA 401 lambs (n = 81) were allocated into three groups: uninfected control, challenged either once (primary-infected animals) or twice (previously-infected animals) with 10,000 Haemonchus contortus L3. Uninfected control and challenged animals were sequentially sacrificed at 3, 7, 15 and 28 days post challenge. In both challenged groups, a clear Th2-oriented immune response was observed in the abomasal lymph node and mucosa. IL-4 and IL-13 mRNA over-expression, recruitment of eosinophils, mast cells and globule leukocytes and production of specific systemic IgG and mucosal IgA were observed earlier in previously-infected animals than in primary-infected ones. At 28 days post infection, no differences between intensities of these responses were observed between the challenged groups. Worm establishment rates were similar in previously-infected and primary-infected lambs. However, reductions of worm development, female fecundity and fecal egg output were observed in previously-infected sheep. We conclude that H. contortus infection in young INRA 401 lambs induced an unequivocal Th2 immune response resulting in the regulation of worm egg production without affecting their establishment.
选择抗性动物和宿主免疫已被提议作为控制胃肠道线虫寄生虫的替代方法。然而，要制定最佳策略，需要更好地了解针对这些寄生虫的保护性免疫所涉及的机制。在本研究中，将3月龄的INRA 401羔羊（n = 81）分为三组：未感染对照组、用10,000条捻转血矛线虫L3幼虫攻击一次（初次感染动物）或两次（先前感染动物）。未感染对照组和攻击组动物在攻击后第3、7、15和28天依次处死。在两个攻击组中，在皱胃淋巴结和黏膜中均观察到明显的以Th2为主的免疫反应。与初次感染动物相比，先前感染动物中更早观察到IL-4和IL-13 mRNA的过表达、嗜酸性粒细胞、肥大细胞和球形白细胞的募集以及特异性全身IgG和黏膜IgA的产生。在感染后28天，攻击组之间这些反应的强度没有差异。先前感染和初次感染的羔羊中蠕虫定植率相似。然而，在先前感染的绵羊中观察到蠕虫发育、雌虫繁殖力和粪便虫卵产量降低。我们得出结论，幼龄INRA 401羔羊感染捻转血矛线虫会诱导明确的Th2免疫反应，从而调节虫卵产生而不影响其定植。
