Jackson F, Miller H R, Newlands G F, Wright S E, Hay L A
Moredun Research Institute, Edinburgh.
Res Vet Sci. 1988 May;44(3):320-3.
Naive and immune sheep, treated with anthelmintic, challenged directly into the abomasum and killed 48 hours later were used to examine the steroid sensitivity, persistence and dose dependency of immune mechanisms which result in the failure of incoming Haemonchus contortus larvae to establish (immune exclusion). Immune exclusion was almost totally abolished by corticosteroid treatment, the mean percentage of larvae establishing in the mucosa of immune sheep was 1.4 per cent of the challenge infection whereas in those treated with dexamethasone it was 24.4 per cent and in naive sheep 27.3 per cent. Immune animals challenged after seven and 42 days without antigenic experience excluded more than 90 per cent of the challenge larvae from their mucosae, whereas those challenged after 84 days without antigenic experience were as susceptible as naive animals. Immune exclusion was dose dependent, animals challenged with 10(6) and 10(5) larvae excluded 93 per cent and 82.5 per cent of the challenge dose whereas those challenged with 10(4) larvae failed to exclude larvae.
用驱虫药处理过的未接触过抗原的绵羊和免疫绵羊，直接接种到皱胃中，并在48小时后处死，用于研究导致进入的捻转血矛线虫幼虫无法定植（免疫排斥）的免疫机制的类固醇敏感性、持续性和剂量依赖性。皮质类固醇处理几乎完全消除了免疫排斥，免疫绵羊黏膜中定植的幼虫平均百分比为攻击感染的1.4%，而地塞米松处理的绵羊为24.4%，未接触过抗原的绵羊为27.3%。在未接触抗原7天和42天后接受攻击的免疫动物，其黏膜中排斥了超过90%的攻击幼虫，而在未接触抗原84天后接受攻击的动物与未接触过抗原的动物一样易感。免疫排斥具有剂量依赖性，用10⁶和10⁵幼虫攻击的动物分别排斥了93%和82.5%的攻击剂量，而用10⁴幼虫攻击的动物未能排斥幼虫。
