Pernthaner A, Stankiewicz M, Cabaj W, Pfeffer A, Green R S, Douch P G
AgResearch, Wallaceville Animal Research Centre, Upper Hutt, New Zealand.
Vet Immunol Immunopathol. 1996 May;51(1-2):137-46. doi: 10.1016/0165-2427(95)05498-7.
Two divergent lines of Romney sheep have been selected on the basis of differences in faecal egg counts (FEC) to natural poly-generic parasite challenge in New Zealand. However, it is not known if the expression of resistance or susceptibility extends to parasitic nematodes that were not a major part of the selection challenge. To examine this, the immune response to infection with Trichostrongylus axei was examined in these sheep lines. Changes in the proportions of CD5+, CD4+, CD8+, T19+ and CD45R+ lymphocytes and parasite specific antibody titres in peripheral blood were monitored each week in six resistant and six susceptible line lambs that were maintained indoors in pens during the course of 14 weekly infections with 10,000 T. axei larvae. No difference in FEC was observed. Similarly, no significant difference in T. axei specific antibody titre between sheep lines was seen although antibody titre increased steadily from Week 4. Significant increases in the proportions of CD5+, CD4+, CD8+ and T19+ cells occurred in both resistant and susceptible line lambs during Weeks 1-4 of infection. Following peak levels, proportions of CD5+, CD4+ and CD8+ cells fell with the rate of decline of CD5+ and CD4+ cells significantly greater in the resistant line lambs. Proportions of CD45R+ cells showed significant changes with time that were the inverse of those of CD5+, CD4+ and CD8+ cells. Susceptible line lambs showed higher proportions of CD5+ and lower proportions of CD45R+ cells than resistant lambs before infection with T. axei. Overall, during infection, these differences were maintained while CD4+ and T19+ levels were higher in the susceptible line lambs.
在新西兰，根据对自然多属寄生虫感染的粪便虫卵计数（FEC）差异，选择了两个不同品系的罗姆尼羊。然而，尚不清楚抗性或易感性的表现是否延伸至那些并非选择挑战主要部分的寄生线虫。为了研究这一点，对这些羊品系感染奥氏毛圆线虫后的免疫反应进行了检测。在14周内每周用10000条奥氏毛圆线虫幼虫对6只抗性品系和6只易感品系的羔羊进行室内圈养感染，每周监测外周血中CD5 +、CD4 +、CD8 +、T19 +和CD45R +淋巴细胞比例以及寄生虫特异性抗体滴度的变化。未观察到FEC有差异。同样，尽管抗体滴度从第4周开始稳步上升，但在羊品系之间未观察到奥氏毛圆线虫特异性抗体滴度有显著差异。在感染的第1 - 4周，抗性品系和易感品系的羔羊中CD5 +、CD4 +、CD8 +和T19 +细胞比例均显著增加。在达到峰值水平后，CD5 +、CD4 +和CD8 +细胞比例下降，抗性品系羔羊中CD5 +和CD4 +细胞的下降速率明显更大。CD45R +细胞比例随时间呈现显著变化，与CD5 +、CD4 +和CD8 +细胞的变化相反。在感染奥氏毛圆线虫之前，易感品系羔羊的CD5 +细胞比例高于抗性羔羊，而CD45R +细胞比例低于抗性羔羊。总体而言，在感染期间，这些差异得以维持，而易感品系羔羊中的CD4 +和T19 +水平更高。
