Chauvin A, Moreau E, Boulard C
Interactions H te-Parasite-Milieu (UMR ENVN/INRA 1034), Ecole Nationale Vétérinaire, Nantes, France.
Vet Res. 2001 Jan-Feb;32(1):87-92. doi: 10.1051/vetres:2001113.
The response to Fasciola hepatica was studied in sheep infected with 5, 30, 150 metacercariae. The animals were necropsied 12 weeks post-infection (p-i) for counting and measuring flukes. Cellular and humoral responses were detected by peripheral eosinophil count, peripheral blood lymphocyte proliferation with excretory-secretory products (FhESP) and ELISA. All sheep were infected at necropsy except one sheep which was infected with 5 metacercariae. Mean parasitic intensities were 40%, 44% and 27% of the infection dose in sheep infected with 5, 30, 150 metacercariae respectively. FhESP-specific lymphocyte responses of the 3 infected groups were significantly enhanced in weeks 3 and 4 p-i (p < 0.05). The kinetics of the specific humoral response were similar for the 3 infected groups but the antibody level was significantly lower in animals infected with 5 metacercariae than in the 2 other infected groups from week 5 p-i to week 12 p-i (p < 0.05). Peripheral eosinophil count was significantly enhanced (p < 0.05) in infected groups. The numbers of peripheral eosinophils were significantly different between the 3 infected groups in week 3, 4 and 6 p-i and were related to infection level. These results confirm that sheep are highly susceptible to F. hepatica infection, even when infection pressure is very low. Peripheral eosinophilia was dependent of the infection level. The immune response was similar in sheep infected with various numbers of flukes.
对感染5、30、150个肝片吸虫囊蚴的绵羊体内对肝片吸虫的反应进行了研究。在感染后12周对动物进行尸检，以计数和测量吸虫。通过外周血嗜酸性粒细胞计数、外周血淋巴细胞与排泄-分泌产物（FhESP）的增殖以及酶联免疫吸附测定（ELISA）来检测细胞和体液反应。除一只感染5个囊蚴的绵羊外，所有绵羊在尸检时均被感染。感染5、30、150个囊蚴的绵羊中，平均寄生强度分别为感染剂量的40%、44%和27%。3个感染组的FhESP特异性淋巴细胞反应在感染后第3周和第4周显著增强（p<0.05）。3个感染组的特异性体液反应动力学相似，但从感染后第5周到第12周，感染5个囊蚴的动物体内抗体水平显著低于其他2个感染组（p<0.05）。感染组外周血嗜酸性粒细胞计数显著升高（p<0.05）。在感染后第3周、第4周和第6周，3个感染组的外周血嗜酸性粒细胞数量存在显著差异，且与感染水平相关。这些结果证实，即使感染压力非常低，绵羊对肝片吸虫感染也高度易感。外周血嗜酸性粒细胞增多取决于感染水平。感染不同数量吸虫的绵羊免疫反应相似。
