Gill H S
Department of Animal Science, University of New England, Armidale, NSW, Australia.
Int J Parasitol. 1994 Aug;24(5):749-56. doi: 10.1016/0020-7519(94)90131-7.
Lymphocyte proliferation and skin hypersensitivity responses to parasite antigens were measured as indicators of cell-mediated immunity in genetically resistant and random-bred lambs following infection with Haemonchus contortus. Responses of PBMC to the mitogens PHA, PWM and LPS were also assessed to determine if infection was associated with suppression of general immune function. All lambs demonstrated significant antigen-specific lymphocyte proliferation prior to experimental infection. The responses did not differ between resistant and random-bred lambs and the correlation between pre-infection stimulation indices and resistance to challenge infection was also not significant. Following infection, PBMC from resistant lambs consistently exhibited higher blastogenic responses to both larval and adult antigens than PBMC from random-bred lambs. Addition of cyclosporin A to the antigen-stimulated cultures resulted in significant inhibition of blastogenesis, suggesting that the cells responding to parasite antigens were predominantly of the T-helper cell phenotype. Proliferation responses of resistant and random-bred sheep were similar for all mitogens tested. However, a transient suppression of lymphocyte reactivity to PHA and PWM was noted in all infected lambs. Responses to LPS remained unaffected during infection. There was no difference in the immediate hypersensitivity responses to intradermal inoculation of parasite antigens between the genotypes. However, the delayed-type hypersensitivity responses to parasite antigens were significantly greater in resistant lambs than those in random-bred lambs. Together, these data suggest that resistant lambs have an enhanced ability to mount parasite-specific cell-mediated immune responses when compared with random-bred lambs and that this may contribute to differences in the susceptibility of two genotypes to haemonchosis.
在用捻转血矛线虫感染遗传抗性和随机繁殖的羔羊后，测量淋巴细胞增殖和对寄生虫抗原的皮肤超敏反应，以此作为细胞介导免疫的指标。还评估了外周血单核细胞（PBMC）对丝裂原PHA、PWM和LPS的反应，以确定感染是否与一般免疫功能的抑制有关。所有羔羊在实验感染前均表现出显著的抗原特异性淋巴细胞增殖。抗性羔羊和随机繁殖羔羊的反应没有差异，感染前刺激指数与对攻击感染的抗性之间的相关性也不显著。感染后，抗性羔羊的PBMC对幼虫和成虫抗原的增殖反应始终高于随机繁殖羔羊的PBMC。向抗原刺激的培养物中添加环孢素A会导致显著的增殖抑制，这表明对寄生虫抗原作出反应的细胞主要是辅助性T细胞表型。对于所有测试的丝裂原，抗性和随机繁殖绵羊的增殖反应相似。然而，在所有感染的羔羊中都观察到淋巴细胞对PHA和PWM的反应出现短暂抑制。感染期间对LPS的反应保持不变。不同基因型之间对皮内接种寄生虫抗原的即刻超敏反应没有差异。然而，抗性羔羊对寄生虫抗原的迟发型超敏反应明显大于随机繁殖羔羊。这些数据共同表明，与随机繁殖的羔羊相比，抗性羔羊具有更强的能力来发动寄生虫特异性细胞介导的免疫反应，这可能导致两种基因型对血矛线虫病易感性的差异。
