Enriquez F J, Cypess R H, Wassom D L
Department of Microbiology, Immunology, and Parasitology, New York State College of Veterinary Medicine, Cornell University, Ithaca 14853.
J Parasitol. 1988 Jun;74(3):409-14.
H-2 congenic strains expressing resistant (H-2q, H-2f) or susceptible (H-2k) haplotypes were compared for their ability to resist challenge infection with N. dubius following a 6- or 14-day ivermectin-abbreviated immunizing infection. B10.BR mice (H-2k) were considerably more resistant to infection when the priming interval was shortened from 14 to 6 days. B10.Q (H-2q) and B10.M (H-2f) mice resisted challenge regardless of which immunization regimen was used. The influence of parasite numbers on the response to challenge was studied by comparing infections in resistant DBA/1 (H-2q) and susceptible CBA/J (H-2k) mice that differ at both H-2 and non-H-2 genes. DBA/1 mice, immunized with 50 or 150 L3 of N. dubius for 14 days, resisted challenge, whereas mice receiving 300 worms did not. In contrast, CBA/J mice failed to resist challenge at all priming doses tested. When the immunizing infection was shortened from 14 to 6 days, DBA/1 mice resisted challenge regardless of priming dose and CBA/J mice resisted challenge only when the highest dose of 300 worms was used for priming. The data suggest that susceptible strains of mice may be preferentially immunosuppressed, particularly at low infective doses, and that suppression is associated with adult worms present in the lumen of the small intestine.
对表达抗性（H-2q、H-2f）或易感（H-2k）单倍型的H-2同源品系进行比较，观察其在经6天或14天伊维菌素缩短免疫感染后抵抗杜氏小袋纤毛虫攻击感染的能力。当启动间隔从14天缩短至6天时，B10.BR小鼠（H-2k）对感染的抵抗力显著增强。无论采用哪种免疫方案，B10.Q（H-2q）和B10.M（H-2f）小鼠都能抵抗攻击。通过比较在H-2和非H-2基因均不同的抗性DBA/1（H-2q）和易感CBA/J（H-2k）小鼠中的感染情况，研究了寄生虫数量对攻击反应的影响。用50或150条杜氏小袋纤毛虫L3免疫14天的DBA/1小鼠能抵抗攻击，而接受300条虫的小鼠则不能。相比之下，CBA/J小鼠在所有测试的启动剂量下都未能抵抗攻击。当免疫感染从14天缩短至6天时，DBA/1小鼠无论启动剂量如何都能抵抗攻击，而CBA/J小鼠只有在使用最高剂量300条虫进行启动时才能抵抗攻击。数据表明，易感小鼠品系可能优先受到免疫抑制，尤其是在低感染剂量时，且这种抑制与小肠肠腔内存在的成虫有关。
