[目的]了解J亚群白血病病毒(ALV-J)感染鸡后抗体反应和带毒排毒的规律,以便为制定鸡群中ALV-J感染的预防控制和净化措施提供可靠的流行病学依据.[方法]1日龄和49日龄SPF鸡分别通过注射、121服和接触感染ALV-J,对各感染组的病毒血症、泄殖腔排毒及抗体反应进行动态检测.[结果]不同日龄感染ALV-J后的病毒血症和抗体的动态有很大差异.1日龄SPF鸡注射感染ALV-J后,自2周起开始可检出泄殖腔p27抗原和病毒血症.注射感染组有71%(5/7)鸡在26周内持续带毒排毒,其中有3只鸡在感染后45周仍带毒排毒.其中一只鸡在16周时产生一过性抗体,另两只鸡完全没有抗体.口服感染组仅11%(1/9)鸡呈持续带毒排毒,44%(4/9)鸡仅呈短暂性带毒排毒,且自第8周起即可检测到较高的抗体水平.同笼接触组既不带毒排毒,也无抗体水平,表明未发生传染.49日龄SPF鸡即使注射攻毒后,在19周内的5次检测中,p27抗原和病毒血症均为阴性.攻毒后1周开始出现抗体反应并维持一段时间.49日龄SPF鸡经口服和接触感染,病毒血症和泄殖腔p27均为阴性,也无抗体反应.[结论]1日龄SPF鸡感染ALV-J很容易发生免疫耐受,感染鸡持续带毒排毒而不产生抗体;49日龄SPF鸡感染后,1周可产生高水平的抗体,但不带毒排毒.不同接种方式对ALV-J感染的动态有很大影响,注射感染诱发的病毒血症和耐受性病毒血症显著高于口服感染.%[Objective] To understand the dynamics of viremia, virus shedding and antibody responses in chickens inoculated with avian lenkosis vrius subgroup J (ALV-J) and provide essential epidemiological data for prevention and eradicationo of ALV-J infection. [Method] Viremia, virus shedding and antibody response were successively measured after inoculation with ALV-J strain HN0001 intraperitoneally ,orally or in contact in SPF chickens at 1 day and 49 days. [Result] The dynamics ofviremia and antiboty responses were very different in chickens inoculated with ALV-J at different ages. Viremia and p27 in cloaca swabs started to be detected from the 2nd week after inoculation with ALV-J at 1-day-old. In the group inoculated intraperitoneally with ALV-J, 71% (5/7) continuously demonstrated viremia and p27-shedding. Vh'emia and virus shedding lasted for at least 45 weeks in 3 chickens. Among them, only 1 chicken showed transient antibody reaction at 16-week-old, another 2 were in tolerant viremia without any antibody reactions. In the group inoculated orally with ALV-J, 11% (1/9) demonstrated persistant viremia and p27-shedding but no antibody response, 44% (4/9) showed transient viremia or p27-shedding, and then antibody responses from 8-week-old. No control bird kept in contact with inoculated birds in the same isolators demonstrated viremia or p27-shedding, and also no antibody responses. It indicated there was no horizontal infection. In chickens intraperitoneally inoculated with ALV-J at 49-day-old, neither viremia nor p27-shedding were detected in 5 separate testing during the 19th week after inoculation, but antibody reaction started to be detected 1 week after inoculation. In the orally inoculated chickens or the contacted control chicken, all samples were negative in vriremia, p27-shedding and antibody reactions. [Conclusion] Inoculation with ALV-J at 1-day-old easily induced immune tolerence, chickens inoculated demonstrated persistant viremia or p27-shedding, but no antibody reactions. Chickens inoculated with ALV-J at 49-day-old, antibody could detected 1 week after inoculation, but no viremia and p27-shedding were detected. Inoculation routes significantly influenced the dynamic variety of ALV-J inoculation, intraperitoneally injection induced higher viremia levels and increased percentages with tolerant viremia when compared to oral inoculation.
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