Wang Feng, Wang Xiaowei, Chen Hongbo, Liu Jianzhu, Cheng Ziqiang
College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an 271018, China.
J Vet Sci. 2011 Sep;12(3):235-41. doi: 10.4142/jvs.2011.12.3.235.
The critical time of avian leukosis virus subgroup J (ALV-J)-mediated immunosuppression was determined by body weight, relative immune organ weight, histopathology, and presence of group specific antigen and antibodies in specific pathogen-free (SPF) chickens. CD4(+) and CD8(+) cell activity in the spleen, total and differential leukocyte counts in blood, and viral RNA levels in spleen were measured. Significant growth suppression was observed in the two ALV-J-infected groups. A strong immune response by infected groups was present in spleen at 2-weeks-of-age, but after 4-weeks-of-age, the response decreased quickly. The thymus and bursa showed persistent immunosuppression until 4-weeks-of-age. Proliferation of fibroblasts and dendritic cells were observed in immune organs at 4- and 5-weeks-of-age. However, the granulocyte cell number was markedly lower in the infected groups than in the control group. In group 1 (day 1 infection) CD4(+) cells increased during the second week but significantly decreased during the fourth week, while group 2 (day 7 infection) showed the opposite effect. Viral RNA increased significantly by the fourth week. These data identify 3~4 weeks post-infection as the key time at which the ALV-J virus exerts its immunosuppressive effects on the host.
通过对无特定病原体（SPF）鸡的体重、相对免疫器官重量、组织病理学以及群特异性抗原和抗体的存在情况进行检测，确定了禽白血病病毒J亚群（ALV-J）介导免疫抑制的关键时期。检测了脾脏中CD4(+)和CD8(+)细胞活性、血液中的白细胞总数和分类计数以及脾脏中的病毒RNA水平。在两个感染ALV-J的组中均观察到显著的生长抑制。感染组在2周龄时脾脏出现强烈的免疫反应，但在4周龄后，反应迅速下降。胸腺和法氏囊在4周龄前一直表现出持续的免疫抑制。在4周龄和5周龄时，免疫器官中观察到成纤维细胞和树突状细胞的增殖。然而，感染组中的粒细胞数量明显低于对照组。在第1组（第1天感染）中，CD4(+)细胞在第二周增加，但在第四周显著减少，而第2组（第7天感染）则表现出相反的效果。到第四周时，病毒RNA显著增加。这些数据确定感染后3至4周是ALV-J病毒对宿主发挥免疫抑制作用的关键时期。
