Salter D W, Payne W, Kung H J, Robinson D, Ewert D, Olson W, Crittenden L B, Fadly A M
a Department of Microbiology , Michigan State University , East Lansing , MI , 48824 , USA.
b Department of Molecular Biology and Microbiology, School of Medicine , Case Western Reserve University , Cleveland , Ohio , 33106 , USA.
Avian Pathol. 1999 Apr;28(2):147-54. doi: 10.1080/03079459994876.
A significant incidence of bursal lymphomas with long latencies was noted in transgenic breeders carrying a benign defective subgroup A avian leukosis provirus, ALVA6, in their germline and maintained free of exposure to avian retroviruses. Serotype 2 Marek's disease (MD) vaccine virus, strain SB-1, a component of the bivalent MD vaccine used to vaccinate the breeders, was suspected as a contributory factor in the increased bursal lymphoma incidence. Although these bursal lymphomas had several characteristics similar to retroviral-induced bursal lymphomas, we found no evidence of retroviral influence based on many virological, immunological and molecular tests that were performed on plasma and tumour cells. These tumours were therefore classified as spontaneous bursal lymphomas, similar to those reported for some specific pathogen-free (SPF) chicken lines. Long-term in vivo experiments in plastic isolators and carefully maintained pens with homozygous and hemizygous ALVA6 and ALVA6-free female chickens (line 0) that were either non-vaccinated, serotype 3 (herpesvirus of turkeys [HVT]; monovalent)-vaccinated, or HVT/SB-1 (bivalent) vaccinated, demonstrated that the incidence of spontaneous bursal lymphomas were significantly higher in those chickens that were vaccinated with the bivalent MD vaccine (P ⩽0.05). In addition, this incidence did not depend on the ALVA6 proviral insert since there was no significant difference in spontaneous bursal lymphoma incidence between bivalent vaccinated hemizygous ALVA6 and ALVA6-free line 0 female chickens. Thus, the increased incidence of spontaneous bursal lymphomas is correlated solely with the presence of SB-1 and is not dependent on the presence of ALVA6.
在种系中携带良性缺陷A亚群禽白血病前病毒ALVA6且未接触禽逆转录病毒的转基因种鸡中，发现了大量潜伏期长的法氏囊淋巴瘤。用于给种鸡接种的二价马立克氏病（MD）疫苗中的2型血清型MD疫苗病毒SB-1株被怀疑是法氏囊淋巴瘤发病率增加的一个促成因素。尽管这些法氏囊淋巴瘤有几个特征与逆转录病毒诱导的法氏囊淋巴瘤相似，但基于对血浆和肿瘤细胞进行的许多病毒学、免疫学和分子检测，我们没有发现逆转录病毒影响的证据。因此，这些肿瘤被归类为自发性法氏囊淋巴瘤，类似于一些特定无特定病原体（SPF）鸡系所报道的肿瘤。在塑料隔离器和精心维护的鸡舍中，对纯合和半合子ALVA6以及不含ALVA6的雌性鸡（0系）进行长期体内实验，这些鸡要么未接种疫苗，要么接种3型血清型（火鸡疱疹病毒[HVT]；单价）疫苗，要么接种HVT/SB-1（二价）疫苗，结果表明，接种二价MD疫苗的鸡中自发性法氏囊淋巴瘤的发病率显著更高（P⩽0.05）。此外，这种发病率并不取决于ALVA6前病毒插入，因为在接种二价疫苗的半合子ALVA6和不含ALVA6的0系雌性鸡之间，自发性法氏囊淋巴瘤发病率没有显著差异。因此，自发性法氏囊淋巴瘤发病率的增加仅与SB-1的存在相关，而不取决于ALVA6的存在。
