Heeney J L, Valli V E
TNO Radiobiological Institute, Rijswijk, The Netherlands.
Lab Invest. 1990 Mar;62(3):339-46.
Detailed genotypic and phenotypic characteristics of enzootic bovine lymphoma were defined to determine if tumor cell characteristics were consistent with the etiologic agent of this disease. Lymphoid tumors from cattle with serologic evidence of bovine leukemia virus (BLV) infection were examined by Southern blot analysis to confirm the presence and copy number of integrated BLV. All cases of enzootic bovine lymphoma examined contained 1 to 4 BLV proviral copies in tumor DNA and revealed immunoglobulin gene rearrangement (Ig). Tumors were further characterized immunohistochemically with a panel of 8 monoclonal antibodies to bovine lymphocyte determinants and B cell differentiation markers. The majority of cases examined expressed Ia/DR, 11 of 17 cases also expressed surface IgM, frequently with another Ig isotype. To definitively characterize the stage of B cell differentiation represented in the transformed phenotype, genotypic evidence of isotype switching was examined in these tumors. Our results demonstrated that enzootic bovine lymphomas are tumors of mature B cells with common characteristics, suggesting that pressures associated with BLV infection which favor tumor development are manifested late in B cell ontogeny, possibly during the isotype switch period.
确定地方性牛淋巴瘤的肿瘤细胞特征是否与该疾病的病原体一致，对其详细的基因型和表型特征进行了定义。通过Southern印迹分析检查来自有牛白血病病毒（BLV）感染血清学证据的牛的淋巴瘤，以确认整合的BLV的存在和拷贝数。所有检查的地方性牛淋巴瘤病例在肿瘤DNA中含有1至4个BLV前病毒拷贝，并显示免疫球蛋白基因重排（Ig）。用一组针对牛淋巴细胞决定簇和B细胞分化标志物的8种单克隆抗体对肿瘤进行进一步的免疫组织化学特征分析。大多数检查病例表达Ia/DR，17例中有11例也表达表面IgM，通常伴有另一种Ig同种型。为了明确表征转化表型中所代表的B细胞分化阶段，在这些肿瘤中检查了同种型转换的基因型证据。我们的结果表明，地方性牛淋巴瘤是具有共同特征的成熟B细胞肿瘤，这表明与有利于肿瘤发展的BLV感染相关的压力在B细胞个体发育后期表现出来，可能在同种型转换期。
