Jaagsiekte sheep retrovirus (JSRV) causes ovine pulmonary adenocarcinoma. JSRV can be transmitted via infected colostrum or milk, which contain somatic cells (SCs) harboring JSRV provirus. Nevertheless, the cell types involved in this form of transmission and the involvement of the mammary gland remain unknown. We separated adherent cells (macrophages and monocytes) by plastic adherence, and lymphocytes (CD4+ and CD8+ T cells, and B cells) by flow cytometry, from SCs in milk samples from 12 naturally infected, PCR blood test JSRV–positive, subclinical ewes. These cell populations were tested by PCR to detect JSRV provirus. The ewes were euthanized, and mammary gland samples were analyzed immunohistochemically to detect JSRV surface protein. We did not detect JSRV provirus in any milk lymphocyte population, but milk adherent cells were positive in 3 of 12 sheep, suggesting a potential major role of this population in the lactogenic transmission of JSRV. Immunohistochemistry did not reveal positive results in mammary epithelial cells, pointing to a lack of participation of the mammary gland in the biological cycle of JSRV and reducing the probability of excretion of free viral particles in colostrum or milk.

Jaagsiekte 绵羊逆转录病毒 (JSRV) 引起绵羊肺腺癌。JSRV 可通过受感染的初乳或牛奶传播，其中含有携带 JSRV 原病毒的体细胞 (SC)。然而，参与这种传播形式的细胞类型和乳腺的参与仍然未知。我们通过塑料粘附分离贴壁细胞（巨噬细胞和单核细胞），通过流式细胞术分离淋巴细胞（CD4+ 和 CD8+ T 细胞和 B 细胞），来自 12 只自然感染、PCR 血液检测 JSRV 阳性、亚临床母羊的牛奶样品中的 SC。通过 PCR 检测这些细胞群以检测 JSRV 前病毒。对母羊实施安乐死，并对乳腺样本进行免疫组织化学分析以检测 JSRV 表面蛋白。我们没有在任何乳淋巴细胞群中检测到 JSRV 前病毒，但 12 只绵羊中有 3 只的牛奶贴壁细胞呈阳性，这表明该群体在 JSRV 的产乳传播中具有潜在的主要作用。免疫组织化学未显示乳腺上皮细胞的阳性结果，表明乳腺缺乏参与 JSRV 的生物循环，并降低了初乳或乳汁中游离病毒颗粒排泄的可能性。