Stone D M, Norton L K, Chambers J C, Meek W J
Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, 99164-7040, USA.
Clin Immunol. 2000 Sep;96(3):280-8. doi: 10.1006/clim.2000.4900.
Bovine leukemia virus (BLV) is an oncogenic retrovirus in the human T cell leukemia virus family. BLV infects B lymphocytes and induces a nonmalignant persistent lymphocytosis (PL) and leukemia/lymphoma in cattle. There is evidence that CD4 T lymphocytes are activated during BLV infection and promote the development of PL. How CD4 T lymphocytes are activated by BLV infection is not known. We observed that CD4 T lymphocytes from PL cattle proliferated in the presence of autologous, irradiated peripheral blood mononuclear cells (PBMC), whereas no proliferation occurred in cell cultures from BLV-infected non-PL cattle. Proliferation required direct contact with metabolically active irradiated PBMC but was not associated with viral protein expression or inhibited by antibodies to BLV. Unexpectedly, B lymphocytes alone failed to account for the irradiated PBMC stimulation of CD4 T lymphocytes. These observations and the magnitude of the proliferative response suggest that activation is polyclonal and involves mechanisms other than BLV antigen-specific stimulation.
牛白血病病毒（BLV）是人类T细胞白血病病毒家族中的一种致癌逆转录病毒。BLV感染B淋巴细胞，并在牛中引发非恶性持续性淋巴细胞增多症（PL）以及白血病/淋巴瘤。有证据表明，CD4 T淋巴细胞在BLV感染期间被激活，并促进PL的发展。目前尚不清楚CD4 T淋巴细胞是如何被BLV感染激活的。我们观察到，来自PL牛的CD4 T淋巴细胞在自体照射外周血单个核细胞（PBMC）存在的情况下会增殖，而来自BLV感染的非PL牛的细胞培养物中则没有增殖现象。增殖需要与代谢活跃的照射PBMC直接接触，但与病毒蛋白表达无关，也不受抗BLV抗体的抑制。出乎意料的是，单独的B淋巴细胞无法解释照射PBMC对CD4 T淋巴细胞的刺激作用。这些观察结果以及增殖反应的程度表明，激活是多克隆的，并且涉及除BLV抗原特异性刺激之外的机制。
