DEVELOPING AN IN VITRO MODEL OF INFECTION OF BOVINE B CELLS WITH BLV

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 牛白血病病毒（BLV）是一种感染牛的逆转录病毒。 它与人类T细胞白血病病毒密切相关。 然而，BLV主要感染B细胞，而不是T细胞。 BLV在约5%的感染动物中引起B细胞淋巴肉瘤，但也可在较大比例的感染牛中引起持续性淋巴细胞增多和其他健康问题。 在先前的出版物中，Isaacson等人报道了实验性感染BLV的牛对各种非BLV抗原的抗体应答增加，并且发现这些动物中表达MHC-II分子的B细胞数量显著增加。 迄今为止，将BLV阴性牛淋巴肉瘤（BL-3）细胞与BLV感染的FLK-BLV细胞的无细胞上清液孵育，已导致BL-3细胞变为BLV PCR阳性。 目前正在确认这些结果，并正在研究用于定量FLK-BLV上清液中BLV的各种方法。 到目前为止，通过逆转录酶试验以及使用BLV敏感的CC 81细胞通过TCID 50试验测定BLV滴度的尝试尚未成功，但仍在继续努力。 此外，BLV感染的BL-3细胞将很快通过流式细胞术测定，以确定体外BLV感染后MHC-II表达水平是否增加。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Bovine leukemia virus (BLV) is a retrovirus that infects cattle. It is closely related to the human T cell leukemia virus. However, BLV mainly infects B cells, rather than T cells. BLV causes a B cell lymphosarcoma in about 5% of infected animals, but can also cause persistent lymphocytosis and other health problems in a larger percentage of infected cattle. In previous publications, Isaacson et al. reported that cattle experimentally infected with BLV had increased antibody responses to various non-BLV antigens, and a significantly increased number of B cells from these animals were found to express MHC-II molecules. To date, incubation of BLV-negative bovine lymphosarcoma (BL-3) cells with cell-free supernatants from BLV-infected FLK-BLV cells has resulted in the BL-3 cells becoming PCR-positive for BLV. These results are currently being confirmed, and various methods for quantitation of BLV in FLK-BLV supernatants are being investigated. Thus far, attempts to determine BLV titers by a reverse transcriptase assay, as well as by a TCID50 assay using BLV-susceptible CC81 cells, have been unsuccessful, but efforts are continuing. In addition, the BLV-infected BL-3 cells will soon be assayed by flow cytometry to determine whether levels of MHC-II expression are increased following in vitro BLV infection.