Investigation of invasion by bovine immunodeficiency-like virus(BIV) in Japan and BIV isolation

牛免疫缺陷样病毒（BIV）侵袭日本的调查及分离牛免疫缺陷样病毒（BIV）是1972年在美国对牛淋巴肉瘤的研究中分离到的。BIV属于牛慢病毒，但其对牛的致病性尚不清楚。虽然在美国、荷兰和瑞士都有牛的抗体呈阳性，但在日本是否存在抗体呈阳性的牛，也不知道是否已经分离出了BIV。目的：探讨日本牛是否具有BIV抗体，如果检测出抗体阳性，能否从牛中分离出BIV。采用间接免疫荧光抗体技术对牛血清进行抗体检测。在7个县检查的2846头牛中，有29头抗体呈阳性。从其中4头牛的外周血淋巴细胞中提取DNA，进行聚合酶链反应（PCR）和southern blot杂交试验；4例均检测到BIV原病毒DNA。这些结果表明日本的牛感染了BIV。目前，我们正计划用BIV抗体阳性的牛的血液进行实验性接种，并从牛身上分离出BIV。

Investigation of invasion by bovine immunodeficiency-like virus (BIV) in Japan and BIV isolationBovine immunodeficiency-like virus (BIV) was isolated during a study of bovine lymphosarcoma in the U.S.A. in 1972. BIV belongs to the bovine lentiviruses, but its pathogenicity for cattle is unknown. Although there are cattle that are positive for antibody to BIV in the U.S.A., the Netherlands, and Switzerland, it is not known even whether antibody-positive cattle are present or not, nor whether BIV has been isolated, in Japan.We investigated whether or not Japanese cattle possess the antibody to BIV, and if antibody-positive cattle were detected, whether BIV could be isolated from the cattle.For detecting cattle infected with BIV, their sera were tested for antibodies by the indirect immunofluorescence antibody technique. Twenty-nine of 2,846 cattle examined in 7 prefectures were positive for the antibody. DNA was extracted from peripheral blood lymphocytes of 4 of these cattle, and subjected to the polymerase chain reaction (PCR) and southern blot hybridization tests ; BIV proviral DNA was detected from all 4. These results suggest that cattle in Japan are infected with BIV. Now we are planning to inoculate cattle experimentally with the blood of cattle positive for BIV antibody and to isolate BIV from the cattle.