Infectivities of Bovine Leukemia Virus in Peripheral Blood Lymphocytes from Naturally Infected Cattle and Their Relation to Persistent Lymphocytosis and Antibody Titers

Abstract

Infectivities of bovine leukemia virus (BLV) in peripheral blood lymphocytes (PBL) from naturally infected cattle were examined by the syncytium infectivity assay. Infectious BLV was detected in PBL from all cattle which were positive in the immunodiffusion test using glycoprotein antigens of BLV. The infectious titers per 5 × 10⁵ PBL from individual cattle were closely associated with the severity of persistent lymphocytosis, but not with the antibody titers to both the glycoprotein and internal protein antigens of BLV.