Bovine Leukemia Virus Involvement In Enzootic Bovine Leukosis

Abstract

Enzootic bovine leukosis is a contagious disease induced by bovine leukemia virus (BLV). It is a chronic disease that develops over a long period and can be schematically divided into three phases: (1) from birth to infection (some animals are already infected at birth), (2) from viral infection to tumorous transformation (a number of infected animals do not develop tumors before being slaughtered), and (3) from tumorous transformation to death. Bovine leukotic lymphocytes, kept in vitro in suitable medium, release detectable amounts of BLV. Short-term cultures of leukocytes from cows with persistent lymphocyotsis or long-term cultures of BLV-infected cells were used to study the morphogenesis of BLV, wherein one system was made of degenerating cells, the other made of healthy fast growing cells. Detection of anti-BLV antibodies includes immunodiffusion using p 24 , p 15 , immunofluorescence (IF), complement fixation (CF), and radioimmunoassay. All these methods are indirect detection methods. They detect BLV infection through the immune reaction of the host. The chapter presents the experiments performed to understand the transmission of BLV to the homologous host.