Establishment of a new bovine leukosis virus producing cell line

Abstract

Due to the prevalence of different bovine leukosis virus (BLV) species in the cattle population in Europe, problems may arise in the serological diagnosis of BLV infections. In addition, earlier investigations demonstrated that contamination of the BLV antigen-producing cell culture systems by bovine viral diarrhea virus (BVDV) may give rise to misinterpretation of serological test results after BVDV vaccination of cattle. By co-cultivation of peripheral leukocytes of a BLV-infected cow with a permanent sheep kidney cell line, a new BLV-producing cell line named PO714 was established. This line carries a BLV provirus of the Belgian species and has been tested to be free of a variety of possibly contaminating viruses and mycoplasms. Investigations of a panel of well-characterised sera by agar gel immunodiffusion (AGID) and capture ELISA (cELISA) tests using antigen prepared from this new cell line in comparison with antigen of the well-known cell line FLK/BLV yielded comparable results. False positive results caused by BVDV cross-reactions could be eliminated when tests were carried out with antigen derived from the new cell line.

Molecular characterization of the env gene from Brazilian field isolates of Bovine Leukemia Virus

“…BLV env sequences (444 nucleotides) from strains 30, 141, 151, 384, 485 e 8513 were submitted to restriction-enzyme site search using the on line software Restriction Mapper, http://www.arabidopsis.org/ cgi-bin/patmatch/RestrictionMapper.pl in order to characterize Brazilian strains according to criteria previously used [20,21]. The results of the restrictionenzyme site search and the phylogenetic analyses were compared.…”

“…Four of six Brazilian isolates were classified in the Australian genotype [20] and two were not classified. Ninety percent of the 309 sequences analyzed by RFLP were classified in Belgian, Australian or Japanese genotypes [20].…”

“…Four of six Brazilian isolates were classified in the Australian genotype [20] and two were not classified. Ninety percent of the 309 sequences analyzed by RFLP were classified in Belgian, Australian or Japanese genotypes [20]. Using another classification model [21], four Brazilian sequences would be classified in Genotype 1 and two in Genotype 6.…”

“…BLV variants were found in different geographic regions [18,19]. These can also be detected by restriction fragment length polymorphism (RFLP) [20,21]. In contrast, there seem to be no serologic sub-groups.…”

Using PCR for early diagnosis of bovine leukemia virus infection in some native cattle

“…Problems also arise with animals exhibiting periodically or permanently low titers of BLV antibodies or low serum titers in the periparturient period (Coulston et al, 1990;Stone et al, 2000). Furthermore, serological tests cannot discriminate between passive maternal immunity and active immunity induced by bovine leukemia infection (Agresti et al, 1993;Eaves et al, 1994;Beier et al, 2004). Analyzing animals over a long period, Eaves et al (1994) showed that some naturally infected BLV provirus-carrying animals developed no BLV antibody titers detectable by ID or ELISA for several months or years after infection.…”