title: Provirus variants of the bovine leukemia virus and their relation to the serological status of naturally infected cattle.
abstract: Infection of cattle with the bovine leukemia virus (BLV) results in a strong permanent antibody response to the BLV antigens some weeks after infection. However, cattle may carry provirus and not have detectable antibody titers. To prove the occurrence of different BLV provirus variants in German cattle and to study the influence of special BLV variants on the immunoreaction, a 444-bp fragment of the env gene of 35 naturally BLV infected animals was analyzed. Seven different groups of BLV provirus variants were found on the basis of restriction fragment length polymorphism. Three BLV provirus variant groups and five additionally sequenced BLV isolates showed a high similarity to BLV provirus isolates from other geographical areas. The variation in nucleotide sequence of the five BLV isolates compared with nine previously sequenced BLV isolates ranged up to 5. 3%. While BLV provirus variant groups A, C, D, E, F, and G were clearly related to agar-gel immunodiffusion test (AGID)- and enzyme-linked immunosorbent assay (ELISA)-positive animals, BLV provirus variant group B was solely found in permanent AGID- and ELISA-negative or in transient ELISA-positive animals. Altogether, these results indicate that special BLV provirus variants may be responsible for atypical forms of BLV infection in cattle.
authors.affiliation: Faculty of Veterinary Medicine, Free University of Berlin, Luisenstrasse 56, Berlin D-10117, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Fechner
authors.forename: P
authors.initials: P
authors.lastname: Blankenstein
authors.forename: A C
authors.initials: AC
authors.lastname: Looman
authors.forename: J
authors.initials: J
authors.lastname: Elwert
authors.forename: L
authors.initials: L
authors.lastname: Geue
authors.forename: C
authors.initials: C
authors.lastname: Albrecht
authors.forename: A
authors.initials: A
authors.lastname: Kurg
authors.forename: D
authors.initials: D
authors.lastname: Beier
authors.forename: O
authors.initials: O
authors.lastname: Marquardt
authors.forename: D
authors.initials: D
authors.lastname: Ebner
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002418:Cattle Diseases / Q000821:virology*; D016583:Enzootic Bovine Leukosis / Q000821:virology*; D014644:Genetic Variation; D001909:Leukemia Virus, Bovine / Q000235:genetics*; D008969:Molecular Sequence Data; D014759:Viral Envelope Proteins / Q000235:genetics*
chemical_list: D014759:Viral Envelope Proteins