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Institute of Diagnostic Virology (IVD)

National Reference Laboratory for Enzootic Bovine Leukosis (EBL)

The Bovine Leukosis Virus (BLV) belongs to the genus ‘Delta-Retrovirus’ within the family of ‘Retroviridae’. The BLV causes persistent infection in cattle and is the causative agent of Enzootic Bovine Leukosis (EBL). The virus primarily infects B lymphocytes. In infected animals, provirus can also be detected in macrophages and endothelial cells. Clinically inapparent courses may persist life-long or develop into other clinical forms of BLV manifestation. Persistent lymphocytosis is a benign, polyclonal proliferation of the peripheral blood lymphocytes which is characterized by an increase in the number of circulating B lymphocytes to between 40 and 80% of the lymphocyte population. Up to two years after infection, infected animals rarely develop persistent lymphocytosis. After 3 to 6 years in contrast, persisting lymphocytosis occurs in 30 to 70% of the naturally infected cattle depending on genetic and environmental factors. As a rule, animals with persistent lymphocytosis do not show any health problems in association with the disease. Tumorous leukosis is characterized by the occurrence of malignant lymphoma. Approx. 1-10% of the BLV infected animals and 10-30% of animals with persistent lymphocytosis develop the tumorous form.

Research focuses on the immunopathogenesis of virus infections in a systemic persistent infection model. In this context, phenotypic analyses of the lymphocyte subpopulations after experimental BLV infection in cattle are carried out.

  1. Detection of proviral DNA of BLV infected cattle by means of nested PCR and real time PCR
  2. Detection of BLV specific antibodies by means of different ELISAs
  3. Detection of BLV specific antibodies by means of agar gel immunodiffusion (AGID) test
  4. Supply of the WOAH and EU reference serum E05
  • Isolation and detection of nucleic acids by means of RT-PCR, nested PCR, and real time PCR
  • Detection of antibodies by ELISA, immunofluorescence, Western blot, and FACS
  • Flow cytometry, cell sorting by MoFlo
  • Cell culture
  • Molecular biological methods for cloning and expression of Proteins 
  • WOAH and EU reference serum for Enzootic Bovine Leukosis ‚E05’ 
  • Regulation on notifiable animal diseases (TierSeuchAnzV) dd 3 November 2004, last modified on 18 December 2009
  • Regulation on Bovine Leukosis (LeukoseV) dd. 13 March 1997, last modified on 20 December 2005
  • WOAH listed disease