Jaagsiekte sheep retrovirus
The Jaagsiekte sheep retrovirus ( JSRV ) is a retrovirus of sheep and leads to infection of a contagious cancer, the pulmonary adenomatosis of sheep, a broncho- alveolar adenocarcinoma. The name Jaagsiekte comes from the South African Afrikaans and refers to the concepts of hunting and disease ( siekte = infirmity ). The virus is widespread in sheep and goats (especially South Africa and the UK). JSRV in 1983 described for the first time. The complete nucleotide sequence of a virus isolate was first published in 1992. Meanwhile, is an established fact that JSRV is the cause of sheep pulmonary adenomatosis.
The special feature of JSRV is its ability alone by a JSRV envelope protein ( Env ), which acts as an oncoprotein to lead in the infected organism to cancer. As the envelope proteins trigger the control of cell division and the transformation of the target cell and set the uncontrolled cell division in motion, is not yet known exactly. Either superimposed on the envelope protein to a receptor of the cell membrane, leading to activation of further information pathways within the cell, or it comes to influencing controlling genes inside the cell directly by the protein.
Target cells of this virus are type II pneumocytes. A still unknown lentivirus may play an additional role in the infection by JSRV.
The first cloned sheep, Dolly had to be euthanized after a JSRV infection and subsequent disease.
The incubation period is very long and can be months to several years. A causal therapy is not known.
- Virus species