Bovine Leukemia Virus
{Uncurated}}
Classification
Domain; Phylum; Class; Order; family [Others may be used. Use NCBI link to find]
Species
NCBI: Taxonomy |
Genus species
Description and Significance
Describe the appearance, habitat, etc. of the organism, and why you think it is important.
Genome Structure
Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence?
Cell Structure, Metabolism and Life Cycle
Interesting features of cell structure; how it gains energy; what important molecules it produces.
Ecology and Pathogenesis
The infection route of BLV is both through horizontal and vertical transmission. BLV is transmitted via direct contact (Kono et al., 1983), milk, and insect bites. One of the most common manners of infection is through blood in milk and flies.
There are three main stages of BVL. The first begins with infection, and a cell contains the virus but is asymptomatic. The steps then begin with the Tax protein, a transcriptional activator of viral gene expression. It may inhibit DNA repair mechanisms, therefore increasing mutations within the DNA,.
The next stage is known as PL, polyclonal proliferation of the virus in cells (called immortalization). Although most BLV-infected cows present no symptoms, PL is a benign form of the disease that describes an increase of untransformed B-lymphocytes in the blood of the animal. However, even after proliferation, it cannot transform cells. For lymphoma to develop, it needs a malignant transformation through a P53 mutant, TNF, or BoLa.
- P53
This gene is a common tumor suppressor gene that works to control cell proliferation and apoptosis. According to a study by Yoko Aida, about half of tumors created by the BLV in cattle also contained missense mutations in p53. This suggests that p53 is one of many genetic changes that play a role in the further development of the disease.
- TNF
Known as a tumor necrosis factor, TNF is a protein made by white blood cells in response to an antigen. It was found to be much higher in animals with lymphoma.
- BoLa
A bovine leukocyte antigen that determines immune responsiveness of the animal. The genetic variations of amino acids influence susceptibility. An example of this is seen in the presence of the amino acids Glu–Arg that confer resistance to PL in BLV-infected cattle.
References
Author
Page authored by _____, student of Prof. Jay Lennon at IndianaUniversity.