TRANSGENIC MICE WITH HTLV-1 RETROVIRUSJapanese scientists have created transgenic mice that carrythe genome of the HTLV-1 retrovirus, and many of these micedevelop symptoms closely matching those of rheumatoidarthritis in people.
Viruses have been suspected as the cause of rheumatoidarthritis. Reporting today in Science, the researchers suggestthat HTLV-1 is one of the etiologic agents in the disease.
The HTLV-1 retrovirus, which causes an adult T cell leukemiaand is related to the AIDS virus, was inserted into a plasmidand injected into fertilized mouse eggs. At 1 year of age, halfof the transgenic mice that resulted showed swollen joints,usually the ankles. The amounts of the mRNA specific to thetransgene in the swollen joints were five to 10 times higherthan in the joints of normal-appearing mice.
The microscopic changes in the affected joints, includingerosion of synovial bone and cartilage, and infiltration byinflammatory cells, "closely resembled rheumatoid arthritis inhumans," the researchers stated.
It is possible that the transgene somehow induced animmunologic disturbance, noted the researchers. In any event,they concluded, the transgenic mice should provide a usefulmodel to investigate the development of the disease in humans.-- Roberta Friedman, Ph.D.
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