HTLV and HIV
Marvin S. Reitz, Jr and Robert C. Gallo
from: Retroviruses: Molecular Biology, Genomics and Pathogenesis (Edited by: Reinhard Kurth and Norbert Bannert). Caister Academic Press, U.K. (2010)
For many years, retroviruses were known to be the cause of many kinds of animal leukemias and hematopoietic tumors. In spite of the high expectation that this would also be true for humans, very little evidence for retroviral involvement in any human diseases was forthcoming. In the late 1970s, however, due to the development of sensitive and specific molecular methods to identify retroviruses and to produce large scale cultures of T lymphocytes, HTLV-I was discovered and implicated as the cause of adult T cell leukemia, a particular and relatively infrequent leukemia prevalent in southern Japan and parts of the Caribbean, and tropical spastic paraparesis, a demyelinating neuropathy similar to multiple sclerosis. The discovery that HTLV-I can be transmitted by breast milk has led to a significant decline in HTLV-I infections in Japan. Although no retroviruses have been identified to date in other human leukemias or related diseases, the efforts that resulted in the discovery of HTLV-I were critical in isolating HIV-1 and identifying it as the cause of AIDS. The ability to grow the HIV-1 in quantity allowed the development of a blood test that has saved countless lives. The development of effective anti-retroviral drugs has made HIV-1 infection a somewhat manageable chronic condition rather than a certain death sentence. Although vaccine trials thus far have been rather disappointing, an effective vaccine is one of our most important needs.