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Which human diseases are caused by the retroviruses HIV and HTLV-1?

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Diagram illustrating the process of retrovirus infection and reverse transcription, showing a retrovirus entering a host cell, releasing viral RNA, reverse transcriptase converting RNA to DNA, integration into the host genome, transcription of new viral RNA, assembly of new virions, and budding from the cell. — Reverse transcriptase After a retrovirus infects a cell, an enzyme known as reverse transcriptase converts viral RNA into proviral DNA in the cytoplasm. Proviral DNA then enters the nucleus, where it is incorporated into the host cell's DNA.

The retroviruses HIV and HTLV-1 are known to cause specific human diseases through the action of the enzyme reverse transcriptase, which allows the viral genetic material to integrate into the host cell's DNA.12

HIV (Human Immunodeficiency Virus)

HIV is the causative agent of acquired immunodeficiency syndrome (AIDS). The virus primarily infects helper T cells, leading to a progressive destruction of the immune system. As the immune system weakens, individuals become susceptible to opportunistic infections—such as pneumonia and tuberculosis—and certain cancers, including Kaposi sarcoma and lymphomas.1234

HTLV-1 (Human T-cell Lymphotropic Virus Type 1)

HTLV-1 is associated with the following human conditions:
* Adult T-cell leukemia (ATL): A form of cancer affecting T cells.12
* HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP): A neurodegenerative condition.1

While millions of people are infected with HTLVs, only a small percentage of those individuals develop these specific diseases.1