This content delves into the nature of viruses, particularly retroviruses like HIV, and their effects on the immune system. It covers the viral life cycle, transmission methods, and the challenges in combating these persistent infections. The role of endogenous retroviruses in evolutionary history and the complex interplay between retroviruses and host immune responses are also discussed, highlighting the importance of research for developing treatments.
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Viruses can only reproduce within the cells of a host organism
RNA and DNA
Viruses can have either single- or double-stranded RNA or DNA as their genetic material
Capsid and Lipid Envelope
Viruses are composed of a protein coat called a capsid and some may also have an outer lipid envelope derived from the host cell membrane
Each type of virus is adapted to infect specific host cells, making them a complex and critical area of study in microbiology
Retroviruses have single-stranded RNA genomes and use the enzyme reverse transcriptase to convert their RNA into DNA within a host cell
HIV and AIDS
HIV, a retrovirus, specifically targets and infects CD4+ T lymphocytes, leading to the destruction of the immune system and the development of AIDS
HTLV and Leukemia
The human T-cell leukemia virus (HTLV), a retrovirus, is linked to certain types of leukemia
Retroviruses are grouped into families based on their replication strategies and morphology, with HIV being particularly notable for its global health impact
Retroviruses enter host cells by binding to a specific receptor and fusing with the cell membrane
Inside the host cell, reverse transcriptase converts viral RNA into DNA, which is then integrated into the host's genome
The viral DNA is transcribed to produce viral RNA and messenger RNA for viral protein synthesis, and new viruses are released from the host cell by budding
Retroviruses elicit an immune response from the host, involving various cellular and molecular defenses
Transcription factors such as NF-κB play a critical role in regulating the expression of genes involved in the innate immune response
Retroviruses have developed mechanisms to evade the immune system, leading to persistent infections and complicating treatment efforts
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Virus living status ambiguity
Viruses blur the line between living and non-living due to their inability to reproduce without a host cell.
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Viral genetic material types
Viruses contain genetic material that can be either RNA or DNA, and this material may be single- or double-stranded.
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Virus structural components
A virus is made up of genetic material encased in a protein shell called a capsid, and some have an additional lipid envelope.
