Question

After cell entry and reverse transcription, HIV can become a latent provirus, inserting itself into the host genome. During this stage, where in the cell is viral DNA normally found? A. Lysosome B. Cytoplasm C. Nucleus D. Storage vesicles

Short answer

C. Nucleus

Step-by-step solution

- Understand the Question

The question is asking about the location of viral DNA during the latent provirus stage of the HIV lifecycle after it has entered the host cell and undergone reverse transcription.

- Recall the HIV Lifecycle

HIV enters a host cell and its RNA is converted into DNA by reverse transcription. This does not occur in the lysosome, cytoplasm, or storage vesicles.

- Identify the Correct Location

After reverse transcription, the viral DNA is integrated into the host's genome. This integration happens within the nucleus of the host cell.

- Choose the Correct Answer

Based on the information, the viral DNA during the latent provirus stage is found in the nucleus.

Key concepts

latent provirus

When referring to a 'latent provirus,' we're discussing a stage in the HIV lifecycle where the virus remains dormant within the host cell. This means the viral DNA is present but not actively producing new virus particles.
The significance of this latent stage is that HIV can hide in immune cells, making it difficult to be detected and eliminated by the body's defenses. This dormancy allows the virus to evade the immune system and antiviral treatments, providing a sanctuary where it can later reactivate and start replicating again.

reverse transcription

Reverse transcription is a pivotal process in the HIV lifecycle where the virus converts its RNA into DNA. HIV is an RNA virus, and upon entering a host cell, it uses an enzyme called reverse transcriptase to carry out this conversion.
This unique enzyme synthesizes DNA from the viral RNA template, creating a complementary DNA strand. This DNA can then be integrated into the host's genetic material.
Without reverse transcription, HIV would not be able to merge with the host cell's DNA, making this step crucial for the virus's ability to replicate and sustain an infection.

host genome integration

Integration into the host genome is a critical phase where the newly made viral DNA becomes permanently inserted into the host cell's DNA.
This event takes place inside the host cell nucleus. A viral enzyme known as integrase facilitates the insertion of viral DNA into the host's genome.
Once integrated, the viral DNA is termed a provirus. It can remain latent or begin producing new viral particles, depending on various cellular signals and conditions. This integration step explains how HIV can persist in the body for long periods and complicates efforts for a complete cure.

nucleus

In the context of the HIV lifecycle, the nucleus of the host cell plays a crucial role. Following reverse transcription, the resulting viral DNA needs to be integrated into the host's genome, and this integration occurs in the nucleus.
The nucleus is the control center of a cell, containing its genetic material in the form of DNA. It houses the cell's chromosomes and regulates all significant processes like replication and transcription.
By integrating into the host's DNA within the nucleus, HIV ensures that its genetic material gets replicated whenever the host cell divides. This enables the virus to propagate and remain a persistent threat within an infected individual.