What Is a Latent HIV Reservoir?

Key Points
  • HIV infects immune system cells in the body and uses the cells' machinery to make copies of itself. These infected cells can go into a resting state and stop producing HIV. A group of infected cells that are not actively producing HIV is called a latent HIV reservoir.
  • Latent HIV reservoirs can wake up and start making more HIV. If someone with HIV is not taking HIV medicines when this happens, the level of HIV in their body (called the viral load) will start to increase.
  • Latent HIV reservoirs can be found in many places throughout the body, and HIV can hide out for years inside reservoirs.

What Is a Latent HIV Reservoir?

A latent HIV reservoir is a group of immune cells in the body that are infected with HIV but are not actively producing new HIV.

HIV attacks immune system cells in the body and uses the cells' machinery to make copies of itself. After entering the body, HIV inserts its genetic blueprint into the DNA of an immune system cell, such as a CD4 cell. The infected cell starts producing HIV proteins that act as the building blocks for new HIV. To find out more about how HIV attacks cells, read the AIDS_info_ HIV Life Cycle fact sheet.

Some HIV-infected cells, however, go into a resting (or latent) state. While in this resting state, the infected cells don't produce new HIV.

When HIV infects cells in this way, it can hide out inside these cells for years, forming a latent HIV reservoir. At any time, cells in the latent reservoir can become active again and start making more HIV.

Where Are Latent HIV Reservoirs Found in the Body?

Latent HIV reservoirs can be found throughout the body, including in the brain, lymph nodes, blood, and digestive tract.

Do HIV Medicines Work Against Latent HIV Reservoirs?

HIV medicines reduce the amount of HIV in the body (called the viral load) by preventing the virus from multiplying. Because the HIV-infected cells in a latent reservoir aren't producing new copies of the virus, HIV medicines have no effect on them.

People with HIV must take a daily combination of HIV medicines (called an HIV regimen) to keep their viral loads low. If someone is not taking HIV medicines when the infected cells of the latent reservoir begin making HIV again, the viral load in the body will start to increase. That's why it's important to continue taking HIV medicines every day as prescribed, even when viral load levels are low.

How Are Researchers Combating Latent HIV Reservoirs?

Finding ways to target and destroy latent reservoirs is one of the major challenges facing HIV researchers. New studies are exploring different strategies for clearing out reservoirs, including:

  • Using gene therapy (which means manipulating genes to treat or prevent disease) to cut out certain HIV genes and inactivate the virus in HIV-infected immune cells.
  • Developing drugs or other methods that reactivate latent HIV reservoirs so that the immune system or new therapies can effectively eliminate them.
  • Developing approaches that enhance the immune system's ability to recognize and clear reactivated latent HIV reservoirs.

This fact sheet is based on information from the following sources:

From the National Institute of Allergy and Infectious Diseases (NIAID):

[Note from TheBody.com: This article was created by AIDSinfo, who last updated it on Aug. 24, 2017. We have cross-posted it with their permission.]