There is currently no cure for human immunodeficiency virus (HIV). Antiretroviral therapy, which remains the most effective treatment, doesn’t completely eliminate the virus. The main obstacle to a cure is the development of reservoirs that allow the HIV to hide below the treatment’s radar. By tracking the virus from the first days after infection, Nicolas Chomont, researcher at the CHUM Research Centre and professor at Université de Montréal, was able to observe when and where these reservoirs form for the very first time.
Relying on blood and lymph node samples from patients who had been infected about ten days prior, the research team demonstrated that reservoirs form much earlier than previously thought. Barely a week after infection, part of the virus sneaks into the genome of certain cells and, rather than replicating, simply remains there in a latent state. Its main targets are CD4+T cells: white blood cells that are responsible for the immune response. Because the virus hidden in the reservoirs doesn’t produce viral particles, the immune defence system is blind to it, and it can persist for decades. When an HIV patient stops taking antiretrovirals, the dormant virus awakens and starts multiplying in the blood.
The first stage of infection, when the reservoirs are just beginning to take root, may therefore be a key time to act. Early intervention could reduce the size of the reservoirs and prevent them from settling permanently. Nicolas Chomont is now focused on testing antiretroviral therapy combined with another molecule that hinders the formation of reservoirs in animal models. If the results in infected macaques are conclusive, the studies will continue in humans. Eliminating viral latency could eventually lead to a cure for HIV.