Tuberculosis (TB) and HIV are two of the world’s deadliest infectious diseases, and they’re far worse when they occur together. Now, Southwest National Primate Research Center (SNPRC) researchers at Texas Biomedical Research Institute have pinpointed an important mechanism that could lead to a new mode of treatment for this co-infection.

It’s been long-assumed the reason people with HIV are more likely to develop TB is a depletion of specific immune cells. However, SNPRC scientists showed other effects of viral co-infection play a crucial role in this process.

Using data from nearly 40 rhesus macaques, the research team found lung-specific chronic immune activation is responsible for the progression of TB. Chronic immune activation is a dysfunction of immune pathways that create molecules (cytokines and chemokines) that fight off pathogens such as bacteria, viruses and fungi.

Professor and SNPRC Director Deepak Kaushal, PhD, used an analogy to explain what this dysfunction caused by an HIV infection does in the body.

“It’s like all the taps and faucets in your house are turned on full blast all the time,” he said. “You are going to lose a lot of water. With this dysfunction, all cytokines and chemokines are constantly being produced to the highest levels. This dysregulates the body’s ability to fight off other infections.”

Even with antiretroviral therapy (ART) for people with HIV, chronic immune activation still persists. Kaushal said this study shows, “we need to develop approaches to target chronic immune activation,” perhaps with a drug that would be an additional therapy to ART.

Kaushal said he is hopeful new treatment strategies could reach the clinic within a decade, and the effects could be huge. Up to a fourth of the world’s population is infected with TB, and this co-infection is considered a global syndemic, meaning the diseases are pandemics infecting people all around the world, and they promote each other.

Understanding TB is a priority for NPRC scientists, and this study is a continuation of the groundbreaking research being done across the organization. Just last year, researchers explored the possibility of treating the disease using a cancer drug.